Sample records for basin ne atlantic

  1. Structure and evolution of the NE Atlantic conjugate margins off Norway and Greenland (Invited)

    NASA Astrophysics Data System (ADS)

    Faleide, J.; Planke, S.; Theissen-Krah, S.; Abdelmalak, M.; Zastrozhnov, D.; Tsikalas, F.; Breivik, A. J.; Torsvik, T. H.; Gaina, C.; Schmid, D. W.; Myklebust, R.; Mjelde, R.

    2013-12-01

    The continental margins off Norway and NE Greenland evolved in response to the Cenozoic opening of the NE Atlantic. The margins exhibit a distinct along-margin segmentation reflecting structural inheritance extending back to a complex pre-breakup geological history. The sedimentary basins at the conjugate margins developed as a result of multiple phases of post-Caledonian rifting from Late Paleozoic time to final NE Atlantic breakup at the Paleocene-Eocene transition. The >200 million years of repeated extension caused comprehensive crustal thinning and formation of deep sedimentary basins. The main rift phases span the following time intervals: Late Permian, late Middle Jurassic-earliest Cretaceous, Early-mid Cretaceous and Late Cretaceous-Paleocene. The late Mesozoic-early Cenozoic rifting was related to the northward propagation of North Atlantic sea floor spreading, but also linked to important tectonic events in the Arctic. The pre-drift extension is quantified based on observed geometries of crustal thinning and stretching factors derived from tectonic modeling. The total (cumulative) pre-drift extension amounts to in the order of 300 km which correlates well with estimates from plate reconstructions based on paleomagnetic data. Final lithospheric breakup at the Paleocene-Eocene transition culminated in a 3-6 m.y. period of massive magmatic activity during breakup and onset of early sea-floor spreading, forming a part of the North Atlantic Volcanic Province. At the outer parts of the conjugate margins, the lavas form characteristic seaward dipping reflector sequences and lava deltas that drilling has demonstrated to be subaerially and/or neritically erupted basalts. The continent-ocean transition is usually well defined as a rapid increase of P-wave velocities at mid- to lower-crustal levels. Maximum igneous crustal thickness of about 18 km is found across the outer Vøring Plateau on the Norwegian Margin, and lower-crustal P-wave velocities of up to 7.3 km

  2. Evidence for Thin Oceanic Crust on the Extinct Aegir Ridge, Norwegian Basin, N.E. Atlantic Derived from Satellite Gravity Inversion

    NASA Astrophysics Data System (ADS)

    Greenhalgh, E. E.; Kusznir, N. J.

    2006-12-01

    Satellite gravity inversion incorporating a lithosphere thermal gravity correction has been used to map crustal thickness and lithosphere thinning factor for the N.E. Atlantic. The inversion of gravity data to determine crustal thickness incorporates a lithosphere thermal gravity anomaly correction for both oceanic and continental margin lithosphere. Predicted crustal thicknesses in the Norwegian Basin are between 7 and 4 km on the extinct Aegir oceanic ridge which ceased sea-floor spreading in the Oligocene. Crustal thickness estimates do not include a correction for sediment thickness and are upper bounds. Crustal thicknesses determined by gravity inversion for the Aegir Ridge are consistent with recent estimates derived using refraction seismology by Breivik et al. (2006). Failure to incorporate a lithosphere thermal gravity anomaly correction produces an over-estimate of crustal thickness. Oceanic crustal thicknesses within the Norwegian Basin are predicted by the gravity inversion to increase to 9-10 km eastwards towards the Norwegian (Moere) and westwards towards the Jan Mayen micro-continent, consistent with volcanic margin continental breakup at the end of the Palaeocene. The observation (from gravity inversion and seismic refraction studies) of thin oceanic crust produced by the Aegir ocean ridge in the Oligocene has implications for the temporal evolution of asthenosphere temperature under the N.E. Atlantic during the Tertiary. Thin Oligocene oceanic crust may imply cool (normal) asthenosphere temperatures during the Oligocene in contrast to elevated asthenosphere temperatures in the Palaeocene and Miocene-Recent as indicated by volcanic margin formation and the formation of Iceland respectively. Gravity inversion also predicts a region of thin oceanic crust to the west of the northern part of the Jan Mayen micro-continent and to the east of the thicker oceanic crust currently being formed at the Kolbeinsey Ridge. Thicker crust (c.f. ocean basins) is

  3. ProAtlantic - The Atlantic Checkpoint - Data Availability and Adequacy in the Atlantic Basin

    NASA Astrophysics Data System (ADS)

    McGrath, F.

    2017-12-01

    DG MAREs Atlantic Checkpoint is a basin scale wide monitoring system assessment activity based upon targeted end-user applications. It is designed to be a benchmark for the assessment of hydrographic, geological, habitat, climate and fisheries data existence and availability in the Atlantic basin. DG MAREs Atlantic Checkpoint service will be delivered by the ProAtlantic project. The objective of this project is to investigate, through appropriate methodologies in the framework of 11 key marine challenges, how current international and national data providers - e.g. EMODNet, Copernicus - meet the requirements of the stakeholders and deliver fit for purpose data. By so doing, the main thematic and geographic gaps will be readily identified in the Atlantic basin for future consideration by DG MARE. For each challenge, specific web products in the form of maps, metadata, spreadsheets and reports will be delivered. These products are not an end by themselves but rather a means of showing whether data were available, let alone accessible. For example, the Fisheries Impact Challenge outputs include data grids (VMS/Seabed) and data adequacy reports. Production of gridded data layers in order to show the extent of fisheries impact on the seafloor involved the identification, acquisition and collation of data sources for the required data types (VMS/Seabed/Habitats Data) in the Atlantic basin. The resulting spatial coverage of these grids indicates the relatively low level of data availability and adequacy across the Atlantic basin. Aside from the data delivered by programmes such as EMODNet and Copernicus, there are a lot of initiatives by regional bodies such as OSPAR and ICES that consist of assembling and disseminating data to address specific issues. Several international projects have delivered research, data collection, and networking around several of the Atlantic Checkpoint challenge topics, namely MPAs, renewable energy assessment, seabed mapping, oil spill

  4. Buried Mesozoic rift basins of Moroccan Atlantic continental margin

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Mohamed, N.; Jabour, H.; El Mostaine, M.

    1995-08-01

    The Atlantic continental margin is the largest frontier area for oil and gas exploration in Morocco. Most of the activity has been concentrated where Upper Jurassic carbonate rocks have been the drilling objectives, with only one significant but non commercial oil discovery. Recent exploration activities have focused on early Mesozoic Rift basins buried beneath the post-rift sediments of the Middle Atlantic coastal plain. Many of these basins are of interest because they contain fine-grained lacustrine rocks that have sufficient organic richness to be classified as efficient oil prone source rock. Location of inferred rift basins beneath the Atlantic coastal plainmore » were determined by analysis of drilled-hole data in combination with gravity anomaly and aeromagnetic maps. These rift basins are characterized by several half graben filled by synrift sediments of Triassic age probably deposited in lacustrine environment. Coeval rift basins are known to be present in the U.S. Atlantic continental margin. Basin modeling suggested that many of the less deeply bored rift basins beneath the coastal plain are still within the oil window and present the most attractive exploration targets in the area.« less

  5. Burial, Uplift and Exhumation History of the Atlantic Margin of NE Brazil

    NASA Astrophysics Data System (ADS)

    Japsen, Peter; Bonow, Johan M.; Green, Paul F.; Cobbold, Peter R.; Chiossi, Dario; Lilletveit, Ragnhild

    2010-05-01

    We have undertaken a regional study of landscape development and thermo-tectonic evo-lution of NE Brazil. Our results reveal a long history of post-Devonian burial and exhuma-tion across NE Brazil. Uplift movements just prior to and during Early Cretaceous rifting led to further regional denudation, to filling of rift basins and finally to formation of the Atlantic margin. The rifted margin was buried by a km-thick post-rift section, but exhumation began in the Late Cretaceous as a result of plate-scale forces. The Cretaceous cover probably extended over much of NE Brazil where it is still preserved over extensive areas. The Late Cretaceous exhumation event was followed by events in the Paleogene and Neogene. The results of these events of uplift and exhumation are two regional peneplains that form steps in the landscape. The plateaux in the interior highlands are defined by the Higher Surface at c. 1 km above sea level. This surface formed by fluvial erosion after the Late Cretaceous event - and most likely after the Paleogene event - and thus formed as a Paleogene pene-plain near sea level. This surface was reburied prior to the Neogene event, in the interior by continental deposits and along the Atlantic margin by marine and coastal deposits. Neo-gene uplift led to reexposure of the Palaeogene peneplain and to formation of the Lower Surface by incision along rivers below the uplifted Higher Surface that characterise the pre-sent landscape. Our results show that the elevated landscapes along the Brazilian margin formed during the Neogene, c. 100 Myr after break-up. Studies in West Greenland have demonstrated that similar landscapes formed during the late Neogene, c. 50 Myr after break-up. Many passive continental margins around the world are characterised by such elevated plateaus and it thus seems possible, even likely, that they may also post-date rifting and continental separation by many Myr.

  6. Geostatistical Interplay Between Geophysical and Geochemical Data: Mapping Litho-Structural Assemblages of Mesozoic Igneous Activities in the Parnaíba Basin (NE Brazil)

    NASA Astrophysics Data System (ADS)

    de Castro, David L.; Oliveira, Diógenes C.; Hollanda, Maria Helena B. M.

    2018-07-01

    Two widespread magmatic events are recorded in the Parnaíba basin (NE Brazil) during the Jurassic/Cretaceous opening of the Central and South Atlantic Oceans. The Early Jurassic ( 200 Ma) lava flows of the Mosquito Formation occur essentially in the western and southern basin segments, representing one of the largest expressions of the Central Atlantic Magmatic Province in the South American Plate. In contrast, sill complexes and dike swarms of the Early Cretaceous (129-124 Ma) Sardinha Formation occur in the eastern part of the basin and are chrono-correlated to the large Paraná-Etendeka igneous province and to the Rio Ceará-Mirim Dike Swarm. We gathered geophysical, well logging, outcrop analogs and geochemical data to recognize geometrical shapes and areal distribution patterns of igneous-related constructions. Seismic and well data reveal hundreds of km wide multilayered sill complexes and dikes, which are widespread across vast regions of the basin without evident structural control from either the Precambrian basement grain or the basin internal architecture. Anomaly enhancement techniques and self-organizing maps (SOM) procedure were applied on airborne magnetic data, unraveling near-surface magmatic features in four distinct magnetic domains. Using SOM analysis, the basaltic rocks were divided into six groups based on magnetic susceptibility and major elements composition. These results suggest common origin for both magmatic episodes, probably a combination of effects of edge-driven convection and large-scale mantle warming under the westward moving West Gondwana during the Central and South Atlantic opening, which caused a shifted emplacement to the east of the igneous rocks in the Parnaíba basin.

  7. Geostatistical Interplay Between Geophysical and Geochemical Data: Mapping Litho-Structural Assemblages of Mesozoic Igneous Activities in the Parnaíba Basin (NE Brazil)

    NASA Astrophysics Data System (ADS)

    de Castro, David L.; Oliveira, Diógenes C.; Hollanda, Maria Helena B. M.

    2018-02-01

    Two widespread magmatic events are recorded in the Parnaíba basin (NE Brazil) during the Jurassic/Cretaceous opening of the Central and South Atlantic Oceans. The Early Jurassic ( 200 Ma) lava flows of the Mosquito Formation occur essentially in the western and southern basin segments, representing one of the largest expressions of the Central Atlantic Magmatic Province in the South American Plate. In contrast, sill complexes and dike swarms of the Early Cretaceous (129-124 Ma) Sardinha Formation occur in the eastern part of the basin and are chrono-correlated to the large Paraná-Etendeka igneous province and to the Rio Ceará-Mirim Dike Swarm. We gathered geophysical, well logging, outcrop analogs and geochemical data to recognize geometrical shapes and areal distribution patterns of igneous-related constructions. Seismic and well data reveal hundreds of km wide multilayered sill complexes and dikes, which are widespread across vast regions of the basin without evident structural control from either the Precambrian basement grain or the basin internal architecture. Anomaly enhancement techniques and self-organizing maps (SOM) procedure were applied on airborne magnetic data, unraveling near-surface magmatic features in four distinct magnetic domains. Using SOM analysis, the basaltic rocks were divided into six groups based on magnetic susceptibility and major elements composition. These results suggest common origin for both magmatic episodes, probably a combination of effects of edge-driven convection and large-scale mantle warming under the westward moving West Gondwana during the Central and South Atlantic opening, which caused a shifted emplacement to the east of the igneous rocks in the Parnaíba basin.

  8. Large-scale deep-water seafloor mapping from the Rockall to the Hatton basins, NE Atlantic

    NASA Astrophysics Data System (ADS)

    Monteys, X.; Thébaudeau, B.; Murcia, C.; Duncan, N.

    2016-02-01

    Multibeam data acquired in 2000 and 2001 during the Irish National Seabed Survey (INSS) are used for the first detailed investigation of the seabed geomorphology and sediment type in the Hatton-Rockall basin area of the North East Atlantic Ocean, covering an area of approximately 80,000 km². The original multibeam survey produced bathymetric and backscatter datasets that allowed the creation of a Digital Terrain Models of approximately 50 m in resolution in water depths between 500 and 3500 m. Near-surface sediments for the entire region haven been classified using features derived from multibeam angular backscatter data (12kHz) and robust unsupervised clustering techniques. Additionally, sub bottom data imaging the shallow stratigraphy and geomagnetic measurements collected at the time of the MBES survey are combined to further characterise some of the features identified. The features presented in detail include parts of the Hatton and Gardar contourite drifts, volcanic mounds identified by their morphology and magnetic signature, deep-water coral mounds, iceberg scours as well as canyons, gullies and escarpments along and down the slopes of the banks and mounds. This study highlights for the first time the variety and complexity of the seafloor present at the seabed in the Irish Hatton-Rockall basin area

  9. Tectono-geomorphic indices of the Erin basin, NE Kashmir valley, India

    NASA Astrophysics Data System (ADS)

    Ahmad, Shabir; Alam, Akhtar; Ahmad, Bashir; Afzal, Ahsan; Bhat, M. I.; Sultan Bhat, M.; Farooq Ahmad, Hakim; Tectonics; Natural Hazards Research Group

    2018-01-01

    The present study aims to assess the tectonic activity in the Erin basin (NE Kashmir) on the basis of several relevant geomorphic indices and field observations. We use Digital Elevation Model (SRTM) and Survey of India (SoI) topographic maps in GIS environment to compute the geomorphic indices. The indices i.e., convex hypsometric curve, high hypsometric integral value (Hi > 0.5), low basin elongation ratio (Eb = 0.17), low mountain front sinuosity values (Smf = 1.08 average), low valley floor width ratios (Vf < 1), topographic assymetric character (T < 1), uneven basin asymmetry factor (AF < 50), elongated shape (Bs > 4) suggest that the area is tectonically active. Moreover, prominent irregularities (knickpoints/knickzones) along longitudinal profile of the Erin River even in homogenous resistant lithology (Panjal trap) and anomalous stream gradient index (SL) values reflect that the Erin basin is dissected by two faults (EF-1 and EF-2) with NNW-SSE and SSW-NNE trends respectively. The results of this preliminary study further substantiate the recent GPS studies, which argue that the maximum strain is accumulating in the NE part of the Kashmir Himalaya.

  10. Basin-wide Millennial Cycles in Arabian Sea Climate Over the Last Glacial

    NASA Astrophysics Data System (ADS)

    Pourmand, A.; Marcantonio, F.

    2005-05-01

    High-frequency Dansgaard-Oeschger (D-O) and Heinrich cycles first discovered in the records of North Atlantic ice and marine sediments have been found to extend beyond the North Atlantic There is ample evidence for these millennial cycles of climate variability in the sediments of the Arabian Sea. We employ uranium-series radionuclide proxies to determine changes in the fluxes of sedimentary components in two cores from the western (W) and northeastern (NE) Arabian Sea in order to investigate fluctuations of export production and wind strength on a large regional scale during the last glacial period. In the NE Arabian Sea off of the Pakistani margin, 230Th-derived detrital (eolian) fluxes are highest during periods consistent with the timing of North Atlantic D-O stadial and H 1-7 events. Authigenic uranium concentrations, which we interpret as a proxy for primary productivity, also show an increase during North Atlantic D-O interstadials. Preliminary results from W Arabian Sea sediments off of the Oman margin corroborate that these millennial cycles in productivity and eolian fluxes are indeed basin-wide events. Authigenic U concentrations in these sediments are, on average, about twice those measured in the NE Arabian Sea, suggesting, qualitatively, an enhancement of primary productivity in the western part of the basin. In contrast, fluxes of eolian material to the Oman margin are, on average, more than 10 times lower than those delivered to the Pakistani margin, even though the patterns of millennial variability are virtually identical. We associate enhanced export production and a decreased eolian input during relatively warmer D-O interstadials with an intensification of southwest monsoonal winds. Similarly, decreased export production is coincident with an increase in eolian fluxes during North Atlantic stadial and H events. These results provide strong evidence for a basin-wide atmospheric teleconnection between Arabian Sea and North Atlantic climate on sub

  11. A 10Be-based sediment budget of the Upper Rhône basin, Central Swiss Alps

    NASA Astrophysics Data System (ADS)

    Stutenbecker, Laura; Delunel, Romain; Schlunegger, Fritz; Akçar, Naki; Christl, Marcus

    2017-04-01

    The Upper Rhône catchment located in southwestern Switzerland is one of the largest Alpine intramontane basins and, due to high topographic gradients and intense glacial conditioning, an important sediment factory in the Alps. Sediment is being produced in around 50 tributary basins, transported along the 150 km long course of the Rhône River, and deposited in the river delta and associated subaquatic canyons within Lake Geneva, its primary sedimentary sink. In order to quantify the modern sediment fluxes in this Alpine basin we infer catchment-wide denudation rates from concentrations of the cosmogenic nuclide 10Be in quartz extracted from modern fluvial sediment of the major tributary basins. Additionally, 10Be-based denudation rates are calculated for 14 locations along the main Rhône River to track downstream changes. Results from the tributary basins show a large scatter of 10Be concentrations and their respective inferred denudation rates, ranging from 9.72 x 104 atoms/g and 0.17 mm/a to 0.13 x 104 atoms/g and 2.64 mm/a. The Rhône basin does show a rather large spatial variability of parameters that are known to possibly influence denudation rates, for example recent rock uplift rates, lithology, precipitation and temperature, as well as geomorphological parameters such as relief, mean elevation and slope values. However, there is no significant correlation between those parameters and the calculated denudation rates. Instead, the denudation rates are found to be positively correlated with the recent glacial cover in the catchments. This suggests that in glaciated basins glaciogenic material with very low 10Be concentrations is the dominating source of sediment, and inferred denudation rates must be interpreted with great care, as they may overestimate the actual rates. Downstream the main Rhône River the 10Be-concentrations are rather stable and do not record significant inputs of the glaciogenic material supplied by the glaciated basins. Possible

  12. South Atlantic sag basins: new petroleum system components

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Henry, S.G.; Mello, M.R.

    Newly discovered pre-salt source rocks, reservoirs and seals need to be included as components to the petroleum systems of both sides of the South Atlantic. These new components lie between the pre-salt rift strata and the Aptian salt layers, forming large, post-rift, thermal subsidence sag basins. These are differentiated from the older rift basins by the lack of syn-rift faulting and a reflector geometry that is parallel to the base salt regional unconformity rather than to the Precambrian basement. These basins are observed in deep water regions overlying areas where both the mantle and the crust have been involved inmore » the extension. This mantle involvement creates post-rift subsiding depocenters in which deposition is continuous while proximal rift-phase troughs with little or no mantle involvement are bypassed and failed to accumulate potential source rocks during anoxic times. These features have been recognized in both West African Kwanza Basin and in the East Brasil Rift systems. The pre-salt source rocks that are in the West African sag basins were deposited in lacustrine brackish to saline water environment and are geochemically distinct from the older, syn-rift fresh to brackish water lakes, as well as from younger, post-salt marine anoxic environments of the drift phase. Geochemical analyses of the source rocks and their oils have shown a developing source rock system evolving from isolated deep rift lakes to shallow saline lakes, and culminating with the infill of the sag basin by large saline lakes to a marginally marine restricted gulf. Sag basin source rocks may be important in the South Atlantic petroleum system by charging deep-water prospects where syn-rift source rocks are overmature and the post-salt sequences are immature.« less

  13. The fish fauna of Ampère Seamount (NE Atlantic) and the adjacent abyssal plain

    NASA Astrophysics Data System (ADS)

    Christiansen, Bernd; Vieira, Rui P.; Christiansen, Sabine; Denda, Anneke; Oliveira, Frederico; Gonçalves, Jorge M. S.

    2015-03-01

    An inventory of benthic and benthopelagic fishes is presented as a result of two exploratory surveys around Ampère Seamount, between Madeira and the Portuguese mainland, covering water depths from 60 to 4,400 m. A total of 239 fishes were collected using different types of sampling gear. Three chondrichthyan species and 31 teleosts in 21 families were identified. The collections showed a vertical zonation with little overlap, but indications for an affinity of species to certain water masses were only vague. Although most of the species present new records for Ampère Seamount, all of them have been known for the NE Atlantic; endemic species were not found. The comparison with fish communities at other NE Atlantic seamounts indicates that despite a high ichthyofaunal similarity, which supports the "stepping stone" hypothesis of species dispersal, some differences can be attributed to the local features of the seamounts.

  14. PRISM3 DOT1 Atlantic Basin Reconstruction

    USGS Publications Warehouse

    Dowsett, Harry; Robinson, Marci; Dwyer, Gary S.; Chandler, Mark; Cronin, Thomas

    2006-01-01

    PRISM3 DOT1 (Pliocene Research, Interpretation and Synoptic Mapping 3, Deep Ocean Temperature 1) provides a three-dimensional temperature reconstruction for the mid-Pliocene Atlantic basin, the first of several regional data sets that will comprise a global mid-Pliocene reconstruction. DOT1 is an alteration of modern temperature values for the Atlantic Ocean in 4 degree x 5 degree cells in 13 depth layers for December 1 based on Mg/Ca-derived BWT estimates from seventeen DSDP and ODP Sites and SST estimates from the PRISM2 reconstruction (Dowsett et al., 1999). DOT1 reflects a vaguely modern circulation system, assuming similar processes of deep-water formation; however, North Atlantic Deep Water (NADW) production is increased, and Antarctic Bottom Water (AABW) production is decreased. Pliocene NADW was approximately 2 degreesC warmer than modern temperatures, and Pliocene AABW was approximately 0.3 degreesC warmer than modern temperatures.

  15. Making sense of the relationships between Ne, Nb and Nc towards defining conservation thresholds in Atlantic salmon (Salmo salar).

    PubMed

    Ferchaud, A-L; Perrier, C; April, J; Hernandez, C; Dionne, M; Bernatchez, L

    2016-10-01

    Effective population size over a generation (Ne) or over a reproductive cycle (Nb) and the adult census size (Nc) are important parameters in both conservation and evolutionary biology. Ne provides information regarding the rate of loss of genetic diversity and can be tracked back in time to infer demographic history of populations, whereas Nb may often be more easily quantified than Nc for short-term abundance monitoring. In this study, we propose (1) an empirical context to Waples et al. (2014) who introduced a correction to bias due to overlapping generations, and (2) a mathematical relationship between Ne and Nb for direct application in Atlantic salmon populations in Québec, Canada. To achieve this, we investigate the relationships between Ne, Nb and Nc in 10 Atlantic salmon populations, Canada, for which we genotyped 100 randomly sampled young-of-the year individuals for 5 consecutive years. The results show a positive correlation between Ne, Nb and Nc, suggesting that Nb is an indicative parameter for tracking effective population size and abundance of Atlantic salmon. However, our model allows predicting Nc from Nb values at 27% that can be partly explained by high variance in Nb/Nc both among populations (37%) and among years (19%). This result illustrates the need for thorough calibration of Nb/Nc before using Nb in monitoring programs, as well as a full understanding of the limits of such an approach. Finally, we discuss the importance of these results for the management of wild populations.

  16. STREAM FLOW BASIN CHARACTERISTICS FOR THE MID-ATLANTIC INTEGRATED ASSESSMENT (MAIA) STUDY AREA

    EPA Science Inventory

    This data set is a GIS coverage of the stream flow basin characteristics for drainage basins of selected US Geological Survey (USGS) gauging stations the United States Environmental Protection Agency (USEPA) Mid-Atlantic Integrated Assessment (MAIA) Project region. This data se...

  17. Statistical Aspects of the North Atlantic Basin Tropical Cyclones: Trends, Natural Variability, and Global Warming

    NASA Technical Reports Server (NTRS)

    Wilson, Robert M.

    2007-01-01

    Statistical aspects of the North Atlantic basin tropical cyclones for the interval 1945- 2005 are examined, including the variation of the yearly frequency of occurrence for various subgroups of storms (all tropical cyclones, hurricanes, major hurricanes, U.S. landfalling hurricanes, and category 4/5 hurricanes); the yearly variation of the mean latitude and longitude (genesis location) of all tropical cyclones and hurricanes; and the yearly variation of the mean peak wind speeds, lowest pressures, and durations for all tropical cyclones, hurricanes, and major hurricanes. Also examined is the relationship between inferred trends found in the North Atlantic basin tropical cyclonic activity and natural variability and global warming, the latter described using surface air temperatures from the Armagh Observatory Armagh, Northern Ireland. Lastly, a simple statistical technique is employed to ascertain the expected level of North Atlantic basin tropical cyclonic activity for the upcoming 2007 season.

  18. Regional uplift episodes along the NE Atlantic margin constrained by stratigraphic and thermochronologic data

    NASA Astrophysics Data System (ADS)

    Holford, S. P.; Green, P. F.; Hillis, R. R.; Duddy, I. R.; Turner, J. P.; Stoker, M. S.

    2008-12-01

    The magma-rich NE Atlantic passive margin provides a superb natural laboratory for studying vertical motions associated with continental rifting and the rift-drift transition. Here we present an extensive apatite fission-track analysis (AFTA) database from the British Isles which we combine with a detailed stratigraphic framework for the Cretaceous-Cenozoic sedimentary record of the NE Atlantic margin to constrain the uplift history along and inboard of this margin during the past 120 Myr. We show that the British Isles experienced a series of uplift episodes which began between 120 and 115 Ma, 65 and 55 Ma, 40 and 25 Ma and 20 and 15 Ma, respectively. Each episode is of regional extent (~100,000 sq km) and represents a major period of exhumation involving removal of up to 1 km or more of section. These uplift episodes can be correlated with a number of major tectonic unconformities recognised within the sedimentary succession of the NE Atlantic margin, suggesting that the margin was also affected by these uplift episodes. Anomalous syn- and post-rift uplift along this margin have been interpreted in terms of permanent and/or transient movements controlled by the Iceland plume, but neither the timing nor distribution of the uplift episodes, with the exception of the 65 to 55 Ma episode, supports a first-order control by plume activity on vertical motions. Each uplift episode correlates closely with key deformation events at adjacent plate boundaries, suggesting a causative link, and we examine the ways in which plate boundary forces can account for the observed uplift episodes. Similar km-scale uplift events are revealed by thermochronological studies in other magma-rich and magma-poor continental margins, e.g. SE Australia, South Africa, Brazil. The low angle unconformities which result from these regional episodes of km-scale burial and subsequent uplift are often incorrectly interpreted as representing periods of non-deposition and tectonic stability. Similar

  19. Observations of elevated Atlantic water heat fluxes at the boundary of the Arctic Basin.

    NASA Astrophysics Data System (ADS)

    Lincoln, Benjamin; Rippeth, Tom; Lenn, Yueng; Bacon, Sheldon

    2014-05-01

    The well documented decline in Arctic Sea Ice cover over the past 30 years has outpaced global models as warming in Polar Regions occurs faster than the global mean. The thermohaline circulation brings warm water from the Atlantic Ocean into the Arctic basin. This Atlantic water circulates at depth and contains sufficient heat to melt the sea ice cover several times over. Recent studies have shown that this Atlantic water has warmed and shoaled over recent decades (Polyakov et al, 2010). The stability of the upper Arctic Ocean has also changed, with stratification reduced in the Eurasian basin but increased in the Canada basin. Along with an increased availability of heat the reduction in sea ice cover allows greater potential for wind to input energy to the ocean to vertically mix heat to the surface and further melt sea ice. Direct measurements of vertical mixing rates across the Arctic are essential to understanding the changes in this supply of heat from below, but are scarce due to the challenges of making such measurements in the harsh Arctic environment. We present measurements of turbulent kinetic energy dissipation (ɛ) within the top 500 m of the water column using microstructure measurements made both in open water and under ice during 4 different years. Mean rates of dissipation in the Atlantic water thermocline are calculated and compared for data collected in the European, Siberian and Canadian Arctic, including measurements from 2007 and 2012 when record minimum sea ice extents were recorded. Diapycnal heat fluxes from the mean Atlantic water dissipation rates were calculated from these mean dissipation rates and show significant variation across the Arctic Basin. Profiles in the deep basin generally revealed very low rates of dissipation were low ɛ<10-9Wkg-1 and as such heat fluxes of AW were correspondingly low Fh=0.1-0.5Wm-2. However double diffusive staircases were present in all such casts and so vertical transfer of heat may be increased by

  20. Integrated Analysis on Gravity and Magnetic Fields of the Hailar Basin, NE China: Implications for Basement Structure and Deep Tectonics

    NASA Astrophysics Data System (ADS)

    Sun, Bin; Wang, Liangshu; Dong, Ping; Wu, YongJing; Li, Changbo; Hu, Bo; Wang, Chong

    2012-11-01

    The Hailar Basin is one of the typical basins among the NE China Basin Groups, which is situated in the east of East Asia Orogene between the Siberia Plate and the North China Plate. Based on the detailed analysis of magnetic, gravity, petrophysical, geothermal and seismological data, we separate the Gravity and Magnetic Anomalies (GMA) into four orders using Wavelet Multi-scale Decomposition (WMD). The apparent depths of causative sources were then assessed by Power Spectrum Analysis (PSA) of each order. Low-order wavelet detail anomalies were used to study the basin's basement structure such as major faults, the basement lithology, uplifts and depressions. High-order ones were used for the inversion of Moho and Curie discontinuities using the Parker method. The results show that the Moho uplifting area of the Hailar Basin is located at the NE part of the basin, the Curie uplifting area is at the NW part, and neither of them is consistent with the basin's sedimentary center. This indicates that the Hailar Basin may differ in basin building pattern from other middle and eastern basins of the basin groups, and the Hailar Basin might be of a passive type. When the Pacific Plate was subducting to NE China, the frontier of the plate lying on the mantle transition zone didn't pass through the Great Khingan Mountains region, so there is not an obvious magma upwelling or lithospheric extension in the Hailar Basin area. Finally, based on the seismological data and results of WMD, a probable 2D crust model is derived from an across-basin profile using the 2D forward modeling of the Bouguer gravity anomaly. The results agree with those from seismic inversion, suggesting WMD is suitable for identifying major crustal density interfaces.

  1. Neogene basin infilling from cosmogenic nuclides (10Be and 21Ne) in Atacama, Chile

    NASA Astrophysics Data System (ADS)

    Sanchez, Caroline; Regard, Vincent; Carretier, Sébastien; Riquelme, Rodrigo; Blard, Pierre-Henri; Campos, Eduardo; Brichau, Stéphanie; Lupker, Marteen; Hérail, Gérard

    2017-04-01

    In the hyperarid Atacama Desert, northern Chile, Neogene sediments host copper rich layers (exotic supergene mineralization). Current mines are excavated into relatively thin (<200-300 m) Neogene basins whose infilling chronology is poorly constrained. We took advantage of one of these mining pits, and sampled for 10Be and 21Ne cosmogenic nuclide dosing. These cosmogenic nuclides help constraining the infilling chronology. Indeed, basin sediments were deposited with a cosmogenic nuclide content acquired on hillslopes. Then within the basin, cosmogenic nuclide concentrations evolved through the competing production (quickly decreasing with depth) and disintegration (not for 21Ne). Sampling depths are at ˜100 m and at ˜50 m below the desert surface. First, 21Ne gives lower boundaries for upstream erosion rates or local sedimentation rate. These bounds are between 2 and 10 m/Ma, which is quite important for the area. The ratio between the two cosmogenic nuclides indicate a maximum burial age of 12 Ma (minimal erosion rate of 15 m/Ma) and is surprisingly similar from bottom to top, indicating a probable rapid infilling. We finally processed a Monte-Carlo inversion. This inversion helps taking into account the post-deposition muonic production of cosmogenic nuclides. Inversion results is dependent on the muonic production scheme. Interestingly, the similarity in concentrations from bottom to top pleads for quite low production at depth. Our data finally indicates a quick infilling between 12.5 and 10 Ma BP accounting for ˜100 m of deposition (minimum sedimentation rate of 40 m/Ma).

  2. Tectonic setting of Cretaceous basins on the NE Tibetan Plateau: Insights from the Jungong basin

    USGS Publications Warehouse

    Craddock, W.H.; Kirby, E.; Dewen, Z.; Jianhui, L.

    2012-01-01

    Quantifying the Cenozoic growth of high topography in the Indo-Asian collision zone remains challenging, due in part to significant shortening that occurred within Eurasia before collision. A growing body of evidence suggests that regions far removed from the suture zone experienced deformation before and during the early phases of Himalayan orogenesis. In the present-day north-eastern Tibetan Plateau, widespread deposits of Cretaceous sediment attest to significant basin formation; however, the tectonic setting of these basins remains enigmatic. We present a study of a regionally extensive network of sedimentary basins that are spatially associated with a system of SE-vergent thrust faults and are now exposed in the high ranges of the north-eastern corner of the Tibetan Plateau. We focus on a particularly well-exposed basin, located ~20km north of the Kunlun fault in the Anyemaqen Shan. The basin is filled by ~900m of alluvial sediments that become finer-grained away from the basin-bounding fault. Additionally, beds in the proximal footwall of the basin-bounding fault exhibit progressive, up-section shallowing and several intraformational unconformities which can be traced into correlative conformities in the distal part of the basin. The observations show sediment accumulated in the basin during fault motion. Regional constraints on the timing of sediment deposition are provided by both fossil assemblages from the Early Cretaceous, and by K-Ar dating of volcanic rocks that floor and cross-cut sedimentary fill. We argue that during the Cretaceous, the interior NE Tibetan Plateau experienced NW-SE contractional deformation similar to that documented throughout the Qinling-Dabie orogen to the east. The Songpan-Ganzi terrane apparently marked the southern limit of this deformation, such that it may have been a relatively rigid block in the Tibetan lithosphere, separating regions experiencing deformation north of the convergent Tethyan margin from regions deforming

  3. North Atlantic Basin Tropical Cyclone Activity in Relation to Temperature and Decadal- Length Oscillation Patterns

    NASA Technical Reports Server (NTRS)

    Wilson, Robert M.

    2009-01-01

    Yearly frequencies of North Atlantic basin tropical cyclones, their locations of origin, peak wind speeds, average peak wind speeds, lowest pressures, and average lowest pressures for the interval 1950-2008 are examined. The effects of El Nino and La Nina on the tropical cyclone parametric values are investigated. Yearly and 10-year moving average (10-yma) values of tropical cyclone parameters are compared against those of temperature and decadal-length oscillation, employing both linear and bi-variate analysis, and first differences in the 10-yma are determined. Discussion of the 2009 North Atlantic basin hurricane season, updating earlier results, is given.

  4. Deep-sea bacterial communities in sediments and guts of deposit-feeding holothurians in Portuguese canyons (NE Atlantic)

    NASA Astrophysics Data System (ADS)

    Amaro, Teresa; Witte, Harry; Herndl, Gerhard J.; Cunha, Marina R.; Billett, David S. M.

    2009-10-01

    Deposit-feeding holothurians often dominate the megafauna in bathyal deep-sea settings, in terms of both abundance and biomass. Molpadia musculus is particularly abundant at about 3400 m depth in the Nazaré Canyon on the NE Atlantic Continental Margin. However, these high abundances are unusual for burrowing species at this depth. The objective of this research was to understand the reasons of the massive occurrence of these molpadiid holothurians in the Nazaré Canyon. To address this question we investigated possible trophic interactions with bacteria at sites where the organic content of the sediment was different (Setúbal and Cascais Canyons, NE Atlantic Continental Margin). The molecular fingerprinting technique of Denaturing Gradient Gel Electrophoresis (DGGE) with band sequencing, combined with non-metric multi-dimensional scaling and statistical analyses, was used to compare the bacterial community diversity in canyon sediments and holothurian gut contents. Our results suggest that M. musculus does not need to develop a specialised gut bacterial community to aid digestion where the sediment is rich in organic matter (Nazaré Canyon); in contrast, such a community may be developed where the sediment is poorer in organic matter (Cascais Canyon).

  5. Greater role for Atlantic inflows on sea-ice loss in the Eurasian Basin of the Arctic Ocean

    NASA Astrophysics Data System (ADS)

    Polyakov, Igor V.; Pnyushkov, Andrey V.; Alkire, Matthew B.; Ashik, Igor M.; Baumann, Till M.; Carmack, Eddy C.; Goszczko, Ilona; Guthrie, John; Ivanov, Vladimir V.; Kanzow, Torsten; Krishfield, Richard; Kwok, Ronald; Sundfjord, Arild; Morison, James; Rember, Robert; Yulin, Alexander

    2017-04-01

    Arctic sea-ice loss is a leading indicator of climate change and can be attributed, in large part, to atmospheric forcing. Here, we show that recent ice reductions, weakening of the halocline, and shoaling of the intermediate-depth Atlantic Water layer in the eastern Eurasian Basin have increased winter ventilation in the ocean interior, making this region structurally similar to that of the western Eurasian Basin. The associated enhanced release of oceanic heat has reduced winter sea-ice formation at a rate now comparable to losses from atmospheric thermodynamic forcing, thus explaining the recent reduction in sea-ice cover in the eastern Eurasian Basin. This encroaching “atlantification” of the Eurasian Basin represents an essential step toward a new Arctic climate state, with a substantially greater role for Atlantic inflows.

  6. Active Eruptions in the NE Lau Basin

    NASA Astrophysics Data System (ADS)

    Resing, J. A.; Embley, R. W.

    2009-12-01

    NE Lau Response Team: K Rubin, E Baker, J Lupton, M Lilley, T Shank, S Merle, R Dziak, T Collasius (Jason 2 Expedition Leader), N Buck, T Baumberger, D Butterfield, D Clague, D Conlin, J Cowen, R Davis, L Evans, J Huber, M Keith, N Keller, P Michael, E Podowski, A-L Reysenbach, K Roe, H Thomas, S Walker. During a May 2009 cruise to W Mata volcano in the NE Lau Basin, we made the first observations of an active eruption on the deep-sea floor. The cruise was organized after volcanic activity was detected at two sites (W Mata volcano and NE Lau Spreading Center, NELSC) during a Nov. 2008 NOAA-PMEL expedition. At that time, both sites had elevated H2 concentrations and volcaniclastic shards in the hydrothermal plumes. Moored hydrophone data since Jan 2009 indicate that the activity at W Mata has been continuous between these expeditions. Results of our cruise and other work suggest that the NE Lau Basin hosts an unusually high level of magmatic activity, making it an ideal location to study the effects of magmatic processes on hydrothermal activity and associated ecosystems. W Mata was visited with 5 ROV Jason 2 dives and 2 dives with the MBARI autonomous mapping vehicle in May 2009. It was actively erupting at the 1200 m deep summit during each, so a hydrophone was deployed locally to collect acoustic data. Ship and shore-based analysis of HD video, molten lava, rocks, sediments, hot spring waters, and micro- and macro biological specimens collected by Jason 2 have provided a wealth of data. The eruption itself was characterized by extrusion of red, molten lava, extensive degassing, formation of large magma bubbles, explosive pyroclast ejection, and the active extrusion of pillow lavas. The erupting magmas are boninite, a relatively rare magma type found only at convergent margins. The hydrothermal fluids are generally acidic and all diffuse fluids collected were microbially active, even those at pH <3. W Mata was host to shrimp similar to those found at several other

  7. An Estimate of North Atlantic Basin Tropical Cyclone Activity for 2008

    NASA Technical Reports Server (NTRS)

    Wilson, Robert M.

    2008-01-01

    The statistics of North Atlantic basin tropical cyclones for the interval 1945-2007 are examined and estimates are given for the frequencies of occurrence of the number of tropical cyclones, number of hurricanes, number of major hurricanes, number of category 4/5 hurricanes, and number of U.S. land-falling hurricanes for the 2008 hurricane season. Also examined are the variations of peak wind speed, average peak wind speed per storm, lowest pressure, average lowest pressure per storm, recurrence rate and duration of extreme events (El Nino and La Nina), the variation of 10-yr moving averages of parametric first differences, and the association of decadal averages of frequencies of occurrence of North Atlantic basin tropical cyclones against decadal averages of Armagh Observatory, Northern Ireland, annual mean temperature (found to be extremely important for number of tropical cyclones and number of hurricanes). Because the 2008 hurricane season seems destined to be one that is non-El Nino-related and is a post-1995 season, estimates of the frequencies of occurrence for the various subsets of storms should be above long-term averages.

  8. Assessing extreme sea levels due to tropical cyclones in the Atlantic basin

    NASA Astrophysics Data System (ADS)

    Muis, Sanne; Lin, Ning; Verlaan, Martin; Winsemius, Hessel; Vatvani, Deepak; Ward, Philip; Aerts, Jeroen

    2017-04-01

    Tropical cyclones (TCs), including hurricanes and typhoons, are characterised by high wind speeds and low pressure and cause dangerous storm surges in coastal areas. Over the last 50 years, storm surge incidents in the Atlantic accounted for more than 1,000 deaths in the United Stated. Recent flooding disasters, such as Hurricane Katrina in New Orleans in 2005 and, Hurricane Sandy in New York in 2012, exemplify the significant TC surge risk in the United States. In this contribution, we build on Muis et al. (2016), and present a new modelling framework to simulate TC storm surges and estimate their probabilities for the Atlantic basin. In our framework we simulate the surge levels by forcing the Global Tide and Surge Model (GTSM) with wind and pressure fields from TC events. To test the method, we apply it to historical storms that occurred between 1988 and 2015 in the Atlantic Basin. We obtain high-resolution meteorological forcing by applying a parametric hurricane model (Holland 1980; Lin and Chavas 2012) to the TC extended track data set (Demuth et al. 2006; updated), which describes the position, intensity and size of the historical TCs. Preliminary results show that this framework is capable of accurately reproducing the main surge characteristics during past events, including Sandy and Katrina. While the resolution of GTSM is limited for local areas with a complex bathymetry, the overall performance of the model is satisfactory for the basin-scale application. For an accurate assessment of risk to coastal flooding in the Atlantic basin it is essential to provide reliable estimates of surge probabilities. However, the length of observed TC tracks is too short to accurately estimate the probabilities of extreme TC events. So next steps are to statistically extend the observed record to many thousands of years (e.g., Emanuel et al. 2006), in order to force GTSM with a large number of synthetic storms. Based on these synthetic simulations, we would be able to

  9. Decadal Trends of Atlantic Basin Tropical Cyclones (1950-1999)

    NASA Technical Reports Server (NTRS)

    Wilson, Robert M.

    2001-01-01

    Ten-year moving averages of the seasonal rates for 'named storms,' tropical storms, hurricanes, and major (or intense) hurricanes in the Atlantic basin suggest that the present epoch is one of enhanced activity, marked by seasonal rates typically equal to or above respective long-term median rates. As an example, the 10-year moving average of the seasonal rates for named storms is now higher than for any previous year over the past 50 years, measuring 10.65 in 1994, or 2.65 units higher than its median rate of 8. Also, the 10-year moving average for tropical storms has more than doubled, from 2.15 in 1955 to 4.60 in 1992, with 16 of the past 20 years having a seasonal rate of three or more (the median rate). For hurricanes and major hurricanes, their respective 10-year moving averages turned upward, rising above long-term median rates (5.5 and 2, respectively) in 1992, a response to the abrupt increase in seasonal rates that occurred in 1995. Taken together, the outlook for future hurricane seasons is for all categories of Atlantic basin tropical cyclones to have seasonal rates at levels equal to or above long-term median rates, especially during non-El Nino-related seasons. Only during El Nino-related seasons does it appear likely that seasonal rates might be slightly diminished.

  10. Geographical PCB and DDT patterns in shearwaters (Calonectris sp.) breeding across the NE Atlantic and the Mediterranean archipelagos.

    PubMed

    Roscales, Jose L; Muñoz-Arnanz, Juan; González-Solís, Jacob; Jiménez, Begoña

    2010-04-01

    Although seabirds have been proposed as useful biomonitors for organochlorine contaminants (OCs) in marine environments, their suitability is still unclear. To understand the geographic variability and the influence of seabird trophic ecology in OC levels, we analyzed PCBs, DDTs, delta(13)C, and delta(15)N in the blood of adult Calonectris shearwaters throughout a vast geographic range within the northeast Atlantic Ocean (from Cape Verde to Azores) and the Mediterranean Sea (from the Alboran Sea to Crete). OC concentrations were greater in birds from the Mediterranean than in those from the Atlantic colonies, showing higher and lower chlorinated PCB profiles, respectively. This large-scale pattern may reflect the influence of historical European runoffs in the Mediterranean basin and diffused sources for OCs in remote Atlantic islands. Spatial patterns also emerged within the Atlantic basin, probably associated with pollutant long-range transport and recent inputs of DDT in the food webs of shearwaters from Cape Verde and the Canary islands. Moreover, a positive association of OC concentrations with delta(15)N within each locality points out diet specialization as a major factor explaining differences in OCs at the intraspecific level. Overall, this study highlights wide range breeding seabirds, such as Calonectris shearwaters, as suitable organisms for biomonitoring large geographic trends of organochlorine contamination in the marine environment.

  11. The stress field below the NE German Basin: effects induced by the Alpine collision

    NASA Astrophysics Data System (ADS)

    Marotta, A. M.; Bayer, U.; Scheck, M.; Thybo, H.

    2001-02-01

    We use a thin-sheet approach for a viscous lithosphere to investigate the effects induced by the Alpine collision on the vertical deformation and regional stress in northern Europe, focusing on the NE German Basin. New seismic studies indicate a flexural-type deep crustal structure under the basin, which may be induced by compressive forces transmitted from the south and related to Alpine tectonics. Finite element techniques are used to solve the vertical deformation and stress field for a viscous European lithosphere with horizontal rheological heterogeneities. Our results support the idea that a relatively strong lithosphere below the northern margin of the German Basin at the transition into the Baltic Shield may explain the characteristic regional stress field, especially the fan-like pattern that is observed within the region.

  12. Geochemical and palynological records for the end-Triassic Mass-Extinction Event in the NE Paris Basin (Luxemburg)

    NASA Astrophysics Data System (ADS)

    Kuhlmann, Natascha; van de Schootbrugge, Bas; Thein, Jean; Fiebig, Jens; Franz, Sven-Oliver; Hanzo, Micheline; Colbach, Robert; Faber, Alain

    2016-04-01

    The End-Triassic mass-extinction event is one of the "big five" mass extinctions in Earth's history. Large scale flood basalt volcanism associated with the break-up of Pangaea, which resulted in the opening of the central Atlantic Ocean, is considered as the leading cause. In addition, an asteroid impact in Rochechouart (France; 201 ± 2 Ma) may have had a local influence on ecosystems and sedimentary settings. The Luxembourg Embayment, in the NE Paris Basin, offers a rare chance to study both effects in a range of settings from deltaic to lagoonal. A multidisciplinary study (sedimentology, geochemistry, palynology) has been carried out on a number of outcrops and cores that span from the Norian to lower Hettangian. Combined geochemical and palynological records from the Boust core drilled in the NE Paris Basin, provide evidence for paleoenvironmental changes associated with the end-Triassic mass-extinction event. The Triassic-Jurassic stratigraphy of the Boust core is well constrained by palynomorphs showing the disappaerance of typical Triassic pollen taxa (e.g. Ricciisporites tuberculates) and the occurrence of the marker species Polypodiisporites polymicroforatus within the uppermost Rhaetian, prior to the Hettangian dominance of Classopollis pollen. The organic carbon stable isotope record (δ13Corg) spanning the Norian to Hettangian, shows a series of prominent negative excursions within the middle Rhaetian, followed by a trend towards more positive values (approx -24 per mille) within the uppermost Rhaetian Argiles de Levallois Member. The lowermost Hettangian is characterized by a major negative excursion, reaching - 30 per mille that occurs in organic-rich sediments. This so-called "main negative excursion" is well-known from other locations, for example from Mariental in Northern Germany and from St Audrie's Bay in England, and Stenlille in Denmark. Based on redox-sensitive trace element records (V, Cr, Ni, Co, Th, U) the lowermost Hettangian in most of

  13. Chemical provinces and dynamic melting of the NE Atlantic mantle

    NASA Astrophysics Data System (ADS)

    Tronnes, R. G.

    2009-12-01

    Low-degree melting of fertile parts of the NE Atlantic mantle yields primitive alkaline basalts in the Icelandic off-rift zones and at Jan Mayen. Olivine tholeiites in the Icelandic rift zones and oceanic spreading ridges are formed by protracted decompressional melting. The V-shaped ridges SW and NE of Iceland indicate that rising, hot material is supplied by a pulsating plume and deflected laterally for distances of about 1000 km from Iceland (Jones et al. GGG 2002; Breivik et al. JGR 2006). Plume material deflected along the rift zones and spreading ridges undergoes mixing with the ambient asthenosphere and extensive melting at shallow level, whereas material deflected in other directions may flow laterally at deeper levels and remain largely unmelted and fertile. A recent investigation of a suite of primitive off-rift basalts from Iceland and Jan Mayen (Debaille et al., 2009, GCA) demonstrated an important source contribution from subcontinental lithospheric mantle (SCLM). Available data on the primitive off-rift basalts and tholeiitic basalts from Iceland and the NE Atlantic ridges indicates the existence of three main composite mantle components, characterized by the following relative isotope ratios (H: high, I: intermediate and L: low ratio) for 87/86Sr, 143/144Nd, 206/204Pb, 187/188Os and 3/4He, respectively: 1. Iceland plume with depleted lower mantle mixed with recycled oceanic crust: I, I, H, H, H 2. Strongly depleted and later re-enriched SCLM: H, L, I, L, L 3. Depleted asthenosphere: L, H, L, I, L The two first composite components contain enriched and depleted subcomponents with distinct isotope signatures. The isotope ratio variations between the fertile components are larger than between the refractory components. The 3/4He ratio, however, is much higher in the depleted plume component than in the depleted SCLM and asthenospheric components. The old SCLM material could in principle be recycled and embedded in the lower mantle and supplied to the

  14. Evidence of a connection between the Atlantic and Mediterranean during the Messinian Salinity Crisis from Pb and Nd isotopes

    NASA Astrophysics Data System (ADS)

    Modestou, Sevasti; Gutjahr, Marcus; Fietzke, Jan; Rodés, Ángel; Frank, Martin; Bolhão Muiños, Susana; Ellam, Rob; Flecker, Rachel

    2014-05-01

    Prior to the opening of the Gibraltar Strait at 5.33 Ma, the Betic (southern Spain) and Rifian (northern Morocco) marine palaeocorridors linked the Mediterranean to the Atlantic. Although the central regions of these corridors have been heavily eroded due to uplift, evidence published to date indicates that both closed before the onset of the Messinian Salinity Crisis (MSC; 5.97 to 5.33 Ma [1, 2]). However, pre-MSC corridor closure presents a paradox, as the volume of halite deposited within the Mediterranean basin requires several times the volume of seawater contained in the basin itself. In this regard, radiogenic isotopes such as Sr, Pb, and Nd can provide key information about the timing of exchange through the Betic and Rifian palaeogateways. Due to the resolvable isotopic difference in Nd isotope signatures of outgoing Mediterranean and incoming Atlantic water masses, demonstrated both for the present day as well as the past environment, this isotope system can be used to identify exchange between these two water bodies. Although less well constrained to date, the Pb isotope system can be used in a similar manner due to its short residence time in seawater and interbasin variability. A high resolution Pb isotope record extracted using laser ablation from ferromanganese crust 3514-6 (recovered from the Lion Seamount, NE Atlantic, water depth 690-940 m) indicates a relatively constant Pb isotope signature before, during and after the MSC period. The previously published [3] Nd isotope record of crust 3514-6 corroborates that the crust was deposited in a current distinct from NE Atlantic Deep water or Antarctic Intermediate Water, the principal currents in the region of the Lion Seamount. The combined Pb and Nd isotope evolution suggests that Mediterranean Outflow Water (MOW) was continuously advected into the NE Atlantic during and after the MSC. Furthermore, preliminary Nd isotope records from Late Miocene sediments collected in the Sorbas Basin, Spain

  15. Statistical Aspects of Tropical Cyclone Activity in the North Atlantic Basin, 1945-2010

    NASA Technical Reports Server (NTRS)

    Wilson, Robert M.

    2012-01-01

    Examined are statistical aspects of the 715 tropical cyclones that formed in the North Atlantic basin during the interval 1945-2010. These 715 tropical cyclones include 306 storms that attained only tropical storm strength, 409 hurricanes, 179 major or intense hurricanes, and 108 storms that struck the US coastline as hurricanes. Comparisons made using 10-year moving average (10-yma) values between tropical cyclone parametric values and surface air and ENSO-related parametric values indicate strong correlations to exist, in particular, against the Armagh Observatory (Northern Ireland) surface air temperature, the Atlantic Multi-decadal Oscillation (AMO) index, the Atlantic Meridional Mode (AMM) index, and the North Atlantic Oscillation (NAO) index, in addition to the Oceanic Ni o index (ONI) and Quasi-Biennial Oscillation (QBO) indices. Also examined are the decadal variations of the tropical cyclone parametric values and a look ahead towards the 2012 hurricane season and beyond.

  16. East and central farming and forest region and Atlantic basin diversified farming region: LRRs N and S

    Treesearch

    Brad D. Lee; John M. Kabrick

    2017-01-01

    The central, unglaciated US east of the Great Plains to the Atlantic coast corresponds to the area covered by LRR N (East and Central Farming and Forest Region) and S (Atlantic Basin Diversified Farming Region). These regions roughly correspond to the Interior Highlands, Interior Plains, Appalachian Highlands, and the Northern Coastal Plains.

  17. Late Quaternary Palaeoceanographic Changes in Sea Surface Conditions in the Tropical Atlantic

    NASA Astrophysics Data System (ADS)

    Fischel, Andrea; Seidenkrantz, Marit-Solveig; Kuijpers, Antoon; Nürnberg, Dirk

    2013-04-01

    Palaeoceanographic changes and the variability in surface water mass hydrography are reconstructed in order to track tropical ocean and climate variability and inter-hemispheric heat exchange through the last 42,000 year BP. Our studies are based on the relative abundance of planktonic foraminifera combined with sea surface temperature approximation based Mg/Ca measurements, XRF scanning and stable oxygen isotope analyses in a 5 m long gravity core Ga307-Win-12GC (17°50.80N, 64°48.7290W), retrieved in the Virgin Island Basin in approx. 3,960 m water depth. The Virgin Island Basin is the deepest part of the Anegada-Jungfern Passage in the northeast Caribbean, one of the most important pathways for water mass exchange between the Central Atlantic and the Caribbean Sea. Due to its bathymetry surface waters as well as deep water mass strata from the northern and southern hemisphere enter the basin, comprising Caribbean Surface Water (CSW), Antarctic Intermediate Water (AAIW), Atlantic Intermediate Water (AIW) and North Atlantic Deep Water (NADW). The planktonic foraminiferal assemblage suggests rather stable sea-surface conditions during the Holocene in the NE Caribbean. However, major changes in the hydrographic setting could be identified within the glacial period. During the glacial period, clear millennial-scale variability in sea-surface temperature and productivity are present. Fluctuations in the relative abundance of Globigerinoides ruber in the sediment core may be correlated to Dansgaard-Oeschger events in the northern North Atlantic. Furthermore an increase in relative abundance of Globorotalia rubescens occurs synchronous with ice rafted debris layers described from the North Atlantic. The faunal changes in the tropical Atlantic may thus be correlated to major climate changes in the North Atlantic, mainly D-O cyclicity as well as Heinrich events. Thus, the synchronous change in water mass distribution and hydrographic cyclicity suggests a possible linkage

  18. Comparative ecology of widely distributed pelagic fish species in the North Atlantic: Implications for modelling climate and fisheries impacts

    NASA Astrophysics Data System (ADS)

    Trenkel, V. M.; Huse, G.; MacKenzie, B. R.; Alvarez, P.; Arrizabalaga, H.; Castonguay, M.; Goñi, N.; Grégoire, F.; Hátún, H.; Jansen, T.; Jacobsen, J. A.; Lehodey, P.; Lutcavage, M.; Mariani, P.; Melvin, G. D.; Neilson, J. D.; Nøttestad, L.; Óskarsson, G. J.; Payne, M. R.; Richardson, D. E.; Senina, I.; Speirs, D. C.

    2014-12-01

    This paper reviews the current knowledge on the ecology of widely distributed pelagic fish stocks in the North Atlantic basin with emphasis on their role in the food web and the factors determining their relationship with the environment. We consider herring (Clupea harengus), mackerel (Scomber scombrus), capelin (Mallotus villosus), blue whiting (Micromesistius poutassou), and horse mackerel (Trachurus trachurus), which have distributions extending beyond the continental shelf and predominantly occur on both sides of the North Atlantic. We also include albacore (Thunnus alalunga), bluefin tuna (Thunnus thynnus), swordfish (Xiphias gladius), and blue marlin (Makaira nigricans), which, by contrast, show large-scale migrations at the basin scale. We focus on the links between life history processes and the environment, horizontal and vertical distribution, spatial structure and trophic role. Many of these species carry out extensive migrations from spawning grounds to nursery and feeding areas. Large oceanographic features such as the North Atlantic subpolar gyre play an important role in determining spatial distributions and driving variations in stock size. Given the large biomasses of especially the smaller species considered here, these stocks can exert significant top-down pressures on the food web and are important in supporting higher trophic levels. The review reveals commonalities and differences between the ecology of widely distributed pelagic fish in the NE and NW Atlantic basins, identifies knowledge gaps and modelling needs that the EURO-BASIN project attempts to address.

  19. Assessment of undiscovered oil and gas resources of the East Coast Mesozoic basins of the Piedmont, Blue Ridge Thrust Belt, Atlantic Coastal Plain, and New England Provinces, 2011

    USGS Publications Warehouse

    Milici, Robert C.; Coleman, James L.; Rowan, Elisabeth L.; Cook, Troy A.; Charpentier, Ronald R.; Kirschbaum, Mark A.; Klett, Timothy R.; Pollastro, Richard M.; Schenk, Christopher J.

    2012-01-01

    During the early opening of the Atlantic Ocean in the Mesozoic Era, numerous extensional basins formed along the eastern margin of the North American continent from Florida northward to New England and parts of adjacent Canada. The basins extend generally from the offshore Atlantic continental margin westward beneath the Atlantic Coastal Plain to the Appalachian Mountains. Using a geology-based assessment method, the U.S. Geological Survey estimated a mean undiscovered natural gas resource of 3,860 billion cubic feet and a mean undiscovered natural gas liquids resource of 135 million barrels in continuous accumulations within five of the East Coast Mesozoic basins: the Deep River, Dan River-Danville, and Richmond basins, which are within the Piedmont Province of North Carolina and Virginia; the Taylorsville basin, which is almost entirely within the Atlantic Coastal Plain Province of Virginia and Maryland; and the southern part of the Newark basin (herein referred to as the South Newark basin), which is within the Blue Ridge Thrust Belt Province of New Jersey. The provinces, which contain these extensional basins, extend across parts of Georgia, South Carolina, North Carolina, Virginia, Maryland, Delaware, Pennsylvania, New Jersey, New York, Connecticut, and Massachusetts.

  20. Plateau growth around the Changma Basin in NE Tibet

    NASA Astrophysics Data System (ADS)

    Vernon, Rowan; Cunningham, Dickson; Zhang, Jin; England, Richard

    2014-05-01

    The Qilian Mountains form one of the most actively uplifting regions of the northeastern Tibetan Plateau and provide an opportunity to study the ongoing, intermediate stages of plateau growth. The crust of the Qilian Mountains consists of an orogenic collage of mid-Proterozoic to mid-Palaeozoic island arc terranes accreted to the North China Craton during the Palaeozoic. NE-directed compression related to the Indo-Asian collision began in the Early Neogene, uplifting fold-thrust mountain ranges which splay south-eastwards from the sinistral northeast-trending Altyn Tagh Fault (ATF). In this study, we investigate the post-Oligocene tectonic evolution of the northern margin of the Tibetan Plateau around the Changma Basin, at the very northeast corner of the Plateau, where the ATF forms a triple junction with the frontal Qilian Shan thrust. Our research involves synthesis of previous geological and geophysical data, remote sensing analysis and field mapping of structures along key transects. The Changma Basin is a relatively low intra-montane basin in the northeast Tibetan Plateau that is receiving alluvial infill from surrounding ranges, but is also being drained by the Su Le River, one of the largest river systems in the northeast Tibetan Plateau. The basin is also internally deforming and inverting along fault and fold zones, as well as being overthrust along some of its margins. Where older basement trends are parallel to neotectonic faults, some reactivation is inferred and locally documented through field observations. Otherwise, the post-Oligocene thrust and oblique-slip faults which are responsible for uplifting various basement blocks and inverting the Changma Basin appear discordant to nearby basement trends. Range-bounding thrust faults with the greatest along-strike continuity and relief generation are assumed to have the largest displacements, whereas other intra-range thrusts that bound uplifted limestone blocks are assumed to have lower amounts of

  1. Turbidity distribution in the Atlantic Ocean

    USGS Publications Warehouse

    Eittreim, S.; Thorndike, E.M.; Sullivan, L.

    1976-01-01

    The regional coverage of Lamont nephelometer data in the North and South Atlantic can be used to map seawater turbidity at all depths. At the level of the clearest water, in the mid-depth regions, the turbidity distribution primarily reflects the pattern of productivity in the surface waters. This suggests that the 'background' turbidity level in the oceans is largely a function of biogenic fallout. The bottom waters of the western Atlantic generally exhibit large increases in turbidity. The most intense benthic nepheloid layers are in the southwestern Argentine basin and northern North American basin; the lowest bottom water turbidity in the western Atlantic is in the equatorial regions. Both the Argentine and North American basin bottom waters appear to derive their high turbidity largely from local resuspension of terrigenous input in these basins. In contrast to the west, the eastern Atlantic basins show very low turbidities with the exception of three regions: the Mediterranean outflow area, the Cape basin, and the West European basin. ?? 1976.

  2. Gene flow between Atlantic and Pacific Ocean basins in three lineages of deep-sea clams (Bivalvia: Vesicomyidae: Pliocardiinae) and subsequent limited gene flow within the Atlantic

    NASA Astrophysics Data System (ADS)

    LaBella, Abigail Leavitt; Van Dover, Cindy L.; Jollivet, Didier; Cunningham, Clifford W.

    2017-03-01

    Pliocardiin (vesicomyid) clams rely on microbial symbionts for nutrition and are obligate inhabitants of deep-sea chemosynthetic ecosystems. Unlike many other invertebrate hosts of chemosynthetic microbes, pliocardiin clams are found in every ocean in a variety of reducing habitats, including hydrothermal vents, cold seeps, organic falls and deep-sea fans. The global distribution of pliocardiin clams suggests historical gene flow between ocean basins. We focus on 3 pliocardiin genera-'Pliocardia' I, Calyptogena and Abyssogena-each of which has a pair of sister clades in the Atlantic and Pacific. Our work tests the hypothesis that historical gene flow between the Atlantic and Pacific Oceans within these genera was interrupted by the closure of the Panamanian seaway and tests whether isolation between the ocean basins is the result of vicariance or past colonization. These questions are investigated in the context of fossil evidence, biogeography and phylogenetics. This study revealed a set of substitution rates consistent with other invertebrate studies (μ=0.8%/My/lineage), and a set consistent with much lower rates often attributed to deep-sea organisms (μ=0.3%/My/lineage). Among the Pacific/Atlantic sister pairs, 'Pliocardia' I COI divergence per lineage is intermediate (2.5%), Calyptogena is the highest (6.1%) and Abyssogena the lowest (0.8%). The substitution rates suggest that 'Pliocardia' I and Calyptogena have histories of at least 2.8 My in the Atlantic, with Calyptogena likely older. The slower rate, however, is inconsistent with both the maximum age of the family and several well studied fossils: leaving the faster rate preferred. With the faster rate, the Abyssogena southwardae clade diverged from its Pacific sister clade around 1 Mya, which likely post-dates the closure of the Isthmus of Panama and the opening of the Bering Strait. In light of this recent divergence, we test the previously proposed hypothesis that there is a high level of ongoing gene

  3. Developing an event-tree probabilistic tsunami inundation model for NE Atlantic coasts: Application to case studies

    NASA Astrophysics Data System (ADS)

    Omira, Rachid; Baptista, Maria Ana; Matias, Luis

    2015-04-01

    This study constitutes the first assessment of probabilistic tsunami inundation in the NE Atlantic region, using an event-tree approach. It aims to develop a probabilistic tsunami inundation approach for the NE Atlantic coast with an application to two test sites of ASTARTE project, Tangier-Morocco and Sines-Portugal. Only tsunamis of tectonic origin are considered here, taking into account near-, regional- and far-filed sources. The multidisciplinary approach, proposed here, consists of an event-tree method that gathers seismic hazard assessment, tsunami numerical modelling, and statistical methods. It presents also a treatment of uncertainties related to source location and tidal stage in order to derive the likelihood of tsunami flood occurrence and exceedance of a specific near-shore wave height during a given return period. We derive high-resolution probabilistic maximum wave heights and flood distributions for both test-sites Tangier and Sines considering 100-, 500-, and 1000-year return periods. We find that the probability that a maximum wave height exceeds 1 m somewhere along the Sines coasts reaches about 55% for 100-year return period, and is up to 100% for 1000-year return period. Along Tangier coast, the probability of inundation occurrence (flow depth > 0m) is up to 45% for 100-year return period and reaches 96% in some near-shore costal location for 500-year return period. Acknowledgements: This work is funded by project ASTARTE - Assessment, STrategy And Risk Reduction for Tsunamis in Europe. Grant 603839, 7th FP (ENV.2013.6.4-3 ENV.2013.6.4-3).

  4. Geochemistry of NE Atlantic non-rifting zones, Iceland and Jan Mayen

    NASA Astrophysics Data System (ADS)

    Tronnes, R. G.; Waight, T.

    2005-12-01

    The fertile components of the NE Atlantic mantle are sampled preferentially by alkaline basalts in the volcanic flank zones of Iceland and in the Jan Mayen and Vesteris seamount areas. Our data from primitive flank zone lavas from Iceland and Jan Mayen demonstrate a HIMU-affinity with enrichment of HFSE, U/Pb, Th/U and Nb/Th. In PM-normalized spider diagrams the least enriched samples have weakly positive Sr-anomalies, whereas the most enriched samples have negative Sr-anomalies. The entire sample suite shows negative Sr-Nd-isotope correlation, whereas the samples of each volcanic system or flank zone generally lack such a correlation. Our data confirm the anomalously high 87/86Sr of the Orafajokull volcanic system in the eastern flank zone. The results are consistent with existing data for other primitive flank zone basalts from Iceland and Jan Mayen. Common geochemical features linking alkaline flank zone basalts and high-degree tholeiitic melts include high 87/86Sr (and probably 176/177Hf) for a given 143/144Nd, negative delta-207Pb (except for Orafajokull) and positive delta-Nb. Alkaline flank zone basalts have generally higher 87/86Sr, 206/204Pb and 18/16O and lower 143/144Nd, 187/188Os and 3/4He than rift zone tholeiites. The different 18/16O ratios in flank and rift zone basalts are consistent with seafloor hydrothermal alteration of the upper and lower parts of recycled oceanic lithosphere, respectively. Olivine-melt fractionation may contribute to the difference. Indications of lower 187/188Os in alkaline basalts compared to nearby rift zone tholeiites could be caused by subduction zone loss of Re from the upper part of recycled slabs. The partial melting and volcanic sampling of the fertile mantle components under Iceland and the NE Atlantic is governed by the crustal structure and geometry of the Icelandic volcanic zones and the lateral deflection of the upwelling heterogeneous mantle source originating under central Iceland. Based on the pattern of V

  5. Developing an Event-Tree Probabilistic Tsunami Inundation Model for NE Atlantic Coasts: Application to a Case Study

    NASA Astrophysics Data System (ADS)

    Omira, R.; Matias, L.; Baptista, M. A.

    2016-12-01

    This study constitutes a preliminary assessment of probabilistic tsunami inundation in the NE Atlantic region. We developed an event-tree approach to calculate the likelihood of tsunami flood occurrence and exceedance of a specific near-shore wave height for a given exposure time. Only tsunamis of tectonic origin are considered here, taking into account local, regional, and far-field sources. The approach used here consists of an event-tree method that gathers probability models for seismic sources, tsunami numerical modeling, and statistical methods. It also includes a treatment of aleatoric uncertainties related to source location and tidal stage. Epistemic uncertainties are not addressed in this study. The methodology is applied to the coastal test-site of Sines located in the NE Atlantic coast of Portugal. We derive probabilistic high-resolution maximum wave amplitudes and flood distributions for the study test-site considering 100- and 500-year exposure times. We find that the probability that maximum wave amplitude exceeds 1 m somewhere along the Sines coasts reaches about 60 % for an exposure time of 100 years and is up to 97 % for an exposure time of 500 years. The probability of inundation occurrence (flow depth >0 m) varies between 10 % and 57 %, and from 20 % up to 95 % for 100- and 500-year exposure times, respectively. No validation has been performed here with historical tsunamis. This paper illustrates a methodology through a case study, which is not an operational assessment.

  6. Water environments: anthropogenic pressures and ecosystem changes in the Atlantic drainage basins of Brazil.

    PubMed

    Marques, Marcia; da Costa, Monica F; Mayorga, Maria Irles de O; Pinheiro, Patrícia R

    2004-02-01

    Densely occupied drainage basins and coastal zones in developing countries that are facing economic growth are likely to suffer from moderate to severe environmental impacts regarding different issues. The catchment basins draining towards the Atlantic coast from northeastern to southern Brazil include a wide range of climatic zones and diverse ecosystems. Within its borders lies the Atlantic rain forest, significant extensions of semiarid thorn forests (caatinga), vast tree and scrub woodlands (cerrado) and most of the 6670 km of the Brazilian coast and its marine ecosystems. In recent decades, human activities have increasingly advanced over these natural resources. Littoralization has imposed a burden on coastal habitats and communities. Most of the native vegetation of the cerrado and caatinga was removed and only 7% of the original Atlantic rainforest still exists. Estuaries, bays and coastal lagoons have been irreversibly damaged. Land uses, damming and water diversion have become the major driving forces for habitat loss and aquatic ecosystem modification. Regardless of the contrast between the drought-affected northeastern Brazil and the much more prosperous and industrialized southeastern/southern Brazil, the impacts on habitat and communities were found equally severe in both cases. Attempts to halt environmental degradation have not been effective. Instead of focusing on natural resources separately, it is suggested that more integrated environmental policies that focus on aquatic ecosystems integrity are introduced.

  7. Genus Gambierdiscus in the Canary Islands (NE Atlantic Ocean) with description of Gambierdiscus silvae sp. nov., a new potentially toxic epiphytic benthic dinoflagellate.

    PubMed

    Fraga, Santiago; Rodríguez, Francisco

    2014-12-01

    Species of the dinoflagellate genus Gambierdiscus are the cause of Ciguatera Fish Poisoning, common in tropical areas. Nevertheless, until recently this syndrome was not reported in the NE Atlantic Ocean. A new photosynthetic dinoflagellate species, Gambierdiscus silvae sp. nov. is described based on samples taken from tide pools on rocky shores of the Canary Islands (NE Atlantic Ocean). Its morphology was studied by light and scanning electron microscopy. The new species is anterioposteriorly compressed, lenticular in shape with an epitheca slightly higher than the hypotheca. It is round in apical view and has a thick smooth theca with many scattered pores. Plate formula is Po, 4', 0a, 6″, 6c, 6s?, 5'″, 0p, 2″″. Plate 2' is hatchet-shaped and Plate 2″″ is very wide and the largest of the hypotheca. Phylogenies inferred from the large subunit nuclear rRNA showed that three G. silvae strains clustered in a well supported sister clade to G. polynesiensis, distinct from the other species. G. australes was observed for the first time in the Atlantic, together with G. excentricus already reported from these islands. This work increases the number of Gambierdiscus species described and shows their unexpected diversity in the Canary Islands. Copyright © 2014 The Authors. Published by Elsevier GmbH.. All rights reserved.

  8. Phanerozoic geological evolution of the Equatorial Atlantic domain

    NASA Astrophysics Data System (ADS)

    Basile, Christophe; Mascle, Jean; Guiraud, René

    2005-10-01

    The Phanerozoic geological evolution of the Equatorial Atlantic domain has been controlled since the end of Early Cretaceous by the Romanche and Saint Paul transform faults. These faults did not follow the PanAfrican shear zones, but were surimposed on Palæozoic basins. From Neocomian to Barremian, the Central Atlantic rift propagated southward in Cassiporé and Marajó basins, and the South Atlantic rift propagated northward in Potiguar and Benue basins. During Aptian times, the Equatorial Atlantic transform domain appeared as a transfer zone between the northward propagating tip of South Atlantic and the Central Atlantic. Between the transform faults, oceanic accretion started during Late Aptian in small divergent segments, from south to north: Benin-Mundaú, deep Ivorian basin-Barreirinhas, Liberia-Cassiporé. From Late Aptian to Late Albian, the Togo-Ghana-Ceará basins appeared along the Romanche transform fault, and Côte d'Ivoire-Parà-Maranhão basins along Saint Paul transform fault. They were rapidly subsiding in intra-continental settings. During Late Cretaceous, these basins became active transform continental margins, and passive margins since Santonian times. In the same time, the continental edge uplifted leading either to important erosion on the shelf or to marginal ridges parallel to the transform faults in deeper settings.

  9. Arctic and N Atlantic Crustal Thickness and Oceanic Lithosphere Distribution from Gravity Inversion

    NASA Astrophysics Data System (ADS)

    Kusznir, Nick; Alvey, Andy

    2014-05-01

    consistent with these basins being oceanic. Larger crustal thicknesses, in the range 20 - 30 km, are predicted for the Lomonosov, Alpha and Mendeleev Ridges. Crustal basement thicknesses of 10-15 km are predicted under the Laptev Sea which is interpreted as highly thinned continental crust formed at the eastward continuation of Eurasia Basin sea-floor spreading. Thin continental or oceanic crust of thickness 7 km or less is predicted under the North Chukchi Basin and has major implications for understanding the Mesozoic and Cenozoic plate tectonic history of the Siberian and Chukchi Amerasia Basin margins. Restoration of crustal thickness and continent-ocean boundary location from gravity inversion may be used to test and refine plate tectonic reconstructions. Using crustal thickness and continental lithosphere thinning factor maps with superimposed shaded-relief free-air gravity anomaly, we improve the determination of pre-breakup rifted margin conjugacy and sea-floor spreading trajectory within the Arctic and N Atlantic basins. By restoring crustal thickness & continental lithosphere thinning maps of the Eurasia Basin & NE Atlantic to their initial post-breakup configuration we show the geometry and segmentation of the rifted continental margins at their time of breakup, together with the location of highly-stretched failed breakup basins and rifted micro-continents. We interpret gravity inversion crustal thicknesses underneath Morris Jessop Rise & Yermak Plateau as continental crust which provided a barrier to the tectonic and palaeo-oceanic linkage between the Arctic & North Atlantic until the Oligocene. Before this time, we link the seafloor spreading within the Eurasia Basin to that in Baffin Bay.

  10. Sensitivity of the North Atlantic Basin to cyclic climatic forcing during the early Cretaceous

    USGS Publications Warehouse

    Dean, W.E.; Arthur, M.A.

    1999-01-01

    Striking cyclic interbeds of laminated dark-olive to black marlstone and bioturbated white to light-gray limestone of Neocomian (Early Cretaceous) age have been recovered at Deep Sea Drilling Project (DSDP) and Ocean Drilling Project (ODP) sites in the North Atlantic. These Neocomian sequences are equivalent to the Maiolica Formation that outcrops in the Tethyan regions of the Mediterranean and to thick limestone sequences of the Vocontian Trough of France. This lithologic unit marks the widespread deposition of biogenic carbonate over much of the North Atlantic and Tethyan seafloor during a time of overall low sealevel and a deep carbonate compensation depth. The dark clay-rich interbeds typically are rich in organic carbon (OC) with up to 5.5% OC in sequences in the eastern North Atlantic. These eastern North Atlantic sequences off northwest Africa, contain more abundant and better preserved hydrogen-rich, algal organic matter (type II kerogen) relative to the western North Atlantic, probably in response to coastal upwelling induced by an eastern boundary current in the young North Atlantic Ocean. The more abundant algal organic matter in sequences in the eastern North Atlantic is also expressed in the isotopic composition of the carbon in that organic matter. In contrast, organic matter in Neocomian sequences in the western North Atlantic along the continental margin of North America has geochemical and optical characteristics of herbaceous, woody, hydrogen-poor, humic, type III kerogen. The inorganic geochemical characteristics of the dark clay-rich (80% CaCO3) interbeds in both the eastern and western basins of the North Atlantic suggest that they contain minor amounts of relatively unweathered eolian dust derived from northwest Africa during dry intervals.

  11. Extensive hydrothermal activity in the NE Lau basin revealed by ROV dives

    NASA Astrophysics Data System (ADS)

    Embley, R. W.; Resing, J. A.; Tebo, B.; Baker, E. T.; Butterfield, D. A.; Chadwick, B.; Davis, R.; de Ronde, C. E. J.; Lilley, M. D.; Lupton, J. E.; Merle, S. G.; Rubin, K. H.; Shank, T. M.; Walker, S. L.; Arculus, R. J.; Bobbitt, A. M.; Buck, N. J.; Caratori Tontini, F.; Crowhurst, P. V.; Mitchell, E.; Olson, E. J.; Ratmeyer, V.; Richards, S.; Roe, K. K.; Kenner-Chavis, P.; Martinez-Lyons, A.; Sheehan, C.; Brian, R.

    2014-12-01

    Dives with the QUEST 4000 ROV (Remotely Operated Vehicle) in September 2012 discovered nine hydrothermal sites in the arc and rear-arc region of the NE Lau Basin in 1150 m to 2630 m depth. These sites, originally detected by water column and seafloor surveys conducted in 2008-2011, include: (1) a paired sulfur-rich/black smoker field on the summit of a tectonically deformed magmatic arc volcano (Niua), (2) fracture-controlled black smoker venting on several small en echelon seamounts (north Matas) that lie between the magmatic arc and the backarc spreading center and (3) a magmatic degassing site on the summit of a dacite cone within a large (~12 km diameter) caldera volcano (Niuatahi). Dives at West Mata Seamount, which was undergoing strombolian volcanic activity and effusive rift-zone eruptions from 2008 to 2010, revealed a dormant volcanic phase in September 2012, with continued low-temperature diffuse venting. The high-temperature venting is likely driven by magmatic heat indicative of underlying partial melt zones and/or melt pockets distributed through the region. The occurrence of the youngest known boninite eruptions on the Mata volcanoes is consistent with subduction fluid flux melting extending into the rear-arc zone. Extension related to the transition from subduction to strike-slip motion of the northern Tonga Arc over the active Subduction-Transform Edge Propagator (STEP) fault probably contributes to the enhanced volcanism/hydrothermal activity in the NE Lau Basin. Chemosynthetic ecosystems at these sites range from mostly motile, lower diversity ecosystems at the eruptive/magmatically-degassing sites to higher diversity ecosystems with less mobile faunal components at the black-smoker systems. The wide range of fluid chemistry, water depth and geologic settings of the hydrothermal systems in this area provides an intriguing template to study the interaction of hydrothermal fluid chemistry, chemosynthetic habitats and their geologic underpinning

  12. Hyperactive hydrothermal activity in the NE Lau basin revealed by ROV dives

    NASA Astrophysics Data System (ADS)

    Embley, R. W.; Resing, J. A.; Tebo, B.; Baker, E. T.; Butterfield, D. A.; Chadwick, B.; Davis, R.; de Ronde, C. E.; Lilley, M. D.; Lupton, J. E.; Merle, S. G.; Rubin, K. H.; Shank, T. M.; Walker, S. L.; Arculus, R. J.; Bobbitt, A. M.; Buck, N.; Caratori Tontini, F.; Crowhurst, P. V.; Mitchell, E.; Olson, E. J.; Ratmeyer, V.; Richards, S.; Roe, K. K.; Keener, P.; Martinez Lyons, A.; Sheehan, C.; Brian, R.

    2013-12-01

    Dives with the QUEST 4000 ROV (Remotely Operated Vehicle) in September 2012 discovered nine hydrothermal sites in the arc and rear-arc region of the NE Lau Basin in 1150 m to 2630 m depth. These sites, originally detected by water column and seafloor surveys conducted in 2008-2011, include: (1) a paired sulfur-rich/black smoker field on the summit of a tectonically deformed magmatic arc volcano (Niua), (2) fracture-controlled black smoker venting on several small en echelon seamounts (north Matas) that lie between the magmatic arc and the backarc spreading center and (3) a magmatic degassing site on the summit of a dacite cone within a large (~12 km diameter) caldera volcano (Niuatahi). Dives at West Mata Seamount, which was undergoing strombolian volcanic activity and effusive rift-zone eruptions from 2008 to 2010, revealed a dormant volcanic phase in September 2012, with continued low-temperature diffuse venting. The high-temperature venting is likely driven by magmatic heat indicative of underlying partial melt zones and/or melt pockets distributed through the region. The occurrence of the youngest known boninite eruptions on the Mata volcanoes is consistent with subduction fluid flux melting extending into the rear-arc zone. Extension related to the transition from subduction to strike-slip motion of the northern Tonga Arc over the active Subduction-Transform Edge Propagator (STEP) fault probably contributes to the enhanced volcanism/hydrothermal activity in the NE Lau Basin. Chemosynthetic ecosystems at these sites range from mostly motile, lower diversity ecosystems at the eruptive/magmatically-degassing sites to higher diversity ecosystems with less mobile faunal components at the black-smoker systems. The wide range of fluid chemistry, water depth and geologic settings of the hydrothermal systems in this area provides an intriguing template to study the interaction of hydrothermal fluid chemistry, chemosynthetic habitats and their geologic underpinning

  13. Nematocarcinus Milne Edwards, 1881 (Crustacea, Decapoda) from Southwestern Atlantic, including the Southern Mid-Atlantic Ridge area.

    PubMed

    Cardoso, Irene A; Burukovsky, Rudolf N

    2014-11-26

    The deep sea shrimp genus Nematocarcinus Milne Edwards, 1881 includes 47 species, ten of them have been recorded from the Atlantic Ocean. Herein, material sampled during three scientific projects (REVIZEE Central Fishery project; Campos Basin Deep Sea Environmental Project; Evaluation of Environmental Heterogeneity in the Campos Basin) made in the Southwestern Atlantic, off Brazil, is examined. In addition, material sampled from the South Mid Atlantic Ridge (MAR-ECO Project) was also examined. Four species are recorded for the first time to the southwestern Atlantic Ocean including Mid Atlantic Ridge area: Nematocarcinus faxoni Burukovsky, 2001; N. gracilipes Filhol, 1884; N. rotundus Crosnier & Forest, 1973 and N. tenuipes Spence-Bate, 1888.

  14. Tropical Cyclones and Climate Controls in the Western Atlantic Basin during the First Half of the Nineteenth Century

    NASA Astrophysics Data System (ADS)

    Mock, C. J.; Dodds, S. F.; Rodgers, M. D.; Patwardhan, A.

    2008-12-01

    This study describes new comprehensive reconstructions of individual Western Atlantic Basin tropical cyclones for each year of the first half of the nineteenth century in the Western Atlantic Basin that are directly compatible and supplement the National Hurricane Center's HURDAT (Atlantic basin hurricane database). Data used for reconstructing tropical cyclones come from ship logbooks, ship protests, diaries, newspapers, and early instrumental records from more than 50 different archival repositories in the United States and the United Kingdom. Tropical cyclone strength was discriminated among tropical storms, hurricanes, major hurricanes, and non-tropical lows at least at tropical storm strength. The results detail the characteristics of several hundred storms, many of them being newly documented, and tracks for all storms were mapped. Overall, prominent active periods of tropical cyclones are evident along the western Atlantic Ocean in the 1830s but Caribbean and Gulf coasts exhibit active periods as being more evident in the 1810s and 1820s. Differences in decadal variations were even more pronounced when examining time series of activity at the statewide scale. High resolution paleoclimate and historical instrumental records of the AMO, NAO, ENSO, Atlantic SSTs, West African rainfall, and volcanic activity explain how different modes in these forcing mechanisms may explain some of the multidecadal and interannual variations. The early nineteenth century active hurricane activity appears to be particularly unique in corresponding with a low (negative index) AMO period, and as they relate to particular synoptic-scale patterns in the latter part of the Little Ice Age. Model simulations offer some hypotheses on such patterns, perhaps suggesting increased baroclinic-related storms and a slight later possible shift in the seasonal peak of tropical cyclones for some areas at times. Some years, such as 1806, 1837, 1838, 1842, and 1846 have particularly very active

  15. Drainage reorganization and divide migration induced by the excavation of the Ebro basin (NE Spain)

    NASA Astrophysics Data System (ADS)

    Vacherat, Arnaud; Bonnet, Stéphane; Mouthereau, Frédéric

    2018-05-01

    Intracontinental endorheic basins are key elements of source-to-sink systems as they preserve sediments eroded from the surrounding catchments. Drainage reorganization in such a basin in response to changing boundary conditions has strong implications on the sediment routing system and on landscape evolution. The Ebro and Duero basins represent two foreland basins, which developed in response to the growth of surrounding compressional orogens, the Pyrenees and the Cantabrian mountains to the north, the Iberian Ranges to the south, and the Catalan Coastal Range to the east. They were once connected as endorheic basins in the early Oligocene. By the end of the Miocene, new post-orogenic conditions led to the current setting in which the Ebro and Duero basins are flowing in opposite directions, towards the Mediterranean Sea and the Atlantic Ocean. Although these two hydrographic basins recorded a similar history, they are characterized by very different morphologic features. The Ebro basin is highly excavated, whereas relicts of the endorheic stage are very well preserved in the Duero basin. The contrasting morphological preservation of the endorheic stage represents an ideal natural laboratory to study the drivers (internal and/or external) of post-orogenic drainage divide mobility, drainage network, and landscape evolution. To that aim, we use field and map observations and we apply the χ analysis of river profiles along the divide between the Ebro and Duero drainage basins. We show here that the contrasting excavation of the Ebro and Duero basins drives a reorganization of their drainage network through a series of captures, which resulted in the southwestward migration of their main drainage divide. Fluvial captures have a strong impact on drainage areas, fluxes, and their respective incision capacity. We conclude that drainage reorganization driven by the capture of the Duero basin rivers by the Ebro drainage system explains the first-order preservation of

  16. Diversity and Systematics of Schizomavella Species (Bryozoa: Bitectiporidae) from the Bathyal NE Atlantic

    PubMed Central

    Reverter-Gil, Oscar; Berning, Björn; Souto, Javier

    2015-01-01

    Eight NE Atlantic and Mediterranean species, which were originally assigned to the genus Schizoporella (Family Schizoporellidae) when introduced, are redescribed and stabilized by typification. Seven of these species are transferred to the bitectiporid genus Schizomavella: S. fischeri, S. glebula, S. neptuni, S. obsoleta, S. richardi, S. triaviculata, and S. triaviculata var. paucimandibulata, which is here raised to species rank. The eighth species, Schizoporella fayalensis, is transferred to the lanceoporid genus Stephanotheca. Schizomavella obsoleta and S. glebula are considered junior subjective synonyms of S. fischeri and S. richardi, respectively. Two new species are described: Schizomavella rectangularis n. sp. from the Strait of Gibraltar, and Schizomavella phterocopa n. sp. from the Great Meteor Bank. A new subgenus, Calvetomavella n. subgen. is established as a result of a phylogenetic analysis based on morphological characters; it includes S. neptuni, S. triaviculata, S. paucimandibulata and S. phterocopa n. sp., together with Schizomavella discoidea and Schizomavella noronhai. The rest of the species remain in the nominotypical subgenus Schizomavella. PMID:26488874

  17. Complexity in Matuyama-Brunhes polarity transitions from North Atlantic IODP/ODP deep-sea sites

    NASA Astrophysics Data System (ADS)

    Channell, J. E. T.

    2017-06-01

    Integrated Ocean Drilling Program (IODP) Expedition 303 to the North Atlantic provided 16 records of the Matuyama-Brunhes polarity transition (MBT), based on u-channel and discrete samples, from holes drilled at three sites (Sites U1304, U1305 and U1306) that have mean Brunhes sedimentation rates of 16-18 cm/kyr. The MBT occurs during the transition from marine isotope stage (MIS) 19c to MIS 18e, with mid-point at ∼773 ka, and a transition duration of ∼8 kyr. Combining the new MBT records, including one new record for the top Jaramillo, with previously published North Atlantic MBT records (ODP Sites 983, 984 and 1063) yields a total of more than 20 high-sedimentation-rate polarity transition records. The MBT yields a repetitive pattern of transitional field states as virtual geomagnetic poles (VGPs) move from high southern latitudes to loop over the Pacific, group in NE Asia, and transit into the mid-latitude South Atlantic before reaching high latitudes in the Northern Hemisphere. The VGPs for the top Jaramillo transition feature a loop over the Pacific, then a NE Asia group before transit over the Indian Ocean to high southerly latitudes. The North Atlantic MBT records described here contrast with longitudinally-constrained VGP paths for the MBT, indicating that relatively low sedimentation rate (∼4 cm/kyr) records of the MBT are heavily smoothed by the remanence acquisition process and do not adequately represent the MBT field. The VGPs at the MBT and top Jaramillo, as measured in the North Atlantic, have similarities with excursion (Iceland Basin) VGP paths, and were apparently guided by maxima in downward vertical flux similar to those seen in the modern non-dipole (ND) field, implying longevity in ND features through time.

  18. Episodes of subsidence and uplift of the conjugate margins of Greenland and Norway after opening of the NE Atlantic

    NASA Astrophysics Data System (ADS)

    Japsen, Peter; Green, Paul F.; Bonow, Johan M.; Chalmers, James A.

    2015-04-01

    We have undertaken a regional study of the thermo-­tectonic development of East Greenland (68-75°N) and of southern Norway (58-64°N). We take advantage of the general observation that that the effects of uplift often are reflected more clearly onshore than offshore, and of the specific condition that the mountains of southern East Greenland expose thick basalts that were extruded onto a largely horizontal lava plain near sea level during breakup of the NE Atlantic at the Paleocene-Eocene transition. It is thus clear that the present-­day elevation of these basalts up to 3.7 km a.s.l. were reached after breakup. Our results based on apatite fission-­track analysis (AFTA) data from East Greenland reveal a long history of post-­Palaeozoic burial and exhumation across the region and show that the terrains of Palaeozoic and older rocks were buried below a 2-3 km­-thick cover prior to a series of Mesozoic events of uplift and exhumation. The AFTA results from southern Norway reveal events of Mesozoic uplift and exhumation that are broadly simultaneous with those in Greenland. Volcanic and sedimentary rocks accumulated on the subsiding, East Greenland margin during and following breakup and then began to be exhumed during late Eocene uplift that preceded a major, early Oligocene plate reorganization in the NE Atlantic. The Norwegian margin also experienced Eocene subsidence and burial. Our AFTA data from southern Norway show evidence of an event of mid­Cenozoic uplift and exhumation that overlap with the early Oligocene onset of progradation of clastic wedges towards the south and with the formation of a major, late Eocene unconformity along the NW European margin. The uplift event at the Eocene-Oligocene transition that affected wide areas in the NE Atlantic domain was followed by two regional events of uplift and incision of the East Greenland margin in the late Miocene and Pliocene whereas the Neogene uplift of southern Norway began in the early Miocene and was

  19. Variability of interleaving structure of Atlantic Water during its propagation along the Eurasian basin (Arctic Ocean) continental margin

    NASA Astrophysics Data System (ADS)

    Zhurbas, Nataliya; Kuzmina, Natalia; Lyzhkov, Dmitry; Ostapchuk, Alexey

    2017-04-01

    In order to give detailed description of the interleaving structure in the Eurasian basin results of observations carried out during NABOS 2008 and Polarstern cruise in 1996 were analyzed. The study was focused on interleaving parameters (structure and vertical scale of intrusions) variability in the upper (150-300 meters) and intermediate (300-700 meters) layers of the ocean. Based on θ,S/θ,σ-diagrams (θ, S and σ are the potential temperature, salinity and potential density, correspondingly) analysis two main results were obtained. First of all it was shown that intrusive layers carried by the mean current along the Eurasian Basin continental margin become deeper relatively isopycnals and thus stimulate ventilation of pycnocline. Second, the area in Eurasian Basin thermocline was found where intrusive layers of large and small scale were absent. This distinctive feature can be explained by intensive mixing between two branches of Atlantic Water, one of which propagates along Eurasian basin continental margin and the other spreads across the basin due to large scale interleaving processes. Among others, one of the possible methods of integral estimation of Atlantic water masses heat and salt contents variations during their expansion along basin continental margin was proposed. Thus it is reasonable to assess variation of square under the θ(S)-diagrams, which illustrate the data obtained from two CTD-stations located on diametrically opposite sides of Eurasian Basin, taking 0.5°C isotherm as a reference value. For verification of the introduced approach the estimates of heat and salt contents variations were made by different methods. Detailed discussion of the results is presented. Work was supported by the Russian Foundation for Basic Research (Grant No 15-05-01479-a).

  20. Interactions Between Vestige Atlantic Tropical Cyclones and Mid-Latitude Storms Over Mediterranean Basin

    NASA Technical Reports Server (NTRS)

    Smith, Eric A.; Mehta, Amita; Mugnai, Alberto; Tripoli, Gregory J.

    2007-01-01

    One of the more interesting tropical-mid-latitude interactions is one that has important effects on precipitation within the Mediterranean basin. This interaction consists of an Atlantic tropical cyclone vestige whose original disturbance travels eastward and northward across Atlantic basin, eventually intermingling with a mid-latitude cyclone entering southern Europe and/or the \\bestern Mediterranean Sea. The period for these interactions is from mid-September through November. If the tropical cyclone and its vestige is able to make the eastward Atlantic transit within the low to mid-levels, or if an upper level potential vorticity perturbation Cjet streak) emitted by a Hurricane in its latter stages within the central Atlantic is able to propagate into and along the longwave pattern affecting the western Mediterranean Sea (MED), then there is the prospect for the tropical cyclone remnant to produce a major modification of the mid-latitude storm system preparing to affect the MED region. For such an occurrence to take place, it is necessary for an amplifying baroclinic perturbation to be already situated to the rear of a longwave trough, or to be excited by the emitted jet streak to the rear of a longwave trough -- in either case, preparing to affect the western MED. The Algiers City flood of 9-10 November 2001, which killed some 700 people, was produced by a Mediterranean cyclone that had been influenced by two vestige Atlantic tropical cyclones, 1,orenzo and Noel. A published modeling study involving various of this study's authors has already described the dynamical development of the Algiers storm as it amplified from a developing baroclinic disturbance in the Rossby wave train, into a northern Africa hazardous flood system, then lingered in the western MED as a semi-intense warm core cyclone. In our new modeling experiments, we investigate the impact of what might have happened in the eventual precipitation field. had the main features of the tropical

  1. Stalling Tropical Cyclones over the Atlantic Basin

    NASA Astrophysics Data System (ADS)

    Nielsen-Gammon, J. W.; Emanuel, K.

    2017-12-01

    Hurricane Harvey produced massive amounts of rain over southeast Texas and southwest Louisiana. Average storm total rainfall amounts over a 10,000 square mile (26,000 square km) area exceeded 30 inches (750 mm). An important aspect of the storm that contributed to the large rainfall totals was its unusual motion. The storm stalled shortly after making landfall, then moved back offshore before once again making landfall five days later. This storm motion permitted heavy rainfall to occur in the same general area for an extended period of time. The unusual nature of this event motivates an investigation into the characteristics and potential climate change influences on stalled tropical cyclones in the Atlantic basin using the HURDAT 2 storm track database for 1866-2016 and downscaled tropical cyclones driven by simulations of present and future climate. The motion of cyclones is quantified as the size of a circle circumscribing all storm locations during a given length of time. For a three-day period, Harvey remained inside a circle with a radius of 123 km. This ranks within the top 0.6% of slowest-moving historical storm instances. Among the 2% of slowest-moving storm instances prior to Harvey, only 13 involved storms that stalled near the continental United States coast, where they may have produced substantial rainfall onshore while tapping into marine moisture. Only two such storms stalled in the month of September, in contrast to 20 September stalls out of the 36 storms that stalled over the nearby open Atlantic. Just four of the stalled coastal storms were hurricanes, implying a return frequency for such storms of much less than once per decade. The synoptic setting of these storms is examined for common features, and historical and projected trends in occurrences of stalled storms near the coast and farther offshore are investigated.

  2. The mid-Miocene structural conversion within the NE Tibetan Plateau from new proof of the interaction between two conflicting fault systems in the western Qaidam Basin

    NASA Astrophysics Data System (ADS)

    Zhao, H.; Wu, L.; Xiao, A.

    2016-12-01

    We present a detailed structural analysis on the fault geometry and Cenozoic development in the Dongping area, northwestern Qaidam Basin, based on the precise 3-D seismic interpretation, remote sensing images and seismic attribute analysis. Two conflicting fault systems distributed in different orientations ( EW-striking and NNW-striking) with opposing senses of shear are recognized and discussed, and the interaction between them provides new insights to the intracontinental deformation of the Qaidam Basin within the NE Tibetan Plateau. The EW-striking fault system constitutes the south part of the Altyn left-slip positive flower structure. Faulting on the EW-striking faults dominated the northwestern Qaidam since 40 Ma in respond to the inception of the Altyn Tagh fault system as a ductile shear zone, tilting the south slope of the Altyn Tagh. Whereas the NNW-striking fault system became the dominant structures since the mid-Miocene ( 15 Ma), induced by the large scale strike-slip of the Altyn Tagh fault which leads to the NE-SW directed compression of the Qaidam Basin. Thus it evidently implies a structural conversion taking place within the NE Tibetan Plateau since the mid-Miocece ( 15 Ma). Interestingly, the preexisting faults possibly restrained the development of the later period faults, while the latter tended to track and link to the former fault traces. Taken the large scale sinistral striking-slip East Kunlun fault system into account, the late Cenozoic intracontinental deformation in the Qaidam Basin showing the dextral transpressional attribute is suggested to be the consequence of the combined effect of its two border sinistral strike-slip faults, which furthermore favors a continuous and lateral-extrusion mechanism of the growth of the NE Tibetan Plateau.

  3. Tropical Cyclone Activity in the North Atlantic Basin During the Weather Satellite Era, 1960-2014

    NASA Technical Reports Server (NTRS)

    Wilson, Robert M.

    2016-01-01

    This Technical Publication (TP) represents an extension of previous work concerning the tropical cyclone activity in the North Atlantic basin during the weather satellite era, 1960-2014, in particular, that of an article published in The Journal of the Alabama Academy of Science. With the launch of the TIROS-1 polar-orbiting satellite in April 1960, a new era of global weather observation and monitoring began. Prior to this, the conditions of the North Atlantic basin were determined only from ship reports, island reports, and long-range aircraft reconnaissance. Consequently, storms that formed far from land, away from shipping lanes, and beyond the reach of aircraft possibly could be missed altogether, thereby leading to an underestimate of the true number of tropical cyclones forming in the basin. Additionally, new analysis techniques have come into use which sometimes has led to the inclusion of one or more storms at the end of a nominal hurricane season that otherwise would not have been included. In this TP, examined are the yearly (or seasonal) and 10-year moving average (10-year moving average) values of the (1) first storm day (FSD), last storm day (LSD), and length of season (LOS); (2) frequencies of tropical cyclones (by class); (3) average peak 1-minute sustained wind speed () and average lowest pressure (); (4) average genesis location in terms of north latitudinal () and west longitudinal () positions; (5) sum and average power dissipation index (); (6) sum and average accumulated cyclone energy (); (7) sum and average number of storm days (); (8) sum of the number of hurricane days (NHD) and number of major hurricane days (NMHD); (9) net tropical cyclone activity index (NTCA); (10) largest individual storm (LIS) PWS, LP, PDI, ACE, NSD, NHD, NMHD; and (11) number of category 4 and 5 hurricanes (N4/5). Also examined are the December-May (D-M) and June-November (J-N) averages and 10-year moving average values of

  4. Beach debris in the Azores (NE Atlantic): Faial Island as a first case study.

    PubMed

    Pieper, Catharina; Ventura, Maria A; Martins, Ana; Cunha, Regina T

    2015-12-30

    Marine debris is widely recognised as a global environmental problem. This study assesses density, type, and temporal trends of marine debris in two sandy beaches of Faial Island (Azores, NE-Atlantic). During seven months (six days per month) the beaches were surveyed by performing 10 random transects at each site. Recorded items within the range 2-30 cm were organised into seven categories. Densities of total debris varied from 0 to 1.940 items m(-2), with plastics dominating both areas. Both beaches, presented the highest debris abundance in February, most probably related to prevailing winds and swell. Location and/or time of year also seemed to influence the type of debris present. These findings provide new insights into debris accumulation rates in the Azores, where no previous studies were made. It also confirms the global trend of increased plastics accumulation on shorelines, highlighting the need for further research in remote islands. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Deep-sea whale fall fauna from the Atlantic resembles that of the Pacific Ocean.

    PubMed

    Sumida, Paulo Y G; Alfaro-Lucas, Joan M; Shimabukuro, Mauricio; Kitazato, Hiroshi; Perez, Jose A A; Soares-Gomes, Abilio; Toyofuku, Takashi; Lima, Andre O S; Ara, Koichi; Fujiwara, Yoshihiro

    2016-02-24

    Whale carcasses create remarkable habitats in the deep-sea by producing concentrated sources of organic matter for a food-deprived biota as well as places of evolutionary novelty and biodiversity. Although many of the faunal patterns on whale falls have already been described, the biogeography of these communities is still poorly known especially from basins other than the NE Pacific Ocean. The present work describes the community composition of the deepest natural whale carcass described to date found at 4204 m depth on Southwest Atlantic Ocean with manned submersible Shinkai 6500. This is the first record of a natural whale fall in the deep Atlantic Ocean. The skeleton belonged to an Antarctic Minke whale composed of only nine caudal vertebrae, whose degradation state suggests it was on the bottom for 5-10 years. The fauna consisted mainly of galatheid crabs, a new species of the snail Rubyspira and polychaete worms, including a new Osedax species. Most of the 41 species found in the carcass are new to science, with several genera shared with NE Pacific whale falls and vent and seep ecosystems. This similarity suggests the whale-fall fauna is widespread and has dispersed in a stepping stone fashion, deeply influencing its evolutionary history.

  6. Deep-sea whale fall fauna from the Atlantic resembles that of the Pacific Ocean

    NASA Astrophysics Data System (ADS)

    Sumida, Paulo Y. G.; Alfaro-Lucas, Joan M.; Shimabukuro, Mauricio; Kitazato, Hiroshi; Perez, Jose A. A.; Soares-Gomes, Abilio; Toyofuku, Takashi; Lima, Andre O. S.; Ara, Koichi; Fujiwara, Yoshihiro

    2016-02-01

    Whale carcasses create remarkable habitats in the deep-sea by producing concentrated sources of organic matter for a food-deprived biota as well as places of evolutionary novelty and biodiversity. Although many of the faunal patterns on whale falls have already been described, the biogeography of these communities is still poorly known especially from basins other than the NE Pacific Ocean. The present work describes the community composition of the deepest natural whale carcass described to date found at 4204 m depth on Southwest Atlantic Ocean with manned submersible Shinkai 6500. This is the first record of a natural whale fall in the deep Atlantic Ocean. The skeleton belonged to an Antarctic Minke whale composed of only nine caudal vertebrae, whose degradation state suggests it was on the bottom for 5-10 years. The fauna consisted mainly of galatheid crabs, a new species of the snail Rubyspira and polychaete worms, including a new Osedax species. Most of the 41 species found in the carcass are new to science, with several genera shared with NE Pacific whale falls and vent and seep ecosystems. This similarity suggests the whale-fall fauna is widespread and has dispersed in a stepping stone fashion, deeply influencing its evolutionary history.

  7. Tectono-stratigraphic evolution and crustal architecture of the Orphan Basin during North Atlantic rifting

    NASA Astrophysics Data System (ADS)

    Gouiza, Mohamed; Hall, Jeremy; Welford, J. Kim

    2017-04-01

    The Orphan Basin is located in the deep offshore of the Newfoundland margin, and it is bounded by the continental shelf to the west, the Grand Banks to the south, and the continental blocks of Orphan Knoll and Flemish Cap to the east. The Orphan Basin formed in Mesozoic time during the opening of the North Atlantic Ocean between eastern Canada and western Iberia-Europe. This work, based on well data and regional seismic reflection profiles across the basin, indicates that the continental crust was affected by several extensional episodes between the Jurassic and the Early Cretaceous, separated by events of uplift and erosion. The preserved tectono-stratigraphic sequences in the basin reveal that deformation initiated in the eastern part of the Orphan Basin in the Jurassic and spread towards the west in the Early Cretaceous, resulting in numerous rift structures filled with a Jurassic-Lower Cretaceous syn-rift succession and overlain by thick Upper Cretaceous to Cenozoic post-rift sediments. The seismic data show an extremely thinned crust (4-16 km thick) underneath the eastern and western parts of the Orphan Basin, forming two sub-basins separated by a wide structural high with a relatively thick crust (17 km thick). Quantifying the crustal architecture in the basin highlights the large discrepancy between brittle extension localized in the upper crust and the overall crustal thinning. This suggests that continental deformation in the Orphan Basin involved, in addition to the documented Jurassic and Early Cretaceous rifting, an earlier brittle rift phase which is unidentifiable in seismic data and a depth-dependent thinning of the crust driven by localized lower crust ductile flow.

  8. Interannual rainfall variability in the Amazon basin and sea-surface temperatures in the equatorial Pacific and the tropical Atlantic Oceans

    NASA Astrophysics Data System (ADS)

    Ronchail, Josyane; Cochonneau, Gérard; Molinier, Michel; Guyot, Jean-Loup; Chaves, Adriana Goretti De Miranda; Guimarães, Valdemar; de Oliveira, Eurides

    2002-11-01

    Rainfall variability in the Amazon basin is studied in relation to sea-surface temperatures (SSTs) in the equatorial Pacific and the northern and southern tropical Atlantic during the 1977-99 period, using the HiBAm original rainfall data set and complementary cluster and composite analyses.The northeastern part of the basin, north of 5 °S and east of 60 °W, is significantly related with tropical SSTs: a rainier wet season is observed when the equatorial Pacific and the northern (southern) tropical Atlantic are anomalously cold (warm). A shorter and drier wet season is observed during El Niño events and negative rainfall anomalies are also significantly associated with a warm northern Atlantic in the austral autumn and a cold southern Atlantic in the spring. The northeastern Amazon rainfall anomalies are closely related with El Niño-southern oscillation during the whole year, whereas the relationships with the tropical Atlantic SST anomalies are mainly observed during the autumn. A time-space continuity is observed between El Niño-related rainfall anomalies in the northeastern Amazon, those in the northern Amazon and south-eastern Amazon, and those in northern South America and in the Nordeste of Brazil.A reinforcement of certain rainfall anomalies is observed when specific oceanic events combine. For instance, when El Niño and cold SSTs in the southern Atlantic are associated, very strong negative anomalies are observed in the whole northern Amazon basin. Nonetheless, the comparison of the cluster and the composite analyses results shows that the rainfall anomalies in the northeastern Amazon are not always associated with tropical SST anomalies.In the southern and western Amazon, significant tropical SST-related rainfall anomalies are very few and spatially variable. The precipitation origins differ from those of the northeastern Amazon: land temperature variability, extratropical perturbations and moisture advection are important rainfall factors, as well

  9. An Extended Forecast of the Frequencies of North Atlantic Basin Tropical Cyclone Activity for 2009

    NASA Technical Reports Server (NTRS)

    Wilson, Robert M.

    2009-01-01

    An extended forecast of the frequencies for the 2009 North Atlantic basin hurricane season is presented. Continued increased activity during the 2009 season with numbers of tropical cyclones, hurricanes, and major hurricanes exceeding long-term averages are indicated. Poisson statistics for the combined high-activity intervals (1950-1965 and 1995-2008) give the central 50% intervals to be 9-14, 5-8, and 2-4, respectively, for the number of tropical cyclones, hurricanes, and major hurricanes, with a 23.4% chance of exceeding 14 tropical cyclones, a 28% chance of exceeding 8 hurricanes, and a 31.9% chance of exceeding 4 major hurricanes. Based strictly on the statistics of the current high-activity interval (1995-2008), the central 50% intervals for the numbers of tropical cyclones, hurricanes, and major hurricanes are 12-18, 6-10, and 3-5, respectively, with only a 5% chance of exceeding 23, 13, or 7 storms, respectively. Also examined are the first differences in 10-yr moving averages and the effects of global warming and decadal-length oscillations on the frequencies of occurrence for North Atlantic basin tropical cyclones. In particular, temperature now appears to be the principal driver of increased activity and storm strength during the current high-activity interval, with near-record values possible during the 2009 season.

  10. An 800-Year Tropical Atlantic Sea Surface Temperature Variability Record From the Cariaco Basin, Venezuela

    NASA Astrophysics Data System (ADS)

    Black, D. E.; Thunell, R. C.; Kaplan, A.; Abahazi, M. A.; Tappa, E. J.

    2007-05-01

    Here we present an eight century tropical Atlantic SST record based on foraminiferal Mg/Ca recovered from Cariaco Basin sediments that have been calibrated to historical instrumental SSTs. Spatial correlations indicate that the proxy record is representative of SSTs over much of the Caribbean and tropical Atlantic. The Mg/Ca-SST record also correlates well with global land and sea surface temperature anomalies, and captures decadal-scale variations in Atlantic tropical storm and hurricane frequency over the late-19th and 20th centuries. The long-term record displays a surprising amount of variability for a tropical location under essentially modern boundary conditions. The tropical North Atlantic does not appear to have experienced a pronounced Medieval Warm Period relative to the complete record. However, strong Little Ice Age cooling of as much as 3 °C occurred between A. D. 1525 and 1625. Spring SSTs gradually rose between A. D. 1650 and 1900 followed by a 2.5 °C warming over the twentieth century. Viewed in the context of the complete record, twentieth century temperatures are not the warmest in the entire record on average, but they do show the largest increase in magnitude and fastest rate of SST change over the last eight hundred years. Spectral analysis of the Mg/Ca-SST data suggests that 2-5 and ~13 year SST variability that is characteristic of tropical Atlantic instrumental records may change through time.

  11. Quantitative analysis of the tectonic subsidence in the Potiguar Basin (NE Brazil)

    NASA Astrophysics Data System (ADS)

    Lopes, Juliana A. G.; de Castro, David L.; Bertotti, Giovanni

    2018-06-01

    The Potiguar Basin, located in the Brazilian Equatorial Margin, evolved from a complex rifting process implemented during the Atlantic Ocean opening in the Jurassic/Cretaceous. Different driving mechanisms were responsible for the onset of an aborted onshore rift and an offshore rift that initiated crustal rupture and the formation of a continental transform margin. Therefore, we applied the backstripping method to quantify the tectonic subsidence during the rift and post-rift phases of Potiguar Basin formation and to analyze the spatial variation of subsidence during the two successive and distinct tectonic events responsible for the basin evolution. The parameters required to apply this methodology were extracted from 2D seismic lines and exploratory well data. The tectonic subsidence curves present periods with moderate subsidence rates (up to 300 m/My), which correspond to the evolution of the onshore Potiguar Rift (∼141 to 128 Ma). From 128-118 Ma, the tectonic subsidence curves show no subsidence in the onshore Potiguar Basin, whereas subsidence occurred at high rates (over 300 m/My) in the offshore rift. The post-rift phase began ca. 118 Ma (Aptian), when the tectonic subsidence drastically slowed to less than 35 m/My, probably related to thermal relaxation. The tectonic subsidence rates in the various sectors of the Potiguar Rift, during the different rift phases, indicate that more intense faulting occurred in the southern portion of the onshore rift, along the main border faults, and in the southeastern portion of the offshore rift. During the post-rift phase, the tectonic subsidence rates increased from the onshore portion towards the offshore portion until the continental slope. The highest rates of post-rift subsidence (up to 35 m/My) are concentrated in the central region of the offshore portion and may be related to lithospheric processes related to the continental crust rupture and oceanic seafloor spreading. The variation in subsidence rates and

  12. The Neogene tectonic evolution and climatic change of the Tianshui Basin, NE Tibetan Plateau

    NASA Astrophysics Data System (ADS)

    Peng, T.; Li, J.; Song, C.; Zhao, Z.; Zhang, J.; Wang, X.; Hui, Z.

    2013-12-01

    The Tianshui Basin, located at the conjunction of NE Tibetan Plateau and Chinese Loess Plateau, has received intensive attention recently. Fine-grained Miocene sediment was identified as loess in its north part and this pushes the onset of Asian aridification into 22 Ma. However, our sedimentological, biomarker, pollen, diatom and mammalian fossils evidence propose that these sediments were suggested to be mudflat/distal fan and floodplain deposit instead of eolian deposit. So detailed tectonic background and climate reconstruction may illustrate the controversy and shed light on the tectonic, climate and ecology interactions. Here we report our integrated studies on the tectonic evolution, climate change and paleoecology reconstruction in the Tianshui basin. Based on the magnetostratigraphy and fossil mammal ages, sedimentological and detrital fission-track thermochronologic (DFT) analysis reveals four episodic tectonic uplift events occurred at ~20 Ma, ~14 Ma, ~9.2-7.4 Ma and ~3.6 Ma along the basin and its adjacent mountains. The timing of these activities at Western Qinling have been documented at many segments of the Tibetan Plateau, so most likely they were the remote response to the ongoing India-Asia collision. Pollen, mammalian fossils and biomarker data permit us to illustrate the paleoenvironment in the Tianshui Basin. During the period of ~17-10 Ma, the climate was generally warm-humid revealed by the broad-leaved forest and low Average Chain Length (ACL) values, when the Paltybelodon and Gomphotherium were roaming near an extensive aquatic setting. In addition, the observed Middle Miocene Climatic Optimum and Middle Miocene Climatic Transition events may be a terrestrial response to global climate changes. During the interval of ~10-6 Ma, the climate was relatively arid characterized by the rapid development of steppe and appearance of the Hipparion fauna, consistent with the biomarker proxy. Although the NE Tibetan Plateau experienced a phase of

  13. A new collective view of oceanography of the Arctic and North Atlantic basins

    NASA Astrophysics Data System (ADS)

    Yashayaev, Igor; Seidov, Dan; Demirov, Entcho

    2015-03-01

    We review some historical aspects of the major observational programs in the North Atlantic and adjacent regions that contributed to establishing and maintaining the global ocean climate monitoring network. The paper also presents the oceanic perspectives of climate change and touches the important issues of ocean climate variability on time scales from years to decades. Some elements of the improved understanding of the causes and mechanisms of variability in the subpolar North Atlantic and adjacent seas are discussed in detail. The sophistication of current oceanographic analysis, especially in connection with the most recent technological breakthroughs - notably the launch of the global array of profiling Argo floats - allows us to approach new challenges in ocean research. We demonstrate how the ocean-climate changes in the subpolar basins and polar seas correlate with variations in the major climate indices such as the North Atlantic Oscillation and Atlantic Multidecadal Oscillation, and discuss possible connections between the unprecedented changes in the Arctic and Greenland ice-melt rates observed over the past decade and variability of hydrographic conditions in the Labrador Sea. Furthermore, a synthesis of shipboard and Argo measurements in the Labrador Sea reveals the effects of the regional climate trends such as freshening of the upper layer - possible causes of which are also discussed - on the winter convection in the Labrador Sea including its strength, duration and spatial extent. These changes could have a profound impact on the regional and planetary climates. A section with the highlights of all papers comprising the Special Issue concludes the Preface.

  14. The Distribution and Appearance of Cold-Water Coral Carbonate Mounds and Mound-Like Structures in the NE Atlantic: Pre-site Appraisal for CARBONATE Drilling

    NASA Astrophysics Data System (ADS)

    Dorschel, B.; Wheeler, A. J.; Monteys, X.

    2007-12-01

    Cold-water coral carbonate mounds on the continental slope of the northeast Atlantic are certainly among the most amazing geological discoveries of the last decade. They developed as a result of hydrological, biological and geological processes with thickets of cold-water corals mainly Lophelia pertus and Madrepora oculata reported from numerous mound sites. Over the last years, research focused on selected mounds e.g. IODP Sites 1317 visited during IODP Expedition 307 has revealed that many of the investigated mounds are true coral built-ups. The recovered mound sediments were composed of loose coral frameworks embedded in a matrix of fine grained hemipelagic sediments. The additional calcium carbonate added by the corals was in the form of fragments and bioeroded fine grained carbonate flakes. This increase in calcium carbonate classifies the mounds as spots of enhanced carbonate accumulation in intermediate water depth. So far, the carbonate stored in submarine carbonate mounds in the northeast Atlantic has not been included in any carbon budget estimations. This was mainly due to the lack of information on the abundance and distribution of those mounds. The recently available high resolution multi-beam bathymetry data recorded during the Irish National Seabed Survey (INSS) allows, for the first time, a mapping of these mounds and mound-like structures enabling an estimation of their abundance and quantification of their contribution to continental slope sediments. Here, we present the first comprehensive overview and quantification of mounds and mound-like structures based on 25m rastered bathymetric data for the Irish sector of the NE Atlantic. Based on the data, we identified over 1600 mound-like structures along the NE Atlantic slope between 46°45'N and 57°30'N. The structures elevate up to 300m above the surrounding seafloor and were usually grouped into distinct provinces often associated with erosive structures such as canyons and moats. 90% of the

  15. Chronology of the Early Toarcian environmental crisis in the Lorraine Sub-Basin (NE Paris Basin)

    NASA Astrophysics Data System (ADS)

    Ruebsam, Wolfgang; Münzberger, Petra; Schwark, Lorenz

    2014-10-01

    Early Toarcian (Jurassic; ∼183 Ma) sediments recorded profound environmental changes, including mass extinction, global warming, marine transgression as well as widespread bottom water anoxia and organic matter accumulation on the Western Tethyan shelf. Enhanced organic matter accumulation was accompanied by a positive carbon isotope excursion (CIE) in pelagic carbonate, which marks the Toarcian Oceanic Anoxic Event. These environmental changes were accompanied by a major perturbation of the global carbon cycle, expressed by negative CIE, interrupting the positive trend. The duration of the carbon cycle perturbation is still debated, with estimates for the negative CIE range from ∼200 to ∼600 kyr. Here we present ultra high-resolution (<1 kyr) measurements of magnetic susceptibility and sediment color from a marine section located in the Lorraine Sub-Basin (NE Paris Basin) documenting Milankovitch-controlled fluctuations in depositional conditions that occurred superimposed onto the overall sea level evolution. Differences in the wavelength of the sedimentary cycles indicate variable sediment accumulation rates that mainly resulted from rapid sea level fluctuations. The most pronounced sea level rise that took place within the uppermost tenuicostatum zone resulted in a strong condensation of the basal Schistes Carton formation. Strong condensation can explain the discrepancy between durations previously calculated for the CIE placed at this stratigraphic interval. Our data support durations of ∼900 kyr and ∼600 kyr for the positive and negative CIE, respectively. The cyclostratigraphy-based timescale further proposes a duration of >555 kyr for the tenuicostatum zone and 1310 kyr for the serpentinum zone. The durations of the elegantulum and falciferum subzones can be estimated to ∼790 kyr and ∼520 kyr, respectively. A change in the orbital response from eccentricity- to obliquity-forcing, evident from other locations, is well-expressed in the Lorraine

  16. Reconstructing the history of the Atlantic Multidecadal Oscillation using high-resolution Mg/Ca paleothermometry from a Cariaco Basin core

    NASA Astrophysics Data System (ADS)

    Wurtzel, J. B.; Black, D. E.; Rahman, S.; Thunell, R.; Peterson, L. C.; Tappa, E.

    2010-12-01

    Instrumental and proxy-reconstructions show the existence of an approximately 70-year periodicity in Atlantic sea surface temperature (SST), known as the Atlantic Multidecadal Oscillation (AMO). The AMO is correlated with circum-tropical Atlantic climate phenomena such as Sahel and Nordeste rainfall, and Atlantic hurricane patterns. Though it has been suggested that the AMO is controlled by thermohaline circulation, much debate exists as to whether the SST fluctuations are a result of anthropogenic forcing or a natural climate mode, or even if the AMO is a true oscillation at all. Our ability to address this issue has been limited by instrumental SST records that rarely extend back more than 50-100 years and proxy reconstructions that are mostly terrestrial-based. Additionally, the modern instrumental variability likely contains an anthropogenic component that is not easily distinguished from the natural background of the system. From a marine sediment core taken in the Cariaco Basin, we have developed a high-resolution SST reconstruction for the past ca. 1500 years using Mg/Ca paleothermometry on seasonally-representative foraminifera, with the most recent data calibrated to the instrumental record. Previous studies have shown Cariaco Basin Mg/Ca-SSTs to be well-correlated to the Caribbean Sea and much of the western tropical Atlantic, which allows us to create a record that can be used to determine pre-anthropogenic rates and ranges of SST variability and observe how they change over time. Averaging the seasonal temperatures derived from the two foraminiferal species over the instrumental period yields a strong correlation to the AMO index from A. D. 1880 through 1970 (r = 0.44, p<0.0001). Wavelet analysis of the proxy average annual SST data indicates that modern AMO variability is not a consistent feature through time, and may be a function of warm-period climate.

  17. Variability of zooplankton communities at Condor seamount and surrounding areas, Azores (NE Atlantic)

    NASA Astrophysics Data System (ADS)

    Carmo, Vanda; Santos, Mariana; Menezes, Gui M.; Loureiro, Clara M.; Lambardi, Paolo; Martins, Ana

    2013-12-01

    Seamounts are common topographic features around the Azores archipelago (NE Atlantic). Recently there has been increasing research effort devoted to the ecology of these ecosystems. In the Azores, the mesozooplankon is poorly studied, particularly in relation to these seafloor elevations. In this study, zooplankton communities in the Condor seamount area (Azores) were investigated during March, July and September 2010. Samples were taken during both day and night with a Bongo net of 200 µm mesh that towed obliquely within the first 100 m of the water column. Total abundance, biomass and chlorophyll a concentrations did not vary with sampling site or within the diel cycle but significant seasonal variation was observed. Moreover, zooplankton community composition showed the same strong seasonal pattern regardless of spatial or daily variability. Despite seasonal differences, the zooplankton community structure remained similar for the duration of this study. Seasonal variability better explained our results than mesoscale spatial variability. Spatial homogeneity is probably related with island proximity and local dynamics over Condor seamount. Zooplankton literature for the region is sparse, therefore a short review of the most important zooplankton studies from the Azores is also presented.

  18. A Glacial Perspective on the Impact of Heinrich Stadials on North Atlantic Climate

    NASA Astrophysics Data System (ADS)

    Bromley, G. R.; Putnam, A. E.; Rademaker, K. M.; Balter, A.; Hall, B. L.

    2017-12-01

    The British Isles contain a rich geologic record of Late Pleistocene ice sheet behaviour in the NE North Atlantic basin. We are using cosmogenic 10Be surface-exposure dating, in conjunction with detailed glacial-geomorphic mapping, to reconstruct the timing and nature of cryospheric change - and thus climate variability - in northern Scotland since the Last Glacial Maximum. Our specific focus is Heinrich Stadial 1 (18,300-14,700 years ago), arguably the most significant abrupt climate event of the last glacial cycle and a major feature in global palaeoclimate records. Such constraint is needed because of currently conflicting models of how these events impact terrestrial environments and a recent hypothesis attributing this disparity to enhanced seasonality in the North Atlantic basin. To date, we have measured 10Be in > 30 samples from glacial erratics located on moraines deposited by the British Ice Sheet as it retreated from the continental shelf to its highland source regions. Our preliminary results indicate that the stadial was characterised by widespread deglaciation driven by atmospheric warming, a pattern that is suggestive of pronounced seasonality. Additionally, we report new exposure ages from moraines deposited during a subsequent phase of alpine glaciation (known locally as the Loch Lomond Readvance) that has long been attributed to the Younger Dryas stadial. With the growing focus on the full expression of stadials, and the inherent vulnerability of Europe to shifts in North Atlantic climate, developing the extant record of terrestrial glaciation and comparing these data to marine records is a critical step towards understanding the drivers of abrupt climate change.

  19. Integrative species delimitation in the deep-sea genus Thaumastosoma Hessler, 1970 (Isopoda, Asellota, Nannoniscidae) reveals a new genus and species from the Atlantic and central Pacific abyss

    NASA Astrophysics Data System (ADS)

    Kaiser, Stefanie; Brix, Saskia; Kihara, Terue C.; Janssen, Annika; Jennings, Robert M.

    2018-02-01

    Combined morphological and molecular analyses provided evidence for a new nannoniscid genus, Ketosoma gen. nov., including new species from abyssal waters of the equatorial NE Atlantic (eastern Vema Fracture Zone), SW Atlantic (Argentine Basin) as well as equatorial NE Pacific (Clarion Clipperton Fracture Zone, CCZ). Using mitochondrial (COI and 16S) and nuclear (18S) DNA markers together with morphological information from light scanning and confocal laser scanning microscopy we found clear differences between Ketosoma and its putative sister taxon Thaumastosoma Hessler, 1970. The new genus can be distinguished from the latter by the presence of a robust seta on pereonite 1 anterolateral corner and the lack of a ventral spine on the female operculum and pereonite 7 amongst others. Different species delimitation (SD) analyses were performed alongside morphological assessment to delineate species within Ketosoma. Here, four new species are described: Ketosoma vemae gen. et sp. nov. and K. hessleri gen. et sp. nov. from the eastern Vema Fracture Zone, K. werneri gen. et sp. nov. from the Argentine Basin and K. ruehlemanni gen. et sp. nov. from the CCZ. There is morphological and genetic evidence for the presence of at least two further Ketosoma species from the CCZ. Species within Thaumastosoma are reassessed; Thaumastosoma platycarpus Hessler, 1970 and T. tenue Hessler, 1970 are redescribed based on type material and the diagnosis updated accordingly. Furthermore, a new Thaumastosoma species, T. diva sp. nov., is described from the Argentine Basin. Thaumastosoma distinctum (Birstein, 1963) and T. jebamoni (George, 2001) are assigned to Ketosoma, with the latter species regarded as a nomen dubium.

  20. New Constraints on the Age of the Opening of the South Atlantic Basin As Revealed By Recently Acquired Magnetic, Gravity and Seismic Reflection Data

    NASA Astrophysics Data System (ADS)

    Hall, S. A.; Bird, D. E.; Danque, H. A.; Grant, J. V.; McLean, D. J.; Towle, P. J.

    2014-12-01

    Detailed, high quality, marine total field magnetic data has been recently acquired over parts of the South Atlantic ocean off the southwestern margin of South Africa. These data display a pattern of well-defined, NW-SE striking linear magnetic anomalies along the margin that can be traced with confidence over distances > 150 km. The anomalies are interpreted to be M-series seafloor spreading anomalies M9 to M11, which are consistent with the initiation of seafloor spreading around 135 Ma (Late Valanginian). Corresponding M-series anomalies M9 and M10 have previously been reported for the conjugate South American margin offshore Argentina, however the presence of the M11 series SE of the Cape Lineament suggests an earlier opening of the southern South Atlantic basin than previously recognized. Breaks in the continuity of the linear anomaly pattern, observed in map view, have generally NE-SW trends and are considered sites of possible fracture zones. One such discontinuity, which we have termed the "Cape Lineament" (CL), marks a significant change in crustal character and Cretaceous depositional history, as revealed by gravity data and seismic reflection data respectively. Crust NW of CL appears to be characterized by greater thicknesses and the presence of seaward dipping reflectors (SDRs), whereas crust SE of CL has more "normal" oceanic thicknesses and SDRs that are either absent or more limited in areal extent. Although linear magnetic anomalies are observed both NW and SE of CL, anomalies to the SE display a better correlation with those predicted by our seafloor spreading model.

  1. Accretionary prism-forearc interactions as reflected in the sedimentary fill of southern Thrace Basin (Lemnos Island, NE Greece)

    NASA Astrophysics Data System (ADS)

    Maravelis, A. G.; Pantopoulos, G.; Tserolas, P.; Zelilidis, A.

    2015-06-01

    Architecture of the well-exposed ancient forearc basin successions of northeast Aegean Sea, Greece, provides useful insights into the interplay between arc magmatism, accretionary prism exhumation, and sedimentary deposition in forearc basins. The upper Eocene-lower Oligocene basin fill of the southern Thrace forearc basin reflects the active influence of the uplifted accretionary prism. Deep-marine sediments predominate the basin fill that eventually shoals upwards into shallow-marine sediments. This trend is related to tectonically driven uplift and compression. Field, stratigraphic, sedimentological, petrographic, geochemical, and provenance data on the lower Oligocene shallow-marine deposits revealed the accretionary prism (i.e. Pindic Cordillera or Biga Peninsula) as the major contributor of sediments into the forearc region. Field investigations in these shallow-marine deposits revealed the occurrence of conglomerates with: (1) mafic and ultramafic igneous rock clasts, (2) low-grade metamorphic rock fragments, and (3) sedimentary rocks. The absence of felsic volcanic fragments rules out influence of a felsic source rock. Geochemical analysis indicates that the studied rocks were accumulated in an active tectonic setting with a sediment source of mainly mafic composition, and palaeodispersal analysis revealed a NE-NNE palaeocurrent trend, towards the Rhodopian magmatic arc. Thus, these combined provenance results make the accretionary prism the most suitable candidate for the detritus forming these shallow-marine deposits.

  2. Geomorphological response of a landscape to long-term tectonic and glacial processes: the upper Rhône basin, Central Swiss Alps

    NASA Astrophysics Data System (ADS)

    Stutenbecker, Laura; Schlunegger, Fritz

    2015-04-01

    The Rhône River in the Central Swiss Alps drains a 5380 km2 large basin that shows a high spatial variability of bedrock lithology, exhumation rate, glacial conditioning and climate. All of these factors were recently discussed to control erosion rates in orogenic settings in general, and particularly in the Alps (e.g. Wittmann et al. 2007, Vernon et al. 2008, Norton et al. 2010a). Thanks to various and densely distributed data, the upper Rhône basin located between the Aar massif and Lake Geneva is a suitable natural laboratory to analyze the landscape's geomorphological state and controlling factors at a basin-scale. In this study, we extract geomorphological parameters along the channels of ca. 50 tributary basins of various sizes that contribute to the sediment budget of the Rhône River either through sediment supply by torrents or debris flows. Their catchments are located in either granitic basement rocks (External Massifs), oceanic meta-sedimentary and ophiolitic rocks (Penninic nappes) or fine-grained continental-margin sediments (Helvetic nappes). The analysis of longitudinal river profiles from DEMs and slope/area relationships show that all tributary rivers within the Rhône basin are in topographic transient state that is expressed by mainly convex or concave-convex channel shapes with several knickpoints of either tectonic-lithological or glacial origin. Furthermore, the frequency distribution of elevations (hypsometry) along the river channel allows identifying glacially inherited morphologies and the recent erosional front. The combination of those different geomorphological data yields to a categorization of the tributary rivers into three endmember groups: (1) streams with highly convex profiles, testifying to a strong glacial inheritance, (2) concave-convex channels with several knickzones and inherited morphologies of past glaciations, (3) predominantly concave, relatively steep rivers with minor knickpoints and inner gorges. Assuming that

  3. Extension style in the Orphan Basin during the Mesozoic North Atlantic rifting

    NASA Astrophysics Data System (ADS)

    Gouiza, Mohamed; Hall, Jeremy

    2013-04-01

    The Orphan Basin, lying along the Newfoundland passive continental margin, has formed in Mesozoic time during the opening of the North Atlantic Ocean and the breakup of Iberia/Eurasia from North America. Regional deep seismic reflection profiles across the basin indicate that the Neoproterozoic basement has been affected by repeated extensional episodes between the Late Triassic/Jurassic and the Early Cretaceous. Deformation initiated in the eastern part of the Orphan basin in the Jurassic and migrated toward the west in the Early Cretaceous, resulting in numerous rift structures filled with Jurassic-Lower Cretaceous syn-rift successions and sealed by thick Upper Cretaceous-Cenozoic post-rift sediments. The seismic data show an extremely attenuated crust underneath the eastern and western part of the deep basin, forming two sub-basins associated with the development of rifting. The two sub-basins are separated by a wide structural high with a relatively thick crust and are bounded to the west by the continental shelf domain. Restoration of the Orphan Basin along a 2D crustal section (520 km long), yields a total amount of stretching of about 144 km, while the total crustal thinning indicates an extension of around 250 km, assuming mass conservation along the section and an initial crustal thickness of 28 km. Brittle deformation accommodated by normal faults is documented in the seismic profiles and affected essentially the present-day upper portion of the crust, and represents only 60% of the total extension which thinned the Orphan crust. The remaining crustal thinning must involve other deformation processes which are not (easily) recognizable in the seismic data. We propose two models that could explain discrepancies between brittle deformation and total crustal thinning during lithospheric extension. The first model assumes the reactivation of pre-rift inherited structures, which act as crustal-scale detachments during the early stages of rifting. The second

  4. Carbon assimilation and transfer through kelp forests in the NE Atlantic is diminished under a warmer ocean climate.

    PubMed

    Pessarrodona, Albert; Moore, Pippa J; Sayer, Martin D J; Smale, Dan A

    2018-06-03

    Global climate change is affecting carbon cycling by driving changes in primary productivity and rates of carbon fixation, release and storage within Earth's vegetated systems. There is, however, limited understanding of how carbon flow between donor and recipient habitats will respond to climatic changes. Macroalgal-dominated habitats, such as kelp forests, are gaining recognition as important carbon donors within coastal carbon cycles, yet rates of carbon assimilation and transfer through these habitats are poorly resolved. Here, we investigated the likely impacts of ocean warming on coastal carbon cycling by quantifying rates of carbon assimilation and transfer in Laminaria hyperborea kelp forests-one of the most extensive coastal vegetated habitat types in the NE Atlantic-along a latitudinal temperature gradient. Kelp forests within warm climatic regimes assimilated, on average, more than three times less carbon and donated less than half the amount of particulate carbon compared to those from cold regimes. These patterns were not related to variability in other environmental parameters. Across their wider geographical distribution, plants exhibited reduced sizes toward their warm-water equatorward range edge, further suggesting that carbon flow is reduced under warmer climates. Overall, we estimated that Laminaria hyperborea forests stored ~11.49 Tg C in living biomass and released particulate carbon at a rate of ~5.71 Tg C year -1 . This estimated flow of carbon was markedly higher than reported values for most other marine and terrestrial vegetated habitat types in Europe. Together, our observations suggest that continued warming will diminish the amount of carbon that is assimilated and transported through temperate kelp forests in NE Atlantic, with potential consequences for the coastal carbon cycle. Our findings underline the need to consider climate-driven changes in the capacity of ecosystems to fix and donate carbon when assessing the impacts of

  5. Tsunami Forecasting in the Atlantic Basin

    NASA Astrophysics Data System (ADS)

    Knight, W. R.; Whitmore, P.; Sterling, K.; Hale, D. A.; Bahng, B.

    2012-12-01

    The mission of the West Coast and Alaska Tsunami Warning Center (WCATWC) is to provide advance tsunami warning and guidance to coastal communities within its Area-of-Responsibility (AOR). Predictive tsunami models, based on the shallow water wave equations, are an important part of the Center's guidance support. An Atlantic-based counterpart to the long-standing forecasting ability in the Pacific known as the Alaska Tsunami Forecast Model (ATFM) is now developed. The Atlantic forecasting method is based on ATFM version 2 which contains advanced capabilities over the original model; including better handling of the dynamic interactions between grids, inundation over dry land, new forecast model products, an optional non-hydrostatic approach, and the ability to pre-compute larger and more finely gridded regions using parallel computational techniques. The wide and nearly continuous Atlantic shelf region presents a challenge for forecast models. Our solution to this problem has been to develop a single unbroken high resolution sub-mesh (currently 30 arc-seconds), trimmed to the shelf break. This allows for edge wave propagation and for kilometer scale bathymetric feature resolution. Terminating the fine mesh at the 2000m isobath keeps the number of grid points manageable while allowing for a coarse (4 minute) mesh to adequately resolve deep water tsunami dynamics. Higher resolution sub-meshes are then included around coastal forecast points of interest. The WCATWC Atlantic AOR includes eastern U.S. and Canada, the U.S. Gulf of Mexico, Puerto Rico, and the Virgin Islands. Puerto Rico and the Virgin Islands are in very close proximity to well-known tsunami sources. Because travel times are under an hour and response must be immediate, our focus is on pre-computing many tsunami source "scenarios" and compiling those results into a database accessible and calibrated with observations during an event. Seismic source evaluation determines the order of model pre

  6. A paleomagnetic and relative paleointensity record from the Argentine Basin (western South Atlantic Ocean) for the last ~125 kyrs

    NASA Astrophysics Data System (ADS)

    Heil, C. W., Jr.; Stoner, J. S.; St-Onge, G.; King, J. W.

    2015-12-01

    The paucity of paleomagnetic records from the western South Atlantic Ocean presents a significant gap in our understanding of the spatial variations in geomagnetic field dynamics as they relate to the occurrence of geomagnetic excursions and changes in field strength. As such, high quality records from this region can help build upon Holocene observations and extend the geographic and temporal data coverage for spherical harmonic models. To that end, we present paleomagnetic directional (inclination) and strength (relative paleointensity) records from two cores from the Argentine Basin (RC11-49 and RC16-88). Although the cores were collected more than 40 years ago, the sediments appear to hold a stable remanence and reliable magnetic directions, as evidenced by their reproducibility between the two cores that are separated by ~25 km. The records show evidence of 4 excursional features in the uppermost 16-m of the sediments from the basin. A comparison of the relative paleointensity records from these cores to the South Atlantic Paleointensity Stack (SAPIS) (Stoner et al., 2002) and the relative paleointensity record from ODP Site 1089 (Stoner et al., 2003) indicate that the sediments reliably record relative changes in geomagnetic field intensity and suggests that the longest record (RC11-49) spans the last ~125 kyrs. Our results indicate that the sediments of the Argentine Basin are an important sedimentary archive of geomagnetic field behavior and strength at least through the Holocene and Late Pleistocene and highlight the need for further studies of cores within the basin.

  7. First Comparison of Remote Vertical Profiles of Refractory Black Carbon between the Atlantic and Pacific Basins on Global Scales

    NASA Astrophysics Data System (ADS)

    Katich, J. M.; Schwarz, J. P.

    2016-12-01

    The NASA Atmospheric Tomography Mission (ATom) provides a first opportunity to obtain vertical profiles of refractory black carbon (rBC) mass mixing ratios over global scale ( 65S - 85 N latitude) in the remote atmosphere over both the Pacific and Atlantic basins. A NOAA single-particle soot photometer (SP2) will fly on the NASA DC-8 research aircraft over July/August of 2016, obtaining near- continuous vertical profiling ( 0.3 to 12 km) over most of the Earth's latitude range, akin to the NSF HIPPO campaign that occurred only over the Pacific basin during 2009-2011. HIPPO analysis suggested both that high altitude rBC mass mixing ratios (MMRs) were likely zonally well mixed, and that global model estimates of remote rBC MMR throughout the upper troposphere globally, and not just over the Pacific, were likely biased high. Here we will present an initial analysis of the new, more complete data set in which Atlantic rBC profiles will be used to assess these prior suppositions.

  8. Statistical emulation of landslide-induced tsunamis at the Rockall Bank, NE Atlantic

    PubMed Central

    Guillas, S.; Georgiopoulou, A.; Dias, F.

    2017-01-01

    Statistical methods constitute a useful approach to understand and quantify the uncertainty that governs complex tsunami mechanisms. Numerical experiments may often have a high computational cost. This forms a limiting factor for performing uncertainty and sensitivity analyses, where numerous simulations are required. Statistical emulators, as surrogates of these simulators, can provide predictions of the physical process in a much faster and computationally inexpensive way. They can form a prominent solution to explore thousands of scenarios that would be otherwise numerically expensive and difficult to achieve. In this work, we build a statistical emulator of the deterministic codes used to simulate submarine sliding and tsunami generation at the Rockall Bank, NE Atlantic Ocean, in two stages. First we calibrate, against observations of the landslide deposits, the parameters used in the landslide simulations. This calibration is performed under a Bayesian framework using Gaussian Process (GP) emulators to approximate the landslide model, and the discrepancy function between model and observations. Distributions of the calibrated input parameters are obtained as a result of the calibration. In a second step, a GP emulator is built to mimic the coupled landslide-tsunami numerical process. The emulator propagates the uncertainties in the distributions of the calibrated input parameters inferred from the first step to the outputs. As a result, a quantification of the uncertainty of the maximum free surface elevation at specified locations is obtained. PMID:28484339

  9. Statistical emulation of landslide-induced tsunamis at the Rockall Bank, NE Atlantic.

    PubMed

    Salmanidou, D M; Guillas, S; Georgiopoulou, A; Dias, F

    2017-04-01

    Statistical methods constitute a useful approach to understand and quantify the uncertainty that governs complex tsunami mechanisms. Numerical experiments may often have a high computational cost. This forms a limiting factor for performing uncertainty and sensitivity analyses, where numerous simulations are required. Statistical emulators, as surrogates of these simulators, can provide predictions of the physical process in a much faster and computationally inexpensive way. They can form a prominent solution to explore thousands of scenarios that would be otherwise numerically expensive and difficult to achieve. In this work, we build a statistical emulator of the deterministic codes used to simulate submarine sliding and tsunami generation at the Rockall Bank, NE Atlantic Ocean, in two stages. First we calibrate, against observations of the landslide deposits, the parameters used in the landslide simulations. This calibration is performed under a Bayesian framework using Gaussian Process (GP) emulators to approximate the landslide model, and the discrepancy function between model and observations. Distributions of the calibrated input parameters are obtained as a result of the calibration. In a second step, a GP emulator is built to mimic the coupled landslide-tsunami numerical process. The emulator propagates the uncertainties in the distributions of the calibrated input parameters inferred from the first step to the outputs. As a result, a quantification of the uncertainty of the maximum free surface elevation at specified locations is obtained.

  10. Intraplate compressional deformation in West-Congo and the Congo basin: related to ridge-puch from the South Atlantic spreading ridge?

    NASA Astrophysics Data System (ADS)

    Delvaux, Damien; Everaerts, Michel; Kongota Isasi, Elvis; Ganza Bamulezi, Gloire

    2016-04-01

    After the break-up and separation of South America from Africa and the initiation of the South-Atlantic mid-oceanic ridge in the Albian, at about 120 Ma, ridge-push forces started to build-up in the oceanic lithosphere and were transmitted to the adjacent continental plates. This is particularly well expressed in the passive margin and continental interior of Central Africa. According to the relations of Wiens and Stein (1985) between ridge-push forces and basal drag in function of the lithospheric age of oceanic plates, the deviatoric stress reaches a compressional maximum between 50 and 100, Ma after the initiation of the spreading ridge, so broadly corresponding to the Paleocene in this case (~70-20 Ma). Earthquake focal mechanism data show that the West-Congo margin and a large part of the Congo basin are still currently under compressional stresses with an horizontal compression parallel to the direction of the active transform fracture zones. We studied the fracture network along the Congo River in Kinshasa and Brazzaville which affect Cambrian sandstones and probably also the late Cretaceous-Paleocene sediments. Their brittle tectonic evolution is compatible with the buildup of ridge-push forces related to the South-Atlantic opening. Further inland, low-angle reverse faults are found affecting Jurassic to Middle Cretaceous cores from the Samba borehole in the Congo basin and strike-slip movements are recorded as a second brittle phase in the Permian cores of the Dekese well, at the southern margin of the Congo basin. An analysis of the topography and river network of the Congo basin show the development of low-amplitude (50-100 m) long wavelengths (100-300 km) undulations that can be interpreted as lithospheric buckling in response to the compressional intraplate stress field generated by the Mid-Atlantic ridge-push. Wiens, D.A., Stein, S., 1985. Implications of oceanic intraplate seismicity for plate stresses, driving forces and theology. Tectonophysics

  11. Structure and degree of magmatism of North and South Atlantic rifted margins

    NASA Astrophysics Data System (ADS)

    Faleide, Jan Inge; Breivik, Asbjørn J.; Blaich, Olav A.; Tsikalas, Filippos; Planke, Sverre; Mansour Abdelmalak, Mohamed; Mjelde, Rolf; Myklebust, Reidun

    2014-05-01

    The structure and evolution of conjugate rifted margins in the South and North Atlantic have been studied mainly based on seismic reflection and refraction profiles, complemented by potential field data and plate reconstructions. All margins exhibit distinct along-margin structural and magmatic changes reflecting both structural inheritance extending back to a complex pre-breakup geological history and the final breakup processes. The sedimentary basins at the conjugate margins developed as a result of multiple phases of rifting, associated with complex time-dependent thermal structure of the lithosphere. A series of conjugate crustal transects reveal tectonomagmatic asymmetry, both along-strike and across the conjugate margin systems. The continent-ocean transitional domain along the magma-dominated margin segments is characterized by a large volume of flood basalts and high-velocity/high-density lower crust emplaced during and after continental breakup. Both the volume and duration of excess magmatism varies. The extrusive and intrusive complexes make it difficult to pin down a COB to be used in plate reconstructions. The continent-ocean transition is usually well defined as a rapid increase of P-wave velocities at mid- to lower crustal levels. The transition is further constrained by comparing the mean P-wave velocity to the thickness of the crystalline crust. By this comparison we can also address the magmatic processes associated with breakup, whether they are convection dominated or temperature dominated. In the NE Atlantic there is a strong correlation between magma productivity and early plate spreading rate, suggesting a common cause. A model for the breakup-related magmatism should be able to explain this correlation, but also the magma production peak at breakup, the along-margin magmatic segmentation, and the active mantle upwelling. It is likely that mantle plumes (Iceland in the NE Atlantic, Tristan da Cunha in the South Atlantic) may have influenced

  12. "Complexity" in Polarity Transitions at the Matuyama-Brunhes Boundary and top Jaramillo in North Atlantic Deep-sea Sediments

    NASA Astrophysics Data System (ADS)

    Channell, J. E. T.

    2016-12-01

    Integrated Ocean Drilling Program (IODP) Expedition 303 to the North Atlantic provided 16 records of the Matuyama-Brunhes polarity transition (MBT) and the top Jaramillo transition, based on u-channel and discrete samples, from holes drilled at three sites (Sites U1304, U1305 and U1306) that have mean Brunhes sedimentation rates of 16-18 cm/kyr. The MBT occurs during the transition from marine isotope stage (MIS) 19.3 to MIS 18.4, with mid-point at 773 ka, and a transition duration of 5-8 kyr. The top Jaramillo occurs during MIS 28 at 992 ka with a similar 5 kyr transition duration. Combining the new records with previously published North Atlantic records (ODP Sites 983, 984 and 1063) yields a total of 24 high sedimentation rate records. The MBT yields a repetitive pattern of transitional field states as virtual geomagnetic poles (VGPs) move from high southern latitudes to loop over the Pacific, cluster in NE Asia, and transit into the mid-latitude South Atlantic before reaching high latitudes in the Northern Hemisphere. The VGPs for the top Jaramillo transition feature a loop over the Pacific, then occupation of the NE Asia cluster before transit over the Indian Ocean to high southerly latitudes. The North Atlantic MBT records described here are very different to the longitudinally constrained North Atlantic VGP paths from MBT records that are the basis for a 2007 Bayesian inversion of the MBT field. We conclude that the relatively low sedimentation rate ( 4 cm/kyr) records utilized in the Bayesian inversion have been heavily smoothed by the remanence acquisition process, and do not adequately represent the MBT field. The VGPs at the MBT and top Jaramillo, as measured in the North Atlantic, have similarities with excursion (Iceland Basin) VGP paths, and are apparently guided by maxima in downward vertical flux in the modern non-dipole (ND) field, implying longevity in ND features through time.

  13. Investigating long-term interactions between phytoplankton and zooplankton in the NE Atlantic and North Sea

    NASA Astrophysics Data System (ADS)

    Khouri, R.; Beaulieu, C.; Henson, S.; Martin, A. P.; Edwards, M.

    2016-02-01

    It is believed that changes in phytoplankton community have happened in the North Sea and NE Atlantic in the past decades. Since phytoplankton are the base of the marine food web, it is essential to understand the causes of such behaviour due its potential to induce change in the wider ecosystem. Whilst the impact of environmental controls, such as climate, have received considerable attention, phytoplankton can also be affected by zooplankton grazing. We investigate how changes in zooplankton impact phytoplankton populations and community composition, and vice-versa. We use data from the Continuous Plankton Recorder survey, an unique dataset that uses the same sampling methodology since 1958 and thus provides long and comparable plankton time-series. We apply statistical modelling to describe the interaction between phytoplankton and zooplankton. The analysis is inspired from techniques available in econometrics literature, which do not require assumptions of normality, independence or stationarity of the time-series. In particular, we discuss wether climatic factors or zooplankton grazing are more relevant to the variability in phytoplankton abundance and community composition.

  14. An Estimate of the North Atlantic Basin Tropical Cyclone Activity for the 2011 Hurricane Season

    NASA Technical Reports Server (NTRS)

    Wilson, Robert M.

    2011-01-01

    Estimates are presented for the expected level of tropical cyclone activity for the 2011 North Atlantic Basin hurricane season. It is anticipated that the frequency of tropical cyclones for the North Atlantic Basin during the 2011 hurricane season will be near to above the post-1995 means. Based on the Poisson distribution of tropical cyclone frequencies for the current more active interval 1995-2010, one computes P(r) = 63.7% for the expected frequency of the number of tropical cyclones during the 2011 hurricane season to be 14 plus or minus 3; P(r) = 62.4% for the expected frequency of the number of hurricanes to be 8 plus or minus 2; P(r) = 79.3% for the expected frequency of the number of major hurricanes to be 3 plus or minus 2; and P(r) = 72.5% for the expected frequency of the number of strikes by a hurricane along the coastline of the United States to be 1 plus or minus 1. Because El Nino is not expected to recur during the 2011 hurricane season, clearly, the possibility exists that these seasonal frequencies could easily be exceeded. Also examined are the effects of the El Nino-Southern Oscillation phase and climatic change (global warming) on tropical cyclone seasonal frequencies, the variation of the seasonal centroid (latitude and longitude) location of tropical cyclone onsets, and the variation of the seasonal peak wind speed and lowest pressure for tropical cyclones.

  15. African aerosols and Atlantic tropical cyclone activities

    NASA Astrophysics Data System (ADS)

    Kafatos, M.; Sun, D.; Sahoo, A.

    2006-12-01

    Previous studies have shown that the Atlantic basin major hurricane (MH) activity is associated with western Sahelian monsoon rainfall, while rainfall in the Sahel is found to be highly anti-correlated with the African dust storms. So if the Atlantic basin MH activity may be anti-correlated with the African dust aerosols? In order to investigate the relationship between the African dust and the tropical cyclone (including both tropical storms and hurricanes) activities in the Atlantic basin, we explore how the African dust may link to Atlantic TC activity by using the long-term (1982-2005) NCEP Reynolds sea surface temperature (SST) product, and tropical cyclone (TC) data from the National Hurricane Center Best Track Files, and the TOMS aerosol index (AI) data, because the TOMS AI positive values are associated with UV-absorbing aerosols, like dust and smoke. Although no significant negative correlation between the TOMS AI and the Atlantic TC or MH frequency and duration is found, the initial locations of the Atlantic tropical cyclones did occur over the ocean where the aerosol loading was low. Our analysis shows that SST over the north tropical Atlantic ocean is anti-correlated with the TOMS aerosol index. This may be due to the radiative forcing of the aerosols. The effects of the dust aerosols carried across the West African region led to a lowering of SST and therefore inhibited tropical cyclogenesis. During 2005, the aerosol loading along the western African coast was unusually low, while the SST over the main development region (MDR) was abnormally high, and the Atlantic TC/hurricane activities became record strong. We propose future observations to test these results.

  16. Geometry and kinematics of the Triassic rift basin in Jameson Land (East Greenland)

    NASA Astrophysics Data System (ADS)

    Guarnieri, Pierpaolo; Brethes, Anaïs.; Rasmussen, Thorkild M.

    2017-04-01

    The Triassic rift basin along the east Greenland margin described in this paper is represented by NE-SW trending basins and highs segmented by NW-SE trending transfer zones. Coarse-grained sediments along the eastern side of Jameson Land are shown to be hosted in half-graben structures belonging to the Carlsberg Fjord Basin that is bounded by NW dipping normal faults mapped and described after fieldwork in the Klitdal area in Liverpool Land. New aeromagnetic and electromagnetic data together with new drill cores allow the reinterpretation of available seismic lines showing the continuation of the Triassic rift basin toward the SW where it is buried under the Upper Triassic postrift sediments and the Jurassic successions of the Jameson Land Basin. The N-S trending Liverpool Land, interpreted as the boundary block of the Triassic basin, is shown to represent a structural high inherited from the Late Carboniferous tectonics and faulted during the Triassic rifting. The Carlsberg Fjord Basin and the Klitdal Fault System described in this paper should be seen as analogues to the Helgeland Basin in the Norwegian offshore that is bounded by the Ylvingen Fault Zone and to the Papa and West of Shetlands Basins that are bounded by the Spine Fault. The Triassic rift zone and transfer faults on both conjugate margins show a straightforward correlation with the trends of the initial spreading line and fracture zones of the northeast Atlantic indicating a possible inheritance of the Triassic rifting.

  17. Mesoscale eddies control meridional heat flux variability in the subpolar North Atlantic

    NASA Astrophysics Data System (ADS)

    Zhao, Jian; Bower, Amy; Yang, Jiayan; Lin, Xiaopei; Zhou, Chun

    2017-04-01

    The meridional heat flux in the subpolar North Atlantic is vital to the climate of the high-latitude North Atlantic. For the basinwide heat flux across a section between Greenland and Scotland, much of the variability occurs in the Iceland basin, where the North Atlantic Current (NAC) carries relatively warm and salty water northward. As a component of the Overturning in the Subpolar North Atlantic Program (OSNAP), WHOI and OUC are jointly operating gliders in the Iceland Basin to continuously monitor the circulation and corresponding heat flux in this eddy-rich region. Based on one year of observations, two circulation regimes in the Iceland basin have been identified: a mesoscale eddy like circulation pattern and northward NAC circulation pattern. When a mesoscale eddy is generated, the rotational currents associated with the eddy lead to both northward and southward flow in the Iceland basin. This is quite different from the broad northward flow associated with the NAC when there is no eddy. The transition between the two regimes coupled with the strong temperature front in the Iceland basin can modify the meridional heat flux on the order of 0.3PW, which is the dominant source for the heat flux change the Iceland Basin. According to high-resolution numerical model results, the Iceland Basin has the largest contribution to the meridional heat flux variability along the section between Greenland and Scotland. Therefore, mesoscale eddies in the Iceland Basin provide important dynamics to control the meridional heat flux variability in the subpolar North Atlantic.

  18. Track-pattern-based seasonal prediction model for intense tropical cyclone activities over the North Atlantic and the western North Pacific basins

    NASA Astrophysics Data System (ADS)

    Choi, W.; Ho, C. H.

    2015-12-01

    Intense tropical cyclones (TCs) accompanying heavy rainfall and destructive wind gusts sometimes cause incredible socio-economic damages in the regions near their landfall. This study aims to analyze intense TC activities in the North Atlantic (NA) and the western North Pacific (WNP) basins and develop their track propensity seasonal prediction model. Considering that the number of TCs in the NA basin is much smaller than that in the WNP basin, different intensity criteria are used; category 1 and above for NA and category 3 and above for WNP based on Saffir-Simpson hurricane wind scale. By using a fuzzy clustering method, intense TC tracks in the NA and the WNP basins are classified into two and three representative patterns, respectively. Each pattern shows empirical relationships with climate variabilities such as sea surface temperature distribution associated with El Niño/La Niña or Atlantic Meridional Mode, Pacific decadal oscillation, upper and low level zonal wind, and strength of subtropical high. The hybrid statistical-dynamical method has been used to develop the seasonal prediction model for each pattern based on statistical relationships between the intense TC activity and seasonal averaged key predictors. The model performance is statistically assessed by cross validation for the training period (1982-2013) and has been applied for the 2014 and 2015 prediction. This study suggests applicability of this model to real prediction work and provide bridgehead of attempt for intense TC prediction.

  19. Managing the impact of climate change on the hydrology of the Gallocanta Basin, NE-Spain.

    PubMed

    Kuhn, Nikolaus J; Baumhauer, Roland; Schütt, Brigitta

    2011-02-01

    The Gallocanta Basin represents an environment highly sensitive to climate change. Over the past 60 years, the Laguna de Gallocanta, an ephemeral lake situated in the closed Gallocanta basin, experienced a sequence of wet and dry phases. The lake and its surrounding wetlands are one of only a few bird sanctuaries left in NE-Spain for grey cranes on their annual migration from Scandinavia to northern Africa. Understanding the impact of climate change on basin hydrology is therefore of utmost importance for the appropriate management of the bird sanctuary. Changes in lake level are only weakly linked to annual rainfall, with reaction times between hours and months after rainfall. Both the total amount of rainfall over the reaction period, as well as individual extreme events, affect lake level. In this study the characteristics and frequencies of daily, event, monthly and bi-monthly rainfall over the past 60 years were analysed. The results revealed a clear link between increased frequencies of high magnitude rainfall and phases of water filling in the Laguna de Gallocanta. In the middle of the 20th century, the absolute amount of rainfall appears to have been more important for lake level, while more recently the frequency of high magnitude rainfall has emerged as the dominant variable. In the Gallocanta Basin, climate change and the distinct and continuing land use change since Spain joined the EU in 1986 have created an environment that is in a more or less constant state of transition. This highlights two challenges faced by hydrologists and climatologists involved in developing water management tools for the Gallocanta Basin in particular, but also other areas with sensitive and rapidly changing environments. Hydrologists have to understand the processes and the spatial and temporal patterns of surface-climate interaction in a watershed to assess the impact of climate change on its hydrology. Climatologists, on the other hand, have to develop climate models

  20. Patterns of landscape form in the upper Rhône basin, Central Swiss Alps, predominantly show lithologic controls despite multiple glaciations and variations in rock uplift rates

    NASA Astrophysics Data System (ADS)

    Stutenbecker, L. A.; Costa, A.; Schlunegger, F.

    2015-10-01

    The development of topography is mainly dependent on the interplay of uplift and erosion, which are in term controlled by various factors including climate, glaciers, lithology, seismic activity and short-term variables such as anthropogenic impact. While most studies have focused on the role of tectonics and climate on the landscape form and underlying processes, less attention has been paid on exploring the controls of lithology on erosion. The Central European Alps are characterized by a large spatial variability in exposed lithologies and as such offer an ideal laboratory to investigate the lithological controls on erosion and landscape form. Here, we focus on the ca. 5400 km2-large upper Rhône basin situated in the Central Swiss Alps to explore how the lithological architecture of the bedrock conditions the Alpine landscape. To this extent, we extract geomorphological parameters along the channels of ca. 50 tributary basins, whose catchments are located in either granitic basement rocks (External massifs), oceanic meta-sedimentary and ophiolitic rocks (Penninic nappes) or fine-grained continental-margin sediments (Helvetic nappes). The analysis of longitudinal river profiles show that all tributary rivers within the Rhône basin are in topographic transient state as testified by mainly convex or concave-convex longitudinal stream channel profiles with several knickpoints of either tectonic or glacial origin. In addition, although the entire Rhône basin shows a strong glacial inheritance (and is still partly glaciated) and some of the highest uplift rates recently measured in the Alps, the river network has responded differently to those perturbations as revealed by the morphometric data. In particular, tributary basins in the Helvetic nappes are the most equilibrated (concave river profiles, overall lower elevations, less steep slope gradients and lowest hypsometric integrals), while the tributaries located in the External massifs are least equilibrated

  1. Two new species of scale worms (Polychaeta: Aphroditiformia) from deep-sea habitats in the Gulf of Cadiz (NE Atlantic).

    PubMed

    Ravara, Ascensão; Cunha, Marina R

    2016-03-31

    Two new species of scale worms are described from the Gulf of Cadiz (NE Atlantic), at depths between 1100 and 2230 m. Australaugeneria iberica sp. nov. (Polynoidae) was obtained from an alcyonarian colony collected at the flank of Carlos Ribeiro mud volcano; it is characterized by the presence of neuropodial hooks only on segment two and by having the first parapodia not enlarged. This is the first report of the genus for the deep sea. The diagnosis of Australaugeneria is emended and a table comparing all species of the genus is provided. Pholoe petersenae sp. nov. (Pholoidae) was collected from the crater of three mud volcanoes (Darwin, Captain Arutyunov and Carlos Ribeiro) in areas of active seepage. This species is characterized by the presence of prostomial peaks and parapodia stylodes and the absence of eyes.

  2. The Atlantic-Mediterranean watershed, river basins and glacial history shape the genetic structure of Iberian poplars.

    PubMed

    Macaya-Sanz, D; Heuertz, M; López-de-Heredia, U; De-Lucas, A I; Hidalgo, E; Maestro, C; Prada, A; Alía, R; González-Martínez, S C

    2012-07-01

    Recent phylogeographic studies have elucidated the effects of Pleistocene glaciations and of Pre-Pleistocene events on populations from glacial refuge areas. This study investigates those effects in riparian trees (Populus spp.), whose particular features may convey enhanced resistance to climate fluctuations. We analysed the phylogeographic structure of 44 white (Populus alba), 13 black (Populus nigra) and two grey (Populus x canescens) poplar populations in the Iberian Peninsula using plastid DNA microsatellites and sequences. We also assessed fine-scale spatial genetic structure and the extent of clonality in four white and one grey poplar populations using nuclear microsatellites and we determined quantitative genetic differentiation (Q(ST) ) for growth traits in white poplar. Black poplar displayed higher regional diversity and lower differentiation than white poplar, reflecting its higher cold-tolerance. The dependence of white poplar on phreatic water was evidenced by strong differentiation between the Atlantic and Mediterranean drainage basins and among river basins, and by weaker isolation by distance within than among river basins. Our results suggest confinement to the lower river courses during glacial periods and moderate interglacial gene exchange along coastlines. In northern Iberian river basins, white poplar had lower diversity, fewer private haplotypes and larger clonal assemblies than in southern basins, indicating a stronger effect of glaciations in the north. Despite strong genetic structure and frequent asexual propagation in white poplar, some growth traits displayed adaptive divergence between drainage and river basins (Q(ST) >F(ST)), highlighting the remarkable capacity of riparian tree populations to adapt to regional environmental conditions. © 2012 Blackwell Publishing Ltd.

  3. Detrital zircon U-Pb geochronology and stratigraphy of the Cretaceous Sanjiang Basin in NE China: Provenance record of an abrupt tectonic switch in the mode and nature of the NE Asian continental margin evolution

    NASA Astrophysics Data System (ADS)

    Zhang, Feng-Qi; Chen, Han-Lin; Batt, Geoffrey E.; Dilek, Yildirim; A, Min-Na; Sun, Ming-Dao; Yang, Shu-Feng; Meng, Qi-An; Zhao, Xue-Qin

    2015-12-01

    The age spectra obtained from 505 spots of detrital zircon U-Pb ages of five representative sandstone samples from the Sanjiang Basin in NE China point to a significant change in its provenance during the Coniacian-Santonian. The predominant detrital source for the Sanjiang Basin during the early Cretaceous was the Zhangguangcai Range magmatic belt and Jiamusi Block along its western and southern periphery, whereas it changed in the late Cretaceous to its eastern periphery. The timing of these inferred changes in the detrital source regions and drainage patterns nearly coincide with the age of a regional unconformity in and across the basin. The time interval of non-deposition and unconformity development was coeval with a transitional period between an extensional tectonic regime in the early Cretaceous and a contractional deformation episode in the late Cretaceous. The Sanjiang Basin evolved during this time window from a backarc to a foreland basin. The migration of the coastal orogenic belt and the fold and thrust belt development farther inland during the late Cretaceous marked the onset of regional-scale shortening and surface uplift in the upper plate of a flat (or very shallow-dipping) subduction zone. The stratigraphic record, the detrital source and geochronology of the basinal strata, and the internal structure of the Sanjiang Basin present, therefore, an important record of a tectonic switch in the nature of continental margin evolution of Northeast Asia during the late Mesozoic.

  4. Tiger sharks can connect equatorial habitats and fisheries across the Atlantic Ocean basin.

    PubMed

    Afonso, André S; Garla, Ricardo; Hazin, Fábio H V

    2017-01-01

    Increasing our knowledge about the spatial ecology of apex predators and their interactions with diverse habitats and fisheries is necessary for understanding the trophic mechanisms that underlie several aspects of marine ecosystem dynamics and for guiding informed management policies. A preliminary assessment of tiger shark (Galeocerdo cuvier) population structure off the oceanic insular system of Fernando de Noronha (FEN) and the large-scale movements performed by this species in the equatorial Atlantic Ocean was conducted using longline and handline fishing gear and satellite telemetry. A total of 25 sharks measuring 175-372 cm in total length (TL) were sampled. Most sharks were likely immature females ranging between 200 and 260 cm TL, with few individuals < 200 cm TL being caught. This contrasts greatly with the tiger shark size-distribution previously reported for coastal waters off the Brazilian mainland, where most individuals measured < 200 cm TL. Also, the movements of 8 individuals measuring 202-310 cm TL were assessed with satellite transmitters for a combined total of 757 days (mean = 94.6 days∙shark-1; SD = 65.6). These sharks exhibited a considerable variability in their horizontal movements, with three sharks showing a mostly resident behavior around FEN during the extent of the respective tracks, two sharks traveling west to the South American continent, and two sharks moving mostly along the middle of the oceanic basin, one of which ending up in the northern hemisphere. Moreover, one shark traveled east to the African continent, where it was eventually caught by fishers from Ivory Coast in less than 474 days at liberty. The present results suggest that young tiger sharks measuring < 200 cm TL make little use of insular oceanic habitats from the western South Atlantic Ocean, which agrees with a previously-hypothesized ontogenetic habitat shift from coastal to oceanic habitats experienced by juveniles of this species in this region. In addition

  5. Tiger sharks can connect equatorial habitats and fisheries across the Atlantic Ocean basin

    PubMed Central

    Garla, Ricardo; Hazin, Fábio H. V.

    2017-01-01

    Increasing our knowledge about the spatial ecology of apex predators and their interactions with diverse habitats and fisheries is necessary for understanding the trophic mechanisms that underlie several aspects of marine ecosystem dynamics and for guiding informed management policies. A preliminary assessment of tiger shark (Galeocerdo cuvier) population structure off the oceanic insular system of Fernando de Noronha (FEN) and the large-scale movements performed by this species in the equatorial Atlantic Ocean was conducted using longline and handline fishing gear and satellite telemetry. A total of 25 sharks measuring 175–372 cm in total length (TL) were sampled. Most sharks were likely immature females ranging between 200 and 260 cm TL, with few individuals < 200 cm TL being caught. This contrasts greatly with the tiger shark size-distribution previously reported for coastal waters off the Brazilian mainland, where most individuals measured < 200 cm TL. Also, the movements of 8 individuals measuring 202–310 cm TL were assessed with satellite transmitters for a combined total of 757 days (mean = 94.6 days∙shark-1; SD = 65.6). These sharks exhibited a considerable variability in their horizontal movements, with three sharks showing a mostly resident behavior around FEN during the extent of the respective tracks, two sharks traveling west to the South American continent, and two sharks moving mostly along the middle of the oceanic basin, one of which ending up in the northern hemisphere. Moreover, one shark traveled east to the African continent, where it was eventually caught by fishers from Ivory Coast in less than 474 days at liberty. The present results suggest that young tiger sharks measuring < 200 cm TL make little use of insular oceanic habitats from the western South Atlantic Ocean, which agrees with a previously-hypothesized ontogenetic habitat shift from coastal to oceanic habitats experienced by juveniles of this species in this region. In

  6. Thermodynamic, geophysical and rheological modeling of the lithosphere underneath the North Atlantic Porcupine Basin (Ireland).

    NASA Astrophysics Data System (ADS)

    Botter, C. D.; Prada, M.; Fullea, J.

    2017-12-01

    The Porcupine is a North-South oriented basin located southwest of Ireland, along the North Atlantic continental margin, formed by several rifting episodes during Late Carboniferous to Early Cretaceous. The sedimentary cover is underlined by a very thin continental crust in the center of the basin (<5 km) that has been generally associated with hyperextension and mantle serpentinization. From North to South lithospheric stretching factors increase drastically from 2 in the North to >10 in the South. In spite of the abundant literature, most of the oil and gas exploration in the Porcupine Basin has been targeting its northern part and is mostly restricted to relatively shallow depths, giving a restrained overview of the basin structure. Therefore, studying the thermodynamic and composition of the deep and broader structures is needed to understand the processes linked to the formation and the symmetry signature of the basin. Here, we model the present-day thermal and compositional structure of the continental crust and lithospheric mantle underneath the Porcupine basin using gravity, seismic, heat flow and elevation data. We use an integrated geophysical-petrological framework where most relevant rock properties (density, seismic velocities) are determined as a function of temperature, pressure and composition. Our modelling approach solves simultaneously the heat transfer, thermodynamic, geopotential, seismic and isostasy equations, and fit the results to all available geophysical and petrological observables (LitMod software). In this work we have implemented a module to compute self-consistently a laterally variable lithospheric elastic thickness based on mineral physics rheological laws (yield strength envelopes over the 3D volume). An appropriate understanding of local and flexural isostatic behavior of the basin is essential to unravel its tectonic history (i.e. stretching factors, subsidence etc.). Our Porcupine basin 3D model is defined by four lithological

  7. Reflection Response of the Parnaíba Basin (NE Brazil) from Seismic Ambient Noise Autocorrelation Functions

    NASA Astrophysics Data System (ADS)

    Julià, Jordi; Schimmel, Martin; Cedraz, Victória

    2017-04-01

    Reflected-wave interferometry relies on the recording of transient seismic signals from random wavefields located beneath recording stations. Under vertical incidence, the recordings contain the full transmission response, which includes the direct wave as well as multiple reverberations from seismic discontinuities located between the wavefields and the receiver. It has been shown that, under those assumptions, the reflection response of the medium can be recovered from the autocorrelation function (ACF) of the transmission response at a given receiver, as if the wavefields had originated themselves at the free surface. This passive approach to seismic reflection profiling has the obvious advantage of being low-cost and non-invasive when compared to its active-source counterpart, and it has been successfully utilized in other sedimentary basins worldwide. In this paper we evaluate the ability of the autocorrelation of ambient seismic noise recorded in the Parnaíba basin - a large Paleozoic basin in NE Brazil - to recover the reflection response of the basin. The dataset was acquired by the Universidade Federal do Rio Grande do Norte during 2015 and 2016 under the Parnaíba Basin Analysis Project (PBAP), a multi-disciplinary and multi-institutional effort funded by BP Energy do Brasil aimed at improving our current understanding of the architecture of this cratonic basin. The dataset consists of about 1 year of continuous ground motion data from 10 short-period, 3-component stations located in the central portion of the basin. The stations were co-located with an existing (active-source) seismic reflection profile that was shot in 2012, making a linear array of about 100 km in aperture and about 10 km inter-station spacing. To develop the autocorrelation at a given station we considered the vertical component of ground motion only, which should result in the P-wave response. The vertical recordings were first split into 10 min-long windows, demeaned, de

  8. Deglacial hydrography and IRD inputs: A comparison of Terminations I and II in the N.E. Atlantic

    NASA Astrophysics Data System (ADS)

    Hibbert, Fiona; Chapman, Mark; Austin, William; Rohling, Eelco

    2015-04-01

    We present a high resolution marine record (MD04-2822) from the N.E. Atlantic. This record captures the demise of the penultimate glaciation (Termination II) in high resolution. The record of co-registered proxies offers the opportunity to investigate the evolution of the last two deglacial events in the North Atlantic. The deglacial evolution of Termination II is much less well documented than the last deglaciation (Termination I). A striking feature of Termination II in the MD04-2822 record, are several large (~1 ‰) oscillations in benthic δ18O, reflecting oscillations in sea level (e.g. Grant et al., 2012, Thomas et al., 2009) and/or deep sea temperatures (cf. Skinner and Shackleton, 2006). Also notable is the markedly different pattern of surface and deep water evolution for the two deglaciations. Termination I is characterised by a short offset between benthic δ18O decrease and δ13C increase (and northwards migration of the polar front) whereas during Termination II, benthic δ13C 'improvement' (and inferred resumption in overturning) occurs only during the Marine Isotope Stage (MIS) 5e plateau, giving the marine record it's characteristic 'drawn-out' appearance. The most conspicuous feature of the penultimate deglacial in most marine cores is Heinrich event 11 (H11), an extensive episode of ice rafted debris (IRD) discharge that spread across the North Atlantic to the margin of what is now the subtropical gyre (Chapman et al., 2000). H11 generally manifests in marine records as one large and long (~ 2.5 ka) event throughout the Termination. In MD04-2822 however, there are multiple IRD events within the Termination. The continued influence of the disintegrating N. hemisphere ice sheets is also evident within the benthic δ13C and surface conditions (the polar front migrates north of the core site early within MIS 5e following a brief SST reversal).

  9. Refinements to Atlantic basin seasonal hurricane prediction from 1 December

    NASA Astrophysics Data System (ADS)

    Klotzbach, Philip J.

    2008-09-01

    Atlantic basin seasonal hurricane predictions have been issued by the Tropical Meteorology Project at Colorado State University since 1984, with early December forecasts being issued every year since early December 1991. These forecasts have yet to show real-time forecast skill, despite several statistical models that have shown considerable hindcast skill. In an effort to improve both hindcast skill and hopefully real-time forecast skill, a modified forecast scheme has been developed using data from 1950 to 2007. Predictors were selected based upon how much variance was explained over the 1950-1989 subperiod. These predictors were then required to explain similar amounts of variance over a latter subperiod from 1990 to 2007. Similar amounts of skill were demonstrated for each of the three predictors selected over the 1950-1989 period, the 1990-2007 period, and the full 1950-2007 period. In addition, significant correlations between individual predictors and physical features known to affect hurricanes during the following August-October (i.e., tropical Atlantic wind shear and sea level pressure changes, ENSO phase changes) were obtained. This scheme uses a new methodology where hindcasts were obtained using linear regression and then ranked to generate final hindcast values. Fifty-four percent of the variance was explained for seasonal Net Tropical Cyclone (NTC) activity over the 1950-2007 period. These hindcasts show considerable differences in landfalling U.S. tropical cyclones, especially for the Florida Peninsula and East Coast. Seven major hurricanes made Florida Peninsula and East Coast landfall during the top 15 largest NTC hindcasts compared with only two major hurricane landfalls in the bottom 15 smallest NTC hindcasts.

  10. Rheological considerations for the modelling of submarine sliding at Rockall Bank, NE Atlantic Ocean

    NASA Astrophysics Data System (ADS)

    Salmanidou, D. M.; Georgiopoulou, A.; Guillas, S.; Dias, F.

    2018-03-01

    Recent scientific research indicates that the Rockall Bank Slide Complex in the NE Atlantic Ocean has formed as the result of repetitive slope failures that can be distinguished in at least three major phases. These sliding episodes took place during and before the Last Glacial Maximum. This work attempts the modelling of each sliding episode with the incorporation of the landslide's rheological properties. The objective is to study the landslide kinematics and final deposition of each episode under a rheological framework that comes in agreement with the field observations. To do so in the present work, we use different types of rheological models to compute the total retarding stress and simulate submarine failure. The Bingham rheology and the frictional rheology are used to model the flow behavior. The scope of this approach is to understand the effect of the two classical laws in landslide kinematics. A rheological model that combines the two regimes is also used. To account for the hydrodynamic drag, the Voellmy model is employed. The results are validated against the field observations on the seabed of the Rockall Trough. The simulations show that for this particular case the Bingham rheology with a small or negligible basal friction produces the best results. The tsunamigenic potential of the episodes is also briefly examined.

  11. Petroleum exploration and the Atlantic OCS

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Edson, G.; Adinolfi, F.; Gray, F.

    1993-08-01

    The largest Atlantic outer continental shelf (OCS) lease sale was the first one, Sale 40 in 1976. Ninety-three Baltimore Canyon Trough petroleum leases were issued, and industry's winning bids total $1.1 billion. The highest bonus bids were for leases overlying the Schlee Dome, then called Great Stone Dome, a large structure with a very large fetch area. By 1981, seven dry wells on the dome moderated this initial flush of optimism. However, subeconomic quantities of gas and light oil were discovered on the nearby Hudson Canyon Block 598-642 structure. Now after 9 lease sales, 410 lease awards, and 46 explorationmore » wells, United States Atlantic petroleum exploration activity is in a hiatus. Fifty-three leases remain active under suspensions of operation. Twenty-one lease blocks, about 50 mi offshore from Cape Hatteras, have been combined as the Manteo Exploration Unit. Mobil and partners submitted an exploration plant for the unit in 1989. The Atlantic OCS has petroleum potential, especially for gas. With only 46 exploration wells, entire basins and plays remain untested. During the present exploration inactivity, some petroleum evaluation of the Atlantic OCS continues by the Minerals Management Service and others. Similarities and differences are being documented between United States basins and the Canadian Scotian Basin, which contains oil and gas in commercial quantities. Other initiatives include geochemical, thermal history, seismic stratigraphic, and petroleum system modeling studies. The gas-prone Atlantic OCS eventually may make an energy contribution, especially to nearby East Coast markets.« less

  12. Invasive species in the Northeastern and Southwestern Atlantic Ocean: A review.

    PubMed

    Castro, Maria Cecilia T de; Fileman, Timothy W; Hall-Spencer, Jason M

    2017-03-15

    The spread of non-native species has been a subject of increasing concern since the 1980s when human-mediated transportation, mainly related to ships' ballast water, was recognized as a major vector for species transportation and spread, although records of non-native species go back as far as 16th Century. Ever increasing world trade and the resulting rise in shipping have highlighted the issue, demanding a response from the international community to the threat of non-native marine species. In the present study, we searched for available literature and databases on shipping and invasive species in the North-eastern (NE) and South-western (SW) Atlantic Ocean and assess the risk represented by the shipping trade between these two regions. There are reports of 44 species associated with high impacts for the NE Atlantic and 15 for the SW Atlantic, although this may be an underestimate. Vectors most cited are ballast water and biofouling for both regions while aquaculture has also been a very significant pathway of introduction and spread of invasive species in the NE Atlantic. Although the two regions have significant shipping traffic, no exchange of invasive species could be directly associated to the shipping between the two regions. However, it seems prudent to bring the exchange of ballast water between the two regions under control as soon as possible. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Evidence of a modern deep water magmatic hydrothermal system in the Canary Basin (eastern central Atlantic Ocean)

    NASA Astrophysics Data System (ADS)

    Medialdea, T.; Somoza, L.; González, F. J.; Vázquez, J. T.; de Ignacio, C.; Sumino, H.; Sánchez-Guillamón, O.; Orihashi, Y.; León, R.; Palomino, D.

    2017-08-01

    New seismic profiles, bathymetric data, and sediment-rock sampling document for the first time the discovery of hydrothermal vent complexes and volcanic cones at 4800-5200 m depth related to recent volcanic and intrusive activity in an unexplored area of the Canary Basin (Eastern Atlantic Ocean, 500 km west of the Canary Islands). A complex of sill intrusions is imaged on seismic profiles showing saucer-shaped, parallel, or inclined geometries. Three main types of structures are related to these intrusions. Type I consists of cone-shaped depressions developed above inclined sills interpreted as hydrothermal vents. Type II is the most abundant and is represented by isolated or clustered hydrothermal domes bounded by faults rooted at the tips of saucer-shaped sills. Domes are interpreted as seabed expressions of reservoirs of CH4 and CO2-rich fluids formed by degassing and contact metamorphism of organic-rich sediments around sill intrusions. Type III are hydrothermal-volcanic complexes originated above stratified or branched inclined sills connected by a chimney to the seabed volcanic edifice. Parallel sills sourced from the magmatic chimney formed also domes surrounding the volcanic cones. Core and dredges revealed that these volcanoes, which must be among the deepest in the world, are constituted by OIB-type, basanites with an outer ring of blue-green hydrothermal Al-rich smectite muds. Magmatic activity is dated, based on lava samples, at 0.78 ± 0.05 and 1.61 ± 0.09 Ma (K/Ar methods) and on tephra layers within cores at 25-237 ky. The Subvent hydrothermal-volcanic complex constitutes the first modern system reported in deep water oceanic basins related to intraplate hotspot activity.Plain Language SummarySubmarine volcanism and associated hydrothermal systems are relevant processes for the evolution of the ocean <span class="hlt">basins</span>, due their impact on the geochemistry of the oceans, their potential to form significant ore</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018GPC...165....1O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018GPC...165....1O"><span>Post-1980 shifts in the sensitivity of boreal tree growth to North <span class="hlt">Atlantic</span> Ocean dynamics and seasonal climate. Tree growth responses to North <span class="hlt">Atlantic</span> Ocean dynamics</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ols, Clémentine; Trouet, Valerie; Girardin, Martin P.; Hofgaard, Annika; Bergeron, Yves; Drobyshev, Igor</p> <p>2018-06-01</p> <p>The mid-20th century changes in North <span class="hlt">Atlantic</span> Ocean dynamics, e.g. slow-down of the <span class="hlt">Atlantic</span> meridional overturning thermohaline circulation (AMOC), have been considered as early signs of tipping points in the Earth climate system. We hypothesized that these changes have significantly altered boreal forest growth dynamics in northeastern North America (NA) and northern Europe (<span class="hlt">NE</span>), two areas geographically adjacent to the North <span class="hlt">Atlantic</span> Ocean. To test our hypothesis, we investigated tree growth responses to seasonal large-scale oceanic and atmospheric indices (the AMOC, North <span class="hlt">Atlantic</span> Oscillation (NAO), and Arctic Oscillation (AO)) and climate (temperature and precipitation) from 1950 onwards, both at the regional and local levels. We developed a network of 6876 black spruce (NA) and 14437 Norway spruce (<span class="hlt">NE</span>) tree-ring width series, extracted from forest inventory databases. Analyses revealed post-1980 shifts from insignificant to significant tree growth responses to summer oceanic and atmospheric dynamics both in NA (negative responses to NAO and AO indices) and <span class="hlt">NE</span> (positive response to NAO and AMOC indices). The strength and sign of these responses varied, however, through space with stronger responses in western and central boreal Quebec and in central and northern boreal Sweden, and across scales with stronger responses at the regional level than at the local level. Emerging post-1980 associations with North <span class="hlt">Atlantic</span> Ocean dynamics synchronized with stronger tree growth responses to local seasonal climate, particularly to winter temperatures. Our results suggest that ongoing and future anomalies in oceanic and atmospheric dynamics may impact forest growth and carbon sequestration to a greater extent than previously thought. Cross-scale differences in responses to North <span class="hlt">Atlantic</span> Ocean dynamics highlight complex interplays in the effects of local climate and ocean-atmosphere dynamics on tree growth processes and advocate for the use of different spatial scales in</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.A23E0322T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.A23E0322T"><span>Assessing the Importance of <span class="hlt">Atlantic</span> <span class="hlt">Basin</span> Tropical Cyclone Steering Currents in Anticipating Landfall Risk</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Truchelut, R.; Hart, R. E.</p> <p>2013-12-01</p> <p>While a number of research groups offer quantitative pre-seasonal assessments of aggregate annual <span class="hlt">Atlantic</span> <span class="hlt">Basin</span> tropical cyclone activity, the literature is comparatively thin concerning methods to meaningfully quantify seasonal U.S. landfall risks. As the example of Hurricane Andrew impacting Southeast Florida in the otherwise quiet 1992 season demonstrates, an accurate probabilistic assessment of seasonal tropical cyclone threat levels would be of immense public utility and economic value; however, the methods used to predict annual activity demonstrate little skill for predicting annual count of landfalling systems of any intensity bin. Therefore, while current models are optimized to predict cumulative seasonal tropical cyclone activity, they are not ideal tools for assessing the potential for sensible impacts of storms on populated areas. This research aims to bridge the utility gap in seasonal tropical cyclone forecasting by shifting the focus of seasonal modelling to the parameters that are most closely linked to creating conditions favorable for U.S. landfalls, particularly those of destructive and costly intense hurricanes. As it is clear from the initial findings of this study that overall activity has a limited influence on sensible outcomes, this project concentrates on detecting predictability and trends in cyclogenesis location and upper-level wind steering patterns. These metrics are demonstrated to have a relationship with landfall activity in the <span class="hlt">Atlantic</span> <span class="hlt">Basin</span> climatological record. By aggregating historic seasonally-averaged steering patterns using newly-available reanalysis model datasets, some atmospheric and oceanic precursors to an elevated risk of North American tropical cyclone landfall have been identified. Work is ongoing to quantify the variance, persistence, and predictability of such patterns over seasonal timescales, with the aim of yielding tools that could be incorporated into tropical cyclone risk mitigation strategies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1912356B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1912356B"><span>Structural and microstructural evolution of fault zones in Cretaceous poorly lithified sandstones of the Rio do Peixe <span class="hlt">basin</span>, Paraiba, <span class="hlt">NE</span> Brazil</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Balsamo, Fabrizio; Nogueira, Francisco; Storti, Fabrizio; Bezerra, Francisco H. R.; De Carvalho, Bruno R.; André De Souza, Jorge</p> <p>2017-04-01</p> <p>In this contribution we describe the structural architecture and microstructural features of fault zones developed in Cretaceous, poorly lithified sandstones of the Rio do Peixe <span class="hlt">basin</span>, <span class="hlt">NE</span> Brazil. The Rio do Peixe <span class="hlt">basin</span> is an E-W-trending, intracontinental half-graben <span class="hlt">basin</span> developed along the Precambrian Patos shear zone where it is abutted by the Porto Alegre shear zone. The <span class="hlt">basin</span> formed during rifting between South America and Africa plates and was reactivated and inverted in a strike-slip setting during the Cenozoic. Sediments filling the <span class="hlt">basin</span> consist of an heterolithic sequence of alternating sandstones, conglomerates, siltstone and clay-rich layers. These lithologies are generally poorly lithified far from the major fault zones. Deformational structures in the <span class="hlt">basin</span> mostly consist of deformation band-dominated fault zones. Extensional and strike-slip fault zones, clusters of deformation bands, and single deformation bands are commonly well developed in the proximity of the <span class="hlt">basin</span>-boundary fault systems. All deformation structures are generally in positive relief with respect to the host rocks. Extensional fault zones locally have growth strata in their hangingwall blocks and have displacement generally <10 m. In map view, they are organized in anastomosed segments with high connectivity. They strike E-W to <span class="hlt">NE</span>-SW, and typically consist of wide fault cores (< 1 m in width) surrounded by up to few-meter wide damage zones. Fault cores are characterized by distributed deformation without pervasive strain localization in narrow shear bands, in which bedding is transposed into foliation imparted by grain preferred orientation. Microstructural observations show negligible cataclasis and dominant non-destructive particulate flow, suggesting that extensional fault zones developed in soft-sediment conditions in a water-saturated environment. Strike-slip fault zones commonly overprint the extensional ones and have displacement values typically lower than about 2 m. They</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.A51H2178C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.A51H2178C"><span>Using trajectories to explain the moisture budget asymmetry between the <span class="hlt">Atlantic</span> and Pacific Oceans</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Craig, P.; Ferreira, D.; Methven, J.</p> <p>2017-12-01</p> <p>The net surface water flux (evaporation minus precipitation minus runoff, E-P-R) of the <span class="hlt">Atlantic</span> Ocean is approximately 0.4 - 0.6 Sv (1 Sv = 109 kg s-1) larger than that of the Pacific Ocean, as shown in atmospheric and oceanic reanalyses and by oceanographic estimates. This asymmetry is linked to the asymmetry in sea surface salinity and the existence of the <span class="hlt">Atlantic</span> Meridional Overturning Circulation. It is shown that the reason for the asymmetry in E-P-R is greater precipitation per unit area over the Pacific south of 30N, while evaporation rates are similar over both <span class="hlt">basins</span>. It is further argued that the Pacific Ocean is anomalous compared to the <span class="hlt">Atlantic</span> and Indian Oceans in terms of atmospheric moisture flux convergence and precipitation across the tropics and subtropics. To clarify the mechanism by which water vapour is exported out of the <span class="hlt">Atlantic</span> <span class="hlt">basin</span> and imported into the Pacific, we use an air mass trajectory model driven by ERA-Interim reanalysis. Using 12-hourly releases of 14-day back trajectories on the boundaries of ocean drainage <span class="hlt">basins</span> over the period 2010-2014, we are able to partition the atmospheric moisture fluxes between <span class="hlt">basins</span> according to their origins (i.e. last contact with the boundary layer). We show that at most a quarter of the E-P-R asymmetry is explained by higher moisture export to the Arctic and Southern <span class="hlt">basins</span> from the <span class="hlt">Atlantic</span> than from the Pacific. The main contributions come from differences in the longitudinal atmospheric transport of moisture between the <span class="hlt">Atlantic</span>, Indian and Pacific <span class="hlt">basins</span>. In particular, during the Asian summer monsoon the recurvature of the low level flow in the Somali Jet results in a much weaker westward moisture transport from the Indian into the <span class="hlt">Atlantic</span> <span class="hlt">basin</span> than across Central America (where it is similar to the zonal average) while there is stronger eastward transport from the Indian to Pacific <span class="hlt">basins</span>. The net effect is stronger moisture convergence into the Pacific, but weaker into the <span class="hlt">Atlantic</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70195036','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70195036"><span>Resource potential of the western North <span class="hlt">Atlantic</span> <span class="hlt">Basin</span></span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Dillon, William P.; Manheim, Frank T.; Jansa, L.F.; Palmason, Gudmundur; Tucholke, Brian E.; Landrum, Richard S.</p> <p>1986-01-01</p> <p>We here consider the petroleum resources only of the off shelf portion of the western North <span class="hlt">Atlantic</span> Ocean. Very little information is available for this region; off the eastern United States, only four petroleum exploration holes have been drilled in one restricted area seaward of the shelf, off the Baltimore Canyon trough. However, by interpreting seismic reflection profiles and Stratigraphie data from the Deep Sea Drilling Project (DSDP) and other wells on the adjacent slope and shelf, we can evaluate the geologic conditions that existed during development of the <span class="hlt">basin</span> and that might lead to petroleum accumulations.The wellknown factors that lead to oil and gas accumulations are availability of source beds, adequate maturation, and the presence of reservoir beds and seals configured to create a trap. The western boundary of the area considered in this paper, the present sloperise break, is one that has developed from the interplay of sedimentation and erosion at the continental margin; these processes are affected by variations in margin subsidence, sedi-ment input, oceanic circulation, sea level, and other factors. Thus the sloperise break has migrated over time and is locally underlain by slope and shelf deposits, as well as deepbasin facies. These changes in depositional environments may well have caused juxtaposition of source and reservoir beds with effective seals.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.A43I0381P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.A43I0381P"><span>The Teleconnection Between <span class="hlt">Atlantic</span> Sea Surface Temperature and Eastern Pacific Tropical Cyclones</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Patricola, C. M.; Saravanan, R.; Chang, P.</p> <p>2016-12-01</p> <p>The El Niño-Southern Oscillation (ENSO) is a major source of seasonal tropical cyclone (TC) predictability, in both local and remote ocean <span class="hlt">basins</span>. Unusually warm eastern tropical Pacific sea-surface temperature (SST) during El Niño tends not only to enhance local TC activity in the eastern North Pacific (ENP) but also to suppress <span class="hlt">Atlantic</span> TCs via well-known teleconnections. Here, we demonstrate that <span class="hlt">Atlantic</span> SST variability likewise exerts a significant influence on remote TC activity in the eastern Pacific <span class="hlt">basin</span> using observations and 27 km resolution tropical channel model simulations. Observed and simulated accumulated cyclone energy in the ENP is substantially reduced during the positive phase of the <span class="hlt">Atlantic</span> Meridional Mode (AMM), which is characterized by warm and cool SST anomalies in the northern and southern tropical <span class="hlt">Atlantic</span> respectively, and vice versa during the cool AMM phase. We find that the observed anti-correlation in seasonal TC activity between the <span class="hlt">Atlantic</span> and ENP <span class="hlt">basins</span> is driven by interannual climate variability in both the tropical Pacific (ENSO) and <span class="hlt">Atlantic</span> (AMM). The physical mechanisms that drive the teleconnection between <span class="hlt">Atlantic</span> SST and ENP TC activity will also be presented. This work provides information that can be used to improve seasonal forecasts and future projections of ENP tropical cyclone activity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005GeoRL..32.8606C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005GeoRL..32.8606C"><span>Control of air-sea CO2 disequilibria in the subtropical <span class="hlt">NE</span> <span class="hlt">Atlantic</span> by planktonic metabolism under the ocean skin</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Calleja, María Ll.; Duarte, Carlos M.; Navarro, Nuria; Agustí, Susana</p> <p>2005-04-01</p> <p>The air-sea CO2 gradient at the subtropical <span class="hlt">NE</span> <span class="hlt">Atlantic</span> was strongly dependent on the metabolism of the planktonic community within the top cms, but independent of that of the communities deeper in the water column. Gross primary production (GPP) and community respiration (R) of the planktonic community within the top cms exceeded those of the communities deeper in the water column by >10-fold and >7 fold, respectively. Net autotrophic metabolism (GPP > R) at the top cms of the water column in some stations drove CO2 uptake by creating a CO2 deficit at the ocean surface, while net heterotrophic metabolism (GPP < R) at the top cms of the water column in other stations resulted in strong CO2 supersaturation, driving CO2 emissions. These results suggest a strong control of the air-sea pCO2 anomaly by intense biological processes.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li class="active"><span>6</span></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_6 --> <div id="page_7" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li class="active"><span>7</span></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="121"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018BVol...80...36E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018BVol...80...36E"><span>Extensive young silicic volcanism produces large deep submarine lava flows in the <span class="hlt">NE</span> Lau <span class="hlt">Basin</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Embley, Robert W.; Rubin, Kenneth H.</p> <p>2018-04-01</p> <p>New field observations reveal that extensive (up to 402 km2) aphyric, glassy dacite lavas were erupted at multiple sites in the recent past in the <span class="hlt">NE</span> Lau <span class="hlt">basin</span>, located about 200 km southwest of Samoa. This discovery of volumetrically significant and widespread submarine dacite lava flows extends the domain for siliceous effusive volcanism into the deep seafloor. Although several lava flow fields were discovered on the flank of a large silicic seamount, Niuatahi, two of the largest lava fields and several smaller ones ("northern lava flow fields") were found well north of the seamount. The most distal portion of the northernmost of these fields is 60 km north of the center of Niuatahi caldera. We estimate that lava flow lengths from probable eruptive vents to the distal ends of flows range from a few km to more than 10 km. Camera tows on the shallower, near-vent areas show complex lava morphology that includes anastomosing tube-like pillow flows and ropey surfaces, endogenous domes and/or ridges, some with "crease-like" extrusion ridges, and inflated lobes with extrusion structures. A 2 × 1.5 km, 30-m deep depression could be an eruption center for one of the lava flow fields. The Lau lava flow fields appear to have erupted at presumptive high effusion rates and possibly reduced viscosity induced by presumptive high magmatic water content and/or a high eruption temperature, consistent with both erupted composition ( 66% SiO2) and glassy low crystallinity groundmass textures. The large areal extent (236 km2) and relatively small range of compositional variation ( σ = 0.60 for wt% Si02%) within the northern lava flow fields imply the existence of large, eruptible batches of differentiated melt in the upper mantle or lower crust of the <span class="hlt">NE</span> Lau <span class="hlt">basin</span>. At this site, the volcanism could be controlled by deep crustal fractures caused by the long-term extension in this rear-arc region. Submarine dacite flows exhibiting similar morphology have been described in ancient</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/wsp/1672/report.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/wsp/1672/report.pdf"><span>Magnitude and frequency of floods in the United States, Part 1-B, North <span class="hlt">Atlantic</span> slope <span class="hlt">basins</span>, New York to York River</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Tice, Richard H.</p> <p>1968-01-01</p> <p>Flood magnitude-frequency relation applicable to streams in the North <span class="hlt">Atlantic</span> slope <span class="hlt">basins</span>, New York to York River, Va., are presented in this report.  The relations are based on flood data collected at 487 gaging stations having 5 or more years of record not materially affected by regulation. For sites on most streams, the magnitude of a flood of any given frequency between 1.1 and 50 years can be determined from two curves - one expressing the relation between the mean annual flood and size of draining <span class="hlt">basin</span> and the other expressing the ratio to the mean annual flood of floods of other recurrence intervals. For New Jersey streams, an adjustment to the mean annual flood is based on the percentage of surface area covered by lakes and swamps in the <span class="hlt">basin</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMOS43D..06K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMOS43D..06K"><span>Virtual Vents: A Microbathymetrical Survey of the Niua South Hydrothermal Field, <span class="hlt">NE</span> Lau <span class="hlt">Basin</span>, Tonga</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kwasnitschka, T.; Köser, K.; Duda, A.; Jamieson, J. W.; Boschen, R.; Gartman, A.; Hannington, M. D.; Funganitao, C.</p> <p>2016-12-01</p> <p>At a diameter of 200 m, the 1100 m deep Niua South hydrothermal field (<span class="hlt">NE</span> Lau <span class="hlt">Basin</span>) was studied in an interdisciplinary approach during the SOI funded Virtual Vents cruise in March of 2016. On the grounds of a previously generated 50 cm resolution AUV multi beam map, the projects backbone is formed by a fully color textured, 5 cm resolution photogrammetrical 3D model. Several hundred smaller and about 15 chimneys larger than 3 m were surveyed including their basal mounds and surrounding environment interconnecting to each other. This model was populated through exhaustive geological, biological and fluid sampling as well as continuous Eh measurements, forming the basis for highly detailed geological structural and biological studies resulting in 3D maps of the entire field. At a reasonable effort, such surveys form the basis for repetitive time series analysis and have the potential of a new standard in seafloor monitoring.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013QSRv...73...14T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013QSRv...73...14T"><span>Cold-water coral carbonate mounds as unique palaeo-archives: the Plio-Pleistocene Challenger Mound record (<span class="hlt">NE</span> <span class="hlt">Atlantic</span>)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Thierens, M.; Browning, E.; Pirlet, H.; Loutre, M.-F.; Dorschel, B.; Huvenne, V. A. I.; Titschack, J.; Colin, C.; Foubert, A.; Wheeler, A. J.</p> <p>2013-08-01</p> <p>Through the interplay of a stabilising cold-water coral framework and a dynamic sedimentary environment, cold-water coral carbonate mounds create distinctive centres of bio-geological accumulation in often complex (continental margin) settings. The IODP Expedition 307 drilling of the Challenger Mound (eastern Porcupine Seabight; <span class="hlt">NE</span> <span class="hlt">Atlantic</span>) not only retrieved the first complete developmental history of a coral carbonate mound, it also exposed a unique, Early-Pleistocene sedimentary sequence of exceptional resolution along the mid-latitudinal <span class="hlt">NE</span> <span class="hlt">Atlantic</span> margin. In this study, a comprehensive assessment of the Challenger Mound as an archive of Quaternary palaeo-environmental change and long-term coral carbonate mound development is presented. New and existing environmental proxy records, including clay mineralogy, planktonic foraminifer and calcareous nannofossil biostratigraphy and assemblage counts, planktonic foraminifer oxygen isotopes and siliciclastic particle-size, are thereby discussed within a refined chronostratigraphic and climatic context. Overall, the development of the Challenger Mound shows a strong affinity to the Plio-Pleistocene evolution of the Northern Hemisphere climate system, albeit not being completely in phase with it. The two major oceanographic and climatic transitions of the Plio-Pleistocene - the Late Pliocene/Early Pleistocene intensification of continental ice-sheet development and the mid-Pleistocene transition to the more extremely variable and more extensively glaciated late Quaternary - mark two major thresholds in Challenger Mound development: its Late Pliocene (>2.74 Ma) origin and its Middle-Late Pleistocene to recent decline. Distinct surface-water perturbations (i.e. water-mass/polar front migrations, productivity changes, melt-water pulses) are identified throughout the sequence, which can be linked to the intensity and extent of ice development on the nearby British-Irish Isles since the earliest Pleistocene. Glaciation</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120015512','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120015512"><span>Estimating the Length of the North <span class="hlt">Atlantic</span> <span class="hlt">Basin</span> Hurricane Season</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wilson, Robert M.</p> <p>2012-01-01</p> <p>For the interval 1945-2011, the length of the hurricane season in the North <span class="hlt">Atlantic</span> <span class="hlt">basin</span> averages about 130 +/- 42 days (the +/-1 standard deviation interval), having a range of 47 to 235 days. Runs-testing reveals that the annual length of season varies nonrandomly at the 5% level of significance. In particular, its trend, as described using 10-yr moving averages, generally has been upward since about 1979, increasing from about 113 to 157 days (in 2003). Based on annual values, one finds a highly statistically important inverse correlation at the 0.1% level of significance between the length of season and the occurrence of the first storm day of the season. For the 2012 hurricane season, based on the reported first storm day of May 19, 2012 (i.e., DOY = 140), the inferred preferential regression predicts that the length of the current season likely will be about 173 +/- 23 days, suggesting that it will end about November 8 +/- 23 days, with only about a 5% chance that it will end either before about September 23, 2012 or after about December 24, 2012.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1998JCli...11.2351M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1998JCli...11.2351M"><span>Variability of the Tropical Ocean Surface Temperatures at Decadal-Multidecadal Timescales. Part I: The <span class="hlt">Atlantic</span> Ocean.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mehta, Vikram M.</p> <p>1998-09-01</p> <p>Gridded time series from the Global Ocean Surface Temperature Atlas were analyzed with a variety of techniques to identify spatial structures and oscillation periods of the tropical <span class="hlt">Atlantic</span> sea surface temperature (SST) variations at decadal timescales, and to develop physical interpretations of statistical patterns of decadal SST variations. Each time series was 110 yr (1882-1991) long. The tropical <span class="hlt">Atlantic</span> SST variations were compared with decadal variations in a 74-yr-long (1912-85) north Nordeste Brazil rainfall time series and a 106-yr-long (1886-1991) tropical <span class="hlt">Atlantic</span> cyclone activity index time series. The tropical <span class="hlt">Atlantic</span> SST variations were also compared with decadal variations in the extratropical <span class="hlt">Atlantic</span> SST.Multiyear to multidecadal variations in the cross-equatorial dipole pattern identified as a dominant empirical pattern of the tropical <span class="hlt">Atlantic</span> SST variations in earlier and present studies are shown to be variations in the approximately north-south gradient of SST anomalies. It is also shown that there was no dynamical-thermodynamical, dipole mode of SST variations during the analysis period. There was a distinct decadal timescale (12-13 yr) of SST variations in the tropical South <span class="hlt">Atlantic</span>, whereas no distinct decadal timescale was found in the tropical North <span class="hlt">Atlantic</span> SST variations. Approximately 80% of the coherent decadal variance in the cross-equatorial SST gradient was `explained' by coherent decadal oscillations in the tropical South <span class="hlt">Atlantic</span> SSTs. There were three, possibly physical, modes of decadal variations in the tropical <span class="hlt">Atlantic</span> SSTs during the analysis period. In the more energetic mode of the North <span class="hlt">Atlantic</span> decadal SST variations, anomalies traveled into the tropical North <span class="hlt">Atlantic</span> from the extratropical North <span class="hlt">Atlantic</span> along the eastern boundary of the <span class="hlt">basin</span>. The anomalies strengthened and resided in the tropical North <span class="hlt">Atlantic</span> for several years, then frequently traveled northward into the mid-high-latitude North <span class="hlt">Atlantic</span> along</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017DSRI..121..190S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017DSRI..121..190S"><span>Relationship between 'live' and dead benthic foraminiferal assemblages in the abyssal <span class="hlt">NE</span> <span class="hlt">Atlantic</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Stefanoudis, Paris V.; Bett, Brian J.; Gooday, Andrew J.</p> <p>2017-03-01</p> <p>Dead foraminiferal assemblages within the sediment mixed layer provide an integrated, time-averaged view of the foraminiferal fauna, while the relationship between dead and live assemblages reflects the population dynamics of different species together with taphonomic processes operating over the last few hundred years. Here, we analysed four samples for 'live' (Rose-Bengal-stained) and dead benthic foraminifera (0-1 cm sediment layer, >150 μm) from four sites in the area of the Porcupine Abyssal Plain Sustained Observatory (PAP-SO; <span class="hlt">NE</span> <span class="hlt">Atlantic</span>, 4850 m water depth). Two sites were located on abyssal hills and two on the adjacent abyssal plain. Our results indicate that the transition from live to dead benthic foraminiferal assemblages involved a dramatic loss of delicate agglutinated and organic-walled tests (e.g. Lagenammina, Nodellum, Reophax) with poor preservation potential, and to a lesser extent that of some relatively fragile calcareous tests (mostly miliolids), possibly a result of dissolution. Other processes, such as the transport of tests by bottom currents and predation, are unlikely to have substantially altered the composition of dead faunas. Positive live to dead ratios suggest that some species (notably Epistominella exigua and Bolivina spathulata) may have responded to recent phytodetritus input. Although the composition of live assemblages seemed to be influenced by seafloor topography (abyssal hills vs. plain), no such relation was found for dead assemblages. We suggest that PAP-SO fossil assemblages are likely to be comparable across topographically contrasting sites, and dominated by calcareous and some robust agglutinated forms with calcitic cement (e.g. Eggerella).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMPP23A1288A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMPP23A1288A"><span>Gateways and Water Mass Mixing in the Late Cretaceous North <span class="hlt">Atlantic</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Asgharian Rostami, M.; Martin, E. E.; MacLeod, K. G.; Poulsen, C. J.; Vande Guchte, A.; Haynes, S.</p> <p>2017-12-01</p> <p>Regions of intermediate/deep water formation and water-mass mixing in the North <span class="hlt">Atlantic</span> are poorly defined for the Late Cretaceous, a time of gateway evolution and cooler conditions following the Mid Cretaceous greenhouse. Improved proxy data combined with modeling efforts are required to effectively evaluate the relationship between CO2, paleogeography, and circulation during this cooler interval. We analyzed and compiled latest Cretaceous (79 - 66 Ma) ɛNd and δ13C records from seven bathyal (paleodepths 0.2 - 2 km) and eight abyssal (paleodepths > 2 km) sites in the North <span class="hlt">Atlantic</span>. Data suggest local downwelling of Northern Component Water (NCW; ɛNd -9.5 and δ13C 1.7 ‰) is the primary source of intermediate/deep water masses in the <span class="hlt">basin</span>. As this water flows southward and ages, δ13C values decrease and ɛNd values increase; however, additional chemical changes at several sites require mixing with contributions from several additional water masses. Lower ɛNd ( -10) and higher δ13C ( 1.9 ‰) values in the deep NW part of the <span class="hlt">basin</span> indicate proximal contributions from a region draining old continental crust, potentially representing deep convection following opening of the Labrador Sea. In the deep <span class="hlt">NE</span> Iberian <span class="hlt">Basin</span>, higher ɛNd ( -7) and lower δ13C ( 0.8 ‰) during the Campanian suggest mixing with a Tethyan source (ɛNd -7 and δ13C 0.1 ‰) whose importance decreased with restriction of that gateway in the Maastrichtian. Data from bathyal sites suggest additional mixing. In the SE Cape Verde region, observed ɛNd variations from -10 in the Campanian to -13 and -12 in the early and late Maastrichtian, respectively, may record variations in output rates of Tethyan and/or NCW sources and Demerara Bottom Water (ɛNd -16), a proposed warm saline intermediate water mass formed in shallow, equatorial seas. Pacific inflow through the Caribbean gateway impacts intermediate sites at Blake Nose (ɛNd values -8), particularly the shallowest site during the late</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JSAES..83...96E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JSAES..83...96E"><span>Geometry and structure of the pull-apart <span class="hlt">basins</span> developed along the western South American-Scotia plate boundary (SW <span class="hlt">Atlantic</span> Ocean)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Esteban, F. D.; Tassone, A.; Isola, J. I.; Lodolo, E.; Menichetti, M.</p> <p>2018-04-01</p> <p>The South American-Scotia plate boundary is a left-lateral fault system which runs roughly E-W for more than 3000 km across the SW <span class="hlt">Atlantic</span> Ocean and the Tierra del Fuego Island, reaching to the west the southern Chile Trench. Analyses of a large dataset of single- and multi-channel seismic reflection profiles acquired offshore has allowed to map the trace of the plate boundary from Tierra del Fuego to the Malvinas Trough, a tectonic depression located in the eastern part of the fault system, and to reconstruct the shape and geometry of the <span class="hlt">basins</span> formed along the principal displacement zone of the fault system. Three main Neogene pull-apart <span class="hlt">basins</span> that range from 70 to 100 km in length, and from 12 to 22 km in width, have been identified along this segment of the plate boundary. These <span class="hlt">basins</span> have elongated shapes with their major axes parallel to the ENE-WSW direction of the fault zone. The sedimentary architecture and the infill geometry of the <span class="hlt">basins</span> suggest that they represent mostly strike-slip dominated transtension <span class="hlt">basins</span> which propagated from E to W. The <span class="hlt">basins</span> imaged by seismic data show in some cases geometrical and structural features linked to the possible reactivation of previous wedge-top <span class="hlt">basins</span> and inherited structures pertaining to the external front of the Magallanes fold-and-thrust compression belt, along which the South American-Scotia fault system has been superimposed. It is suggested that the sequence of the elongated <span class="hlt">basins</span> occur symmetrically to a thorough going strike-slip fault, in a left-stepping geometrical arrangement, in a manner similar to those <span class="hlt">basins</span> seen in other transcurrent environments.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16.6957J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16.6957J"><span>GPS deformation rates in the Bajo Segura <span class="hlt">Basin</span> (<span class="hlt">NE</span> of the Eastern Betic Shear Zone, SE Spain)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jesús Borque, María; Sánchez-Alzola, Alberto; Estévez, Antonio; García-Tortosa, Francisco J.; Martín-Rojas, Iván; Molina, Sergio; Alfaro, Pedro; Rodríguez-Caderot, Gracia; de Lacy, Clara; García-Armenteros, Juan Antonio; Avilés, Manuel; Herrera, Antonio; Rosa-Cintas, Sergio; Gil, Antonio J.</p> <p>2014-05-01</p> <p>The Bajo Segura <span class="hlt">Basin</span>, located in the <span class="hlt">NE</span> end of the Eastern Betic Shear Zone, is one of the areas with highest seismic activity of the Iberian Peninsula. It is bounded by the Crevillente Fault to the north and the Bajo Segura Fault to the south, and it is characterized by a Late Miocene to Quaternary folded cover. We estimate the present-day deformation of the study area from a GPS network with 11 sites. Observation campaigns were carried out four times (June 1999, September 2001, September 2002 and September 2013). We used the 6.2 version of GIPSY-OASIS software to process GPS data in Precise Point Positioning mode (PPP). In order to obtain the position time series in the whole period of these episodic campaigns, all the GPS observations from 1999 to 2013 campaigns were processed with an identical standard procedure. We compared our velocity field estimation with respect to GEODVEL tectonic model to obtain the residual velocity field of the Bajo Segura <span class="hlt">Basin</span>. We estimated a ~N-S shortening with deformation rates varying between 0.2 and 0.6 mm/yr. These results are consistent with local geological deformation rates although slightly higher. They also fit well with regional geodetic data estimated for the Western Mediterranean.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017DSRI..126..115S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017DSRI..126..115S"><span>Deep-sea benthic habitats modeling and mapping in a <span class="hlt">NE</span> <span class="hlt">Atlantic</span> seamount (Galicia Bank)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Serrano, A.; González-Irusta, J. M.; Punzón, A.; García-Alegre, A.; Lourido, A.; Ríos, P.; Blanco, M.; Gómez-Ballesteros, M.; Druet, M.; Cristobo, J.; Cartes, J. E.</p> <p>2017-08-01</p> <p>This study presents the results of seafloor habitat identification and mapping of a <span class="hlt">NE</span> <span class="hlt">Atlantic</span> deep seamount. An ;assemble first, predict later; approach has been followed to identify and map the benthic habitats of the Galicia Bank (NW Iberian). Biotic patterns inferred from the survey data have been used to drive the definition of benthic assemblages using multivariate tools. Eight assemblages, four hard substrates and four sedimentary ones, have been described from a matrix of structural species. Distribution of these assemblages was correlated with environmental factors (multibeam and backscatter data) using binomial GAMs. Finally, the distribution model of each assemblage was applied to produce continuous maps and pooled in a final map with the distribution of the main benthic habitats. Depth and substrate type are key factors when determining soft bottom communities, whereas rocky habitat distribution is mainly explained by rock slope and orientation. Enrichment by northern water masses (LSW) arriving to GB and possible zooplankton biomass increase at vertical-steep walls by ;bottom trapping; can explain the higher diversity of habitat providing filter-feeders at slope rocky breaks. These results concerning vulnerable species and habitats, such as Lophelia and Madrepora communities and black and bamboo coral aggregations were the basis of the Spanish proposal of inclusion within the Natura 2000 network. The aim of the present study was to establish the scientific criteria needed for managing and protecting those environmental values.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009QuRes..71..121G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009QuRes..71..121G"><span>Patterns of human occupation during the early Holocene in the Central Ebro <span class="hlt">Basin</span> (<span class="hlt">NE</span> Spain) in response to the 8.2 ka climatic event</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>González-Sampériz, P.; Utrilla, P.; Mazo, C.; Valero-Garcés, B.; Sopena, MC.; Morellón, M.; Sebastián, M.; Moreno, A.; Martínez-Bea, M.</p> <p>2009-03-01</p> <p>The Central Ebro River <span class="hlt">Basin</span> (<span class="hlt">NE</span> Spain) is the most northern area of truly semi-arid Mediterranean climate in Europe and prehistoric human occupation there has been strongly influenced by this extreme environmental condition. Modern climate conditions single out this region due to the harsh environment, characterised by the highest absolute summer temperatures of the Ebro River <span class="hlt">Basin</span>. The Bajo Aragón region (SE Ebro River <span class="hlt">Basin</span>) was intensively populated during the Early Holocene (9400-8200 cal yr BP) but the settlements were abandoned abruptly at around 8200 cal yr BP. We propose that this "archaeological silence" was caused by the regional impact of the global abrupt 8.2 ka cold event. Available regional paleoclimate archives demonstrate the existence of an aridity crisis then that interrupted the humid Early Holocene. That environmental crisis would have forced hunter-gatherer groups from the Bajo Aragón to migrate to regions with more favourable conditions (i.e. more humid mountainous areas) and only return in the Neolithic. Coherently, archaeological sites persist during this crisis in the nearby Iberian Range (Maestrazgo) and the North Ebro River area (Pre-Pyrenean mountains and along the northwestern Ebro <span class="hlt">Basin</span>).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JGRC..123..708Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JGRC..123..708Z"><span>Changes in Bottom Water Physical Properties Above the Mid-<span class="hlt">Atlantic</span> Ridge Flank in the Brazil <span class="hlt">Basin</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhao, Jian; Thurnherr, Andreas M.</p> <p>2018-01-01</p> <p>Warming of abyssal waters in recent decades has been widely documented around the global ocean. Here repeat hydrographic data collected in 1997 and 2014 near a deep fracture zone canyon in the eastern Brazil <span class="hlt">Basin</span> are used to quantify the long-term change. Significant changes are found in the Antarctic Bottom Water (AABW) within the canyon. The AABW in 2014 was warmer (0.08 ± 0.06°C), saltier (0.01 ± 0.005), and less dense (0.005 ± 0.004 kg m-3) than in 1997. In contrast, the change in the North <span class="hlt">Atlantic</span> Deep Water has complicated spatial structure and is almost indistinguishable from zero at 95% confidence. The resulting divergence in vertical displacement of the isopycnals modifies the local density stratification. At its peak, the local squared buoyancy frequency (N2) near the canyon is reduced by about 20% from 1997 to 2014. Similar reduction is found in the basinwide averaged profiles over the Mid-<span class="hlt">Atlantic</span> Ridge flank along 25°W in years 1989, 2005, and 2014. The observed changes in density stratification have important implications for internal tide generation and dissipation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19910063775&hterms=biomass+production&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dbiomass%2Bproduction','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19910063775&hterms=biomass+production&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dbiomass%2Bproduction"><span><span class="hlt">Basin</span>-scale estimates of oceanic primary production by remote sensing - The North <span class="hlt">Atlantic</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Platt, Trevor; Caverhill, Carla; Sathyendranath, Shubha</p> <p>1991-01-01</p> <p>The monthly averaged CZCS data for 1979 are used to estimate annual primary production at ocean <span class="hlt">basin</span> scales in the North <span class="hlt">Atlantic</span>. The principal supplementary data used were 873 vertical profiles of chlorophyll and 248 sets of parameters derived from photosynthesis-light experiments. Four different procedures were tested for calculation of primary production. The spectral model with nonuniform biomass was considered as the benchmark for comparison against the other three models. The less complete models gave results that differed by as much as 50 percent from the benchmark. Vertically uniform models tended to underestimate primary production by about 20 percent compared to the nonuniform models. At horizontal scale, the differences between spectral and nonspectral models were negligible. The linear correlation between biomass and estimated production was poor outside the tropics, suggesting caution against the indiscriminate use of biomass as a proxy variable for primary production.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMPP11B1345K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMPP11B1345K"><span>The timing of termination I in benthic δ18O of the <span class="hlt">Atlantic</span>, Pacific, and Mediterranean <span class="hlt">basins</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Konijnendijk, T.</p> <p>2014-12-01</p> <p>Terminations used to be regarded as effectively globally synchronous events. As such they were used (amongst other features) in aligning cores by Lisiecki and Raymo (2005) in their widely accepted global benthic stack. Skinner and Shackleton (2005) showed, however, that this assumption of synchronicity may not hold. In a detailed study of the last glacial-interglacial transition, an <span class="hlt">Atlantic</span> record from the Iberian Margin and a record from the deep eastern equatorial Pacific - both dated by 14C for a solid, independent age estimate - show a significant discrepancy in timing: ~4,000 years. Indeed, in 2009 Lisiecki and Raymo published a separate reconstruction for the <span class="hlt">Atlantic</span> and Pacific records in their stack, and found indications for diachronous termination signals for the last five terminations. We compared the <span class="hlt">Atlantic</span> and Pacific records of Skinner and Shackleton (2005) to the benthic isotope record of ODP site 968 in the eastern Mediterranean published by Ziegler et al. (2010), to see how the Mediterranean record feeds into this discussion. The age model for this record is constrained by the carbon dated boundaries of saproprel 1 as well as correlation to the radiometrically dated cave record of Sanbao-Hulu (Wang et al., 2008). The benthic δ18O record of ODP site 968 resembles the Pacific record much more than the geographically closer Iberian Margin record. This raises questions: whether the Late Glacial/Early Holocene benthic record of MD99-2334K on the Iberian Margin is representative of <span class="hlt">Atlantic</span> benthic δ18O; what oceanographic factors could have influenced the benthic δ18O of the sites involved; whether there is, after all, a globally synchronous, two-step deglaciation in the Mediterranean, <span class="hlt">Atlantic</span>, and Pacific <span class="hlt">basins</span>. Lisiecki and Raymo, 2005. DOI: 10.1029/2004PA001071 Lisiecki and Raymo, 2005. DOI: 10.1029/2009PA001732 Skinner and Shackleton, 2005: DOI: 10.1016/j.quascirev.2004.11.008 Wang et al. 2008: doi:10.1038/nature06692. Ziegler et al., 2010</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20080045467','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20080045467"><span>Interannual Variability of Boreal Summer Rainfall in the Equatorial <span class="hlt">Atlantic</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gu, Guojun; Adler, Robert F.</p> <p>2007-01-01</p> <p>Tropical <span class="hlt">Atlantic</span> rainfall patterns and variation during boreal summer [June-July-August (JJA)] are quantified by means of a 28-year (1979-2006) monthly precipitation dataset from the Global Precipitation Climatology Project (GPCP). Rainfall variability during boreal spring [March-April-May (MAM)] is also examined for comparison in that the most intense interannual variability is usually observed during this season. Comparable variabilities in the Intertropical Convergence Zone (ITCZ) strength and the <span class="hlt">basin</span>-mean rainfall are found during both seasons. Interannual variations in the ITCZ's latitudinal location during JJA however are generally negligible, in contrasting to intense year-to-year fluctuations during MAM. Sea surface temperature (SST) oscillations along the equatorial region (usually called the <span class="hlt">Atlantic</span> Nino events) and in the tropical north <span class="hlt">Atlantic</span> (TNA) are shown to be the two major local factors modulating the tropical <span class="hlt">Atlantic</span> climate during both seasons. During MAM, both SST modes tend to contribute to the formation of an evident interhemispheric SST gradient, thus inducing anomalous shifting of the ITCZ and then forcing a dipolar structure of rainfall anomalies across the equator primarily in the western <span class="hlt">basin</span>. During JJA the impacts however are primarily on the ITCZ strength likely due to negligible changes in the ITCZ latitudinal location. The <span class="hlt">Atlantic</span> Nino reaches its peak in JJA, while much weaker SST anomalies appear north of the equator in JJA than in MAM, showing decaying of the interhemispheric SST mode. SST anomalies in the tropical central-eastern Pacific (the El Nino events) have a strong impact on tropical <span class="hlt">Atlantic</span> including both the tropical north <span class="hlt">Atlantic</span> and the equatorial-southern <span class="hlt">Atlantic</span>. However, anomalous warming in the tropical north <span class="hlt">Atlantic</span> following positive SST anomalies in the tropical Pacific disappears during JJA because of seasonal changes in the large-scale circulation cutting off the ENSO influence passing through the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1914729D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1914729D"><span>Observing mass exchange with the Lofoten <span class="hlt">Basin</span> using surface drifters</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dugstad, Johannes S.; LaCasce, Joe; Koszalka, Inga M.; Fer, Ilker</p> <p>2017-04-01</p> <p>The Lofoten <span class="hlt">Basin</span> in the Nordic Seas plays a central role in the global overturning circulation, acting as a reservoir for northward-flowing <span class="hlt">Atlantic</span> water. Substantial heat loss occurs here, permitting the waters to become denser and eventually sink nearer the Arctic. Idealized modeling studies and theoretical arguments suggest the warm water enters the Lofoten <span class="hlt">Basin</span> via eddy transport from the boundary current over the adjacent continental slope. But there is no observational evidence that this is the major contribution to mass exchange between the warm <span class="hlt">Atlantic</span> Current and the <span class="hlt">Basin</span>. How the <span class="hlt">basin</span> waters exit also remains a mystery. Surface drifters offer an unique possibility to study the pathways of the boundary-<span class="hlt">basin</span> exchange of mass and heat. We thereby examine trajectories of surface drifters released in the Nordic Seas in the POLEWARD and PROVOLO experiments, and supplemented by historical data from the Global Drifter Array. Contrary to the idea that the boundary current eddies are the main source, the results suggest that fluid is entering the Lofoten <span class="hlt">Basin</span> from all sides. However, the drifters exit preferentially in the northeast corner of the <span class="hlt">basin</span>. This asymmetry likely contributes to the extended residence times of the warm <span class="hlt">Atlantic</span> waters in the Lofoten <span class="hlt">Basin</span>. We consider various measures to quantify the effect, and test whether this is captured in a high resolution numerical model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20000012410','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20000012410"><span>Statistical Aspects of Major (Intense) Hurricanes in the <span class="hlt">Atlantic</span> <span class="hlt">Basin</span> During the Past 49 Hurricane Seasons (1950-1998): Implications for the Current Season</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wilson, Robert M.</p> <p>1999-01-01</p> <p>Statistical aspects of major (intense) hurricanes, those of category 3 or higher on the Saffir-Simpson scale (e.g., having a maximum sustained wind speed of greater than or equal to 50 M s (exp -1)), in the <span class="hlt">Atlantic</span> <span class="hlt">basin</span> during the interval of 1950-1998 are investigated in relation to the El Nino-Southern Oscillation cycle and to the postulated "more" versus "less" activity modes for intense hurricane activity. Based on Poisson statistics, when the hurricane season is simply classified as "non-El Nino-related" (NENR), the probability of having three or more intense hurricanes is approx. 53%, while it is only approx. 14% when it is classified as "El Nino-related" (ENR). Including the activity levels ("more" versus "less"), the probability of having three or more intense hurricanes is computed to be approx. 71% for the "more-NENR" season, 30% for the "less-NENR" season, 17% for the "more-ENR" season, and 12% for the "less-ENR" season. Because the 1999 hurricane season is believed to be a "more-NENR" season, the number of intense hurricanes forming in the <span class="hlt">Atlantic</span> <span class="hlt">basin</span> should be above average in number, probably about 4 plus or minus 1 or higher.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21048764','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21048764"><span>Reversed flow of <span class="hlt">Atlantic</span> deep water during the Last Glacial Maximum.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Negre, César; Zahn, Rainer; Thomas, Alexander L; Masqué, Pere; Henderson, Gideon M; Martínez-Méndez, Gema; Hall, Ian R; Mas, José L</p> <p>2010-11-04</p> <p>The meridional overturning circulation (MOC) of the <span class="hlt">Atlantic</span> Ocean is considered to be one of the most important components of the climate system. This is because its warm surface currents, such as the Gulf Stream, redistribute huge amounts of energy from tropical to high latitudes and influence regional weather and climate patterns, whereas its lower limb ventilates the deep ocean and affects the storage of carbon in the abyss, away from the atmosphere. Despite its significance for future climate, the operation of the MOC under contrasting climates of the past remains controversial. Nutrient-based proxies and recent model simulations indicate that during the Last Glacial Maximum the convective activity in the North <span class="hlt">Atlantic</span> Ocean was much weaker than at present. In contrast, rate-sensitive radiogenic (231)Pa/(230)Th isotope ratios from the North <span class="hlt">Atlantic</span> have been interpreted to indicate only minor changes in MOC strength. Here we show that the <span class="hlt">basin</span>-scale abyssal circulation of the <span class="hlt">Atlantic</span> Ocean was probably reversed during the Last Glacial Maximum and was dominated by northward water flow from the Southern Ocean. These conclusions are based on new high-resolution data from the South <span class="hlt">Atlantic</span> Ocean that establish the <span class="hlt">basin</span>-scale north to south gradient in (231)Pa/(230)Th, and thus the direction of the deep ocean circulation. Our findings are consistent with nutrient-based proxies and argue that further analysis of (231)Pa/(230)Th outside the North <span class="hlt">Atlantic</span> <span class="hlt">basin</span> will enhance our understanding of past ocean circulation, provided that spatial gradients are carefully considered. This broader perspective suggests that the modern pattern of the <span class="hlt">Atlantic</span> MOC-with a prominent southerly flow of deep waters originating in the North <span class="hlt">Atlantic</span>-arose only during the Holocene epoch.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140012580','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140012580"><span>Statistical Aspects of North <span class="hlt">Atlantic</span> <span class="hlt">Basin</span> Tropical Cyclones During the Weather Satellite Era, 1960-2013. Part 2</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wilson, Robert M.</p> <p>2014-01-01</p> <p>This Technical Publication (TP) is part 2 of a two-part study of the North <span class="hlt">Atlantic</span> <span class="hlt">basin</span> tropical cyclones that occurred during the weather satellite era, 1960-2013. In particular, this TP examines the inferred statistical relationships between 25 tropical cyclone parameters and 9 specific climate-related factors, including the (1) Oceanic Niño Index (ONI), (2) Southern Oscillation Index (SOI), (3) <span class="hlt">Atlantic</span> Multidecadal Oscillation (AMO) index, (4) Quasi-Biennial Oscillation (QBO) index, (5) North <span class="hlt">Atlantic</span> Oscillation (NAO) index of the Climate Prediction Center (CPC), (6) NAO index of the Climate Research Unit (CRU), (7) Armagh surface air temperature (ASAT), (8) Global Land-Ocean Temperature Index (GLOTI), and (9) Mauna Loa carbon dioxide (CO2) (MLCO2) index. Part 1 of this two-part study examined the statistical aspects of the 25 tropical cyclone parameters (e.g., frequencies, peak wind speed (PWS), accumulated cyclone energy (ACE), etc.) and provided the results of statistical testing (i.e., runs-testing, the t-statistic for independent samples, and Poisson distributions). Also, the study gave predictions for the frequencies of the number of tropical cyclones (NTC), number of hurricanes (NH), number of major hurricanes (NMH), and number of United States land-falling hurricanes (NUSLFH) expected for the 2014 season, based on the statistics of the overall interval 1960-2013, the subinterval 1995-2013, and whether the year 2014 would be either an El Niño year (ENY) or a non-El Niño year (NENY).</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li class="active"><span>7</span></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_7 --> <div id="page_8" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li class="active"><span>8</span></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="141"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.A23F0362C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.A23F0362C"><span>Influence of SST from Pacific and <span class="hlt">Atlantic</span> Ocean and atmospheric circulation in the precipitation regime of <span class="hlt">basin</span> from Brazilian SIN</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Custodio, M. D.; Ramos, C. G.; Madeira, P.; de Macedo, A. L.</p> <p>2013-12-01</p> <p>The South American climate presents tropical, subtropical and extratropical features because of its territorial extension, being influenced by a variety of dynamical systems with different spatial and temporal scales which result in different climatic regimes in their subregions. Furthermore, the precipitation regime in South America is influenced by low-frequency phenomena as El Niño-Southern Oscillation (ENSO), the <span class="hlt">Atlantic</span> dipole and the Madden Julian Oscilation (MJO), in other words, is directly influenced by variations of the Sea Surface Temperature (SST). Due to the importance of the precipitation for many sectors including the planning of productive activities, such as agriculture, livestock and hydropower energy, many studies about climate variations in Brazil have tried to determine and explain the mechanisms that affect the precipitation regime. However, because of complexity of the climate system, and consequently of their impacts on the global precipitation regime, its interactions are not totally understood and therefore misrepresented in numerical models used to forecast climate. The precipitation pattern over hydrographic <span class="hlt">basin</span> which form the Brasilian National Interconnected System (Sistema Interligado Nacional-SIN) are not yet known and therefore the climate forecast of these regions still presents considerable failure that need to be corrected due to its economic importance. In this context, the purpose here is to determine the precipitation patterns on the Brazilian SIN, based on SST and circulation observed data. In a second phase a forecast climate model for these regions will be produced. In this first moment 30 years (1983 to 2012) of SST over Pacific and <span class="hlt">Atlantic</span> Ocean were analyzed, along with wind in 850 and 200 hPa and precipitation observed data. The precipitation patterns were analyzed through statistical analyses for interannual (ENSO) and intraseasonal (MJO) anomalies for these variables over the SIN <span class="hlt">basin</span>. Subsequently, these</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMPP51C1083C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMPP51C1083C"><span>A high-resolution Holocene speleothem record from <span class="hlt">NE</span> Romania: the nexus of Arctic and North <span class="hlt">Atlantic</span> atmospheric circulations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Constantin, S.; Pourmand, A.; Moldovan, O.; Sharifi, A.; Mehterian, S.; Swart, P. K.</p> <p>2017-12-01</p> <p>The Romanian Carpathians act as a geomorphological barrier between different atmospheric circulation systems over Central and Eastern Europe; the NW of Romania lies under the remote influence of the North <span class="hlt">Atlantic</span> oscillation, while the <span class="hlt">NE</span> is influenced by the Arctic climate. In NW Romania, previous stable isotope studies of speleothems have not yielded a clear account of abrupt climate oscillations during the Holocene. Here we present results from a stalagmite collected from the Tauşoare Cave, located in <span class="hlt">NE</span> Carpathians. The chronology of stalagmite T141 is based on 15 high-precision Th/U dates ranging between 32 and 1.1 ka with a continuous growth between 13.3 and 1.1 ka. The portion of the record within the Holocene was analyzed for δ18O and δ13C at a resolution ranging between 15 to 200 years/sample. The resulting δ18O record captures the Younger Dryas (YD) event centered at 12.9 ka, with δ18O values about 4 ‰ more depleted than those corresponding to the Holocene Climatic Optimum. The 8.2 ka event appears to be also captured in the record, although less prominent. The T141 isotope record is significantly different when compared to coeval records measured in speleothems from NW Carpathians, which do not exhibit marked changes during the YD or 8.2 ka events. This is likely due to the contrasting effect of temperature and atmospheric transport on δ18O signal in NW Romania. Within a distance of 200 km to the east, on the eastern flank of the Carpathian range, the δ18O signal of the Arctic circulation appears to be more prominent and clearly exhibits a positive relationship with temperature changes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016CRGeo.348..368L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016CRGeo.348..368L"><span>New characterization aspects of carbonate accumulation horizons in Chalky Champagne (<span class="hlt">NE</span> of the Paris <span class="hlt">Basin</span>, France)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Linoir, Damien; Thomachot-Schneider, Céline; Gommeaux, Maxime; Fronteau, Gilles; Barbin, Vincent</p> <p>2016-05-01</p> <p>The soil profiles of the Champagne area (<span class="hlt">NE</span> of Paris <span class="hlt">Basin</span>, France) occasionally show carbonate accumulation horizons (CAHs). From the top to the bottom, these soil profiles include a rendic leptosol horizon, a Quaternary cryoturbated paleosol (QCP), and a chalky substratum. The CAHs are located in the top part of the QCP. This study is aimed at highlighting the specific characteristics of CAHs compared to other soil profile horizons using geophysics, geochemistry, micromorphology, and mercury injection porosimetry. It is the first essential step for understanding the impact of CAHs on water transfers into the Champagne soil profiles. Our analyses show that Champagne CAHs are not systematically characterized by a typical induration unlike generally put forward in the regional literature. They are more porous and heterogeneous than their parent material (QCP). Carbonate accumulation horizons are also characterized by singular colorimetric parameters that are linked to their geochemical specific content, even if they bear a signature of the initial QCP before the pedogenic modification.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3346459','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3346459"><span>Microbial Functioning and Community Structure Variability in the Mesopelagic and Epipelagic Waters of the Subtropical Northeast <span class="hlt">Atlantic</span> Ocean</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Arístegui, Javier; Gasol, Josep M.; Herndl, Gerhard J.</p> <p>2012-01-01</p> <p>We analyzed the regional distribution of bulk heterotrophic prokaryotic activity (leucine incorporation) and selected single-cell parameters (cell viability and nucleic acid content) as parameters for microbial functioning, as well as bacterial and archaeal community structure in the epipelagic (0 to 200 m) and mesopelagic (200 to 1,000 m) subtropical Northeast <span class="hlt">Atlantic</span> Ocean. We selectively sampled three contrasting regions covering a wide range of surface productivity and oceanographic properties within the same <span class="hlt">basin</span>: (i) the eddy field south of the Canary Islands, (ii) the open-ocean <span class="hlt">NE</span> <span class="hlt">Atlantic</span> Subtropical Gyre, and (iii) the upwelling filament off Cape Blanc. In the epipelagic waters, a high regional variation in hydrographic parameters and bacterial community structure was detected, accompanied, however, by a low variability in microbial functioning. In contrast, mesopelagic microbial functioning was highly variable between the studied regions despite the homogeneous abiotic conditions found therein. More microbial functioning parameters indicated differences among the three regions within the mesopelagic (i.e., viability of cells, nucleic acid content, cell-specific heterotrophic activity, nanoflagellate abundance, prokaryote-to-nanoflagellate abundance ratio) than within the epipelagic (i.e., bulk activity, nucleic acid content, and nanoflagellate abundance) waters. Our results show that the mesopelagic realm in the Northeast <span class="hlt">Atlantic</span> is, in terms of microbial activity, more heterogeneous than its epipelagic counterpart, probably linked to mesoscale hydrographical variations. PMID:22344670</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010DSRI...57..157B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010DSRI...57..157B"><span>Reproductive patterns of the abyssal asteroid Styracaster elongatus from the <span class="hlt">N.E</span>. <span class="hlt">Atlantic</span> Ocean</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Benítez-Villalobos, Francisco; Díaz-Martínez, Julia P.</p> <p>2010-01-01</p> <p>We analysed the reproductive biology of the asteroid species Styracaster elongatus based on time-series samples from a 5000-m-deep site on the Porcupine Abyssal Plain (<span class="hlt">N.E</span>. <span class="hlt">Atlantic</span>). The ratio of males to females, the gonadosomatic index (GI), and pyloric caecum index (PCI) were determined and the results were corroborated by histological examination of the gonads. Fecundity and oocyte-size distribution were determined by histological and image analyses. Styracaster elongatus is a gonochoric asteroid and the ratio of males to females was not significantly different throughout the year. Oogenesis was asynchronous. The previtellogenic oocytes grew to a size of ˜230 μm before undergoing vitellogenesis. Maximum oocyte size was ˜620 μm. The ovary volume was mainly occupied by small previtellogenic oocytes (100-150 μm) at any one time. Mean GI was 6.38±3.30 for females and 9.04±4.1 for males. Mean PCI was 7.44±1.66 for females and 7.66±1.46 for males. Mean fecundity was 16,373±5988 oocites per female. There were no seasonal variations in GI and fecundity. There was evidence of a pyiloric caecum seasonal development for females and males. For S. elongatus there is no direct relationship among seasonal primary production at the surface and production of vitellogenic oocytes. Nevertheless, this species takes advantage of the pulse of phytodetritus to the seabed by increasing the storage of nutrients in the pyloric caecum in order to maintain a constant production of eggs and sperm.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29535333','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29535333"><span><span class="hlt">Atlantic</span> deep water circulation during the last interglacial.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Luo, Yiming; Tjiputra, Jerry; Guo, Chuncheng; Zhang, Zhongshi; Lippold, Jörg</p> <p>2018-03-13</p> <p>Understanding how the <span class="hlt">Atlantic</span> Meridional Overturning Circulation (AMOC) evolved during crucial past geological periods is important in order to decipher the interplay between ocean dynamics and global climate change. Previous research, based on geological proxies, has provided invaluable insights into past AMOC changes. However, the causes of the changes in water mass distributions in the <span class="hlt">Atlantic</span> during different periods remain mostly elusive. Using a state-of-the-art Earth system model, we show that the bulk of NCW in the deep South <span class="hlt">Atlantic</span> Ocean below 4000 m migrated from the western <span class="hlt">basins</span> at 125 ka to the eastern <span class="hlt">basins</span> at 115 ka, though the AMOC strength is only slightly reduced. These changes are consistent with proxy records, and it is mainly due to more penetration of the AABW at depth at 115 ka, as a result of a larger density of AABW formed at 115 ka. Our results show that depth changes in regional deep water pathways can result in large local changes, while the overall AMOC structure hardly changes. Future research should thus be careful when interpreting single proxy records in terms of large-scale AMOC changes, and considering variability of water-mass distributions on sub-<span class="hlt">basin</span> scale would give more comprehensive interpretations of sediment records.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4540421','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4540421"><span>Nanometer-Scale Pore Characteristics of Lacustrine Shale, Songliao <span class="hlt">Basin</span>, <span class="hlt">NE</span> China</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Wang, Min; Yang, Jinxiu; Wang, Zhiwei; Lu, Shuangfang</p> <p>2015-01-01</p> <p>In shale, liquid hydrocarbons are accumulated mainly in nanometer-scale pores or fractures, so the pore types and PSDs (pore size distributions) play a major role in the shale oil occurrence (free or absorbed state), amount of oil, and flow features. The pore types and PSDs of marine shale have been well studied; however, research on lacustrine shale is rare, especially for shale in the oil generation window, although lacustrine shale is deposited widely around the world. To investigate the relationship between nanometer-scale pores and oil occurrence in the lacustrine shale, 10 lacustrine shale core samples from Songliao <span class="hlt">Basin</span>, <span class="hlt">NE</span> China were analyzed. Analyses of these samples included geochemical measurements, SEM (scanning electron microscope) observations, low pressure CO2 and N2 adsorption, and high-pressure mercury injection experiments. Analysis results indicate that: (1) Pore types in the lacustrine shale include inter-matrix pores, intergranular pores, organic matter pores, and dissolution pores, and these pores are dominated by mesopores and micropores; (2) There is no apparent correlation between pore volumes and clay content, however, a weak negative correlation is present between total pore volume and carbonate content; (3) Pores in lacustrine shale are well developed when the organic matter maturity (Ro) is >1.0% and the pore volume is positively correlated with the TOC (total organic carbon) content. The statistical results suggest that oil in lacustrine shale mainly occurs in pores with diameters larger than 40 nm. However, more research is needed to determine whether this minimum pore diameter for oil occurrence in lacustrine shale is widely applicable. PMID:26285123</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26285123','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26285123"><span>Nanometer-Scale Pore Characteristics of Lacustrine Shale, Songliao <span class="hlt">Basin</span>, <span class="hlt">NE</span> China.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wang, Min; Yang, Jinxiu; Wang, Zhiwei; Lu, Shuangfang</p> <p>2015-01-01</p> <p>In shale, liquid hydrocarbons are accumulated mainly in nanometer-scale pores or fractures, so the pore types and PSDs (pore size distributions) play a major role in the shale oil occurrence (free or absorbed state), amount of oil, and flow features. The pore types and PSDs of marine shale have been well studied; however, research on lacustrine shale is rare, especially for shale in the oil generation window, although lacustrine shale is deposited widely around the world. To investigate the relationship between nanometer-scale pores and oil occurrence in the lacustrine shale, 10 lacustrine shale core samples from Songliao <span class="hlt">Basin</span>, <span class="hlt">NE</span> China were analyzed. Analyses of these samples included geochemical measurements, SEM (scanning electron microscope) observations, low pressure CO2 and N2 adsorption, and high-pressure mercury injection experiments. Analysis results indicate that: (1) Pore types in the lacustrine shale include inter-matrix pores, intergranular pores, organic matter pores, and dissolution pores, and these pores are dominated by mesopores and micropores; (2) There is no apparent correlation between pore volumes and clay content, however, a weak negative correlation is present between total pore volume and carbonate content; (3) Pores in lacustrine shale are well developed when the organic matter maturity (Ro) is >1.0% and the pore volume is positively correlated with the TOC (total organic carbon) content. The statistical results suggest that oil in lacustrine shale mainly occurs in pores with diameters larger than 40 nm. However, more research is needed to determine whether this minimum pore diameter for oil occurrence in lacustrine shale is widely applicable.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.T53B4669W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.T53B4669W"><span>Growth of Transgressive Sills in Mechanically Layered Media: Faroe Islands, <span class="hlt">NE</span> <span class="hlt">Atlantic</span> Margin</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Walker, R. J.</p> <p>2014-12-01</p> <p>Igneous sills represent an important contribution to upper crustal magma transport, acting as magma conduits and stores (i.e. as sill networks, or as nascent magma chambers). Complex sill-network intrusion in <span class="hlt">basin</span> settings can have significant impact on subsurface fluid flow (e.g., water aquifer and hydrocarbon systems), geothermal systems, the maturation of hydrocarbons, and methane release. Models for these effects are critically dependent on the models for sill emplacement. This study focuses on staircase-geometry sills in the Faroe Islands, on the European <span class="hlt">Atlantic</span> Margin, which are hosted in mechanically layered lavas (1-20 m thick) and basaltic volcaniclastic units (1-30 m thick). The sills range from 20-50 m thick, with each covering ~17 km2, and transgressing a vertical range of ~480 m. Steps in the sills are elliptical in cross section, and discontinuous laterally, forming smooth transgressive ramps, hence are interpreted as representing initial stages of sill propagation as magma fingers, which inflate through time to create a through-going sheet. Although steps correspond to the position of some host rock layer interfaces and volcaniclastic horizons, most interfaces are bypassed. The overall geometry of the sills is consistent with ENE-WSW compression, and NNW-SSE extension, and stress anisotropy-induced transgression. Local morphology indicates that mechanical layering suppressed tensile stress ahead of the crack tip, leading to a switch in minimum and intermediate stress axes, facilitating lateral sill propagation as fingers, and resulting in a stepped transgressive geometry.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AGUFMOS51E..02W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AGUFMOS51E..02W"><span>Tsunami Warning Services for the U.S. and Canadian <span class="hlt">Atlantic</span> Coasts</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Whitmore, P. M.; Knight, W.</p> <p>2008-12-01</p> <p>In January 2005, the National Oceanic and Atmospheric Administration (NOAA) developed a tsunami warning program for the U.S. <span class="hlt">Atlantic</span> and Gulf of Mexico coasts. Within a year, this program extended further to the <span class="hlt">Atlantic</span> coast of Canada and the Caribbean Sea. Warning services are provided to U.S. and Canadian coasts (including Puerto Rico and the Virgin Islands) by the NOAA/West Coast and Alaska Tsunami Warning Center (WCATWC) while the NOAA/Pacific Tsunami Warning Center (PTWC) provides services for non-U.S. entities in the Caribbean <span class="hlt">Basin</span>. The Puerto Rico Seismic Network (PRSN) is also an active partner in the Caribbean <span class="hlt">Basin</span> warning system. While the nature of the tsunami threat in the <span class="hlt">Atlantic</span> <span class="hlt">Basin</span> is different than in the Pacific, the warning system philosophy is similar. That is, initial messages are based strictly on seismic data so that information is provided to those at greatest risk as fast as possible while supplementary messages are refined with sea level observations and forecasts when possible. The Tsunami Warning Centers (TWCs) acquire regional seismic data through many agencies, such as the United States Geological Survey, Earthquakes Canada, regional seismic networks, and the PRSN. Seismic data quantity and quality are generally sufficient throughout most of the <span class="hlt">Atlantic</span> area-of-responsibility to issue initial information within five minutes of origin time. Sea level data are mainly provided by the NOAA/National Ocean Service. Coastal tide gage coverage is generally denser along the <span class="hlt">Atlantic</span> coast than in the Pacific. Seven deep ocean pressure sensors (DARTs), operated by the National Weather Service (NWS) National Data Buoy Center, are located in the <span class="hlt">Atlantic</span> <span class="hlt">Basin</span> (5 in the <span class="hlt">Atlantic</span> Ocean, 1 in the Caribbean, and 1 in the Gulf of Mexico). The DARTs provide TWCs with the means to verify tsunami generation in the <span class="hlt">Atlantic</span> and provide critical data with which to calibrate forecast models. Tsunami warning response criteria in the <span class="hlt">Atlantic</span> <span class="hlt">Basin</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1990PalOc...5..459B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1990PalOc...5..459B"><span>Salinity history of the northern <span class="hlt">Atlantic</span> during the last deglaciation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Broecker, Wallace S.</p> <p>1990-08-01</p> <p>The claim has been made (see Broecker et al., 1988) that production of North <span class="hlt">Atlantic</span> Deep Water terminated during Younger Dryas time and that the onset of this termination occurred about 11,000 years ago when the flow of meltwater from a large segment of the southern margin of the Laurentide ice sheet was diverted from the Mississippi to the St. Lawrence drainage. Fairbanks [1989] points out a serious weakness in this argument. Based on a sea level curve derived from radiocarbon dates on coral obtained from borings made off the Barbados coast, he suggests that a lull in the melting of the ice caps during Younger Dryas time may have more than compensated for the impact of the diversion. The purpose of this paper is to reassess the situation regarding the origin of the Younger Dryas in light of this new evidence. Currently the salinity of surface waters in the northern <span class="hlt">Atlantic</span> is influenced by three fluxes. Water vapor transport from the <span class="hlt">Atlantic</span> drainage <span class="hlt">basin</span> to the Pacific-Indian <span class="hlt">basin</span> tends to raise the salinity of the entire <span class="hlt">Atlantic</span>. The excess over evaporation of precipitation and runoff poleward of 40°N tends to reduce the salinity of waters in this region relative to the <span class="hlt">Atlantic</span> average. The conveyor circulation of the <span class="hlt">Atlantic</span> trades more salty waters of the <span class="hlt">Atlantic</span> with less salty waters outside the <span class="hlt">Atlantic</span> tending to drive down the <span class="hlt">Atlantic</span>'s salinity. The conveyor circulation also flushes the northern <span class="hlt">Atlantic</span>, pushing its salinity toward the mean for the <span class="hlt">Atlantic</span>. During the period of deglaciation meltwater emanating from the Laurentide and Scandinavian ice sheets was also important. This flux tended to lower not only the salinity of the entire <span class="hlt">Atlantic</span> but also the salinity of surface waters in the northern <span class="hlt">Atlantic</span> relative to the <span class="hlt">Atlantic</span>'s mean. As deepwater formation in the northern <span class="hlt">Atlantic</span> depends critically on the salinity of surface waters, the interactions among these fluxes can change the strength of the conveyor.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.A51L..06W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.A51L..06W"><span>The Oceanic Contribution to <span class="hlt">Atlantic</span> Multi-Decadal Variability</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wills, R. C.; Armour, K.; Battisti, D. S.; Hartmann, D. L.</p> <p>2017-12-01</p> <p><span class="hlt">Atlantic</span> multi-decadal variability (AMV) is typically associated with variability in ocean heat transport (OHT) by the <span class="hlt">Atlantic</span> Meridional Overturning Circulation (AMOC). However, recent work has cast doubt on this connection by showing that slab-ocean climate models, in which OHT cannot vary, exhibit similar variability. Here, we apply low-frequency component analysis to isolate the variability of <span class="hlt">Atlantic</span> sea-surface temperatures (SSTs) that occurs on decadal and longer time scales. In observations and in pre-industrial control simulations of comprehensive climate models, we find that AMV is confined to the extratropics, with the strongest temperature anomalies in the North <span class="hlt">Atlantic</span> subpolar gyre. We show that warm subpolar temperatures are associated with a strengthened AMOC, increased poleward OHT, and local heat fluxes from the ocean into the atmosphere. In contrast, the traditional index of AMV based on the <span class="hlt">basin</span>-averaged SST anomaly shows warm temperatures preceded by heat fluxes from the atmosphere into the ocean, consistent with the atmosphere driving this variability, and shows a weak relationship with AMOC. The autocorrelation time of the <span class="hlt">basin</span>-averaged SST index is 1 year compared to an autocorrelation time of 5 years for the variability of subpolar temperatures. This shows that multi-decadal variability of <span class="hlt">Atlantic</span> SSTs is sustained by OHT variability associated with AMOC, while atmosphere-driven SST variability, such as exists in slab-ocean models, contributes primarily on interannual time scales.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20050180334','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20050180334"><span>Interannual Rainfall Variability in the Tropical <span class="hlt">Atlantic</span> Region</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gu, Guojun</p> <p>2005-01-01</p> <p>Rainfall variability on seasonal and interannual-to-interdecadal time scales in the tropical <span class="hlt">Atlantic</span> is quantified using a 25-year (1979-2003) monthly rainfall dataset from the Global Precipitation Climatology Project (GPCP). The ITCZ measured by monthly rainfall between 15-37.5 deg W attains its peak as moving to the northernmost latitude (4-10 deg N) during July-September in which the most total rainfall is observed in the tropical <span class="hlt">Atlantic</span> <span class="hlt">basin</span> (17.5 deg S-22.5 deg N, 15 deg-37.5 deg W); the ITCZ becomes weakest during January-February with the least total rainfall as it moves to the south. In contrast, rainfall variability on interannual to interdecadal time scales shows a quite different seasonal preference. The most intense interannual variability occurs during March-May when the ITCZ tends to be near the equator and becomes weaker. Significant, negative correlations between the ITCZ strength and latitude anomalies are observed during boreal spring and early summer. The ITCZ strength and total rainfall amount in the tropical <span class="hlt">Atlantic</span> <span class="hlt">basin</span> are significantly modulated by the Pacific El Nino and the <span class="hlt">Atlantic</span> equatorial mode (or <span class="hlt">Atlantic</span> Nino) particularly during boreal spring and summer; whereas the impact of the <span class="hlt">Atlantic</span> interhemispheric mode is considerably weaker. Regarding the anomalous latitudes of the ITCZ, the influence can come from both local, i.e., the <span class="hlt">Atlantic</span> interhemispheric and equatorial modes, and remote forcings, i. e., El Nino; however, a direct impact of El Nino on the latitudes of the ITCZ can only be found during April-July, not in winter and early spring in which the warmest SST anomalies are usually observed in the equatorial Pacific.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ClDy...49.2061E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ClDy...49.2061E"><span>Impact of tropical <span class="hlt">Atlantic</span> sea-surface temperature biases on the simulated atmospheric circulation and precipitation over the <span class="hlt">Atlantic</span> region: An ECHAM6 model study</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Eichhorn, Astrid; Bader, Jürgen</p> <p>2017-09-01</p> <p>As many coupled atmosphere-ocean general circulation models, the coupled Earth System Model developed at the Max Planck Institute for Meteorology suffers from severe sea-surface temperature (SST) biases in the tropical <span class="hlt">Atlantic</span>. We performed a set of SST sensitivity experiments with its atmospheric model component ECHAM6 to understand the impact of tropical <span class="hlt">Atlantic</span> SST biases on atmospheric circulation and precipitation. The model was forced by a climatology of observed global SSTs to focus on simulated seasonal and annual mean state climate. Through the superposition of varying tropical <span class="hlt">Atlantic</span> bias patterns extracted from the MPI-ESM on top of the control field, this study investigates the relevance of the seasonal variation and spatial structure of tropical <span class="hlt">Atlantic</span> biases for the simulated response. Results show that the position and structure of the Intertropical Convergence Zone (ITCZ) across the <span class="hlt">Atlantic</span> is significantly affected, exhibiting a dynamically forced shift of annual mean precipitation maximum to the east of the <span class="hlt">Atlantic</span> <span class="hlt">basin</span> as well as a southward shift of the oceanic rain belt. The SST-induced changes in the ITCZ in turn affect seasonal rainfall over adjacent continents. However not only the ITCZ position but also other effects arising from biases in tropical <span class="hlt">Atlantic</span> SSTs, e.g. variations in the wind field, change the simulation of precipitation over land. The seasonal variation and spatial pattern of tropical <span class="hlt">Atlantic</span> SST biases turns out to be crucial for the simulated atmospheric response and is essential for analyzing the contribution of SST biases to coupled model mean state biases. Our experiments show that MPI-ESM mean-state biases in the <span class="hlt">Atlantic</span> sector are mainly driven by SST biases in the tropical <span class="hlt">Atlantic</span> while teleconnections from other <span class="hlt">basins</span> seem to play a minor role.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018GeoRL..45..471P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018GeoRL..45..471P"><span>The Response of <span class="hlt">Atlantic</span> Tropical Cyclones to Suppression of African Easterly Waves</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Patricola, Christina M.; Saravanan, R.; Chang, Ping</p> <p>2018-01-01</p> <p><span class="hlt">Atlantic</span> tropical cyclone (TC) genesis is strongly linked with African easterly waves (AEWs) on the synoptic time scale. However, the TC-AEW relationship is unclear on interannual to climate time scales, and it is unknown whether AEWs are necessary to maintain climatological TC frequency, that is, whether TCs are limited by AEWs. We investigated the impact of AEW suppression on seasonal <span class="hlt">Atlantic</span> TC activity using a 10-member ensemble of regional climate model simulations in which AEWs were either prescribed or removed through the lateral boundary condition. The climate model experiments produced no significant change in seasonal <span class="hlt">Atlantic</span> TC number, indicating that AEWs are not necessary to maintain climatological <span class="hlt">basin</span>-wide TC frequency even though TCs readily originate from these types of disturbances. This suggests that the specific type of "seedling" disturbance is unimportant for determining <span class="hlt">basin</span>-wide seasonal <span class="hlt">Atlantic</span> TC number and that in the absence of AEWs, TCs will generate by other mechanisms. The results imply that changes in the presence of AEWs may not be reliable predictors of seasonal variability and future change in <span class="hlt">Atlantic</span> TC frequency.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/publication/?seqNo115=323920','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/publication/?seqNo115=323920"><span>Registration of <span class="hlt">NE</span> Trailblazer C-1, <span class="hlt">NE</span> Trailblazer C0, <span class="hlt">NE</span> Trailblazer C2, <span class="hlt">NE</span> Trailblazer C3, <span class="hlt">NE</span> Trailblazer C4, and <span class="hlt">NE</span> Trailblazer C5 Switchgrass Germplasms</span></a></p> <p><a target="_blank" href="https://www.ars.usda.gov/research/publications/find-a-publication/">USDA-ARS?s Scientific Manuscript database</a></p> <p></p> <p></p> <p><span class="hlt">NE</span> Trailblazer C-1 (GP-101, PI 672015), <span class="hlt">NE</span> Trailblazer C0 (GP-100, PI 672014), <span class="hlt">NE</span> Trailblazer C2 (GP-102, PI 672016), <span class="hlt">NE</span> Trailblazer C3 (GP-103, PI 672017), <span class="hlt">NE</span> Trailblazer C4 (GP-104, PI 672018), and <span class="hlt">NE</span> Trailblazer C5 (GP-105, PI 672019) switchgrass (Panicum virgatum L.) germplasms were released by ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012BGD.....916907S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012BGD.....916907S"><span>Macrofauna community inside and outside of the Darwin Mounds SAC, <span class="hlt">NE</span> <span class="hlt">Atlantic</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Serpetti, N.; Gontikaki, E.; Narayanaswamy, B. E.; Witte, U.</p> <p>2012-11-01</p> <p>Over the past two decades, growing concerns have been raised regarding the effects of towed fishing gears, such as trawls and dredges, on deep-sea biodiversity and ecosystem functioning. Trawling disturbs the benthic communities both physically and biologically, and can eliminate the most vulnerable organisms and modify habitat structure; chronically disturbed communities are often dominated by opportunistic species. The European Union is under obligation to designate a network of offshore Special Areas of Conservation (SACs) and Marine Protected Areas (MPAs) by the end of 2012 based on the perceived expectation that these networks will help protect marine biodiversity and that within these areas, faunal abundance and diversity will be higher than the surrounding fished areas. The Darwin Mounds, only discovered in 1998, are located in the Rockall Trough, <span class="hlt">NE</span> <span class="hlt">Atlantic</span> at a depth of ~ 1000 m. Deep-water trawling regularly took place in the region of the Darwin Mounds; however in 2004 the mounds were designated as the first offshore SAC in UK and the area is now closed to bottom trawling. As part of the HERMIONE programme the influence of human impact on the Oceans was one of the key themes and in June 2011, an investigation of the macrofaunal community structure at comparable sites both inside and outside of the Darwin Mound SAC was undertaken. Macrofaunal communities were found to differ significantly, with the difference mostly driven by changes in the abundance of polychaetes, crustaceans and nematodes whilst no significant differences were seen for the other phyla. Whereas overall macrofaunal abundance was higher outside the SAC compared to within, this pattern varies considerably between phyla. Diversity indices showed no significant differences between protected and unprotected sites. This could indicate that a few years of preservation are not enough time to determine a recovery by the macrofaunal community of cold-water ecosystems and that a continued</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18780210','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18780210"><span>PAHs and PCBs deposited in surficial sediments along a rural to urban transect in a mid-<span class="hlt">Atlantic</span> coastal river <span class="hlt">basin</span> (USA).</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Foster, Gregory D; Cui, Vickie</p> <p>2008-10-01</p> <p>PAHs and PCBs were measured in river sediments along a 226 km longitudinal transect that spanned rural to urban land use settings through Valley and Ridge, Piedmont Plateau and Coastal Plain physiographic provinces in the Potomac River <span class="hlt">basin</span> (mid-<span class="hlt">Atlantic</span> USA). A gradient in PAH concentrations was found in river bed sediments along the upstream transect in the Potomac and Shenandoah Rivers that correlated with population densities in the nearby sub-<span class="hlt">basins</span>. Sediment PAH concentrations halved per each approximately 40 km of transect distance upstream (i.e., the half-concentration distance) from the urban center (Washington, DC) of the Potomac River <span class="hlt">basin</span> in direct proportion to population density. The PAH molecular composition was consistent across all geologic provinces, revealing a dominant pyrogenic source. Fluoranthene to perylene ratios served as useful markers for urban inputs, with a ratio > 2.4 observed in sediments near urban structures such as roadways, bridges and sewer outfalls. PCBs in sediments were not well correlated with population densities along the river <span class="hlt">basin</span> transect, but the highest concentrations were found in the urban Coastal Plain region near Washington, DC and in the Shenandoah River near a known industrial Superfund site. PAHs were moderately correlated with sediment total organic carbon (TOC) in the Shenandoah River and Coastal Plain Potomac River regions, but TOC was poorly correlated with PCB concentrations throughout the entire <span class="hlt">basin</span>. Although both PAHs and PCBs are widely recognized as urban-derived contaminants, their concentration profiles and geochemistry in river sediments were uniquely different throughout the upper Potomac River <span class="hlt">basin</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JGRD..122.6882D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JGRD..122.6882D"><span>Congo <span class="hlt">Basin</span> precipitation: Assessing seasonality, regional interactions, and sources of moisture</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dyer, Ellen L. E.; Jones, Dylan B. A.; Nusbaumer, Jesse; Li, Harry; Collins, Owen; Vettoretti, Guido; Noone, David</p> <p>2017-07-01</p> <p>Precipitation in the Congo <span class="hlt">Basin</span> was examined using a version of the National Center for Atmospheric Research Community Earth System Model (CESM) with water tagging capability. Using regionally defined water tracers, or tags, the moisture contribution from different source regions to Congo <span class="hlt">Basin</span> precipitation was investigated. We found that the Indian Ocean and evaporation from the Congo <span class="hlt">Basin</span> were the dominant moisture sources and that the <span class="hlt">Atlantic</span> Ocean was a comparatively small source of moisture. In both rainy seasons the southwestern Indian Ocean contributed about 21% of the moisture, while the recycling ratio for moisture from the Congo <span class="hlt">Basin</span> was about 25%. Near the surface, a great deal of moisture is transported from the <span class="hlt">Atlantic</span> into the Congo <span class="hlt">Basin</span>, but much of this moisture is recirculated back over the <span class="hlt">Atlantic</span> in the lower troposphere. Although the southwestern Indian Ocean is a major source of Indian Ocean moisture, it is not associated with the bulk of the variability in precipitation over the Congo <span class="hlt">Basin</span>. In wet years, more of the precipitation in the Congo <span class="hlt">Basin</span> is derived from Indian Ocean moisture, but the spatial distribution of the dominant sources is shifted, reflecting changes in the midtropospheric circulation over the Indian Ocean. During wet years there is increased transport of moisture from the equatorial and eastern Indian Ocean. Our results suggest that reliably capturing the linkages between the large-scale circulation patterns over the Indian Ocean and the local circulation over the Congo <span class="hlt">Basin</span> is critical for future projections of Congo <span class="hlt">Basin</span> precipitation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..1615441Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..1615441Z"><span>Partitioned transpression in the Triassic Aghdarband <span class="hlt">basin</span>: evidence for a Cimmerian deformation in <span class="hlt">NE</span> IRAN:</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zanchi, Andrea; Zanchetta, Stefano; Balini, Marco; Ghassemi, Mohammad Reza</p> <p>2014-05-01</p> <p>The Lower-Middle Triassic Aghdarband <span class="hlt">Basin</span>, <span class="hlt">NE</span> Iran, consists of a strongly deformed arc-related marine succession deposited along the southern margin of Eurasia (Turan domain) in a highly mobile tectonic context. The marine deposits are unconformably covered by Upper Triassic continental beds, marking the Cimmerian collision of Iran with Eurasia. The Aghdarband <span class="hlt">Basin</span> is a key-area for the study of the Cimmerian events, as the Triassic units were severely folded and thrust short time after the collision and were unconformably covered by the gently deformed Middle Jurassic succession which seals the Cimmerian structures. The Triassic deposits form a north-verging thrust stack interacting with an important left-lateral strike-slip shear zone exposed in the northernmost part of the <span class="hlt">basin</span>. Transpressional structures as strike-slip faults and vertical folds are here associated with high angle reverse faults forming intricate positive flower structures. Systematic asymmetry of major and parasitic folds, as well as their geometrical features indicate that they generated in a left-lateral transpressional regime roughly coeval to thrust imbrication to the south, as a consequence of a marked strain partitioning. Aim of this presentation is to describe in detail the deformational structures of the Aghdarband region, based on structural mapping and detailed original mesoscopic field analyses, resuming from the excellent work performed in the '70s by Ruttner (1991). Our work is focused on the pre mid-Jurassic structures which can be related to the final stages of the Cimmerian deformation resulting from the oblique collision of the Iranian microplate with the southern margin of Eurasia, the so-called Turan domain. We will finally discuss the kinematic significance of the Late Triassic oblique convergence zone of Aghdarband in the frame of strain partitioning in transpressional deformation. Structural weakness favouring strain partitioning can be related to inversion of syn</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li class="active"><span>8</span></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_8 --> <div id="page_9" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li class="active"><span>9</span></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="161"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMPP14B..04M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMPP14B..04M"><span>Northern control of Southern Source Water deglacial circulation in Rockall Trough, <span class="hlt">N.E</span>. <span class="hlt">Atlantic</span>.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>McCave, I. N. N.; Hibbert, F. D.; Channell, J. E. T.; Austin, W. E. N.</p> <p>2014-12-01</p> <p>Core MD04-2822 from northern Rockall Trough at 2300 m water depth contains a high resolution record of changes in the vigour of the deep circulation determined by variation in the Sortable Silt mean size (SS) over the period 21-0 ka (LGM to present). The record has excellent age control from C-14 and correlation of Np(s) to Greenland ice cores (NGRIP GICC05 scale) (Hibbert et al., 2010, JQS, Austin & Hibbert, 2012, QSR). The record displays a slowdown in deep circulation from 20 to 17.5ka, a faster H-1a and slower H-1b (16.4-14.7 ka), a faster B-A with evident slowing at Older Dryas and IACP, and slow YD. The Holocene shows slower flows around 8.4-7.5, 6.3-5.5 and 3.5 -2.7 ka as well as the Little Ice Age. The a/b differentiation of the Heinrich event is mirrored by changes in d18O at NGRIP with boundaries at 17.8 and 16.3 ka on GICC05 tentatively correlated with H-1b. Benthic Carbon isotope (d13C) variations and values are very similar to those found at 3150 m water depth off Portugal (Skinner & Shackleton, 2004, PaleO), where Shackleton et al (2000, PaleO) show that the water mass is strongly SSW influenced in both warm and cold periods. At the present day there is evidence of SSW (LDW of McCartney, 1992 Progr in O) in Rockall Trough from silicate values greater than those of <span class="hlt">NE</span> <span class="hlt">Atlantic</span> Deep water of northern overflow origin. We suggest that bottom water in the Trough during deglaciation contained a major component of southern origin. This is consistent with suggested upper bounds of SSW at ~2000 m elsewhere in the N. <span class="hlt">Atlantic</span>. This water appears to have responded dynamically to northern hemisphere climatic forcing, although supplied from around Antarctica. In this, its behaviour is similar to the changes in circulation vigour recorded by Pa/Th at 4500 m on Bermuda Rise that must also have been dominated by SSW (McManus et al., 2004, Nature) The κARM/κ grain size parameter reflecting fine magnetite grain size proxy which is sensitive to grain sizes well below</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20010035867','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20010035867"><span>Characterizing the Spatial and Temporal Distribution of Aerosol Optical Thickness Over the <span class="hlt">Atlantic</span> <span class="hlt">Basin</span> Utilizing GOES-8 Multispectral Data</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Fox, Robert; Prins, Elaine Mae; Feltz, Joleen M.</p> <p>2001-01-01</p> <p>In recent years, modeling and analysis efforts have suggested that the direct and indirect radiative effects of both anthropogenic and natural aerosols play a major role in the radiative balance of the earth and are an important factor in climate change calculations. The direct effects of aerosols on radiation and indirect effects on cloud properties are not well understood at this time. In order to improve the characterization of aerosols within climate models it is important to accurately parameterize aerosol forcing mechanisms at the local, regional, and global scales. This includes gaining information on the spatial and temporal distribution of aerosols, transport regimes and mechanisms, aerosol optical thickness, and size distributions. Although there is an expanding global network of ground measurements of aerosol optical thickness and size distribution at specific locations, satellite data must be utilized to characterize the spatial and temporal extent of aerosols and transport regimes on regional and global scales. This study was part of a collaborative effort to characterize aerosol radiative forcing over the <span class="hlt">Atlantic</span> <span class="hlt">basin</span> associated with the following three major aerosol components in this region: urban/sulfate, Saharan dust, and biomass burning. In-situ ground measurements obtained by a network of sun photometers during the Smoke Clouds and Radiation Experiment in Brazil (SCAR-B) and the Tropospheric Aerosol Radiative Forcing Observational Experiment (TARFOX) were utilized to develop, calibrate, and validate a Geostationary Operational Environmental Satellite (GOES)-8 aerosol optical thickness (AOT) product. Regional implementation of the GOES-8 AOT product was used to augment point source measurements to gain a better understanding of the spatial and temporal distributions of <span class="hlt">Atlantic</span> <span class="hlt">basin</span> aerosols during SCAR-B and TARFOX.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018AREPS..46..327F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018AREPS..46..327F"><span><span class="hlt">Atlantic</span>-Pacific Asymmetry in Deep Water Formation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ferreira, David; Cessi, Paola; Coxall, Helen K.; de Boer, Agatha; Dijkstra, Henk A.; Drijfhout, Sybren S.; Eldevik, Tor; Harnik, Nili; McManus, Jerry F.; Marshall, David P.; Nilsson, Johan; Roquet, Fabien; Schneider, Tapio; Wills, Robert C.</p> <p>2018-05-01</p> <p>While the <span class="hlt">Atlantic</span> Ocean is ventilated by high-latitude deep water formation and exhibits a pole-to-pole overturning circulation, the Pacific Ocean does not. This asymmetric global overturning pattern has persisted for the past 2–3 million years, with evidence for different ventilation modes in the deeper past. In the current climate, the <span class="hlt">Atlantic</span>-Pacific asymmetry occurs because the <span class="hlt">Atlantic</span> is more saline, enabling deep convection. To what extent the salinity contrast between the two <span class="hlt">basins</span> is dominated by atmospheric processes (larger net evaporation over the <span class="hlt">Atlantic</span>) or oceanic processes (salinity transport into the <span class="hlt">Atlantic</span>) remains an outstanding question. Numerical simulations have provided support for both mechanisms; observations of the present climate support a strong role for atmospheric processes as well as some modulation by oceanic processes. A major avenue for future work is the quantification of the various processes at play to identify which mechanisms are primary in different climate states.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013DSRII..86..111M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013DSRII..86..111M"><span>Morphology, taxonomic status and distribution of the opisthobranch mollusc Coryphella (s.l.) japonica from the central deep water <span class="hlt">basin</span> of the Sea of Japan</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Martynov, Alexander V.</p> <p>2013-02-01</p> <p>The opisthobranch fauna (Gastropoda: Opisthobranchia) of the deep sea <span class="hlt">basins</span> of the Sea of Japan is reviewed. A detailed description of the most common deep sea nudibranch species Coryphella japonicaVolodchenko, 1941 is given based on materials from various expeditions (including R/V "Vityaz" cruises and SoJaBio project). Distinct morphological features of C. japonica are discussed and its valid taxonomic status is confirmed. The considerable radular variability of C. japonica for the first time is documented using a scanning electron microscope. Unique features of the bathymetric distribution of C. japonica ranging from shelf to the abyssal depths are discussed in connection with the "pseudabyssal area" concept. C. japonica was compared to its assumed synonym C. salmonacea, and to similar C. athadona. Material from all these species, including types of C. japonica, was examined externally, anatomically via dissection, and SEM. C. salmonacea is restricted to North <span class="hlt">Atlantic</span> and Arctic only, whereas C. japonica inhabits <span class="hlt">NE</span> Pacific including deep water <span class="hlt">basins</span> of the Sea of Japan.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JGRF..122.2223K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JGRF..122.2223K"><span>Landslide Frequency and Failure Mechanisms at <span class="hlt">NE</span> Gela <span class="hlt">Basin</span> (Strait of Sicily)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kuhlmann, J.; Asioli, A.; Trincardi, F.; Klügel, A.; Huhn, K.</p> <p>2017-11-01</p> <p>Despite intense research by both academia and industry, the parameters controlling slope stability at continental margins are often speculated upon. Lack of core recovery and age control on failed sediments prevent the assessment of failure timing/frequency and the role of prefailure architecture as shaped by paleoenvironmental changes. This study uses an integrated chronological framework from two boreholes and complementary ultrahigh-resolution acoustic profiling in order to assess (1) the frequency of submarine landsliding at the continental margin of <span class="hlt">NE</span> Gela <span class="hlt">Basin</span> and (2) the associated mechanisms of failure. Accurate age control was achieved through absolute radiocarbon dating and indirect dating relying on isotope stratigraphic and micropaleontological reconstructions. A total of nine major slope failure events have been recognized that occurred within the last 87 kyr ( 10 kyr return frequency), though there is evidence for additional syndepositional, small-scaled transport processes of lower volume. Preferential failure involves translational movement of mudflows along subhorizontal surfaces that are induced by sedimentological changes relating to prefailure stratal architecture. Along with sequence-stratigraphic boundaries reflecting paleoenvironmental fluctuations, recovered core material suggests that intercalated volcaniclastic layers are key to the basal confinement and lateral movement of these events in the study area. Another major predisposing factor is given by rapid loading of fine-grained homogenous strata and successive generation of excess pore pressure, as expressed by several fluid escape structures. Recurrent failure, however, requires repeated generation of favorable conditions, and seismic activity, though low if compared to many other Mediterranean settings, is shown to represent a legitimate trigger mechanism.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMOS31B1397R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMOS31B1397R"><span>North <span class="hlt">Atlantic</span> near-surface salinity contrasts and intra-<span class="hlt">basin</span> water vapor transfer</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Reagan, J. R.; Seidov, D.; Boyer, T.</p> <p>2017-12-01</p> <p>The geographic distribution of near-surface salinity (NSS) in the North <span class="hlt">Atlantic</span> is characterized by a very salty (>37) subtropical region contrasting with a much fresher (<35) subpolar area. Multiple studies have shown that preserving this salinity contrast is important for maintaining the <span class="hlt">Atlantic</span> Meridional Overturning Circulation (AMOC), and that changes to this salinity balance may reduce the strength of the AMOC. High subtropical salinity is primarily due to evaporation (E) dominating precipitation (P), whereas low subpolar salinity is at least partly due to precipitation dominating evaporation. Present-day understanding of the fate of water vapor in the atmosphere over the extratropical North <span class="hlt">Atlantic</span> is that the precipitation which falls in the subpolar region primarily originates from the water vapor produced through evaporation in the subtropical North <span class="hlt">Atlantic</span>. With this knowledge and in conjunction with a basic understanding of North <span class="hlt">Atlantic</span> storm tracks—the main meridional transport conduits in mid and high latitudes— a preliminary time and spatial correlation analysis was completed to relate the North <span class="hlt">Atlantic</span> decadal climatological salinity between 1985 and 2012 to the evaporation and precipitation climatologies for the same period. Preliminary results indicate that there is a clear connection between subtropical E-P and subpolar NSS. Additional results and potential implications will be presented and discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015E%26PSL.432..493Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015E%26PSL.432..493Z"><span>Origin of increased terrigenous supply to the <span class="hlt">NE</span> South American continental margin during Heinrich Stadial 1 and the Younger Dryas</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Yancheng; Chiessi, Cristiano M.; Mulitza, Stefan; Zabel, Matthias; Trindade, Ricardo I. F.; Hollanda, Maria Helena B. M.; Dantas, Elton L.; Govin, Aline; Tiedemann, Ralf; Wefer, Gerold</p> <p>2015-12-01</p> <p>We investigate the redistribution of terrigenous materials in the northeastern (<span class="hlt">NE</span>) South American continental margin during slowdown events of the <span class="hlt">Atlantic</span> Meridional Overturning Circulation (AMOC). The compilation of stratigraphic data from 108 marine sediment cores collected across the western tropical <span class="hlt">Atlantic</span> shows an extreme rise in sedimentation rates off the Parnaíba River mouth (about 2°S) during Heinrich Stadial 1 (HS1, 18-15 ka). Sediment core GeoB16206-1, raised offshore the Parnaíba River mouth, documents relatively constant 143Nd/144Nd values (expressed as εNd(0)) throughout the last 30 ka. Whereas the homogeneous εNd(0) data support the input of fluvial sediments by the Parnaíba River from the same source area directly onshore, the increases in Fe/Ca, Al/Si and Rb/Sr during HS1 indicate a marked intensification of fluvial erosion in the Parnaíba River drainage <span class="hlt">basin</span>. In contrast, the εNd(0) values from sediment core GeoB16224-1 collected off French Guiana (about 7°N) suggest Amazon-sourced materials within the last 30 ka. We attribute the extremely high volume of terrigenous sediments deposited offshore the Parnaíba River mouth during HS1 to (i) an enhanced precipitation in the catchment region and (ii) a reduced North Brazil Current, which are both associated with a weakened AMOC.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140011820','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140011820"><span>Statistical Aspects of North <span class="hlt">Atlantic</span> <span class="hlt">Basin</span> Tropical Cyclones During the Weather Satellite Era, 1960-2013: Part 1</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wilson, Robert M.</p> <p>2014-01-01</p> <p>A tropical cyclone is described as a warm-core, nonfrontal, synoptic-scale system that originates over tropical or subtropical waters, having organized deep convection and closed surface wind circulation (counterclockwise in the Northern Hemisphere) about a well defined center. When its sustained wind speed equals 34-63 kt, it is called a tropical (or subtropical) storm and is given a name (i.e., alternating male and female names, beginning in 1979); when its sustained wind speed equals 64-95 kt, it is called a hurricane (at least in the Eastern Pacific and North <span class="hlt">Atlantic</span> <span class="hlt">basin</span>); and when its sustained wind speed equals 96 kt or higher, it is called an intense or major hurricane (i.e., categories 3-5 on the Saffir-Simpson Hurricane Wind Scale). Although tropical cyclones have been reported and described since the voyages of Columbus, a detailed record of their occurrences extends only from 1851 to the present, with the most reliable portion extending only from about 1945 to the present, owing to the use of near-continuous routine reconnaissance aircraft monitoring flights and the use of satellite imagery (beginning in 1960; see Davis). Even so, the record may still be incomplete, possibly missing at least one tropical cyclone per yearly hurricane season, especially prior to the use of continuous satellite monitoring. In fact, often an unnamed tropical cyclone is included in the year-end listing of events at the conclusion of the season, following post-season analysis (e.g., as happened in 2011 and 2013, each having one unnamed event). In this two-part Technical Publication (TP), statistical aspects of the North <span class="hlt">Atlantic</span> <span class="hlt">basin</span> tropical cyclones are examined for the interval 1960-2013, the weather satellite era. Part 1 examines some 25 parameters of tropical cyclones (e.g., frequencies, peak wind speed (PWS), accumulated cyclone energy (ACE), etc.), while part 2 examines the relationship of these parameters against specific climate-related factors. These studies are</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018ClDy..tmp.2342S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018ClDy..tmp.2342S"><span>Contrasting spatial structures of <span class="hlt">Atlantic</span> Multidecadal Oscillation between observations and slab ocean model simulations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sun, Cheng; Li, Jianping; Kucharski, Fred; Xue, Jiaqing; Li, Xiang</p> <p>2018-04-01</p> <p>The spatial structure of <span class="hlt">Atlantic</span> multidecadal oscillation (AMO) is analyzed and compared between the observations and simulations from slab ocean models (SOMs) and fully coupled models. The observed sea surface temperature (SST) pattern of AMO is characterized by a <span class="hlt">basin</span>-wide monopole structure, and there is a significantly high degree of spatial coherence of decadal SST variations across the entire North <span class="hlt">Atlantic</span> <span class="hlt">basin</span>. The observed SST anomalies share a common decadal-scale signal, corresponding to the <span class="hlt">basin</span>-wide average (i. e., the AMO). In contrast, the simulated AMO in SOMs (AMOs) exhibits a tripole-like structure, with the mid-latitude North <span class="hlt">Atlantic</span> SST showing an inverse relationship with other parts of the <span class="hlt">basin</span>, and the SOMs fail to reproduce the observed strong spatial coherence of decadal SST variations associated with the AMO. The observed spatial coherence of AMO SST anomalies is identified as a key feature that can be used to distinguish the AMO mechanism. The tripole-like SST pattern of AMOs in SOMs can be largely explained by the atmosphere-forced thermodynamics mechanism due to the surface heat flux changes associated with the North <span class="hlt">Atlantic</span> Oscillation (NAO). The thermodynamic forcing of AMOs by the NAO gives rise to a simultaneous inverse NAO-AMOs relationship at both interannual and decadal timescales and a seasonal phase locking of the AMOs variability to the cold season. However, the NAO-forced thermodynamics mechanism cannot explain the observed NAO-AMO relationship and the seasonal phase locking of observed AMO variability to the warm season. At decadal timescales, a strong lagged relationship between NAO and AMO is observed, with the NAO leading by up to two decades, while the simultaneous correlation of NAO with AMO is weak. This lagged relationship and the spatial coherence of AMO can be well understood from the view point of ocean dynamics. A time-integrated NAO index, which reflects the variations in <span class="hlt">Atlantic</span> meridional overturning</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1995DSRI...42.1773S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1995DSRI...42.1773S"><span>Regionally and seasonally differentiated primary production in the North <span class="hlt">Atlantic</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sathyendranath, Shubha; Longhurst, Alan; Caverhill, Carla M.; Platt, Trevor</p> <p>1995-10-01</p> <p>A bio-geochemical classification of the N. <span class="hlt">Atlantic</span> <span class="hlt">Basin</span> is presented according to which the <span class="hlt">basin</span> is first divided into four primary algal domains: Polar, West-Wind, Trades and Coastal. These are in turn sub-divided into smaller provinces. The classification is based on differences in the physical environment which are likely to influence regional algal dynamics. The seasonally-differentiated parameters of the photosynthesis-light curve ( P-I curve) and parameters that define the vertical structure in chlorophyll profile are then established for each province, based on an analysis of an archive of over 6000 chlorophyll profiles, and over 1800 P-I curves. These are then combined with satellite-derived chlorophyll data for the N. <span class="hlt">Atlantic</span>, and information on cloud cover, to compute primary production at the annual scale. using a model that computes spectral transmission of light underwater, and spectral, photosynthetic response of phytoplankton to available light. The results are compared with earlier, satellite-derived, estimates of <span class="hlt">basin</span>-scale primary production.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013DSRII..98...75B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013DSRII..98...75B"><span>Organic matter composition and macrofaunal diversity in sediments of the Condor Seamount (Azores, <span class="hlt">NE</span> <span class="hlt">Atlantic</span>)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bongiorni, Lucia; Ravara, Ascensão; Parretti, Paola; Santos, Ricardo S.; Rodrigues, Clara F.; Amaro, Teresa; Cunha, Marina R.</p> <p>2013-12-01</p> <p>In recent years increasing knowledge has been accumulated on seamounts ecology; however their sedimentary environments and associated biological communities remain largely understudied. In this study we investigated quantity and biochemical composition of organic matter and macrofaunal diversity in sediments of the Condor Seamount (<span class="hlt">NE</span> <span class="hlt">Atlantic</span>, Azores). In order to test the effect of the seamount on organic matter distribution, sediment samples were collected in 6 areas: the summit, the northern and southern flanks and bases, and in an external far field site. Macrofauna abundance and diversity were investigated on the summit, the southern flank and in the far field site. The organic matter distribution reflected the complex hydrodynamic conditions occurring on the Condor. Concentrations of organic matter compounds were generally lower on the whole seamount than in the far field site and on the seamount summit compared to flanks and bases. A clear difference was also evident between the northern and southern slopes of the Condor, suggesting a role of the seamount in conditioning sedimentation processes and distribution of food resources for benthic consumers. Macrofauna assemblages changed significantly among the three sampling sites. High abundance and dominance, accompanied by low biodiversity, characterized the macrofauna community on the Condor summit, while low dominance and high biodiversity were observed at the flank. Our results, although limited to five samples on the seamount and two off the seamount, do not necessarily support the paradigm that seamounts are more biodiverse than the surrounding seafloor. However, the abundance (and biomass), functional diversity and taxonomical distinctiveness of the macrofaunal assemblages from the Condor Seamount suggest that seamounts habitats may play a relevant role in adding to the regional biodiversity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA348965','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA348965"><span>Interannual Variability of the <span class="hlt">Atlantic</span> Water in the Arctic <span class="hlt">Basin</span></span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>1996-01-01</p> <p>3778-3784, 1987. 4. Anderson L.G., Bjork G., Holby 0., Jones E.P., Kattner G., Kolterman K.P., Liljebad B ., Lindegren R., Rudels B ., Swift J. Water...Res., part A, 36, pp. 475 - 482 , 1989. 6. Antonov J. Recent climatic changes of the vertical thermal structure of the North <span class="hlt">Atlantic</span> Ocean and the...North Pacific Ocean. - J. of Climate, v.6, pp.1928-1942, 1993. 7. Blinov N.I. and Popkov S.N. About the heat exchange of <span class="hlt">Atlantic</span> Waters in the Arctic</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EGUGA..14.9901O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EGUGA..14.9901O"><span>Tsunami Risk in the <span class="hlt">NE</span> <span class="hlt">Atlantic</span>: Pilot Study for Algarve Portugal and Applications for future TWS</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Omira, R.; Baptista, M. A.; Catita, C.; Carrilho, F.; Matias, L.</p> <p>2012-04-01</p> <p>Tsunami risk assessment is an essential component of any Tsunami Early Warning System due to its significant contribution to the disaster reduction by providing valuable information that serve as basis for mitigation preparedness and strategies. Generally, risk assessment combines the outputs of the hazard and the vulnerability assessment for considered exposed elements. In the <span class="hlt">NE</span> <span class="hlt">Atlantic</span> region, the tsunami hazard is relatively well established through compilation of tsunami historical events, evaluation of tsunamigenic sources and impact computations for site-specific coastal areas. While, tsunami vulnerability remains poorly investigated in spite of some few studies that focused on limited coastal areas of the Gulf of Cadiz region. This work seeks to present a pilot study for tsunami risk assessment that covers about 170 km of coasts of Algarve region, south of Portugal. This area of high coastal occupation and touristic activities was strongly impacted by the 1755 tsunami event as reported in various historical documents. An approach based upon a combination of tsunami hazard and vulnerability is developed in order to take into account the dynamic aspect of tsunami risk in the region that depends on the variation of hazard and vulnerability of exposed elements from a coastal point to other. Hazard study is based upon the consideration of most credible earthquake scenarios and the derivation of hazard maps through hydrodynamic modeling of inundation and tsunami arrival time. The vulnerability assessment is performed by: i) the analysis of the occupation and the population density, ii) derivation of evacuation maps and safe shelters, and iii) the analysis of population response and evacuation times. Different risk levels ranging from "low" to "high" are assigned to the coats of the studied area. Variation of human tsunami risk between the high and low touristic seasons is also considered in this study and aims to produce different tsunami risk-related scenarios</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29475689','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29475689"><span>Current status of deepwater oil spill modelling in the Faroe-Shetland Channel, Northeast <span class="hlt">Atlantic</span>, and future challenges.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gallego, Alejandro; O'Hara Murray, Rory; Berx, Barbara; Turrell, William R; Beegle-Krause, C J; Inall, Mark; Sherwin, Toby; Siddorn, John; Wakelin, Sarah; Vlasenko, Vasyl; Hole, Lars R; Dagestad, Knut Frode; Rees, John; Short, Lucy; Rønningen, Petter; Main, Charlotte E; Legrand, Sebastien; Gutierrez, Tony; Witte, Ursula; Mulanaphy, Nicole</p> <p>2018-02-01</p> <p>As oil reserves in established <span class="hlt">basins</span> become depleted, exploration and production moves towards relatively unexploited areas, such as deep waters off the continental shelf. The Faroe-Shetland Channel (FSC, <span class="hlt">NE</span> <span class="hlt">Atlantic</span>) and adjacent areas have been subject to increased focus by the oil industry. In addition to extreme depths, metocean conditions in this region characterise an environment with high waves and strong winds, strong currents, complex circulation patterns, sharp density gradients, and large small- and mesoscale variability. These conditions pose operational challenges to oil spill response and question the suitability of current oil spill modelling frameworks (oil spill models and their forcing data) to adequately simulate the behaviour of a potential oil spill in the area. This article reviews the state of knowledge relevant to deepwater oil spill modelling for the FSC area and identifies knowledge gaps and research priorities. Our analysis should be relevant to other areas of complex oceanography. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005AGUFMPP52C..08G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005AGUFMPP52C..08G"><span>High Resolution Upwelling Cycles in Guaymas and Cariaco <span class="hlt">Basins</span> over the late Holocene: Coupling Between the Western <span class="hlt">Atlantic</span> and Eastern Pacific?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Goni, M. A.</p> <p>2005-12-01</p> <p>The recent past history of sea surface temperature (SST) conditions in two wind-dominated upwelling systems, Guaymas <span class="hlt">Basin</span> (Gulf of California) and Cariaco <span class="hlt">Basin</span> (Venezuela) was investigated using the alkenone-based UK'37 index. Both of these systems undergo marked seasonal SST changes of 4-10 degrees C, which are associated with wind-driven upwelling and thermal stratification cycles. Both Guaymas and Cariaco <span class="hlt">Basins</span> are also characterized by suboxic to anoxic bottom waters that result in undisturbed, varved sediments. Confirmation that the seasonal SST trends are accurately incorporated into the UK'37 ratios of sinking particles was achieved using sediment trap samples. Analyses of sediment cores from Guaymas and Cariaco <span class="hlt">Basins</span> yielded high-resolution (decadal) records of SST conditions in the overlying water column from 1700 to 2000 AD. The trends in the UK'37 index revealed general increases in the SST at both sites over that last 300 years associated with the end of the little ice age. However, in addition to this long-term trend, higher-frequency (~ 50 years) changes in SST that ranged from 1-3 degrees C were observed. We speculate that these decadal trends in SST reflect variations in the intensity of wind-driven upwelling at these sites. Most interestingly, there is a marked contrast in the timing of the SST values between Guaymas and Cariaco so that periods of enhanced upwelling in Guyamas <span class="hlt">Basin</span> are characterized by decreased upwelling in Cariaco <span class="hlt">Basin</span> (and vice versa). We propose that these contrasting records reflect differences in the response of wind-driven upwelling to changes in the position of the Intertropical Convergence Zone over the western <span class="hlt">Atlantic</span> and the subtropical High over the eastern Pacific. The connection between these two upwelling systems and its significance for paleoreconstruction studies will be explored further.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16.6928G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16.6928G"><span>Rapid inundation estimates using coastal amplification laws in the western Mediterranean <span class="hlt">basin</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gailler, Audrey; Loevenbruck, Anne; Hébert, Hélène</p> <p>2014-05-01</p> <p>Numerical tsunami propagation and inundation models are well developed and have now reached an impressive level of accuracy, especially in locations such as harbors where the tsunami waves are mostly amplified. In the framework of tsunami warning under real-time operational conditions, the main obstacle for the routine use of such numerical simulations remains the slowness of the numerical computation, which is strengthened when detailed grids are required for the precise modeling of the coastline response of an individual harbor. Thus only tsunami offshore propagation modeling tools using a single sparse bathymetric computation grid are presently included within the French Tsunami Warning Center (CENALT), providing rapid estimation of tsunami warning at western Mediterranean and <span class="hlt">NE</span> <span class="hlt">Atlantic</span> <span class="hlt">basins</span> scale. We present here a preliminary work that performs quick estimates of the inundation at individual harbors from these high sea forecasting tsunami simulations. The method involves an empirical correction based on theoretical amplification laws (either Green's or Synolakis laws). The main limitation is that its application to a given coastal area would require a large database of previous observations, in order to define the empirical parameters of the correction equation. As no such data (i.e., historical tide gage records of significant tsunamis) are available for the western Mediterranean and <span class="hlt">NE</span> <span class="hlt">Atlantic</span> <span class="hlt">basins</span>, we use a set of synthetic mareograms, calculated for both fake events and well-known historical tsunamigenic earthquakes in the area. This synthetic dataset is obtained through accurate numerical tsunami propagation and inundation modeling by using several nested bathymetric grids of increasingly fine resolution close to the shores (down to a grid cell size of 3m in some Mediterranean harbors). Non linear shallow water tsunami modeling performed on a single 2' coarse bathymetric grid are compared to the values given by time-consuming nested grids</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26618788','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26618788"><span>Melting barriers to faunal exchange across ocean <span class="hlt">basins</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>McKeon, C Seabird; Weber, Michele X; Alter, S Elizabeth; Seavy, Nathaniel E; Crandall, Eric D; Barshis, Daniel J; Fechter-Leggett, Ethan D; Oleson, Kirsten L L</p> <p>2016-02-01</p> <p>Accelerated loss of sea ice in the Arctic is opening routes connecting the <span class="hlt">Atlantic</span> and Pacific Oceans for longer periods each year. These changes may increase the ease and frequency with which marine birds and mammals move between the Pacific and <span class="hlt">Atlantic</span> Ocean <span class="hlt">basins</span>. Indeed, recent observations of birds and mammals suggest these movements have intensified in recent decades. Reconnection of the Pacific and <span class="hlt">Atlantic</span> Ocean <span class="hlt">basins</span> will present both challenges to marine ecosystem conservation and an unprecedented opportunity to examine the ecological and evolutionary consequences of interoceanic faunal exchange in real time. To understand these changes and implement effective conservation of marine ecosystems, we need to further develop modeling efforts to predict the rate of dispersal and consequences of faunal exchange. These predictions can be tested by closely monitoring wildlife dispersal through the Arctic Ocean and using modern methods to explore the ecological and evolutionary consequences of these movements. © 2015 John Wiley & Sons Ltd.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016E%26PSL.438..122H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016E%26PSL.438..122H"><span>Deglacial diatom production in the tropical North <span class="hlt">Atlantic</span> driven by enhanced silicic acid supply</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hendry, Katharine R.; Gong, Xun; Knorr, Gregor; Pike, Jennifer; Hall, Ian R.</p> <p>2016-03-01</p> <p>Major shifts in ocean circulation are thought to be responsible for abrupt changes in temperature and atmospheric CO2 during the last deglaciation, linked to variability in meridional heat transport and deep ocean carbon storage. There is also widespread evidence for shifts in biological production during these times of deglacial CO2 rise, including enhanced diatom production in regions such as the tropical <span class="hlt">Atlantic</span>. However, it remains unclear as to whether this diatom production was driven by enhanced wind-driven upwelling or density-driven vertical mixing, or by elevated thermocline concentrations of silicic acid supplied to the surface at a constant rate. Here, we demonstrate that silicic acid supply at depth in the <span class="hlt">NE</span> <span class="hlt">Atlantic</span> was enhanced during the abrupt climate events of the deglaciation. We use marine sediment archives to show that an increase in diatom production during abrupt climate shifts could only occur in regions of the <span class="hlt">NE</span> <span class="hlt">Atlantic</span> where the deep supply of silicic acid could reach the surface. The associated changes are indicative of enhanced regional wind-driven upwelling and/or weakened stratification due to circulation changes during phases of weakened <span class="hlt">Atlantic</span> meridional overturning. Globally near-synchronous pulses of diatom production and enhanced thermocline concentrations of silicic acid suggest that widespread deglacial surface-driven breakdown of stratification, linked to changes in atmospheric circulation, had major consequences for biological productivity and carbon cycling.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JAfES..96..168S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JAfES..96..168S"><span>Facies analysis, palaeoenvironmental reconstruction and stratigraphic development of the Early Cretaceous sediments (Lower Bima Member) in the Yola Sub-<span class="hlt">basin</span>, Northern Benue Trough, <span class="hlt">NE</span> Nigeria</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sarki Yandoka, Babangida M.; Abubakar, M. B.; Abdullah, Wan Hasiah; Amir Hassan, M. H.; Adamu, Bappah U.; Jitong, John S.; Aliyu, Abdulkarim H.; Adegoke, Adebanji Kayode</p> <p>2014-08-01</p> <p>The Benue Trough of Nigeria is a major rift <span class="hlt">basin</span> formed from the tension generated by the separation of African and South American plates in the Early Cretaceous. It is geographically sub-divided into Southern, Central and Northern Benue portions. The Northern Benue Trough comprises two sub-<span class="hlt">basins</span>; the N-S trending Gongola Sub-<span class="hlt">basin</span> and the E-W trending Yola Sub-<span class="hlt">basin</span>. The Bima Formation is the oldest lithogenetic unit occupying the base of the Cretaceous successions in the Northern Benue Trough. It is differentiated into three members; the Lower Bima (B1), the Middle Bima (B2) and the Upper Bima (B3). Facies and their stratigraphical distribution analyses were conducted on the Lower Bima Member exposed mainly at the core of the <span class="hlt">NE</span>-SW axially trending Lamurde Anticline in the Yola Sub-<span class="hlt">basin</span>, with an objective to interpret the paleodepositional environments, and to reconstruct the depositional model and the stratigraphical architecture. Ten (10) lithofacies were identified on the basis of lithology, grain size, sedimentary structures and paleocurrent analysis. The facies constitute three (3) major facies associations; the gravelly dominated, the sandy dominated and the fine grain dominated. These facies and facies associations were interpreted and three facies successions were recognized; the alluvial-proximal braided river, the braided river and the lacustrine-marginal lacustrine. The stratigraphic architecture indicates a rifted (?pull-apart) origin as the facies distribution shows a progradational succession from a shallow lacustrine/marginal lacustrine (at the axial part of the <span class="hlt">basin</span>) to alluvial fan (sediment gravity flow)-proximal braided river (gravel bed braided river) and braided river (channel and overbank) depositional systems. The facies stacking patterns depict sedimentation mainly controlled by allogenic factors of climate and tectonism.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.noaanews.noaa.gov/stories2014/20140522_hurricaneoutlook_atlantic.html','SCIGOVWS'); return false;" href="http://www.noaanews.noaa.gov/stories2014/20140522_hurricaneoutlook_atlantic.html"><span>NOAA predicts near-normal or below-normal 2014 <span class="hlt">Atlantic</span> hurricane season</span></a></p> <p><a target="_blank" href="http://www.science.gov/aboutsearch.html">Science.gov Websites</a></p> <p></p> <p></p> <p>Related link: <span class="hlt">Atlantic</span> <span class="hlt">Basin</span> Hurricane Season Outlook Discussion <em>El</em> Niño/Southern Oscillation (ENSO predicts near-normal or below-normal 2014 <span class="hlt">Atlantic</span> hurricane season <em>El</em> Niño expected to develop and . The main driver of this year's outlook is the anticipated development of <em>El</em> Niño this summer. <em>El</em> NiÃ</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li class="active"><span>9</span></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_9 --> <div id="page_10" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active"><span>10</span></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="181"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010BGD.....7.3061A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010BGD.....7.3061A"><span>The trophic biology of the holothurian Molpadia musculus at 3500 m in the Nazaré Canyon (<span class="hlt">NE</span> <span class="hlt">Atlantic</span>)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Amaro, T.; Bianchelli, S.; Billett, D. S. M.; Cunha, M. R.; Pusceddu, A.; Danovaro, R.</p> <p>2010-04-01</p> <p>Megafaunal organisms play a key role in the deep-sea ecosystem functioning. At 3500 m depth in the Nazaré Canyon, <span class="hlt">NE</span> <span class="hlt">Atlantic</span>, very high abundances of the infaunal holothurian Molpadia musculus were found. Sediment samples and holothurians were collected by ROV and experiments were conducted in situ in incubation chambers. The biochemical composition of the sediment (in terms of proteins, carbohydrates and lipids), the holothurians' gut contents and holothurians' faecal material were analysed. In the sediments, proteins were the dominant organic compound, followed by carbohydrates and lipids. In the holothurian gut contents, conversely, protein concentrations were higher than the other compounds and decreased significantly as the material passed through the digestive tract. About 33±1% of the proteins were digested already in the mid gut, with a final digestion rate equal to 67±1%. Carbohydrates and lipids were ingested in smaller amounts and digested with lower efficiencies (23±11% and 50±11%, respectively). As a result, biopolymeric C digestion rate was on average 62±3%. We also calculated that the entire holothurians' population could remove from the sediment about 0.49±0.13 g biopolymeric C and 0.13±0.03 g N m-2 d-1. These results suggest that the M. musculus plays a key role in the benthic tropho-dynamics and biogeochemical processes of the Nazaré Canyon.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017QSRv..166..188S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017QSRv..166..188S"><span>Chronology of fluvial terrace sequences for large <span class="hlt">Atlantic</span> rivers in the Iberian Peninsula (Upper Tagus and Duero drainage <span class="hlt">basins</span>, Central Spain)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Silva, Pablo G.; Roquero, Elvira; López-Recio, Mario; Huerta, Pedro; Martínez-Graña, Antonio M.</p> <p>2017-06-01</p> <p>This work analyses the chronology of fluvial terrace sequences of the two most important fluvial <span class="hlt">basins</span> from central Spain draining to the <span class="hlt">Atlantic</span> Ocean (Upper Tagus and Duero drainage <span class="hlt">basins</span>). Both <span class="hlt">basins</span> evolved under similar Mediterranean climatic conditions throughout the Pleistocene and present comparable number of fluvial terraces (16-17) after excluding the higher terrace levels of the Tagus (T1-T5) entrenched in the Raña surface. These higher ;rañizo terraces; was formed in response to fan-head trenching in this high alluvial piedmont (+220 m) and therefore not properly controlled by Quaternary fluvial downcutting. The study accomplishes the implementation of multiple regression analyses for terrace height-age relationships. To transform relative terrace heights above the present river thalwegs (i.e. +100 m) in numerical ages a ;height-age transference function; has been developed on the basis of preliminary statistical geochronological approaches proposed for Central Spain. The resultant height-age transference function gather 73 published geochronological data for terrace sequences, featuring a 3rd Order Polynomial Function (R2 0.90). This function describes the overall trend of valley downcutting for the last c. 2.3 Ma in Central Spain and is used to assign numerical ages to terrace levels at different relative elevation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EGUGA..14.2826G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EGUGA..14.2826G"><span>Late Cretaceous-Paleocene strike-slip faults along the East Greenland margin (63°N to 75°N): constraints for the North East <span class="hlt">Atlantic</span> opening</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Guarnieri, P.</p> <p>2012-04-01</p> <p>The East Greenland margin is a long stretch starting from 60°N up to 81°N in a distance of almost 3000 km. It represents the conjugate of the European margin now separated by the North East <span class="hlt">Atlantic</span> (NEA). After a long period of E-W extension and almost N-S oriented rift <span class="hlt">basins</span> since Early Cretaceous, separation between Greenland and Europe began at 55 Ma following a <span class="hlt">NE</span>-SW oriented line of breakup and the emplacement of the North <span class="hlt">Atlantic</span> Igneous Province (NAIP). Post-breakup thermal subsidence followed in the Eocene, and the Oligocene initiated a period of plate re-organization together with the initial separation of Jan Mayen microcontinent, a complex tectonic history with inversion structures and uplifts along both the East Greenland and European margins. The effect of this history is represented by exhumed sedimentary <span class="hlt">basins</span>, dyke swarms, fault systems, intrusive centers, shield volcanoes and plateau lavas constituting highest mountain of Greenland with some peaks up to 3700 m (e.g. Watkins Bjerge). During expeditions for fieldwork in East Greenland (2009 to 2011) to collect new geological and structural data related to the North East <span class="hlt">Atlantic</span> tectonics, four areas were visited: Skjoldungen 63°N, Kangerlussuaq 68°N, Traill Ø 72°N and Wollaston Forland 75°N. More than 1000 measurement of fault-slip data for structural analysis along major faults were collected and helicopter flights to collect oblique pictures for 3D-photogeology and 3D-mapping were taken. Kinematic analysis of brittle deformation associated with Late Cretaceous-Paleocene rift shows strike-slip movements. Palaeo-stress tensors reconstructed from fault-slip data highlight a <span class="hlt">NE</span>-SW maximum horizontal stress in a strike-slip tectonic setting along the entire East Greenland margin (Guarnieri 2011a; Guarnieri 2011b; Guarnieri et al. 2011). Structural data show clear evidence for oblique rifting that corresponds in time to the "volcanic rift" (61-55 Ma) with in some cases the magmatic</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28783913','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28783913"><span>Sea level anomaly in the North <span class="hlt">Atlantic</span> and seas around Europe: Long-term variability and response to North <span class="hlt">Atlantic</span> teleconnection patterns.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Iglesias, Isabel; Lorenzo, M Nieves; Lázaro, Clara; Fernandes, M Joana; Bastos, Luísa</p> <p>2017-12-31</p> <p>Sea level anomaly (SLA), provided globally by satellite altimetry, is considered a valuable proxy for detecting long-term changes of the global ocean, as well as short-term and annual variations. In this manuscript, monthly sea level anomaly grids for the period 1993-2013 are used to characterise the North <span class="hlt">Atlantic</span> Ocean variability at inter-annual timescales and its response to the North <span class="hlt">Atlantic</span> main patterns of atmospheric circulation variability (North <span class="hlt">Atlantic</span> Oscillation, Eastern <span class="hlt">Atlantic</span>, Eastern <span class="hlt">Atlantic</span>/Western Russia, Scandinavian and Polar/Eurasia) and main driven factors as sea level pressure, sea surface temperature and wind fields. SLA variability and long-term trends are analysed for the North <span class="hlt">Atlantic</span> Ocean and several sub-regions (North, Baltic and Mediterranean and Black seas, Bay of Biscay extended to the west coast of the Iberian Peninsula, and the northern North <span class="hlt">Atlantic</span> Ocean), depicting the SLA fluctuations at <span class="hlt">basin</span> and sub-<span class="hlt">basin</span> scales, aiming at representing the regions of maximum sea level variability. A significant correlation between SLA and the different phases of the teleconnection patterns due to the generated winds, sea level pressure and sea surface temperature anomalies, with a strong variability on temporal and spatial scales, has been identified. Long-term analysis reveals the existence of non-stationary inter-annual SLA fluctuations in terms of the temporal scale. Spectral density analysis has shown the existence of long-period signals in the SLA inter-annual component, with periods of ~10, 5, 4 and 2years, depending on the analysed sub-region. Also, a non-uniform increase in sea level since 1993 is identified for all sub-regions, with trend values between 2.05mm/year, for the Bay of Biscay region, and 3.98mm/year for the Baltic Sea (no GIA correction considered). The obtained results demonstrated a strong link between the atmospheric patterns and SLA, as well as strong long-period fluctuations of this variable in spatial and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014PrOce.122...92M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014PrOce.122...92M"><span>Linking benthic hydrodynamics and cold-water coral occurrences: A high-resolution model study at three cold-water coral provinces in the <span class="hlt">NE</span> <span class="hlt">Atlantic</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mohn, Christian; Rengstorf, Anna; White, Martin; Duineveld, Gerard; Mienis, Furu; Soetaert, Karline; Grehan, Anthony</p> <p>2014-03-01</p> <p>Observations from numerous cold-water coral locations in the <span class="hlt">NE</span> <span class="hlt">Atlantic</span> show energetic near-bottom flow dynamics along the European continental margin at individual coral mounds and mound clusters. Dynamics are largely controlled by tide-topography interaction generating and enhancing periodic motions such as trapped waves, freely propagating internal tides and internal hydraulic jumps. In this study, linkages between key abiotic parameters and cold water coral occurrences are explored across entire cold-water coral mound provinces using an integrated modelling and observational approach. The 3-D ocean circulation model ROMS-AGRIF was applied to simulate near-bottom hydrodynamic conditions at three provinces in the <span class="hlt">NE</span> <span class="hlt">Atlantic</span> (Logachev mounds, Arc mounds and Belgica mounds) adopting a nested model setup with a central grid resolution of 250 m. Simulations were carried out with a focus on accurate high-resolution topography and tidal forcing. The central model bathymetry was taken from high-resolution INSS (Irish National Seabed Survey) seafloor mapping data. The model was integrated over a full one-year reference period starting from the 1st January 2010. Interannual variability was not considered. Tidal forcing was obtained from a global solution of the Oregon State University (OSU) inverse tidal model. Modelled fields of benthic currents were validated against available independent in situ observations. Coral assemblage patterns (presence and absence locations) were obtained from benthic surveys of the EU FP7 CoralFISH programme and supplemented by data from additional field surveys. Modelled near-bottom currents, temperature and salinity were analysed for a 1-month subset (15th April to 15th May 2010) corresponding to the main CoralFISH survey period. The model results show intensified near-bottom currents in areas where living corals are observed by contrast with coral absence and random background locations. Instantaneous and time-mean current speeds at</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3741395','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3741395"><span>Population Structure and Dispersal Patterns within and between <span class="hlt">Atlantic</span> and Mediterranean Populations of a Large-Range Pelagic Seabird</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Genovart, Meritxell; Thibault, Jean-Claude; Igual, José Manuel; Bauzà-Ribot, Maria del Mar; Rabouam, Corinne; Bretagnolle, Vincent</p> <p>2013-01-01</p> <p>Dispersal is critically linked to the demographic and evolutionary trajectories of populations, but in most seabird species it may be difficult to estimate. Using molecular tools, we explored population structure and the spatial dispersal pattern of a highly pelagic but philopatric seabird, the Cory's shearwater Calonectris diomedea. Microsatellite fragments were analysed from samples collected across almost the entire breeding range of the species. To help disentangle the taxonomic status of the two subspecies described, the <span class="hlt">Atlantic</span> form C. d. borealis and the Mediterranean form C. d. diomedea, we analysed genetic divergence between subspecies and quantified both historical and recent migration rates between the Mediterranean and <span class="hlt">Atlantic</span> <span class="hlt">basins</span>. We also searched for evidence of isolation by distance (IBD) and addressed spatial patterns of gene flow. We found a low genetic structure in the Mediterranean <span class="hlt">basin</span>. Conversely, strong genetic differentiation appeared in the <span class="hlt">Atlantic</span> <span class="hlt">basin</span>. Even if the species was mostly philopatric (97%), results suggest recent dispersal between <span class="hlt">basins</span>, especially from the <span class="hlt">Atlantic</span> to the Mediterranean (aprox. 10% of migrants/generation across the last two generations). Long-term gene flow analyses also suggested an historical exchange between <span class="hlt">basins</span> (about 70 breeders/generation). Spatial analysis of genetic variation indicates that distance is not the main factor in shaping genetic structure in this species. Given our results we recommend gathering more data before concluded whether these taxa should be treated as two species or subspecies. PMID:23950986</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.V33D3134M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.V33D3134M"><span>Cosmogenic Nuclides 10Be-21<span class="hlt">Ne</span> Burial Dating of Middle Miocene Sedimentary Formation of the Hongliu Valley in Southern Ningxia <span class="hlt">Basin</span>: A Case of Isotopic Geochronology Study for the Cenozoic Sedimentary Strata</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ma, Y.; Zhang, H.; Wang, W.; Wu, Y.; Pang, J.; Zheng, D.; Li, D.</p> <p>2015-12-01</p> <p>Chronology studies for the Cenozoic sedimentary strata based on the magnetostratigraphy cannot afford the unique chronological sequences in the absence of absolute ages from biostratigraphy or volcanic ash chronology. In situ-produced cosmogenic nuclides provide a powerful tool for the sediment dating based on the time-dependent concentration ratio of two nuclides, which are produced in the same mineral but with different half-lives. Thereinto, 10Be-26Al is the most widely used nuclide pairs, of which the available dating range spans the Plio-Pleistocene. But the coupling of 10Be with the stable nuclide 21<span class="hlt">Ne</span> would significantly improve the burial dating range up to the middle Miocene, which is promising in revolutionizing the chronology study for the Late Cenozoic terrestrial sedimentary sequences. We have applied 10Be-21<span class="hlt">Ne</span> pair for dating the middle Miocene sediments of the Hongliu Valley in southern Ningxia <span class="hlt">basin</span>. Two major features of the sediments are involved in our study: (1) sediments originated from the steady erosion of the source area, and (2) the burial depth of our sample after deposition is time dependent due to the gradual accumulation of sediments into <span class="hlt">basin</span>. The post-burial nuclide production is estimated to be less than 3%, including the contribution by muon interactions, of the total nuclide concentrations measured in our sample. Our 10Be-21<span class="hlt">Ne</span> analysis demonstrates the age of the burial sample is 12.4(+0.6/-0.4) Ma, and the erosion rate at the source area is 0.26±0.01 cm ka-1. The sample's burial age is consistent with the age constraint set by the Hongliugou Formation (16.7-5.4 Ma) which we collected the sample in. Vertebrate fossils of Platybelodon tongxinensis with an age between 12 and 15 Ma exhumated along with our sample further verifies the reliability of our dating results for the middle Miocene sediments.This study has shown the improved age range of cosmogenic-nuclide burial dating method by incorporating the stable nuclide 21<span class="hlt">Ne</span>, and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.H41G0925W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.H41G0925W"><span>Noble Gas Signatures in Antrim Shale Gas in the Michigan <span class="hlt">Basin</span> - Assessing Compositional Variability and Transport Processes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wen, T.; Castro, M. C.; Ellis, B. R.; Hall, C. M.; Lohmann, K. C.; Bouvier, L.</p> <p>2014-12-01</p> <p>Recent studies in the Michigan <span class="hlt">Basin</span> looked at the atmospheric and terrigenic noble gas signatures of deep brines to place constraints on the past thermal history of the <span class="hlt">basin</span> and to assess the extent of vertical transport processes within this sedimentary system. In this contribution, we present noble gas data of shale gas samples from the Antrim shale formation in the Michigan <span class="hlt">Basin</span>. The Antrim shale was one of the first economic shale-gas plays in the U.S. and has been actively developed since the 1980's. This study pioneers the use of noble gases in subsurface shale gas in the Michigan <span class="hlt">Basin</span> to clarify the nature of vertical transport processes within the sedimentary sequence and to assess potential variability of noble gas signatures in shales. Antrim Shale gas samples were analyzed for all stable noble gases (He, <span class="hlt">Ne</span>, Ar, Kr, Xe) from samples collected at depths between 300 and 500m. Preliminary results show R/Ra values (where R and Ra are the measured and atmospheric 3He/4He ratios, respectively) varying from 0.022 to 0.21. Although most samples fall within typical crustal R/Ra range values (~0.02-0.05), a few samples point to the presence of a mantle He component with higher R/Ra ratios. Samples with higher R/Ra values also display higher 20<span class="hlt">Ne</span>/22<span class="hlt">Ne</span> ratios, up to 10.4, and further point to the presence of mantle 20<span class="hlt">Ne</span>. The presence of crustally produced nucleogenic 21<span class="hlt">Ne</span> and radiogenic 40Ar is also apparent with 21<span class="hlt">Ne</span>/22<span class="hlt">Ne</span> ratios up to 0.033 and 40Ar/36Ar ratios up to 312. The presence of crustally produced 4He, 21<span class="hlt">Ne</span> and 40Ar is not spatially homogeneous within the Antrim shale. Areas of higher crustal 4He production appear distinct to those of crustally produced 21<span class="hlt">Ne</span> and 40Ar and are possibly related the presence of different production levels within the shale with varying concentrations of parent elements.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19980024228','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19980024228"><span>Origin of Ozone NO(x) in the Tropical Troposphere: A Photochemical Analysis of Aircraft Observations Over the South <span class="hlt">Atlantic</span> <span class="hlt">Basin</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Jacob, D. J.; Heikes, B. G.; Fan, S.-M.; Logan, J. A.; Mauzerall, D. L.; Bradshaw, J. D.; Singh, H. B.; Gregory, G. L.; Talbot, R. W.; Blake, D. R.; <a style="text-decoration: none; " href="javascript:void(0); " onClick="displayelement('author_19980024228'); toggleEditAbsImage('author_19980024228_show'); toggleEditAbsImage('author_19980024228_hide'); "> <img style="display:inline; width:12px; height:12px; " src="images/arrow-up.gif" width="12" height="12" border="0" alt="hide" id="author_19980024228_show"> <img style="width:12px; height:12px; display:none; " src="images/arrow-down.gif" width="12" height="12" border="0" alt="hide" id="author_19980024228_hide"></p> <p>1996-01-01</p> <p>The photochemistry of the troposphere over the South <span class="hlt">Atlantic</span> <span class="hlt">basin</span> is examined by modeling of aircraft observations up to 12-km altitude taken during the TRACE A expedition in September-October 1992. A close balance is found in the 0 to 12-km column between photochemical production and loss Of O3, with net production at high altitudes compensating for weak net loss at low altitudes. This balance implies that O3 concentrations in the 0-12 km column can be explained solely by in situ photochemistry; influx from the stratosphere is negligible. Simulation of H2O2, CH3OOH, and CH2O concentrations measured aboard the aircraft lends confidence in the computations of O3 production and loss rates, although there appears to be a major gap in current understanding of CH2O chemistry in the marine boundary layer. The primary sources of NO(x) over the South <span class="hlt">Atlantic</span> <span class="hlt">Basin</span> appear to be continental (biomass burning, lightning, soils). There is evidence that NO(x) throughout the 0 to 12-km column is recycled from its oxidation products rather than directly transported from its primary sources. There is also evidence for rapid conversion of HNO3 to NO(x) in the upper troposphere by a mechanism not included in current models. A general representation of the O3 budget in the tropical troposphere is proposed that couples the large scale Walker circulation and in situ photochemistry. Deep convection in the rising branches of the Walker circulation injects NO(x) from combustion, soils, and lightning to the upper troposphere, leading to O3 production; eventually, the air subsides and net O3 loss takes place in the lower troposphere, closing the O3 cycle. This scheme implies a great sensitivity of the oxidizing power of the atmosphere to NO(x) emissions in the tropics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22218015-comparison-triple-point-temperatures-sup-ne-sup-ne-normal-ne','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22218015-comparison-triple-point-temperatures-sup-ne-sup-ne-normal-ne"><span>Comparison of the triple-point temperatures of {sup 20}<span class="hlt">Ne</span>, {sup 22}<span class="hlt">Ne</span> and normal <span class="hlt">Ne</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Nakano, T.; Tamura, O.; Nagao, K.</p> <p>2013-09-11</p> <p>At the National Metrology Institute of Japan (NMIJ), the triple points of {sup 20}<span class="hlt">Ne</span> and {sup 22}<span class="hlt">Ne</span> were realized using modular sealed cells, Ec3<span class="hlt">Ne</span>20 and Ec8<span class="hlt">Ne</span>22, made by the Istituto Nazionale di Ricerca Metrologica (INRiM) in Italy. The difference of the triple-point temperatures of {sup 20}<span class="hlt">Ne</span> and {sup 22}<span class="hlt">Ne</span> was estimated by using the sub-range of standard platinum resistance thermometers (SPRTs) calibrated by NMIJ on the International Temperature Scale of 1990 (ITS-90). The melting curves obtained with the Ec3<span class="hlt">Ne</span>20 and Ec8<span class="hlt">Ne</span>22 cells show narrow widths (0.1 mK) over a wide range of the inverse of the melted fraction (1/F) frommore » 1/F=1 to 1/F=10. The liquidus point T{sub tp} estimated by the melting curves from F∼0.5 to F∼0.85 using the Ec8<span class="hlt">Ne</span>22 is 0.146 29 (4) K higher than that using the Ec3<span class="hlt">Ne</span>20 cell, which is in good agreement with that observed by INRiM using the same cells. After correction of the effect of impurities and other isotopes for Ec3<span class="hlt">Ne</span>20 and Ec8<span class="hlt">Ne</span>22 cells, the difference of T{sub tp} between pure {sup 20}<span class="hlt">Ne</span> and pure {sup 22}<span class="hlt">Ne</span> is estimated to be 0.146 61 (4) K, which is consistent with the recent results reported elsewhere. The sub-ranges of SPRTs computed by using the triple point of {sup 20}<span class="hlt">Ne</span> or {sup 22}<span class="hlt">Ne</span> realized by the Ec3<span class="hlt">Ne</span>20 cell or the Ec8<span class="hlt">Ne</span>22 cell in place of the triple point of <span class="hlt">Ne</span> for the defining fixed point of the ITS-90 are in good agreement with those realized on the basis of the ITS-90 at NMIJ within 0.03 mK, which is much smaller than the non-uniqueness and the sub-range inconsistency of SPRTs.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20150019489','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20150019489"><span>Mid-Pliocene <span class="hlt">Atlantic</span> Meridional Overturning Circulation Not Unlike Modern</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Zhang, Z.-S.; Nisancioglu, K. H.; Chandler, M. A.; Haywood, A. M.; Otto-Bliesner, B. L.; Ramstein, G.; Stepanek, C.; Abe-Ouchi, A.; Chan, W. -L.; Sohl, L. E.</p> <p>2013-01-01</p> <p>In the Pliocene Model Intercomparison Project (PlioMIP), eight state-of-the-art coupled climate models have simulated the mid-Pliocene warm period (mPWP, 3.264 to 3.025 Ma). Here, we compare the <span class="hlt">Atlantic</span> Meridional Overturning Circulation (AMOC), northward ocean heat transport and ocean stratification simulated with these models. None of the models participating in PlioMIP simulates a strong mid-Pliocene AMOC as suggested by earlier proxy studies. Rather, there is no consistent increase in AMOC maximum among the PlioMIP models. The only consistent change in AMOC is a shoaling of the overturning cell in the <span class="hlt">Atlantic</span>, and a reduced influence of North <span class="hlt">Atlantic</span> Deep Water (NADW) at depth in the <span class="hlt">basin</span>. Furthermore, the simulated mid-Pliocene <span class="hlt">Atlantic</span> northward heat transport is similar to the pre-industrial. These simulations demonstrate that the reconstructed high-latitude mid-Pliocene warming can not be explained as a direct response to an intensification of AMOC and concomitant increase in northward ocean heat transport by the <span class="hlt">Atlantic</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EGUGA..1411400S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EGUGA..1411400S"><span>Rifting by continental rotation, mantle flow and hotspot volcanism in the salt-depositing South <span class="hlt">Atlantic</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Szatmari, P.</p> <p>2012-04-01</p> <p>Rabinowitz & LaBrecque (1979) proposed that Africa and South America separated between 130 Ma and 107 Ma by 11.1° rigid plate rotation about an Euler pole in <span class="hlt">NE</span> Brazil. According to those authors, the two continents remained contiguous in the north as the wedge-shaped South <span class="hlt">Atlantic</span> opened up between them and deposited salt mostly over oceanic crust. Subsequent seismic profiling and drilling showed that salt, restricted to north of the volcanic proto-Walvis Ridge, deposited over rift sediments and stretched-thinned continental crust. Increasingly accurate restorations by Nürnberg & Müller (1991), Aslanian et al. (2009), Torsvik et al. (2009), and Moulin et al. (2010) differentiated in both continents several rigid plates separated by active deformation zones. Still, tectonic analysis of the rifted margins indicates that the main Early Cretaceous event was the clockwise rotation of South America about an Euler pole in its northeast. Both rifting and volcanism, including the Paraná-Etendeka large igneous province, where most flood basalts erupted at 134.6 ± 0.6 Ma (Thiede & Vasconcelos, 2010), were controlled by distance and orientation of rift segments relative to that pole in <span class="hlt">NE</span> Brazil. Rifting was active from latest Jurassic to early Albian time (Magnavita et al., 2011) over inherited late Proterozoic fold-thrust belts. By Aptian time a long, dry wedge-shaped <span class="hlt">basin</span> formed north of the volcanic barrier of the proto-Walvis Ridge, widening southward to 700 km and subsiding deep below sea level in the Santos <span class="hlt">Basin</span>. The <span class="hlt">basin</span> was filled with oil-rich lacustrine limestone and marine salt, each more than 2 km thick, deposited in often desiccating shallow water over the partially hyperextended continental crust of the São Paulo Plateau (Zalán et al., 2010; Magnavita et al., 2011; Szatmari, 2011). Further south marine sediments deposited over oceanic crust. Surface subsidence of the long, deep sediment-starved rift wedge was shaped, prior to the deposition of the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1813350B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1813350B"><span>Towards quantifying long-term erosion rates in the Campine <span class="hlt">Basin</span>, <span class="hlt">NE</span> Belgium</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Beerten, Koen; Vanacker, Veerle</p> <p>2016-04-01</p> <p>The Campine <span class="hlt">Basin</span>, <span class="hlt">NE</span> Belgium, is situated between the uplifting Ardennes Massif and rapidly subsiding Roer Valley Graben. It contains a thick series of marine, estuarine and continental Neogene and Quaternary sediments, locally more than 300 m. As a result of relief inversion during the Quaternary, the Campine Plateau is nowadays a distinct morphological feature in this <span class="hlt">basin</span>. Its surface elevation dips from 100 m in the south to 30 m in the north over a distance of about 60 km, which is the result of differential uplift. The Campine Plateau is covered by Early and Middle Pleistocene erosion-resistant fluvial sediments from the Rhine and Meuse and can thus be regarded as a fluvial terrace. The age of deposition and time of abandonment of the terrace have not yet been resolved by direct numerical dating. In this study, we apply the cosmogenic radionuclide (CRN) profiling technique that, in ideal circumstances, allows one to constrain the exposure age, burial age and amount of post-depositional erosion of the landform. Samples were taken from a 3.5 m deep cross-section in coarse river sands that were deposited by the river Rhine, and now situated at an altitude of about 50 m (a.s.l.). Nine of them were prepared for CRN measurements according to state-of-the-art techniques. The in-situ 10Be concentration of the samples was determined using accelerator mass spectrometry (ETH, Zurich). The in-situ 10Be concentrations are 1.5x10e5 atoms/g for the uppermost sample (at 0.3 m depth) and 0.9x10e5 at/g for the lowermost sample (at 3.1 m depth), yielding an estimated 0.6x10e5 at/g of radionuclide accumulation following sediment deposition. Using forward modelling, we solved for the exposure duration and erosion rate that best fit the measured in-situ 10Be depth profile data, nuclide inheritance and their associated analytical uncertainties. Model optimisation is here based on the sum of chi-squared between the measured and modelled 10Be concentrations. When taking previous</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3896027','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3896027"><span>Historical DNA reveals the demographic history of <span class="hlt">Atlantic</span> cod (Gadus morhua) in medieval and early modern Iceland</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Ólafsdóttir, Guðbjörg Ásta; Westfall, Kristen M.; Edvardsson, Ragnar; Pálsson, Snæbjörn</p> <p>2014-01-01</p> <p><span class="hlt">Atlantic</span> cod (Gadus morhua) vertebrae from archaeological sites were used to study the history of the Icelandic <span class="hlt">Atlantic</span> cod population in the time period of 1500–1990. Specifically, we used coalescence modelling to estimate population size and fluctuations from the sequence diversity at the cytochrome b (cytb) and Pantophysin I (PanI) loci. The models are consistent with an expanding population during the warm medieval period, large historical effective population size (<span class="hlt">NE</span>), a marked bottleneck event at 1400–1500 and a decrease in <span class="hlt">NE</span> in early modern times. The model results are corroborated by the reduction of haplotype and nucleotide variation over time and pairwise population distance as a significant portion of nucleotide variation partitioned across the 1550 time mark. The mean age of the historical fished stock is high in medieval times with a truncation in age in early modern times. The population size crash coincides with a period of known cooling in the North <span class="hlt">Atlantic</span>, and we conclude that the collapse may be related to climate or climate-induced ecosystem change. PMID:24403343</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24403343','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24403343"><span>Historical DNA reveals the demographic history of <span class="hlt">Atlantic</span> cod (Gadus morhua) in medieval and early modern Iceland.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ólafsdóttir, Guðbjörg Ásta; Westfall, Kristen M; Edvardsson, Ragnar; Pálsson, Snæbjörn</p> <p>2014-02-22</p> <p><span class="hlt">Atlantic</span> cod (Gadus morhua) vertebrae from archaeological sites were used to study the history of the Icelandic <span class="hlt">Atlantic</span> cod population in the time period of 1500-1990. Specifically, we used coalescence modelling to estimate population size and fluctuations from the sequence diversity at the cytochrome b (cytb) and Pantophysin I (PanI) loci. The models are consistent with an expanding population during the warm medieval period, large historical effective population size (<span class="hlt">NE</span>), a marked bottleneck event at 1400-1500 and a decrease in <span class="hlt">NE</span> in early modern times. The model results are corroborated by the reduction of haplotype and nucleotide variation over time and pairwise population distance as a significant portion of nucleotide variation partitioned across the 1550 time mark. The mean age of the historical fished stock is high in medieval times with a truncation in age in early modern times. The population size crash coincides with a period of known cooling in the North <span class="hlt">Atlantic</span>, and we conclude that the collapse may be related to climate or climate-induced ecosystem change.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFMOS22C..05N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFMOS22C..05N"><span>Pb isotope signatures in the North <span class="hlt">Atlantic</span>: initial results from the U.S. GEOTRACES North <span class="hlt">Atlantic</span> Transect</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Noble, A.; Echegoyen-Sanz, Y.; Boyle, E. A.</p> <p>2012-12-01</p> <p>This study presents Pb isotope data from the US GEOTRACES North <span class="hlt">Atlantic</span> Transect (US-GT-NAT) sampled during two cruises that took place during Fall 2010 and 2011. Almost all of the Pb in the modern ocean is derived from anthropogenic sources, and the North <span class="hlt">Atlantic</span> has received major Pb inputs from the United States and Europe due to emissions from leaded gasoline and high temperature industrial processes. During the past three decades, Pb fluxes to the North <span class="hlt">Atlantic</span> have decreased following the phasing out of leaded gasoline in the United States and Europe. Following the concentrations and isotope ratios of Pb in this <span class="hlt">basin</span> over time reveals the temporal evolution of Pb in this highly-affected <span class="hlt">basin</span>. The Pb isotope signatures reflect the relative importance of changing inputs from the United States and Europe as leaded gasoline was phased out faster in the United States relative to Europe. In the western North <span class="hlt">Atlantic</span>, a shallow (~100-200m) low Pb-206/Pb-207 ratio feature was observed near the Subtropical Underwater salinity peak at many stations across the transect, coincident with shallow subsurface maxima in Pb concentration. This water mass originates from high-salinity surface water near 25°N (Defant), which is in the belt of European-Pb-gas-contaminated African aerosols, which we confirmed by Pb-206/Pb-207 ~ 1.17 from upper ocean samples from US-GT-NAT station 18 (23.24degN,38.04degW). At the Mid-<span class="hlt">Atlantic</span> Ridge station, Pb scavenging onto iron oxides and sulfide was observed by a decrease in Pb concentrations within the TAG hydrothermal plume, although the isotopic signature within the plume was slightly (~3 permil) lower than the surrounding waters possibly indicating a small contribution of hydrothermal Pb or preferential uptake of the lighter isotope. In the Mediteranean Outflow plume near Lisbon, Pb-206/Pb-207 (~1.178) is also strongly influenced by European Pb. Further results from the section will be presented as more data will be available by the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017Tectp.712..289S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017Tectp.712..289S"><span>A reassessment of the Archean-Mesoproterozoic tectonic development of the southeastern Chhattisgarh <span class="hlt">Basin</span>, Central India through detailed aeromagnetic analysis</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sridhar, M.; Ramesh Babu, V.; Markandeyulu, A.; Raju, B. V. S. N.; Chaturvedi, A. K.; Roy, M. K.</p> <p>2017-08-01</p> <p>We constrained the geological framework over polydeformed Paleoproterozoic Sonakhan Greenstone Belt and addressed the tectonic evolution of Singhora <span class="hlt">basin</span> in the fringes of Bastar Craton, central India by utilizing aeromagnetic data interpretation, 2.5D forward modelling and 3D magnetic susceptibility inversions. The Sonakhan Greenstone Belt exposes volcano-sedimentary sequences of the Sonakhan Group within NNW-SSE to NW-SE trending linear belts surrounded by granite gneisses, which are unconformably overlain by sedimentary rocks of Chhattisgarh <span class="hlt">Basin</span>. The orientations of aeromagnetic anomalies are coincident with geological trends and appear to correlate with lithology and geologic structure. Regional magnetic anomalies and lineaments reveal both NNW-SSE and <span class="hlt">NE</span>-SW trends. Prominent E-W trending linear, high amplitude magnetic anomalies are interpreted as the Trans-Chhattisgarh Aeromagnetic Lineament (TCAL). NW-SE trending aeromagnetic signatures related to Sonakhan Greenstone Belt extends below the Singhora sedimentary rocks and forms the basement in the west. The analysis suggests that TCAL is a block fault with northern block down-thrown and affected the basement rocks comprising the Sonakhan Greenstone Belt and Samblapur Granitoids. The episode of faulting represented by the TCAL is pre-Singhora sedimentation and played a vital role in <span class="hlt">basin</span> evolution. The basement configuration image generated by estimates of depth to magnetic basement suggests a complex pattern of NNE-SSW to <span class="hlt">NE</span>-SW trending depressions separated by a linear N-S trending basement ridge. It is inferred from the 3D magnetic susceptibility inversion that the thickness of sediments is more towards the eastern <span class="hlt">basin</span> margin and the N-S ridge is a manifestation of post sedimentary faulting. Results of 2.5D modelling of a WNW-ESE profile across the Singhora <span class="hlt">Basin</span> combined with results from 3D inversion suggest suggests the <span class="hlt">basin</span> subsidence was controlled by <span class="hlt">NE</span>-SW trending regional faults in an active</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007PhDT.......212B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007PhDT.......212B"><span>Characteristics of tropical cyclones in the North <span class="hlt">Atlantic</span> and East Pacific</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Barrett, Bradford Scott</p> <p></p> <p>In this dissertation, I present a series of investigations to expand our understanding of TCs in the East Pacific and North <span class="hlt">Atlantic</span> <span class="hlt">basins</span>. First, I developed and applied a climatological tool that quickly and succinctly displays the spread of historical TC tracks for any point in the North <span class="hlt">Atlantic</span> <span class="hlt">basin</span>. This tool is useful in all parts of a <span class="hlt">basin</span> because it is derived from prior storm motion trajectories and summarily captures the historical synoptic and mesoscale steering patterns. It displays the strength of the climatological signal and allow for rapid qualitative comparison between historical TC tracks and NWP models. Second, I have used a robust statistical technique to quantify the relationships between fifteen different metrics of TC activity in nine ocean <span class="hlt">basins</span> and twelve climate indices of the leading modes of atmospheric and oceanic variability. In a thorough, encyclopedic manner, over 12,000 Spearman rank correlation coefficients were calculated and examined to identify relationships between TCs and their environment. This investigation was not limited to the East Pacific or North <span class="hlt">Atlantic</span>, and new climatic associations were found between seasonal levels of TC activity and the major climate indices across the nine <span class="hlt">basins</span>. This information is critical to forecasters, economists, actuaries, energy traders, and societal planners who apply knowledge of levels of TC activity on intraseasonal to interdecadal timescales. The statistics are also valuable to climatologists seeking to understand how regional TC frequency will change as the global climate warms. Third, I have examined the leading intraseasonal mode of atmospheric and oceanic variability, the Madden-Julian Oscillation (MJO), and discovered statistically significant relationships with the frequency of TC genesis, intensification, and landfall over the nine <span class="hlt">basins</span>. Like the significance of the longer-period oscillations to the frequency of TC activity on intraseasonal and longer timescales, these</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018DSRII.148...54G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018DSRII.148...54G"><span>Biodiversity and distribution of polynoid and spionid polychaetes (Annelida) in the Vema Fracture Zone, tropical North <span class="hlt">Atlantic</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Guggolz, Theresa; Lins, Lidia; Meißner, Karin; Brandt, Angelika</p> <p>2018-02-01</p> <p>During the Vema-TRANSIT (Bathymetry of the Vema-Fracture Zone and Puerto Rico TRench and Abyssal <span class="hlt">AtlaNtic</span> BiodiverSITy Study) expedition from December, 2014 to January, 2015, a transect along the Vema Fracture Zone in the equatorial <span class="hlt">Atlantic</span> was surveyed and sampled at about 10°N. The Vema Fracture Zone is one of the largest fracture zones of the Mid-<span class="hlt">Atlantic</span> Ridge and it is characterized by a large left-lateral offset. Benthic communities of the transect and the abyssal <span class="hlt">basins</span> on both sides were investigated to examine whether the Mid-<span class="hlt">Atlantic</span> Ridge serves as a physical barrier for these organisms, or if there is a potential connection from east to west via the Vema Fracture Zone. Samples comprised 4149 polychaetes, belonging to 42 families. Exemplary, Polynoidae and Spionidae, both typical deep-sea families with high abundances in all investigated regions, were identified up to species level. The present results show significant differences in polychaete faunistic composition between both sides of the Mid-<span class="hlt">Atlantic</span> Ridge. Moreover, the eastern and western Vema Fracture Zone characterizes divergent habitats, since the two <span class="hlt">basins</span> differ in sedimentology and environmental variables (e.g. temperature, salinity), hence characterizing divergent habitats. Most species found were restricted to either eastern or western VFZ, but there was a trans-Mid-<span class="hlt">Atlantic</span> Ridge distribution of certain abundant species observed, indicating that the Mid-<span class="hlt">Atlantic</span> Ridge might rather act limiting to dispersal between ocean <span class="hlt">basins</span> than as an absolute barrier. Given the abyssal valley formed by the Vema Fracture Zone and its role in oceanic currents, this seafloor feature may well represent exchange routes between eastern and western faunas.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JAESc.158..186X','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JAESc.158..186X"><span>Subsidence transition during the post-rift stage of the Dongpu Sag, Bohai Bay <span class="hlt">Basin</span>, <span class="hlt">NE</span> China: A new geodynamic model</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Xu, Han; Wang, Xin-Wen; Yan, Dan-Ping; Qiu, Liang</p> <p>2018-06-01</p> <p>The Dongpu Sag, located in the Bohai Bay <span class="hlt">Basin</span>, <span class="hlt">NE</span> China, is a Cenozoic continental rift <span class="hlt">basin</span>. The post-rift evolution of the Dongpu Sag is associated with the development of petroleum reservoirs and has implications for Neogene-Quaternary <span class="hlt">basin</span> evolution along the eastern margin of Eurasia. To determine the nature and origin of post-rift subsidence in the Dongpu Sag, we apply backstripping, modified strain-rate inversion, and revised finite extension modelling techniques, using data from 14 real and synthetic wells that are intersected by three seismic lines. Our results reveal discrepancies by subsidence based on backstripping of well data (the observed subsidence) minus that predicted by modified strain-rate inversion and revised finite extension modelling (the predicted subsidence). During the Miocene, the observed subsidence was smaller than the predicted subsidence, leaving negative discrepancies referred to here as "insufficient subsidence" ranging from -343 to -96 m. In contrast, during the Pliocene-Quaternary the observed subsidence was greater than the predicted subsidence by +123 to +407 m, which left positive discrepancies referred to as "over-sufficient subsidence". Therefore, we infer a transition from insufficient to over-sufficient subsidence during the post-rift stage. Normal faulting that started at ca. 5.3 Ma is estimated to have produced only ∼20% of the over-sufficient subsidence. Therefore, the remaining over-sufficient subsidence, as well as the preceding insufficient subsidence and the transition between the two, were likely controlled by lithosphere processes. We propose a new tectonic model in which variations in the conditions (e.g. rate, direction, and angle) associated with subduction of the Pacific plate resulted in a change of heat flow decreasing from a linear to a curvilinear pattern, leading to a transition from insufficient to over-sufficient subsidence.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active"><span>10</span></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_10 --> <div id="page_11" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="201"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014PrOce.129..244M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014PrOce.129..244M"><span>The North <span class="hlt">Atlantic</span> Ocean as habitat for Calanus finmarchicus: Environmental factors and life history traits</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Melle, Webjørn; Runge, Jeffrey; Head, Erica; Plourde, Stéphane; Castellani, Claudia; Licandro, Priscilla; Pierson, James; Jonasdottir, Sigrun; Johnson, Catherine; Broms, Cecilie; Debes, Høgni; Falkenhaug, Tone; Gaard, Eilif; Gislason, Astthor; Heath, Michael; Niehoff, Barbara; Nielsen, Torkel Gissel; Pepin, Pierre; Stenevik, Erling Kaare; Chust, Guillem</p> <p>2014-12-01</p> <p>Here we present a new, pan-<span class="hlt">Atlantic</span> compilation and analysis of data on Calanus finmarchicus abundance, demography, dormancy, egg production and mortality in relation to <span class="hlt">basin</span>-scale patterns of temperature, phytoplankton biomass, circulation and other environmental characteristics in the context of understanding factors determining the distribution and abundance of C. finmarchicus across its North <span class="hlt">Atlantic</span> habitat. A number of themes emerge: (1) the south-to-north transport of plankton in the northeast <span class="hlt">Atlantic</span> contrasts with north-to-south transport in the western North <span class="hlt">Atlantic</span>, which has implications for understanding population responses of C. finmarchicus to climate forcing, (2) recruitment to the youngest copepodite stages occurs during or just after the phytoplankton bloom in the east whereas it occurs after the bloom at many western sites, with up to 3.5 months difference in recruitment timing, (3) the deep <span class="hlt">basin</span> and gyre of the southern Norwegian Sea is the centre of production and overwintering of C. finmarchicus, upon which the surrounding waters depend, whereas, in the Labrador/Irminger Seas production mainly occurs along the margins, such that the deep <span class="hlt">basins</span> serve as collection areas and refugia for the overwintering populations, rather than as centres of production, (4) the western North <span class="hlt">Atlantic</span> marginal seas have an important role in sustaining high C. finmarchicus abundance on the nearby coastal shelves, (5) differences in mean temperature and chlorophyll concentration between the western and eastern North <span class="hlt">Atlantic</span> are reflected in regional differences in female body size and egg production, (6) regional differences in functional responses of egg production rate may reflect genetic differences between western and eastern populations, (7) dormancy duration is generally shorter in the deep waters adjacent to the lower latitude western North <span class="hlt">Atlantic</span> shelves than in the east, (8) there are differences in stage-specific daily mortality rates between</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JSAES..82...62V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JSAES..82...62V"><span>Oldest record of Mathildellidae (Crustacea: Decapoda: Goneplacoidea) associated with Retroplumidae from the Upper Cretaceous of <span class="hlt">NE</span> Mexico</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vega, Francisco J.; Ahyong, Shane T.; Espinosa, Belinda; Flores-Ventura, José; Luna, Laura; González-González, Arturo H.</p> <p>2018-03-01</p> <p>A new genus and species of the Mathildellidae Prebranchioplax cretacica (Crustacea: Decapoda: Goneplacoidea) is reported from shallow marine sediments of the upper Campanian Parras Shale and Cerro del Pueblo Formation (Parras <span class="hlt">Basin</span>), Coahuila, <span class="hlt">NE</span> Mexico. Prebranchioplax cretacica was collected from siliceous concretions associated with more abundant specimens of the retroplumid Costacopluma mexicana Vega and Perrilliat, 1989. P. cretacica bears similarities to Eocene species of Branchioplax from Japan, USA (Alaska and Washington), England, Hungary and Tajikistan as well as with Eogeryonidae (Portunoidea) species from the Upper Cretaceous of Spain and Marocarcinidae (Styracocarcinus) from Morocco. However, clear differences in the carapace frontal shape places P. cretacica in the Mathildellidae. This record represents the oldest known Mathildellidae, and along with the Retroplumidae, appear to have originated during the Late Cretaceous in ancient seas of Mexico, with a wide distribution during Paleogene times becoming restricted today to deep waters of the Indo-Pacific region and <span class="hlt">Atlantic</span> Ocean. Comments on preservation and morphology of Costacopluma mexicana are also included. Crab specimens preserved in siliceous concretions from one locality (Entronque) show peculiar desiccation marks, and a possible model of taphonomy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JMS...143...73C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JMS...143...73C"><span>Cetacean occurrence and spatial distribution: Habitat modelling for offshore waters in the Portuguese EEZ (<span class="hlt">NE</span> <span class="hlt">Atlantic</span>)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Correia, Ana M.; Tepsich, Paola; Rosso, Massimiliano; Caldeira, Rui; Sousa-Pinto, Isabel</p> <p>2015-03-01</p> <p>In the Portuguese Economic Exclusive Zone (EEZ) (<span class="hlt">NE</span> <span class="hlt">Atlantic</span>), little survey effort dedicated to cetacean species has been carried out in offshore waters. As a consequence, data on their occurrence, distribution and habitat preferences is scarce. In this area, 48 sea surveys along fixed transects within Continental Portugal and Madeira Island were performed in 2012 and 2013, from July to October, using platforms of opportunity. We used an environmental envelope approach and GAM habitat models to identify the role of oceanographic, topographic and geographical variables in shaping cetacean distribution. Results demonstrate the richness of offshore waters in this area as in 10,668 nmi sampled, we recorded 218 sightings from at least nine cetacean species, resulting in an overall ER of 2.04 sightings/100 nmi. The interaction of topographic and oceanographic features was shown to influence the distribution of the species/groups along the routes. Among the sighted species, only common dolphin showed a preference for coastal waters, while for all the other species high seas proved to be determinant. This result reinforces the need to address conservation issues in open ocean. This preliminary assessment showed the importance of the entire area for the distribution of different cetacean species and allowed the identification of several species/group specific potential suitable habitats. Considering the Habitats Directive resolutions, ACCOBAMS priorities, EEZ extension for the area and Maritime Spatial Planning Directive, and the urgent need for management plans, we suggest that the sampling strategy here presented is a cost-effective method to gather valuable data, to be used to improve cetacean habitat models in the area.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.A51L..03T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.A51L..03T"><span>Forced and Internal Multi-Decadal Variability in the North <span class="hlt">Atlantic</span> and their Climate Impacts</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ting, M.</p> <p>2017-12-01</p> <p><span class="hlt">Atlantic</span> Multidecadal Variability (AMV), a <span class="hlt">basin</span>-wide North <span class="hlt">Atlantic</span> sea surface temperature warming or cooling pattern varying on decadal and longer time scales, is one of the most important climate variations in the <span class="hlt">Atlantic</span> <span class="hlt">basin</span>. The AMV has shown to be associated with significant climate impacts regionally and globally, from <span class="hlt">Atlantic</span> hurricane activities, frequency and severity of droughts across North America, as well as rainfall anomalies across the African Sahel and northeast Brazil. Despite the important impacts of the AMV, its mechanisms are not completely understood. In particular, it is not clear how much of the historical <span class="hlt">Atlantic</span> SST fluctuations were forced by anthropogenic sources such as greenhouse warming and aerosol cooling, versus driven internally by changes in the coupled ocean-atmosphere processes in the <span class="hlt">Atlantic</span>. Using climate models such as the NCAR large ensemble simulations, we were able to successfully separate the forced and internally generated North <span class="hlt">Atlantic</span> sea surface temperature anomalies through a signal-to-noise maximizing Empirical Orthogonal Function (S/N EOF) analysis method. Two forced modes were identified with one representing a hemispherical symmetric mode and one asymmetric mode. The symmetric mode largely represents the greenhouse forced component while the asymmetric mode resembles the anthropogenic aerosol forcing. When statistically removing both of the forced modes, the residual multidecadal <span class="hlt">Atlantic</span> SST variability shows a very similar structure as the AMV in the preindustrial simulation. The distinct climate impacts of each of these modes are also identified and the implications and challenges for decadal climate prediction will be discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20100019157','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20100019157"><span>An Estimate of the North <span class="hlt">Atlantic</span> <span class="hlt">Basin</span> Tropical Cyclone Activity for the 2010 Hurricane Season</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wilson, Robert M.</p> <p>2010-01-01</p> <p>Estimates are presented for the tropical cyclone activity expected for the 2010 North <span class="hlt">Atlantic</span> <span class="hlt">basin</span> hurricane season. It is anticipated that the 2010 season will be more active than the 2009 season, reflecting increased frequencies more akin to that of the current more active phase that has been in vogue since 1995. Averages (+/- 1 sd) during the current more active phase are 14.5+/-4.7, 7.8+/-3.2, 3.7+/-1.8, and 2+/- 2, respectively, for the number of tropical cyclones (NTC), the number of hurricanes (NH), the number of major hurricanes (NMH), and the number of United States (U.S.) land-falling hurricanes (NUSLFH). Based on the "usual" behavior of the 10-yma parametric first differences, one expects NTC = 19+/-2, NH = 14+/-2, NMH = 7+/-2, and NUSLFH = 4+/-2 for the 2010 hurricane season; however, based on the "best guess" 10-yma values of surface-air temperature at the Armagh Observatory (Northern Ireland) and the Oceanic Nino Index, one expects NTC > or equals 16, NH > or equals 14, NMH > or equals 7, and NUSLFH > or equals 6.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70010929','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70010929"><span>Suspended particulate loads and transports in the nepheloid layer of the abyssal <span class="hlt">Atlantic</span> Ocean</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Biscaye, P.E.; Eittreim, S.L.</p> <p>1977-01-01</p> <p>Vertical profiles of light scattering from over 1000 L-DGO nephelometer stations in the <span class="hlt">Atlantic</span> Ocean have been used to calculate mass concentrations of suspended particles based on a calibration from the western North American <span class="hlt">Basin</span>. From these data are plotted the distributions of particulate concentrations at clear water and in the more turbid near-bottom water. Clear water is the broad minimum in concentration and light scattering that occurs at varying mid-depths in the water column. Concentrations at clear water are as much as one-to-two orders of magnitude lower than those in surface water but still reflect a similar geographic distribution: relatively higher concentrations at ocean margins, especially underneath upwelling areas, and the lowest concentrations underneath central gyre areas. These distributions within the clear water reflect surface-water biogenic productivity, lateral injection of particles from shelf areas and surface circulation patterns and require that the combination of downward vertical and horizontal transport processes of particles retain this pattern throughout the upper water column. Below clear water, the distribution of standing crops of suspended particulate concentrations in the lower water column are presented. The integration of mass of all particles per unit area (gross particulate standing crop) reflects a relative distribution similar to that at the surface and at clear water levels, superimposed on which is the strong imprint of boundary currents along the western margins of the <span class="hlt">Atlantic</span>. Reducing the gross particulate standing crop by the integral of the concentration of clear water yields a net particulate standing crop. The distribution of this reflects primarily the interaction of circulating abyssal waters with the ocean bottom, i.e. a strong nepheloid layer which is coincident with western boundary currents and which diminishes in intensity equatorward. The resuspended particulate loads in the nepheloid layer of the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.H21B1027P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.H21B1027P"><span>Spatial Scaling of Floods in <span class="hlt">Atlantic</span> Coastal Watersheds</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Plank, C.</p> <p>2013-12-01</p> <p>Climate and land use changes are altering global, regional and local hydrologic cycles. As a result, past events may not accurately represent the events that will occur in the future. Methods for hydrologic prediction, both statistical and deterministic, require adequate data for calibration. Streamflow gauges tend to be located on large rivers. As a result, statistical flood frequency analysis, which relies on gauge data, is biased towards large watersheds. Conversely, the complexity of parameterizing watershed processes in deterministic hydrological models limits these to small watersheds. Spatial scaling relationships between drainage <span class="hlt">basin</span> area and discharge can be used to bridge these two methodologies and provide new approaches to hydrologic prediction. The relationship of discharge (Q) to drainage <span class="hlt">basin</span> area (A) can be expressed as a power function: Q = αAθ. This study compares scaling exponents (θ) and coefficients (α) for floods of varying magnitude across a selection of major <span class="hlt">Atlantic</span> Coast watersheds. Comparisons are made by normalizing flood discharges to a reference area bankfull discharge for each watershed. These watersheds capture the geologic and geomorphic transitions along the <span class="hlt">Atlantic</span> Coast from narrow bedrock-dominated river valleys to wide coastal plain watersheds. Additionally, there is a range of hydrometeorological events that cause major floods in these <span class="hlt">basins</span> including tropical storms, thunderstorm systems and winter-spring storms. The mix of flood-producing events changes along a gradient as well, with tropical storms and hurricanes increasing in dominance from north to south as a significant cause of major floods. Scaling exponents and coefficients were determined for both flood quantile estimates (e.g. 1.5-, 10-, 100-year floods) and selected hydrometeorological events (e.g. hurricanes, summer thunderstorms, winter-spring storms). Initial results indicate that southern coastal plain watersheds have lower scaling exponents (θ) than</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015ClDy...44..229R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015ClDy...44..229R"><span>Combined influences of seasonal East <span class="hlt">Atlantic</span> Pattern and North <span class="hlt">Atlantic</span> Oscillation to excite <span class="hlt">Atlantic</span> multidecadal variability in a climate model</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ruprich-Robert, Yohan; Cassou, Christophe</p> <p>2015-01-01</p> <p>The physical processes underlying the internal component of the <span class="hlt">Atlantic</span> Multidecadal Variability (AMV) are investigated from a 1,000-yr pre-industrial control simulation of the CNRM-CM5 model. The low-frequency fluctuations of the <span class="hlt">Atlantic</span> Meridional Overturning Circulation (AMOC) are shown to be the main precursor for the model AMV. The full life cycle of AMOC/AMV events relies on a complex time-evolving relationship with both North <span class="hlt">Atlantic</span> Oscillation (NAO) and East <span class="hlt">Atlantic</span> Pattern (EAP) that must be considered from a seasonal perspective in order to isolate their action; the ocean is responsible for setting the multidecadal timescale of the fluctuations. AMOC rise leading to a warm phase of AMV is statistically preceded by wintertime NAO+ and EAP+ from ~Lag -40/-20 yrs. Associated wind stress anomalies induce an acceleration of the subpolar gyre (SPG) and enhanced northward transport of warm and saline subtropical water. Concurrent positive salinity anomalies occur in the Greenland-Iceland-Norwegian Seas in link to local sea-ice decline; those are advected by the Eastern Greenland Current to the Labrador Sea participating to the progressive densification of the SPG and the intensification of ocean deep convection leading to AMOC strengthening. From ~Lag -10 yrs prior an AMOC maximum, opposite relationship is found with the NAO for both summer and winter seasons. Despite negative lags, NAO- at that time is consistent with the atmospheric response through teleconnection to the northward shift/intensification of the Inter Tropical Convergence Zone in link to the ongoing warming of tropical north <span class="hlt">Atlantic</span> <span class="hlt">basin</span> due to AMOC rise/AMV build-up. NAO- acts as a positive feedback for the full development of the model AMV through surface fluxes but, at the same time, prepares its termination through negative retroaction on AMOC. Relationship between EAP+ and AMOC is also present in summer from ~Lags -30/+10 yrs while winter EAP- is favored around the AMV peak. Based on</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..1611667P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..1611667P"><span>Role of tropical Indian and <span class="hlt">Atlantic</span> Oceans variability on ENSO</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Prodhomme, Chloé; Terray, Pascal; Masson, Sebastien; Boschat, Ghyslaine</p> <p>2014-05-01</p> <p>There are strong evidences of an interaction between tropical Indian, <span class="hlt">Atlantic</span> and Pacific Oceans. Nevertheless, these interactions remain deeply controversial. While some authors claim the tropical Indian and <span class="hlt">Atlantic</span> oceans only play a passive role with respect to ENSO, others suggest a driving role for these two <span class="hlt">basins</span> on ENSO. The mecanisms underlying these relations are not fully understood and, in the Indian Ocean, the possible role of both modes of tropical variability (the Indian Ocean Dipole (IOD) and the Indian Ocean <span class="hlt">Basin</span> mode (IOB)) remain unclear. To better quantify and understand how the variability of the tropical Indian and <span class="hlt">Atlantic</span> Oceans impact ENSO variability, we performed two sensitivity experiments using the SINTEX-F2 coupled model. For each experiment, we suppressed the variability of SST and the air-sea coupling in either the tropical Indian Ocean or tropical <span class="hlt">Atlantic</span> Ocean by applying a strong nudging of the SST to the observed SST climatology. In both experiments, the ENSO periodicity increases. In the <span class="hlt">Atlantic</span> experiment, our understanding of this increased periodicity is drastically limited by the strongly biased mean state in this region. Conversely, in the Indian Ocean experiment, the increase of ENSO periodicity is related to the absence of the IOB following the El Niño peak, which leads to a decrease of westerly winds in the western Pacific during late winter and spring after the peak. These weaker westerlies hinders the transition to a La Niña phase and thus increase the duration and periodicity of the event.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3125230','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3125230"><span>Polymorphism, selection and tandem duplication of transferrin genes in <span class="hlt">Atlantic</span> cod (Gadus morhua) - Conserved synteny between fish monolobal and tetrapod bilobal transferrin loci</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p></p> <p>2011-01-01</p> <p>Background The two homologous iron-binding lobes of transferrins are thought to have evolved by gene duplication of an ancestral monolobal form, but any conserved synteny between bilobal and monolobal transferrin loci remains unexplored. The important role played by transferrin in the resistance to invading pathogens makes this polymorphic gene a highly valuable candidate for studying adaptive divergence among local populations. Results The <span class="hlt">Atlantic</span> cod genome was shown to harbour two tandem duplicated serum transferrin genes (Tf1, Tf2), a melanotransferrin gene (MTf), and a monolobal transferrin gene (Omp). Whereas Tf1 and Tf2 were differentially expressed in liver and brain, the Omp transcript was restricted to the otoliths. Fish, chicken and mammals showed highly conserved syntenic regions in which monolobal and bilobal transferrins reside, but contrasting with tetrapods, the fish transferrin genes are positioned on three different linkage groups. Sequence alignment of cod Tf1 cDNAs from Northeast (<span class="hlt">NE</span>) and Northwest (NW) <span class="hlt">Atlantic</span> populations revealed 22 single nucleotide polymorphisms (SNP) causing the replacement of 16 amino acids, including eight surface residues revealed by the modelled 3D-structures, that might influence the binding of pathogens for removal of iron. SNP analysis of a total of 375 individuals from 14 trans-<span class="hlt">Atlantic</span> populations showed that the Tf1-<span class="hlt">NE</span> variant was almost fixed in the Baltic cod and predominated in the other <span class="hlt">NE</span> <span class="hlt">Atlantic</span> populations, whereas the NW <span class="hlt">Atlantic</span> populations were more heterozygous and showed high frequencies of the Tf-NW SNP alleles. Conclusions The highly conserved synteny between fish and tetrapod transferrin loci infers that the fusion of tandem duplicated Omp-like genes gave rise to the modern transferrins. The multiple nonsynonymous substitutions in cod Tf1 with putative structural effects, together with highly divergent allele frequencies among different cod populations, strongly suggest evidence for positive</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21612617','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21612617"><span>Polymorphism, selection and tandem duplication of transferrin genes in <span class="hlt">Atlantic</span> cod (Gadus morhua)--conserved synteny between fish monolobal and tetrapod bilobal transferrin loci.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Andersen, Øivind; De Rosa, Maria Cristina; Pirolli, Davide; Tooming-Klunderud, Ave; Petersen, Petra E; André, Carl</p> <p>2011-05-25</p> <p>The two homologous iron-binding lobes of transferrins are thought to have evolved by gene duplication of an ancestral monolobal form, but any conserved synteny between bilobal and monolobal transferrin loci remains unexplored. The important role played by transferrin in the resistance to invading pathogens makes this polymorphic gene a highly valuable candidate for studying adaptive divergence among local populations. The <span class="hlt">Atlantic</span> cod genome was shown to harbour two tandem duplicated serum transferrin genes (Tf1, Tf2), a melanotransferrin gene (MTf), and a monolobal transferrin gene (Omp). Whereas Tf1 and Tf2 were differentially expressed in liver and brain, the Omp transcript was restricted to the otoliths. Fish, chicken and mammals showed highly conserved syntenic regions in which monolobal and bilobal transferrins reside, but contrasting with tetrapods, the fish transferrin genes are positioned on three different linkage groups. Sequence alignment of cod Tf1 cDNAs from Northeast (<span class="hlt">NE</span>) and Northwest (NW) <span class="hlt">Atlantic</span> populations revealed 22 single nucleotide polymorphisms (SNP) causing the replacement of 16 amino acids, including eight surface residues revealed by the modelled 3D-structures, that might influence the binding of pathogens for removal of iron. SNP analysis of a total of 375 individuals from 14 trans-<span class="hlt">Atlantic</span> populations showed that the Tf1-<span class="hlt">NE</span> variant was almost fixed in the Baltic cod and predominated in the other <span class="hlt">NE</span> <span class="hlt">Atlantic</span> populations, whereas the NW <span class="hlt">Atlantic</span> populations were more heterozygous and showed high frequencies of the Tf-NW SNP alleles. The highly conserved synteny between fish and tetrapod transferrin loci infers that the fusion of tandem duplicated Omp-like genes gave rise to the modern transferrins. The multiple nonsynonymous substitutions in cod Tf1 with putative structural effects, together with highly divergent allele frequencies among different cod populations, strongly suggest evidence for positive selection and local adaptation in</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140016688','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140016688"><span>On the Sizes of the North <span class="hlt">Atlantic</span> <span class="hlt">Basin</span> Tropical Cyclones Based on 34- and 64-kt Wind Radii Data, 2004-2013</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wilson, Robert M.</p> <p>2014-01-01</p> <p>At end of the 2012 hurricane season the National Hurricane Center retired the original HURDAT dataset and replaced it with the newer version HURDAT2, which reformatted the original data and included additional information, in particular, estimates of the 34-, 50, and 64-kt wind radii for the interval 2004-2013. During the brief 10-year interval, some 164 tropical cyclones are noted to have formed in the North <span class="hlt">Atlantic</span> <span class="hlt">basin</span>, with 77 becoming hurricanes. Hurricane Sandy (2012) stands out as being the largest individual storm that occurred in the North <span class="hlt">Atlantic</span> <span class="hlt">basin</span> during the 2004 -2013 timeframe, both in terms of its 34- and 64-kt wind radii and wind areas, having maximum 34- and 64-kt wind radii, maximum wind areas, and average wind areas each more than 2 standard deviations larger than the corresponding means. In terms of the largest yearly total 34-kt wind area (i.e., the sum of all individual storm 34-kt wind areas during the year), the year 2010 stands out as being the largest (about 423 × 10(exp 6) nmi(exp 2)), compared to the mean of about 174 × 10(exp 6) nmi(exp 2)), surpassing the year 2005 (353 x 10(exp 6) nmi(exp 2)) that had the largest number of individual storms (28). However, in terms of the largest yearly total 64-kt wind area, the year 2005 was the largest (about 9 × 10(exp 6) nmi(exp 2)), compared to the mean of about 3 × 106 nmi(exp 2)). Interesting is that the ratio of total 64-kt wind area to total 34-kt wind area has decreased over time, from 0.034 in 2004 to 0.008 in 2013.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017GBioC..31..745D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017GBioC..31..745D"><span>Ventilation versus biology: What is the controlling mechanism of nitrous oxide distribution in the North <span class="hlt">Atlantic</span>?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>de la Paz, Mercedes; García-Ibáñez, Maribel I.; Steinfeldt, Reiner; Ríos, Aida F.; Pérez, Fiz F.</p> <p>2017-04-01</p> <p>The extent to which water mass mixing and ocean ventilation contribute to nitrous oxide (N2O) distribution at the scale of oceanic <span class="hlt">basins</span> is poorly constrained. We used novel N2O and chlorofluorocarbon measurements along with multiparameter water mass analysis to evaluate the impact of water mass mixing and <span class="hlt">Atlantic</span> Meridional Overturning Circulation (AMOC) on N2O distribution along the Observatoire de la variabilité interannuelle et décennale en Atlantique Nord (OVIDE) section, extending from Portugal to Greenland. The biological N2O production has a stronger impact on the observed N2O concentrations in the water masses traveling northward in the upper limb of the AMOC than those in recently ventilated cold water masses in the lower limb, where N2O concentrations reflect the colder temperatures. The high N2O tongue, with concentrations as high as 16 nmol kg-1, propagates above the isopycnal surface delimiting the upper and lower AMOC limbs, which extends from the eastern North <span class="hlt">Atlantic</span> <span class="hlt">Basin</span> to the Iceland <span class="hlt">Basin</span> and coincides with the maximum N2O production rates. Water mixing and <span class="hlt">basin</span>-scale remineralization account for 72% of variation in the observed distribution of N2O. The mixing-corrected stoichiometric ratio N2O:O2 for the North <span class="hlt">Atlantic</span> <span class="hlt">Basin</span> of 0.06 nmol/μmol is in agreement with ratios of N2O:O2 for local N2O anomalies, suggesting than up to 28% of N2O production occurs in the temperate and subpolar <span class="hlt">Atlantic</span>, an overlooked region for N2O cycling. Overall, our results highlight the importance of taking into account mixing, O2 undersaturation when water masses are formed and the increasing atmospheric N2O concentrations when parameterizing N2O:O2 and biological N2O production in the global oceans.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AGUFM.H23D1009M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AGUFM.H23D1009M"><span>Geologic Storage at the <span class="hlt">Basin</span> Scale: Region-Based <span class="hlt">Basin</span> Modeling, Powder River <span class="hlt">Basin</span> (PRB), <span class="hlt">NE</span> Wyoming and SE Montana</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Melick, J. J.; Gardner, M. H.</p> <p>2008-12-01</p> <p>Carbon capture and storage from the over 2000 power plants is estimated at 3-5 GT/yr, which requires large- scale geologic storage of greenhouse gasses in sedimentary <span class="hlt">basins</span>. Unfortunately, determination of <span class="hlt">basin</span> scale storage capacity is currently based on oversimplified geologic models that are difficult to validate. Simplification involves reducing the number of geologic parameters incorporated into the model, modeling with large grid cells, and treatment of subsurface reservoirs as homogeneous media. The latter problem reflects the focus of current models on fluid and/or fluid-rock interactions rather than fluid movement and migration pathways. For example, homogeneous models over emphasize fluid behavior, like the buoyancy of super-critical CO2, and hence overestimate leakage rates. Fluid mixing and fluid-rock interactions cannot be assessed with models that only investigate these reactions at a human time scale. Preliminary and conservative estimates of the total pore volume for the PRB suggest 200 GT of supercritical CO2 can be stored in this typical onshore sedimentary <span class="hlt">basin</span>. The connected pore volume (CPV) however is not included in this estimate. Geological characterization of the CPV relates subsurface storage units to the most prolific reservoir classes (RCs). The CPV, number of well penetrations, supercritical storage area, and potential leakage pathways characterize each RC. Within each RC, a hierarchy of stratigraphic cycles is populated with stationary sedimentation regions that control rock property distributions by correlating environment of deposition (EOD) to CPV. The degree to which CPV varies between RCs depends on the geology and attendant heterogeneity retained in the fluid flow model. Region-based modeling of the PRB incorporates 28000 wells correlated across a 70,000 Km2 area, 2 km thick on average. Within this <span class="hlt">basin</span>, five of the most productive RCs were identified from production history and placed in a fourfold stratigraphic framework</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017IJEaS.106.2461M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017IJEaS.106.2461M"><span>Superposition of tectonic structures leading elongated intramontane <span class="hlt">basin</span>: the Alhabia <span class="hlt">basin</span> (Internal Zones, Betic Cordillera)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Martínez-Martos, Manuel; Galindo-Zaldivar, Jesús; Martínez-Moreno, Francisco José; Calvo-Rayo, Raquel; Sanz de Galdeano, Carlos</p> <p>2017-10-01</p> <p>The relief of the Betic Cordillera was formed since the late Serravallian inducing the development of intramontane <span class="hlt">basins</span>. The Alhabia <span class="hlt">basin</span>, situated in the central part of the Internal Zones, is located at the intersection of the Alpujarran Corridor, the Tabernas <span class="hlt">basin</span>, both trending E-W, and the NW-SE oriented Gádor-Almería <span class="hlt">basin</span>. The geometry of the <span class="hlt">basin</span> has been constrained by new gravity data. The <span class="hlt">basin</span> is limited to the North by the Sierra de Filabres and Sierra Nevada antiforms that started to develop in Serravallian times under N-S shortening and to the south by Sierra Alhamilla and Sierra de Gádor antiforms. Plate convergence in the region rotated counter-clockwise in Tortonian times favouring the formation of E-W dextral faults. In this setting, <span class="hlt">NE</span>-SW extension, orthogonal to the shortening direction, was accommodated by normal faults on the SW edge of Sierra Alhamilla. The Alhabia <span class="hlt">basin</span> shows a cross-shaped depocentre in the zone of synform and fault intersection. This field example serves to constrain recent counter-clockwise stress rotation during the latest stages of Neogene-Quaternary <span class="hlt">basin</span> evolution in the Betic Cordillera Internal Zones and underlines the importance of studying the <span class="hlt">basins</span>' deep structure and its relation with the tectonic structures interactions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..1616894S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..1616894S"><span>The Miocene-Pliocene unconformity in the North Betic corridor. The expression of the reflector "M" in the <span class="hlt">Atlantic</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sierro, Francisco J.; Ledesma, Santiago; A: Flores, Jose; Garcia-Castellanos, Daniel; Hernandez-Molina, Javier</p> <p>2014-05-01</p> <p>The Miocene Pliocene boundary is associated in the Mediterranean to a major flooding of <span class="hlt">Atlantic</span> water that terminated with the Messinian salinity crisis. In many seismic profiles all over the Mediterranean margins this event is linked to an erosion surface that separates the Messinian evaporitic units from the overlying open marine Pliocene sediments. This unconformity originally identified as reflector "M" can be traced to the deep <span class="hlt">basins</span> as a paraconformity / local erosional surface that has been usually named as Horizon M. This erosive surface in Mediterranean continental margins has been linked to a pronounced drawdown of base level triggered during the Messinian. In consequence, this unconformity should be only expressed in the Mediterranean. However, a significant unconformity has been recognized in the Guadalquivir <span class="hlt">basin</span> and in the Gulf of Cadiz in the <span class="hlt">Atlantic</span> side of Iberia that is identified as a Messinian canyon deepening towards the <span class="hlt">Atlantic</span>. Recently, the cyclostratigraphic and biostratigraphic analyses of various logs recovered by different oil and gas exploration companies over the last decades allowed us to accurately date this major discontinuity in the Guadalquivir <span class="hlt">basin</span> and the Gulf of Cadiz, as well as to compare sedimentary cycles in the <span class="hlt">Atlantic</span> with those of the Mediterranean. The astronomical tuning of these cycles unambiguously links this discontinuity in the <span class="hlt">Atlantic</span> with the Miocene Pliocene boundary, raising important questions about the origin of this major event. We explore the potential origins for this discontinuity, including the tectonic vertical motions of the Betic-Guadalquivir system, or the presence of a seaway undergoing intense bottom-current circulation between the Mediterranean and the <span class="hlt">Atlantic</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/7201819-late-paleozoic-paleolatitude-paleogeography-midland-basin-texas','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/7201819-late-paleozoic-paleolatitude-paleogeography-midland-basin-texas"><span>Late Paleozoic paleolatitude and paleogeography of the Midland <span class="hlt">basin</span>, Texas</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Walker, D.A.; Golonka, J.; Reid, A.M.</p> <p>1992-04-01</p> <p>During the Late Pennsylvanian through Early Permian, the Midland <span class="hlt">basin</span> was located in the low latitudes. In the Desmoinesian (Strawn), the <span class="hlt">basin</span> was astride the equator; during the Missourian (Canyon), the center of the <span class="hlt">basin</span> had migrated northward so it was located at 1-2N latitude. In the Virgilian (Cisco), the <span class="hlt">basin</span> center was located around 2-4N latitude, and by the Wolfcampian, it was positioned at around 4-6N latitude. From the Desmoinesian (312 Ma) through the Missourian (306 Ma), the relative motion of the <span class="hlt">basin</span> was 63<span class="hlt">NE</span>. Later during the Virgilian (298 Ma) to Wolfcampian (280 Ma), the direction of motionmore » was 24<span class="hlt">NE</span>. This change in motion reflects a major tectonic event, occurring between the Missourian and Virgilian, that greatly modifed the movement of the Laurentian (North American) plate. At that time, Laurentia had collided with Gondwana and become part of the supercontinent Pangea. Throughout the late Paleozoic, Laurentia was rotated so the Midland <span class="hlt">basin</span> was oriented 43{degree} northeast from its current setting. Late Paleozoic paleogeography and paleolatitude controlled the direction of prevailing winds and ocean currents, thereby influencing the distribution of carbonate facies in the Midland <span class="hlt">basin</span>. Present prevailing winds and ocean currents have been shown to have a major impact on modern carbonate sedimentation and facies distribution in Belize, the Bahamas and Turks, and Caicos. A clearer understanding of how late Paleozoic latitude and geography affected sedimentation helps explain and predict the distribution of carbonates throughout the Midland <span class="hlt">basin</span>.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1996IJEaS..85..567K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1996IJEaS..85..567K"><span>Ferromanganese crusts as indicators for paleoceanographic events in the <span class="hlt">NE</span> <span class="hlt">Atlantic</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Koschinsky, A.; Halbach, P.; Hein, J. R.; Mangini, A.</p> <p></p> <p>Hydrogenetic ferromanganese crusts reflect the chemical conditions of the seawater from which they formed. Fine-scale geochemical analysis of crust layers in combination with age determinations can therefore be used to investigate paleoceanographic changes which are recorded in geochemical gradients in the crusts. At Tropic seamount (off northwest Africa), uniform crust growth influenced by terrigenous input from the African continent occurred during approximately the past 12Ma. Phosphatization of these crusts is minor. In contrast, crusts from Lion seamount, located between Madeira and the Portuguese coast, display a much more variable growth history. A pronounced increase in Ni, Cu, and Zn is observed in some intervals of the crusts, which probably reflects increased surface productivity. A thick older phosphatized generation occurs in many samples. Hydrographic profiles indicate that Mediterranean outflow water (MOW) may play an important role in the composition of these crusts. 10Be dating of one sample confirms that the interruption of the MOW during the Messinian salinity crisis (6.2-5Ma ago) resulted in changes in element composition. Sr-isotope dating of the apatite phase of the old crust generation has been carried out to obtain a minimum age for the older generation of <span class="hlt">Atlantic</span> crusts and to determine whether crust phosphatization in the <span class="hlt">Atlantic</span> can be related to phosphatization episodes recorded in Pacific crusts. The preliminary data show that the old phosphatized crust generation might be as old as approximately 30-40Ma.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70018140','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70018140"><span>Ferromanganese crusts as indicators for paleoceanographic events in the <span class="hlt">NE</span> <span class="hlt">Atlantic</span></span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Koschinsky, A.; Halbach, P.; Hein, J.R.; Mangini, A.</p> <p>1996-01-01</p> <p>Hydrogenetic ferromanganese crusts reflect the chemical conditions of the seawater from which they formed. Fine-scale geochemical analysis of crust layers in combination with age determinations can therefore be used to investigate paleoceanographic changes which are recorded in geochemical gradients in the crusts. At Tropic seamount (off northwest Africa), uniform crust growth influenced by terrigenous input from the African continent occurred during approximately the past 12 Ma. Phosphatization of these crusts is minor. In contrast, crusts from Lion seamount, located between Madeira and the Portuguese coast, display a much more variable growth history. A pronounced increase in Ni, Cu, and Zn is observed in some intervals of the crusts, which probably reflects increased surface productivity. A thick older phosphatized generation occurs in many samples. Hydrographic profiles indicate that Mediterranean outflow water (MOW) may play an important role in the composition of these crusts. 10Be dating of one sample confirms that the interruption of the MOW during the Messinian salinity crisis (6.2-5 Ma ago) resulted in changes in element composition. Sr-isotope dating of the apatite phase of the old crust generation has been carried out to obtain a minimum age for the older generation of <span class="hlt">Atlantic</span> crusts and to determine whether crust phosphatization in the <span class="hlt">Atlantic</span> can be related to phosphatization episodes recorded in Pacific crusts. The preliminary data show that the old phosphatized crust generation might be as old as approximately 30-40 Ma.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.A53D2278H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.A53D2278H"><span>On the Impact of Sea Level Fingerprints on the Estimation of the Meridional Geostrophic Transport in the <span class="hlt">Atlantic</span> <span class="hlt">Basin</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hsu, C. W.; Velicogna, I.</p> <p>2017-12-01</p> <p>The mid-ocean geostrophic transport accounts for more than half of the seasonal and inter-annual variabilities in <span class="hlt">Atlantic</span> meridional overturning circulation (AMOC) based on the in-situ measurement from RAPID MOC/MOCHA array since 2004. Here, we demonstrate that the mid-ocean geostrophic transport estimates derived from ocean bottom pressure (OBP) are affected by the sea level fingerprint (SLF), which is a variation of the equi-geopotential height (relative sea level) due to rapid mass unloading of the entire Earth system and in particular from glaciers and ice sheets. This potential height change, although it alters the OBP, should not be included in the derivation of the mid-ocean geostrophic transport. This "pseudo" geostrophic-transport due to the SLF is in-phase with the seasonal and interannual signal in the upper mid-ocean geostrophic transport. The east-west SLF gradient across the <span class="hlt">Atlantic</span> <span class="hlt">basin</span> could be mistaken as a north-south geostrophic transport that increases by 54% of its seasonal variability and by 20% of its inter-annual variability. This study demonstrates for the first time the importance of this pseudo transport in both the annual and interannual signals by comparing the SLF with in-situ observation from RAPID MOC/MOCHA array. The pseudo transport needs to be taken into account if OBP measurements and remote sensing are used to derive mid-ocean geostrophic transport.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_11 --> <div id="page_12" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="221"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ClDy...49.4263Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ClDy...49.4263Z"><span>Basinwide response of the <span class="hlt">Atlantic</span> Meridional Overturning Circulation to interannual wind forcing</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhao, Jian</p> <p>2017-12-01</p> <p>An eddy-resolving Ocean general circulation model For the Earth Simulator (OFES) and a simple wind-driven two-layer model are used to investigate the role of momentum fluxes in driving the <span class="hlt">Atlantic</span> Meridional Overturning Circulation (AMOC) variability throughout the <span class="hlt">Atlantic</span> <span class="hlt">basin</span> from 1950 to 2010. Diagnostic analysis using the OFES results suggests that interior baroclinic Rossby waves and coastal topographic waves play essential roles in modulating the AMOC interannual variability. The proposed mechanisms are verified in the context of a simple two-layer model with realistic topography and only forced by surface wind. The topographic waves communicate high-latitude anomalies into lower latitudes and account for about 50% of the AMOC interannual variability in the subtropics. In addition, the large scale Rossby waves excited by wind forcing together with topographic waves set up coherent AMOC interannual variability patterns across the tropics and subtropics. The comparisons between the simple model and OFES results suggest that a large fraction of the AMOC interannual variability in the <span class="hlt">Atlantic</span> <span class="hlt">basin</span> can be explained by wind-driven dynamics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4134232','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4134232"><span>Promiscuous Speciation with Gene Flow in Silverside Fish Genus Odontesthes (Atheriniformes, Atherinopsidae) from South Western <span class="hlt">Atlantic</span> Ocean <span class="hlt">Basins</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>García, Graciela; Ríos, Néstor; Gutiérrez, Verónica; Varela, Jorge Guerra; Bouza Fernández, Carmen; Pardo, Belén Gómez; Portela, Paulino Martínez</p> <p>2014-01-01</p> <p>The present paper integrates phylogenetic and population genetics analyses based on mitochondrial and nuclear molecular markers in silversides, genus Odontesthes, from a non-sampled area in the SW <span class="hlt">Atlantic</span> Ocean to address species discrimination and to define Managements Units for sustainable conservation. All phylogenetic analyses based on the COI mitochondrial gene were consistent to support the monophyly of the genus Odontesthes and to include O. argentinensis, O. perugiae-humensis and some O. bonariensis haplotypes in a basal polytomy conforming a major derivative clade. Microsatellites data revealed somewhat higher genetic variability values in the O. argentinensis-perugia populations than in O. bonariensis and O. perugia-humensis taxa. Contrasting population genetics structuring emerged from mitochondrial and microsatellites analyses in these taxa. Whereas mitochondrial data supported two major groups (O. argentinensis-perugia-humensis vs. O. bonariensis-perugiae-humensis populations), microsatellite data detected three major genetic entities represented by O. bonariensis, O. perugiae-humensis and an admixture of populations belonging to O. argentinensis-perugiae respectively. Therefore, the star COI polytomy in the tree topology involving these taxa could be interpreted by several hypothetic scenarios such as the existence of shared ancestral polymorphisms, incomplete lineage sorting in a radiating speciation process and/or reticulation events. Present findings support that promiscuous and recent contact between incipient species sharing asymmetric gene flow exchanges, blurs taxa boundaries yielding complicated taxonomy and Management Units delimitation in silverside genus Odontesthes from SW <span class="hlt">Atlantic</span> Ocean <span class="hlt">basins</span>. PMID:25126842</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25126842','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25126842"><span>Promiscuous speciation with gene flow in silverside fish genus Odontesthes (Atheriniformes, Atherinopsidae) from south western <span class="hlt">Atlantic</span> Ocean <span class="hlt">basins</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>García, Graciela; Ríos, Néstor; Gutiérrez, Verónica; Varela, Jorge Guerra; Bouza Fernández, Carmen; Pardo, Belén Gómez; Portela, Paulino Martínez</p> <p>2014-01-01</p> <p>The present paper integrates phylogenetic and population genetics analyses based on mitochondrial and nuclear molecular markers in silversides, genus Odontesthes, from a non-sampled area in the SW <span class="hlt">Atlantic</span> Ocean to address species discrimination and to define Managements Units for sustainable conservation. All phylogenetic analyses based on the COI mitochondrial gene were consistent to support the monophyly of the genus Odontesthes and to include O. argentinensis, O. perugiae-humensis and some O. bonariensis haplotypes in a basal polytomy conforming a major derivative clade. Microsatellites data revealed somewhat higher genetic variability values in the O. argentinensis-perugia populations than in O. bonariensis and O. perugia-humensis taxa. Contrasting population genetics structuring emerged from mitochondrial and microsatellites analyses in these taxa. Whereas mitochondrial data supported two major groups (O. argentinensis-perugia-humensis vs. O. bonariensis-perugiae-humensis populations), microsatellite data detected three major genetic entities represented by O. bonariensis, O. perugiae-humensis and an admixture of populations belonging to O. argentinensis-perugiae respectively. Therefore, the star COI polytomy in the tree topology involving these taxa could be interpreted by several hypothetic scenarios such as the existence of shared ancestral polymorphisms, incomplete lineage sorting in a radiating speciation process and/or reticulation events. Present findings support that promiscuous and recent contact between incipient species sharing asymmetric gene flow exchanges, blurs taxa boundaries yielding complicated taxonomy and Management Units delimitation in silverside genus Odontesthes from SW <span class="hlt">Atlantic</span> Ocean <span class="hlt">basins</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1812183B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1812183B"><span>Distributed deformation structures in shallow water carbonates subsiding through a simple stress field (Jandaira Formation, <span class="hlt">NE</span> Brazil)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bertotti, Giovanni; Bisdom, Kevin; Bezerra, Hilario; Reijmer, John; Cazarin, Carol</p> <p>2016-04-01</p> <p>Despite the scarcity of major deformation structures such as folds and faults, the flat-lying, post-rift shallow water carbonates of the Jandaira Formation (Potiguar <span class="hlt">Basin</span>, <span class="hlt">NE</span> Brazil) display well-organized fracture systems distributed of tens of km2. Structures observed in the outcropping carbonates are sub-vertical, generally N-S trending mode I and hybrid veins and barren fractures, sub-vertical roughly E-W trending stylolites and sub-horizontal stylolites. These features developed during subsidence in a simple and constant stress field characterized by, beside gravity, a significant horizontal stress probably of tectonic origin. The corresponding depth curves have different origin and slopes and, therefore, cross each other resulting in position of the principal stresses which change with depth. As a result, the type and amount of fractures affecting subsiding rocks change despite the fact that the far-field stresses remain constant. Following early diagenesis and porosity elimination in the first 100-200m depth, Jandaira carbonates experienced wholesale fracturing at depths of 400-800m resulting in a network of NNW-<span class="hlt">NE</span> trending fractures partly organized in conjugate sets with a low interfault angle and a sub-vertical intersection, and sub-vertical stylolites roughly perpendicular to the fractures. Intense fluid circulation was activated as a consequence through the carbonates. With increasing subsidence, sub-horizontal stylolites formed providing calcite which precipitated in the open fractures transforming them in veins. The Jandaira formation lost thereby the permeability it had reached during the previous stage. Because of the lack of major deformation, the outcrops of the Jandaira Formation is an excellent analog for carbonate reservoirs in the Middle East, South <span class="hlt">Atlantic</span> and elsewhere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015DSRII.116..262S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015DSRII.116..262S"><span>Elemental ratios and enrichment factors in aerosols from the US-GEOTRACES North <span class="hlt">Atlantic</span> transects</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shelley, Rachel U.; Morton, Peter L.; Landing, William M.</p> <p>2015-06-01</p> <p>The North <span class="hlt">Atlantic</span> receives the highest aerosol (dust) input of all the oceanic <span class="hlt">basins</span>. Dust deposition provides essential bioactive elements, as well as pollution-derived elements, to the surface ocean. The arid regions of North Africa are the predominant source of dust to the North <span class="hlt">Atlantic</span> Ocean. In this study, we describe the elemental composition (Li, Na, Mg, Al, P, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Rb, Sr, Cd, Sn, Sb, Cs, Ba, La, Ce, Nd, Pb, Th, U) of the bulk aerosol from samples collected during the US-GEOTRACES North <span class="hlt">Atlantic</span> Zonal Transect (2010/11) in order to highlight the differences between a Saharan dust end-member and the reported elemental composition of the upper continental crust (UCC), and the implications this has for identifying trace element enrichment in aerosols across the North <span class="hlt">Atlantic</span> <span class="hlt">basin</span>. As aerosol titanium (Ti) is less soluble than aerosol aluminum (Al), it is a more conservative tracer for lithogenic aerosols and trace element-to-Ti ratios. However, the presence of Ti-rich fine aerosols can confound the interpretation of elemental enrichments, making Al a more robust tracer of aerosol lithogenic material in this region.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.A21B0030B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.A21B0030B"><span>A volcanic wind-stress origin of the <span class="hlt">Atlantic</span> Multidecadal Oscillation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Birkel, S. D.; Mayewski, P. A.; Maasch, K. A.; Auger, J.; Lyon, B.</p> <p>2016-12-01</p> <p>The <span class="hlt">Atlantic</span> Multidecadal Oscillation (AMO) is a mode of sea-surface temperature (SST) variability in the North <span class="hlt">Atlantic</span> that has significant impact on global climate. Most previous studies ascribe the origin of the AMO to oceanic mechanisms, and suggest only a limited role for the atmosphere. Here, we suggest that the AMO is manifested from <span class="hlt">basin</span>-wide changes in surface wind stress that arise in response to episodic volcanic activity. Our interpretation is based on historical SST, reanalysis, and stratospheric aerosol optical thickness data, wherein it is evident that cool (warm) intervals of the AMO coincide with emergence of strong (weak) winds and high (low) volcanic activity. We find that SST excursions ultimately develop from atmospheric forcing as volcanic events project onto the North <span class="hlt">Atlantic</span> Oscillation (NAO). A volcanic signature is particularly evident beneath the westerlies in the subpolar region south of Greenland, where several large SST excursions occur coincident with identifiable major eruptions. High latitude surface waters cool when NAO+ circulation, which includes a deepened Icelandic Low, draws cold flow out of the Labrador Sea and into the subpolar region. Important feedbacks that cause SST anomalies to spread across the <span class="hlt">basin</span> include cloud cover, wind-driven upwelling, and entrainment of Saharan dust into the tropical easterlies. Finally, we speculate that cooling in the North <span class="hlt">Atlantic</span> observed since 2011 could be linked to renewed volcanic activity over Iceland, namely from the eruptions of Grímsvötn (2011) and Bárðarbunga (2014). An important question remains how North <span class="hlt">Atlantic</span> SST variability will evolve as atmospheric circulation becomes increasingly modified by human activity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ClDy...48..241M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ClDy...48..241M"><span>Variability in warm-season atmospheric circulation and precipitation patterns over subtropical South America: relationships between the South <span class="hlt">Atlantic</span> convergence zone and large-scale organized convection over the La Plata <span class="hlt">basin</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mattingly, Kyle S.; Mote, Thomas L.</p> <p>2017-01-01</p> <p>Warm-season precipitation variability over subtropical South America is characterized by an inverse relationship between the South <span class="hlt">Atlantic</span> convergence zone (SACZ) and precipitation over the central and western La Plata <span class="hlt">basin</span> of southeastern South America. This study extends the analysis of this "South American Seesaw" precipitation dipole to relationships between the SACZ and large, long-lived mesoscale convective systems (LLCSs) over the La Plata <span class="hlt">basin</span>. By classifying SACZ events into distinct continental and oceanic categories and building a logistic regression model that relates LLCS activity across the region to continental and oceanic SACZ precipitation, a detailed account of spatial variability in the out-of-phase coupling between the SACZ and large-scale organized convection over the La Plata <span class="hlt">basin</span> is provided. Enhanced precipitation in the continental SACZ is found to result in increased LLCS activity over northern, northeastern, and western sections of the La Plata <span class="hlt">basin</span>, in association with poleward atmospheric moisture flux from the Amazon <span class="hlt">basin</span> toward these regions, and a decrease in the probability of LLCS occurrence over the southeastern La Plata <span class="hlt">basin</span>. Increased oceanic SACZ precipitation, however, was strongly related to reduced atmospheric moisture and decreased probability of LLCS occurrence over nearly the entire La Plata <span class="hlt">basin</span>. These results suggest that continental SACZ activity and large-scale organized convection over the northern and eastern sections of the La Plata <span class="hlt">basin</span> are closely tied to atmospheric moisture transport from the Amazon <span class="hlt">basin</span>, while the warm coastal Brazil Current may also play an important role as an evaporative moisture source for LLCSs over the central and western La Plata <span class="hlt">basin</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4461265','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4461265"><span>Multilocus Bayesian Estimates of Intra-Oceanic Genetic Differentiation, Connectivity, and Admixture in <span class="hlt">Atlantic</span> Swordfish (Xiphias gladius L.)</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Smith, Brad L.; Lu, Ching-Ping; García-Cortés, Blanca; Viñas, Jordi; Yeh, Shean-Ya; Alvarado Bremer, Jaime R.</p> <p>2015-01-01</p> <p>Previous genetic studies of <span class="hlt">Atlantic</span> swordfish (Xiphias gladius L.) revealed significant differentiation among Mediterranean, North <span class="hlt">Atlantic</span> and South <span class="hlt">Atlantic</span> populations using both mitochondrial and nuclear DNA data. However, limitations in geographic sampling coverage, and the use of single loci, precluded an accurate placement of boundaries and of estimates of admixture. In this study, we present multilocus analyses of 26 single nucleotide polymorphisms (SNPs) within 10 nuclear genes to estimate population differentiation and admixture based on the characterization of 774 individuals representing North <span class="hlt">Atlantic</span>, South <span class="hlt">Atlantic</span>, and Mediterranean swordfish populations. Pairwise F ST values, AMOVA, PCoA, and Bayesian individual assignments support the differentiation of swordfish inhabiting these three <span class="hlt">basins</span>, but not the current placement of the boundaries that separate them. Specifically, the range of the South <span class="hlt">Atlantic</span> population extends beyond 5°N management boundary to 20°N-25°N from 45°W. Likewise the Mediterranean population extends beyond the current management boundary at the Strait of Gibraltar to approximately 10°W. Further, admixture zones, characterized by asymmetric contributions of adjacent populations within samples, are confined to the Northeast <span class="hlt">Atlantic</span>. While South <span class="hlt">Atlantic</span> and Mediterranean migrants were identified within these Northeast <span class="hlt">Atlantic</span> admixture zones no North <span class="hlt">Atlantic</span> migrants were identified respectively in these two neighboring <span class="hlt">basins</span>. Owing to both, the characterization of larger number of loci and a more ample spatial sampling coverage, it was possible to provide a finer resolution of the boundaries separating <span class="hlt">Atlantic</span> swordfish populations than previous studies. Finally, the patterns of population structure and admixture are discussed in the light of the reproductive biology, the known patterns of dispersal, and oceanographic features that may act as barriers to gene flow to <span class="hlt">Atlantic</span> swordfish. PMID:26057382</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018Tectp.722..383Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018Tectp.722..383Y"><span>Cenozoic pulsed compression of Da'an-Dedu Fault Zone in Songliao <span class="hlt">Basin</span> (<span class="hlt">NE</span> China) and its implications for earthquake potential: Evidence from seismic data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yu, Zhongyuan; Zhang, Peizhen; Min, Wei; Wei, Qinghai; Zhao, Bin</p> <p>2018-01-01</p> <p>The Da'an-Dedu Fault Zone (DDFZ) is a major tectonic feature cutting through the Songliao <span class="hlt">Basin</span> from south to north in <span class="hlt">NE</span> China. Pulsed compression deformation of DDFZ during the Cenozoic implies a complex geodynamic process, and the latest stage of which occurred in the Quaternary directly influences the present seismicity of the interior <span class="hlt">basin</span>. Although most of the evidence for Quaternary deformation about the Songliao <span class="hlt">Basin</span> in the past decades was concentrated in marginal faults, all five earthquake swarms with magnitudes over 5.0 along the buried DDFZ with no surface expression during the past 30 years suggest it is a main seismogenic structure with seismic potential, which should deserve more attention of geologists. However, limited by the coverage of the Quaternary sedimentary and absence of strong historic and instrumental earthquakes records (M > 7), the geometric pattern, Quaternary activity and seismic potential of the DDFZ remain poorly understood. Thus, unlike previous geophysical studies focused on crust/mantle velocity structure across the fault and the aim of exploring possible mineral resources in the <span class="hlt">basin</span>, in this study we have integrated a variety of the latest seismic data and drilling holes from petroleum explorations and shallow-depth seismic reflection profiles, to recognize the Cenozoic pulsed compression deformation of the DDFZ, and to discuss its implication for earthquake potential. The results show that at least four stages of compression deformation have occurred along the DDFZ in the Cenozoic: 65 Ma, 23 Ma, 5.3 Ma, and 1.8 Ma, respectively, although the geodynamic process behind which still in dispute. The results also imply that the tectonic style of the DDFZ fits well with the occurrence of modern seismic swarms. Moderate earthquake potential (M ≤ 7.0) is suggested along the DDFZ.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUOSPO14H2898M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUOSPO14H2898M"><span>Biogeochemical and physical controls on the distribution of dissolved organic carbon in the deep Gulf of Mexico and <span class="hlt">basins</span> of the Caribbean</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Margolin, A. R.; Hansell, D. A.</p> <p>2016-02-01</p> <p>Over the past two decades, significant advances have been made in understanding dissolved organic carbon (DOC) distributions in the <span class="hlt">Atlantic</span> and throughout the global ocean. Surprisingly, however, little is known about DOC distributions in the <span class="hlt">Atlantic</span>'s neighboring Gulf of Mexico (GoM) and Caribbean due to few observations, especially in their deep layers. To address the dearth of DOC data in the GoM and Caribbean, samples were collected during multiple cruises spanning the region, allowing comparisons between the deep layers of the <span class="hlt">basins</span>. Additionally, complementary biogeochemical (oxygen, nutrients) and physical (temperature, salinity) measurements were made to aid in DOC interpretation, which show clear distinctions between the deep waters of the GoM, <span class="hlt">basins</span> of the Caribbean and <span class="hlt">Atlantic</span>. The unique characteristics of these deep layers result from exchanges being restricted to narrow passages that separate the <span class="hlt">basins</span>, limiting the deep water renewal to periodic overflows of relatively dense water, capable of penetrating below the 2000 m sill depths. Furthermore, hydrocarbon seeps (in GoM) and hydrothermal activity (in Caribbean), along with the offshore oil industry have the potential to alter deep DOC concentrations regionally, which are considered here. Samples collected below 250 m show that concentrations decrease with depth, ranging from 40-50 µmol kg-1. Compared to the <span class="hlt">Atlantic</span>, the GoM and Venezuelan <span class="hlt">Basin</span> concentrations are lower, while they are similar to the <span class="hlt">Atlantic</span> in the Yucatan <span class="hlt">Basin</span>; responsible processes are inferred.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3233691','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3233691"><span>Dubinectes infirmus, a new species of deep-water Munnopsidae (Crustacea, Isopoda, Asellota) from the Argentine <span class="hlt">Basin</span>, South <span class="hlt">Atlantic</span> Ocean</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Malyutina, Marina; Brandt, Angelika</p> <p>2011-01-01</p> <p>Abstract Dubinectes infirmus sp. n., Munnopsidae, is described from the Argentine <span class="hlt">Basin</span>, southwest <span class="hlt">Atlantic</span>, at depths between 4586–4607 m. The new species is distinguished by a narrow rim of the pleotelson posterior margin which is not raising over its dorsal surface; article 3 of the antennula is subequal in length to article 2; distomedial lobes of male pleopod 1 are of same size as distolateral lobes; stylet of male pleopod 2 is subequal in length to protopod; uropod exopod is more than a half of endopod length. Some generic characters which are weakly pronounced in the new species or have different state are defined more precisely in the revised diagnosis of Dubinectes. The modified diagnosis of the genus, a key to the species of Dubinectes as well as the distribution of the genus are presented. PMID:22207784</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110022533','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110022533"><span>Observed Recent Trends in Tropical Cyclone Rainfall Over Major Ocean <span class="hlt">Basins</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lau, K. M.; Zhou, Y. P.</p> <p>2011-01-01</p> <p>In this study, we use Tropical Rainfall Measuring Mission (TRMM) and Global Precipitation Climatology Project (GPCP) rainfall data together with historical storm track records to examine the trend of tropical cyclone (TC) rainfall in major ocean <span class="hlt">basins</span> during recent decades (1980-2007). We find that accumulated total rainfall along storm tracks for all tropical cyclones shows a weak positive trend over the whole tropics. However, total rainfall associated with weak storms, and intense storms (Category 4-5) both show significant positive trends, while total rainfall associated with intermediate storms (Category1-3) show a significant negative trend. Storm intensity defined as total rain produced per unit storm also shows increasing trend for all storm types. <span class="hlt">Basin</span>-wide, from the first half (1980-1993) to the second half (1994-2007) of the data period, the North <span class="hlt">Atlantic</span> shows the pronounced increase in TC number and TC rainfall while the Northeast Pacific shows a significant decrease in all storm types. Except for the Northeast Pacific, all other major <span class="hlt">basins</span> (North <span class="hlt">Atlantic</span>, Northwest Pacific, Southern Oceans, and Northern Indian Ocean) show a significant increase in total number and rainfall amount in Category 4-5 storms. Overall, trends in TC rainfall in different ocean <span class="hlt">basins</span> are consistent with long-term changes in the ambient large-scale environment, including SST, vertical wind shear, sea level pressure, mid-tropospheric humidity, and Maximum Potential Intensity (MPI). Notably the pronounced positive (negative) trend of TC rainfall in the North <span class="hlt">Atlantic</span> (Northeast Pacific) appears to be related to the most (least) rapid increase in SST and MPI, and the largest decrease (increase) in vertical wind shear in the region, relative to other ocean <span class="hlt">basins</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://rosap.ntl.bts.gov/view/dot/29633','DOTNTL'); return false;" href="https://rosap.ntl.bts.gov/view/dot/29633"><span>Mariner's guide for hurricane awareness in the North <span class="hlt">Atlantic</span> <span class="hlt">basin</span>.</span></a></p> <p><a target="_blank" href="http://ntlsearch.bts.gov/tris/index.do">DOT National Transportation Integrated Search</a></p> <p></p> <p>2000-08-01</p> <p>This guide will hopefully aid the Mariner in understanding the complex structure and behavior of : tropical cyclones in the North <span class="hlt">Atlantic</span> Ocean. Once armed with this knowledge, and the information : on where to acquire forecasts and guidance for cur...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014DSRI...89...84F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014DSRI...89...84F"><span>Reproductive and feeding spatial dynamics of the black scabbardfish, Aphanopus carbo Lowe, 1839, in <span class="hlt">NE</span> <span class="hlt">Atlantic</span> inferred from fatty acid and stable isotope analyses</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Farias, Inês; Figueiredo, Ivone; Janeiro, Ana Isabel; Bandarra, Narcisa Maria; Batista, Irineu; Morales-Nin, Beatriz</p> <p>2014-07-01</p> <p>The black scabbardfish (Aphanopus carbo) is a benthopelagic species widely distributed across the <span class="hlt">NE</span> <span class="hlt">Atlantic</span>, where it is admitted to perform a clockwise migration throughout its life cycle stimulated by feeding and reproduction. To overcome the limitations of direct observation of this species, fatty acids profile (FA) and δ15N and δ13C stable isotopes (SI) were analyzed in the muscle tissue of the black scabbardfish and related with diet and maturity. Specimens were collected in four geographic areas in the <span class="hlt">NE</span> <span class="hlt">Atlantic</span>: Iceland, the west of the British Isles, mainland Portugal, and Madeira. For all areas, the FA profile was related with the different phases of the reproductive cycle and with diet, whereas the SI were related with diet, environmental characteristics, such as latitude and depth, and particulate organic matter (POM). Stomach content of black scabbardfish caught off mainland Portugal was analyzed and the most frequent prey item identified was the lophogastrid crustacean Gnathophausia zoea, followed by the cephalopod Mastigotheutis spp. and the teleost Rouleina maderensis. For specimens from Iceland and the west of the British Isles, monounsaturated fatty acids (MUFA) were the most important FA, followed by polyunsaturated (PUFA) and saturated FA (SFA), whereas for specimens from mainland Portugal and from Madeira the sequences were PUFA>MUFA>SFA and PUFA>SFA>MUFA, respectively. Immature specimens from the first three areas were found to be accumulating oleic acid which is an intermediate product of the metabolic pathway that transforms SFA to MUFA and these into PUFA. Specimens caught off Madeira were mature and showed a significant prevalence of ARA and DHA which are PUFA with an important role in reproduction. δ15N was significantly higher in the muscle of black scabbardfish from Madeira, whereas δ13C was significantly lower in specimens from Iceland. The low isotopic ratios as well as the prevalence of certain fatty acid trophic markers (FATM</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JAfES.134..345A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JAfES.134..345A"><span>Paleodepositional environment and age of Kanawa Member of Pindiga Formation, Gongola Sub-<span class="hlt">basin</span>, Northern Benue Trough, <span class="hlt">NE</span> Nigeria: Sedimentological and palynological approach</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Aliyu, Abdulkarim H.; Mamman, Y. D.; Abubakar, M. B.; Sarki Yandoka, Babangida M.; Jitong, John Shirputda; Shettima, Bukar</p> <p>2017-10-01</p> <p>Sedimentogical and palynological investigations of the Kanawa Member of Pindiga Formation in the Gongola Sub-<span class="hlt">basin</span>, Northern Benue Trough, <span class="hlt">NE</span> Nigeria were carried out in order to determine the paleoenvironment and age of the sediments. Three main lithofacies were identified from the measured sedimentary log section, namely; the wave rippled sandstones, the limestones (with ammonites, bivalves and gastropods) and the clay-shale. The facies were interpreted to have been deposited in a marine environment. Based on palynological studies, Kanawa Member consists of two palynozones, namely; Cretacaeiporites scabratus and Triorites africaensis. The Triorites africaensis zone is characterized by species of T. africaensis, Gnetaceaepollenites sp. 1, Cretacaeiporites polygonalis, Monosulcites sp., Cretacaeiporites scabratus, Elaterocolpites castelainii and is dated Late Cenomanian whilst the Cretacaeiporites scabratus zone is characterized by the dominance of C. scabratus, C. mulleri and Tricolporopollenites sp and is dated Early Turonian. The Kanawa Member is therefore, dated Late Cenomanian to early Turonian.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.5438H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.5438H"><span>The role of major rift faults in the evolution of deformation bands in the Rio do Peixe <span class="hlt">Basin</span>, Brazil</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hilario Bezerra, Francisco; Araujo, Renata; Maciel, Ingrid; Cezar Nogueira, Francisco; Balsamo, Fabrizio; Storti, Fabrizio; Souza, Jorge Andre; Carvalho, Bruno</p> <p>2017-04-01</p> <p>Many studies have investigated on the evolution and properties of deformation bands, but their occurrence and relationships with <span class="hlt">basin</span>-boundary faults remain elusive when the latter form by brittle reactivation of structural inheritance in crystalline basements. The main objective of our study was to systematically record the location, kinematics, geometry, and density of deformation bands in the early Cretaceous Rio do Peixe <span class="hlt">basin</span>, <span class="hlt">NE</span> Brazil, and analyze their relationship with major syn-rift fault zones. Reactivation in early Cretaceous times of continental-scale ductile shear zones led to the development of rift <span class="hlt">basins</span> in <span class="hlt">NE</span> Brazil. These shear zones form a network of <span class="hlt">NE</span>- and E-W-trending structures hundreds of kilometers long and 3-10 km wide. They were active in the Brasiliano orogeny at 540-740 Ma. Brittle reactivation of these structures occurred in Neocomian times ( 140-120 Ma) prior the breakup between the South American and African plates in the late Cretaceous. The Rio do Peixe <span class="hlt">basin</span> formed at the intersection between the <span class="hlt">NE</span>-SW-striking Portalegre shear zone and the E-W-striking Patos shear zone. The brittle fault systems developed by the shear zone reactivation are the Portalegre Fault and the Malta Fault, respectively. In this research we used field structural investigations and drone imagery with centimetric resolution. Our results indicate that deformation bands occur in poorly sorted, medium to coarse grain size sandstones and localize in 3-4 km wide belts in the hanging wall of the two main syn-rifts fault systems. Deformation bands formed when sandstones were not completely lithified. They strike <span class="hlt">NE</span> along the Portalegre Fault and E-W along the Malta Fault and have slip lineations with rake values ranging from 40 to 90. The kinematics recorded in deformation bands is consistent with that characterizing major rift fault systems, i.e. major extension with a strike-slip component. Since deformations bands are typical sub-seismic features, our findings</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/5276452-fracture-zones-equatorial-atlantic-breakup-western-pangea','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/5276452-fracture-zones-equatorial-atlantic-breakup-western-pangea"><span>Fracture zones in the equatorial <span class="hlt">Atlantic</span> and the breakup of western Pangea</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Jones, E.J.W.</p> <p>1987-06-01</p> <p>The early breakup of western Pangea has been investigated by mapping the pattern of fracture zones and distribution of seismic reflectors within the sedimentary cover of the <span class="hlt">Atlantic</span> between the Cape Verde Islands and the equator. Two distinct sets of transverse oceanic lineaments are present, separated by the Guinea Fracture Zone near lat 10/sup 0/N. Lineaments to the north are associated with the formation of the central <span class="hlt">Atlantic</span> in the Late Jurassic and Early Cretaceous; those in the south relate to the Cretaceous opening of the South <span class="hlt">Atlantic</span>. The Guinea Fracture Zone is thus the conjugate of the Jurassic transformmore » boundary under peninsular Florida, which linked the <span class="hlt">Atlantic</span> with the Gulf of Mexico. The distribution of dated seismic reflectors suggests that deposition of deep-water sediments was confined to the region north of the Guinea transform until Aptian time, when the Sierra Leone <span class="hlt">Basin</span> began to open. The latter started to widen at least 15 m.y. after the initiation of the Cape <span class="hlt">Basin</span> off southwest Africa, an age difference that can be explained if a short-lived plate boundary developed in either Africa or South America during the Early Cretaceous. Neither the trends of the equatorial fracture zones nor the seismic stratigraphy supports the existence of a predrift gap between west Africa and Brazil.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=Eurasia&id=EJ442131','ERIC'); return false;" href="https://eric.ed.gov/?q=Eurasia&id=EJ442131"><span>Infectious Disease and the Demography of the <span class="hlt">Atlantic</span> Peoples.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Crosby, Alfred W.</p> <p>1991-01-01</p> <p>Discusses effects of disease on the <span class="hlt">Atlantic</span> <span class="hlt">basin</span> after Christopher Columbus established contact between the hemispheres. Emphasizes the decimation of the native populations of the Americas when exposed to illnesses common in Eurasia and Africa. Relates the epidemics to the development of the slave trade and the rise of the middle class in…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008PEPI..167...71J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008PEPI..167...71J"><span>Palaeomagnetism of the loess/palaeosol sequence in Viatovo (<span class="hlt">NE</span> Bulgaria) in the Danube <span class="hlt">basin</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jordanova, Diana; Hus, Jozef; Evlogiev, Jordan; Geeraerts, Raoul</p> <p>2008-03-01</p> <p>The results of a palaeomagnetic investigation of a 27 m thick loess/palaeosol sequence in Viatovo (<span class="hlt">NE</span> Bulgaria) are presented in this paper. The sequence consists of topsoil S 0, seven loess horizons (L 1-L 7) and six interbedded palaeosols (S 1-S 6) overlying a red clay (terra rossa) complex. Magnetic viscosity experiments, IRM acquisition, AMS analysis and NRM stepwise alternating and thermal demagnetisation experiments of pilot samples were implemented for precise determination of the characteristic remanence and construction of a reliable magnetostratigraphical scheme. Analysis of IRM acquisition curves using the expectation - maximization algorithm of Heslop et al. [Heslop, D., Dekkers, M., Kruiver, P., van Oorschot, H., 2002. Analysis of isothermal remanent magnetization acquisition curves using the expectation - maximization algorithm. Geophys. J. Int., 148, 58-64] suggests that the best fitting is obtained by three coercivity components. Component 1 corresponds to SD maghemite/magnetite, while component 2 is probably related to the presence of oxidised detrital magnetites. The third component shows varying coercivities depending on the degree of pedogenic alteration of the samples and probably reflects the presence of detrital magnetite grains oxidised at different degree. The relevance of the Viatovo section as a key representative sequence for the loess cover in the Danube <span class="hlt">basin</span> is confirmed by the presence of geomagnetic polarity changes in the lower part of the sequence. The youngest one recorded in the seventh loess unit L 7 can be identified as corresponding to the Matuyama/Brunhes palaeomagnetic polarity transition. Two normal magnetozones were found in the red clay complex, probably corresponding to the Jaramillo and Olduvai subchronozones of the Matuyama chron.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26270210','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26270210"><span>Vascular epiphytes of the <span class="hlt">Atlantic</span> Forest in the Sinos River <span class="hlt">basin</span>, state of Rio Grande do Sul, Brazil: richness, floristic composition and community structure.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Barbosa, M D; Becker, D F P; Cunha, S; Droste, A; Schmitt, J L</p> <p>2015-05-01</p> <p>The <span class="hlt">Atlantic</span> Forest, which has a vast epiphytic richness, is a priority area for preservation, listed as one of the five most important world hotspots. Vascular epiphyte richness, composition and community structure were studied in two fragments, one of the ombrophilous (29º43'42"S and 50º22'00"W) and the other of the seasonal (29º40'54"S and 51º06'56"W) forest, both belonging to the <span class="hlt">Atlantic</span> Forest biome in the Sinos River <span class="hlt">basin</span>, Rio Grande do Sul, Brazil. In each fragment, 40 trees, divided into four ecological zones, were analyzed. In each zone, the occurrence of the species was recorded, and the importance value of each species was calculated according to the frequency of phorophytes and intervals, and cover scores. The Shannon index was calculated for the two communities. In the fragment of the ombrophilous forest (F1), 30 epiphytic species were recorded, and in the seasonal forest (F2), 25. The highest importance value was found for Microgramma squamulosa (Kaulf.) de la Sota in both fragments. The diversity indexes for F1 (H'=2.72) and F2 (H'=2.55) were similar and reflected the subtropical location of the areas. The decrease in mean richness in both fragments in zone 3 (internal crown) to zone 4 (external crown) may be associated with time and space availability for epiphyte occupation and microclimate variations. Exclusive species were found in the areas, which suggest that a greater number of preserved fragments may result in a greater number of preserved epiphytic species in the Sinos River <span class="hlt">basin</span>.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_12 --> <div id="page_13" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="241"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18267896','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18267896"><span>Amazon <span class="hlt">Basin</span> climate under global warming: the role of the sea surface temperature.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Harris, Phil P; Huntingford, Chris; Cox, Peter M</p> <p>2008-05-27</p> <p>The Hadley Centre coupled climate-carbon cycle model (HadCM3LC) predicts loss of the Amazon rainforest in response to future anthropogenic greenhouse gas emissions. In this study, the atmospheric component of HadCM3LC is used to assess the role of simulated changes in mid-twenty-first century sea surface temperature (SST) in Amazon <span class="hlt">Basin</span> climate change. When the full HadCM3LC SST anomalies (SSTAs) are used, the atmosphere model reproduces the Amazon <span class="hlt">Basin</span> climate change exhibited by HadCM3LC, including much of the reduction in Amazon <span class="hlt">Basin</span> rainfall. This rainfall change is shown to be the combined effect of SSTAs in both the tropical <span class="hlt">Atlantic</span> and the Pacific, with roughly equal contributions from each <span class="hlt">basin</span>. The greatest rainfall reduction occurs from May to October, outside of the mature South American monsoon (SAM) season. This dry season response is the combined effect of a more rapid warming of the tropical North <span class="hlt">Atlantic</span> relative to the south, and warm SSTAs in the tropical east Pacific. Conversely, a weak enhancement of mature SAM season rainfall in response to <span class="hlt">Atlantic</span> SST change is suppressed by the atmospheric response to Pacific SST. This net wet season response is sufficient to prevent dry season soil moisture deficits from being recharged through the SAM season, leading to a perennial soil moisture reduction and an associated 30% reduction in annual Amazon <span class="hlt">Basin</span> net primary productivity (NPP). A further 23% NPP reduction occurs in response to a 3.5 degrees C warmer air temperature associated with a global mean SST warming.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PalOc..31..365R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PalOc..31..365R"><span>Paleoseawater density reconstruction and its implication for cold-water coral carbonate mounds in the northeast <span class="hlt">Atlantic</span> through time</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rüggeberg, Andres; Flögel, Sascha; Dullo, Wolf-Christian; Raddatz, Jacek; Liebetrau, Volker</p> <p>2016-03-01</p> <p>Carbonate buildups and mounds are impressive biogenic structures throughout Earth history. In the recent <span class="hlt">NE</span> <span class="hlt">Atlantic</span>, cold-water coral (CWC) reefs form giant carbonate mounds of up to 300 m of elevation. The expansion of these coral carbonate mounds is paced by climatic changes during the past 2.7 Myr. Environmental control on their development is directly linked to controls on its main constructors, the reef-building CWCs. Seawater density has been identified as one of the main controlling parameter of CWC growth in the <span class="hlt">NE</span> <span class="hlt">Atlantic</span>. One possibility is the formation of a pycnocline above the carbonate mounds, which is increasing the hydrodynamic regime, supporting elevated food supply, and possibly facilitating the distribution of coral larvae. The potential to reconstruct past seawater densities from stable oxygen isotopes of benthic foraminifera has been further developed: a regional equation gives reliable results for three different settings, peak interglacials (e.g., Holocene), peak glacials (e.g., Last Glacial Maximum), and intermediate setting (between the two extremes). Seawater densities are reconstructed for two different <span class="hlt">NE</span> <span class="hlt">Atlantic</span> CWC carbonate mounds in the Porcupine Seabight indicating that the development of carbonate mounds is predominantly found at a seawater density range between 27.3 and 27.7 kg m-3 (σΘ notation). Comparable to recent conditions, we interpret the reconstructed density range as a pycnocline serving as boundary layer, on which currents develop, carrying nutrition and possibly coral larvae. The close correlation of CWC reef growth with reconstructed seawater densities through the Pleistocene highlights the importance of pycnoclines and intermediate water mass dynamics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006AGUFM.U35A..01C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006AGUFM.U35A..01C"><span><span class="hlt">Atlantic</span> Ocean Circulation and Climate: The Current View From the Geological Record</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Curry, W.</p> <p>2006-12-01</p> <p>Several recent advances in our understanding of past ocean circulation come from geological reconstructions using deep sea sediment proxies of water mass structure and flow. Put together, the observations suggest that the <span class="hlt">Atlantic</span> Ocean during the last glacial period (21,000 years ago) was very different from today. Geochemical tracers document a shoaling of North <span class="hlt">Atlantic</span> Deep Water and a much greater volume of deep waters with an Antarctic origin. Sedimentary pore water profiles have detected a reversal in the salinity gradient between northern and southern deep water sources. Uranium-series decay products in North <span class="hlt">Atlantic</span> sediments indicate that the southward transport of North <span class="hlt">Atlantic</span> Deep Water was as much as 30-40% reduced from today's transport. Ocean-margin density reconstructions are consistent with a one third reduction in transport through the Florida Straits. A reversed cross-<span class="hlt">basin</span> density gradient in the South <span class="hlt">Atlantic</span> calls for a different intermediate water circulation in the South <span class="hlt">Atlantic</span>. The glacial <span class="hlt">Atlantic</span> circulation appears to be best explained by a reduced influence of North <span class="hlt">Atlantic</span> deep water sources and much greater influence of Antarctic deep water sources. More recent changes in <span class="hlt">Atlantic</span> circulation have been much more modest. During the Little Ice Age (LIA - a much smaller cooling event about 200 to 600 years ago), transport of the Florida Current was reduced by about 10%, significant but a much smaller reduction than observed during the glacial period. There is little evidence for a change in the distribution or geochemistry of the water masses during the LIA. For both climate events (the glacial and the LIA) reduced Florida Current transport was accompanied by increased salinity of its surface waters, linking changes in ocean circulation to large scale changes in surface water hydrology. A feedback between the circulation of the <span class="hlt">Atlantic</span> Ocean and the climate of the tropics has been proposed before and also seen in some coupled</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA510965','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA510965"><span>Low-Latitude Western North <span class="hlt">Atlantic</span> Climate Variability During the Past Millennium: Insights from Proxies and Models</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2009-09-01</p> <p>simulations indicate extratropical North <span class="hlt">Atlantic</span> climate can influence the meridional position of the ITCZ [Chiang and Bitz, 2005; Broccoli et al...record from the Cariaco <span class="hlt">Basin</span>: Baseline variability, twentieth-century warming, and <span class="hlt">Atlantic</span> hurricane frequency. Paleoceanography, 22. Broccoli ...SSTs were not markedly cooler during the LIA suggests that the ITCZ may have responded to extra- tropical cooling. Idealized simulations [ Broccoli et al</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016DSRI..115...48R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016DSRI..115...48R"><span>Migration and diving behavior of Centrophorus squamosus in the <span class="hlt">NE</span> <span class="hlt">Atlantic</span>. Combining electronic tagging and Argo hydrography to infer deep ocean trajectories</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rodríguez-Cabello, Cristina; González-Pola, Cesar; Sánchez, Francisco</p> <p>2016-09-01</p> <p>A total of nine leafscale gulper sharks Centrophorus squamosus (Bonnaterre, 1788), were tagged with pop-up, satellite, archival, transmitting tags (PSAT) in the Marine Protected Area (MPA) of El Cachucho (Le Danois Bank) located in waters to the north of Spain, (<span class="hlt">NE</span> <span class="hlt">Atlantic</span>). Tags provided data on time, pressure and temperature that were used to examine movement patterns and diving behavior. Data collected from Argo floats in the study area have been used to devise a simple geolocation algorithm to infer the probable routes followed by this species. Tag release points revealed that C. squamosus moved both to the west (Galician waters) and to the north (Porcupine Bank) from the tagging area, suggesting well defined preferred pathways. The inferred trajectories indicated that sharks alternate periods constrained to specific geographical regions with quick and prompt movements covering large distances. Two sharks made conspicuous diurnal vertical migrations being at shallower depths around midnight and at maximum depths at midday, while other sharks did not make vertical migrations. Vertical movements were done smoothly and independently of the fish swimming long-distances or resting in the area. Overall results confirm that this species is highly migratory, supporting speeds of 20 nautical miles.day-1 and well capable to swim and make vertical migrations well above the abyssal plain.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19990021448','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19990021448"><span>Deciphering the Long-Term Trend of <span class="hlt">Atlantic</span> <span class="hlt">Basin</span> Intense Hurricanes: More Active Versus Less Active During the Present Epoch</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wilson, Robert M.</p> <p>1998-01-01</p> <p>During the interval of 1944-1997, 120 intense hurricanes (i.e., those of category 3 or higher on the Saffir-Simpson hurricane damage potential scale) were observed in the <span class="hlt">Atlantic</span> <span class="hlt">basin</span>, having an annual frequency of 0-7 events per year, being more active prior to the mid 1960's than thereafter (hence a possible two-state division: more active versus less active), and being preferentially lower during El Nino years as compared to non-El Nino years. Because decadal averages of the frequency of intense hurricanes closely resemble those of average temperature anomalies for northern hemispheric and global standards and of the average temperature at the Armagh Observatory (Northern Ireland), a proxy for climatic change, it is inferred that the long-term trends of the annual frequency of intense hurricanes and temperature may be statistically related. Indeed, on the basis of 4- and 10-yr moving averages, one finds that there exists strong linear associations between the annual frequency of intense hurricanes in the <span class="hlt">Atlantic</span> <span class="hlt">basin</span> and temperature (specially, when temperature slightly leads). Because the long-term leading trends of temperature are now decidedly upward, beginning about the mid 1980's, it is inferred that the long-term consequential trends of the annual frequency of intense hurricanes should now also be upward, having begun near 1990, suggesting that a return to the more active state probably has already occurred. However, because of the anomalous El Nino activity of the early to mid 1990's, the switch from the less active to the more active state essentially went unnoticed (a marked increase in the number of intense hurricanes was not observed until the 1995 and 1996 hurricane seasons, following the end of the anomalous El Nino activity). Presuming that a return to the more active state has, indeed, occurred, one expects the number of seasonal intense hurricanes during the present epoch (continuing through about 2012) to usually be higher than average (i</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018E%26PSL.481..236W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018E%26PSL.481..236W"><span>Spatio-temporal dynamics of hydrographic reorganizations and iceberg discharges at the junction between the Northeast <span class="hlt">Atlantic</span> and Norwegian Sea <span class="hlt">basins</span> surrounding Heinrich event 4</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wary, Mélanie; Eynaud, Frédérique; Kissel, Catherine; Londeix, Laurent; Rossignol, Linda; Lapuyade, Joanna; Castéra, Marie-Hélène; Billy, Isabelle</p> <p>2018-01-01</p> <p>Dansgaard-Oeschger and Heinrich events constitute ones of the most enigmatic features of the last glacial period. Many studies have focused on their characteristic millennial climatic variability, testing atmospheric/cryospheric/oceanic couplings, but major uncertainties and discrepancies still remain. A new scenario, robustly supported by an approach coupling paleoreconstructions and freshwater hosing experiments simulating Heinrich-type perturbations, has recently emerged. Reconciling most of the up to now hypothesized theories, it suggests the occurrence of a regional seesaw between a cooled-down North <span class="hlt">Atlantic</span> Ocean and warmed-up Nordic Seas during cold atmospheric phases, in relation to enhanced subsurface advection of warm <span class="hlt">Atlantic</span> waters re-emerging in the Norwegian Sea. The associated ocean warming, thus reaching Nordic <span class="hlt">basins</span> at a critical location beyond the Faeroe-Shetland sill, is proposed to be involved in the concomitant release of European icebergs. Here we further investigate this promising scenario over the 35-41 ka BP interval by (i) outlining its precise spatial pattern in a crucial area, i.e. the junction between the North <span class="hlt">Atlantic</span> and the Norwegian Sea close to European ice-sheets, (ii) resolving its very fine temporal and regional evolution during critical transitions associated with the onset of warm advection, i.e. Greenland Interstadial to Greenland Stadial and Greenland Interstadial to Heinrich Stadial, and (iii) assessing its impact on the spatio-temporal dynamic of iceberg discharges from the European and Laurentide ice-sheets during cold stadial episodes especially including Heinrich event 4.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017OcSci..13..873H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017OcSci..13..873H"><span><span class="hlt">Atlantic</span> water flow through the Faroese Channels</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hansen, Bogi; Poulsen, Turið; Margretha Húsgarð Larsen, Karin; Hátún, Hjálmar; Østerhus, Svein; Darelius, Elin; Berx, Barbara; Quadfasel, Detlef; Jochumsen, Kerstin</p> <p>2017-11-01</p> <p>Through the Faroese Channels - the collective name for a system of channels linking the Faroe-Shetland Channel, Wyville Thomson <span class="hlt">Basin</span>, and Faroe Bank Channel - there is a deep flow of cold waters from Arctic regions that exit the system as overflow through the Faroe Bank Channel and across the Wyville Thomson Ridge. The upper layers, in contrast, are dominated by warm, saline water masses from the southwest, termed <span class="hlt">Atlantic</span> water. In spite of intensive research over more than a century, there are still open questions on the passage of these waters through the system with conflicting views in recent literature. Of special note is the suggestion that there is a flow of <span class="hlt">Atlantic</span> water from the Faroe-Shetland Channel through the Faroe Bank Channel, which circles the Faroes over the slope region in a clockwise direction. Here, we combine the observational evidence from ship-borne hydrography, moored current measurements, surface drifter tracks, and satellite altimetry to address these questions and propose a general scheme for the <span class="hlt">Atlantic</span> water flow through this channel system. We find no evidence for a continuous flow of <span class="hlt">Atlantic</span> water from the Faroe-Shetland Channel to the Faroe Bank Channel over the Faroese slope. Rather, the southwestward-flowing water over the Faroese slope of the Faroe-Shetland Channel is totally recirculated within the combined area of the Faroe-Shetland Channel and Wyville Thomson <span class="hlt">Basin</span>, except possibly for a small release in the form of eddies. This does not exclude a possible westward flow over the southern tip of the Faroe Shelf, but even including that, we estimate that the average volume transport of a Circum-Faroe Current does not exceed 0.5 Sv (1 Sv = 106 m3 s-1). Also, there seems to be a persistent flow of <span class="hlt">Atlantic</span> water from the western part of the Faroe Bank Channel into the Faroe-Shetland Channel that joins the Slope Current over the Scottish slope. These conclusions will affect potential impacts from offshore activities in the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009EnGeo..56.1461M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009EnGeo..56.1461M"><span>Classification and statistical analysis of mine spoils chemical composition from Oliete <span class="hlt">basin</span> (Teruel, <span class="hlt">NE</span> Spain)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Meseguer, S.; Sanfeliu, T.; Jordán, M. M.</p> <p>2009-02-01</p> <p>The Oliete <span class="hlt">basin</span> (Early Cretaceous, <span class="hlt">NE</span> Teruel, Spain) is one of the most important areas for the supply of mine spoils used as ball clays for the production of white and red stoneware in the Spanish ceramic industry of wall and floor tiles. This study corresponds to the second part of the paper published recently by Meseguer et al. (Environ Geol 2008) about the use of mine spoils from Teruel coal mining district. The present study shows a statistical data analysis from chemical data (major, minor and trace elements). The performed statistical analysis of chemical data included descriptive statistics and cluster analysis (with ANOVA and Scheffé methods). The cluster analysis of chemical data provided three main groups: C3 with the highest mean SiO2 content (66%) and lowest mean Al2O3 content (20%); C2 with lower SiO2 content (48%) and higher mean Al2O3 content (28%); and C1 with medium values for the SiO2 and Al2O3 mean content. The main applications of these materials are refractory, white and red ceramics, stoneware, heavy ceramics (including red earthenware, bricks and roof tiles), and components of white Portland cement and aluminous cement. Clays from group 2 are used in refractories (with higher kaolinite content, and constrictions to CaO + MgO and K2O + Na2O contents). All materials can be used in fine ceramics (white or red, according to the Fe2O3 + TiO2 content).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20170001699','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20170001699"><span><span class="hlt">Ne</span>-20/<span class="hlt">Ne</span>-22 in the Martian Atmosphere: New Evidence from Martian Meteorites</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Park, J.; Nyquist, L. E.; Herzog, G. F.; Nagao, K.; Mikouchi, T.; Kusakabe, M.</p> <p>2017-01-01</p> <p>Analyses of <span class="hlt">Ne</span> trapped in "pods" of impact melt in the Elephant Moraine 79001 (EET 79001) Martian meteorite led to suggest (<span class="hlt">Ne</span>-20/<span class="hlt">Ne</span>-22) approx.10 in the Martian atmosphere (MA). In contrast, obtained trapped (<span class="hlt">Ne</span>-20/<span class="hlt">Ne</span>-22)Tr approx.7 from an impact melt vein in Yamato 793605 (Y-793605) and concluded that the isotopic composition of Martian <span class="hlt">Ne</span> remained poorly defined. A "pyroxene-rich" separate from Dhofar 378 (Dho 378) analyzed gave a comparatively high trapped <span class="hlt">Ne</span> concentration and (<span class="hlt">Ne</span>-20/<span class="hlt">Ne</span>-22) = 7.3+/-0.2 in agreement with the Y-793605 value. We explore the hypothesis that Martian <span class="hlt">Ne</span> was trapped in the Dho 378 meteorite in a manner similar to entrapment of terrestrial <span class="hlt">Ne</span> in tektites strengthening the "Martian atmosphere" interpretation. We also report new data for Northwest Africa 7034 (NWA 7034) that are consistent with the <span class="hlt">Ne</span> data for Dho 378.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007AGUFM.B22A..06T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007AGUFM.B22A..06T"><span>Hydrodynamic Conditions Influencing Cold-Water Coral Carbonate Mound Development (Challenger Mound, Porcupine Seabight, <span class="hlt">NE</span> <span class="hlt">Atlantic</span>): a Contribution to IODP Exp307</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Thierens, M.; Odonnell, R.; Stuut, J.; Titschack, J.; Dorschel, B.; Wheeler, A. J.</p> <p>2007-12-01</p> <p>Cold-water coral carbonate mounds are complex geo-biological systems, originating from the interplay of hydrodynamic, sedimentological and biological factors. As changes in hydrodynamic and sedimentary regime are assumed to be amongst the main controls on mound evolution, reconstruction of the hydrodynamic and palaeoclimatic microenvironment on-mound, compared to the background environmental conditions (as seen off- mound), contributes to the fundamental understanding of these intriguing features and the development of a cold- water coral carbonate mound development model. Challenger Mound, one of the large cold-water coral carbonate mounds along the eastern Porcupine Seabight continental margin (<span class="hlt">NE</span> <span class="hlt">Atlantic</span>, SW off Ireland), was successfully drilled during IODP Expedition 307, providing the first complete recovery of a continuous sedimentary sequence through a carbonate mound. High-resolution particle size analysis of the terrigenous sediment component is used as primary proxy for reconstructing the hydrodynamic conditions during mound development. First results indicate repeated shifts in hydrodynamic conditions during sediment deposition on Challenger Mound, from lower-energetic conditions to higher-energetic environments and visa versa, which might reflect environmental variation over interglacial-glacial timescales throughout the whole mound development period. In conjunction with other available data, this dataset provides insight in local current regimes and sediment dynamics, the specific role of cold-water corals in these complex geo-biological systems and the differentiation of different sediment contributors to the coral mound system and its surroundings.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.A53D2282M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.A53D2282M"><span>Decadal Variability of Temperature and Salinity in the Northwest <span class="hlt">Atlantic</span> Ocean</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mishonov, A. V.; Seidov, D.; Reagan, J. R.; Boyer, T.; Parsons, A. R.</p> <p>2017-12-01</p> <p>There are only a few regions in the World Ocean where the density of observations collected over the past 60 years is sufficient for reliable data mapping with spatial resolutions finer than one-degree. The Northwest <span class="hlt">Atlantic</span> <span class="hlt">basin</span> is one such regions where a spatial resolution of gridded temperature and salinity fields, comparable to those generated by eddy-resolving numerical models of ocean circulation, has recently becomes available. Using the new high-resolution Northwest <span class="hlt">Atlantic</span> Regional Climatology, built on quarter-degree and one-tenth-degree resolution fields, we analyzed decadal variability and trends of temperature and salinity over 60 years in the Northwest <span class="hlt">Atlantic</span>, and two 30-year ocean climates of 1955-1984 and 1985-2012 to evaluate the oceanic climate shift in this region. The 30-year climate shift is demonstrated using an innovative 3-D visualization of temperature and salinity. Spatial and temporal variability of heat accumulation found in previous research of the entire North <span class="hlt">Atlantic</span> Ocean persists in the Northwest <span class="hlt">Atlantic</span> Ocean. Salinity changes between two 30-year climates were also computed and are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26843658','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26843658"><span>Genetic diversity of the <span class="hlt">NE</span> <span class="hlt">Atlantic</span> sea urchin Strongylocentrotus droebachiensis unveils chaotic genetic patchiness possibly linked to local selective pressure.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Norderhaug, K M; Anglès d'Auriac, M B; Fagerli, C W; Gundersen, H; Christie, H; Dahl, K; Hobæk, A</p> <p></p> <p>We compared the genetic differentiation in the green sea urchin Strongylocentrotus droebachiensis from discrete populations on the <span class="hlt">NE</span> <span class="hlt">Atlantic</span> coast. By using eight recently developed microsatellite markers, genetic structure was compared between populations from the Danish Strait in the south to the Barents Sea in the north (56-79°N). Urchins are spread by pelagic larvae and may be transported long distances by northwards-going ocean currents. Two main superimposed patterns were identified. The first showed a subtle but significant genetic differentiation from the southernmost to the northernmost of the studied populations and could be explained by an isolation by distance model. The second pattern included two coastal populations in mid-Norway (65°N), NH and NS, as well as the northernmost population of continental Norway (71°N) FV. They showed a high degree of differentiation from all other populations. The explanation to the second pattern is most likely chaotic genetic patchiness caused by introgression from another species, S. pallidus, into S. droebachiensis resulting from selective pressure. Ongoing sea urchin collapse and kelp forests recovery are observed in the area of NH, NS and FV populations. High gene flow between populations spanning more than 22° in latitude suggests a high risk of new grazing events to occur rapidly in the future if conditions for sea urchins are favourable. On the other hand, the possibility of hybridization in association with collapsing populations may be used as an early warning indicator for monitoring purposes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29668011','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29668011"><span>Effective population size and the genetic consequences of commercial whaling on the humpback whales (Megaptera novaeangliae) from Southwestern <span class="hlt">Atlantic</span> Ocean.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Cypriano-Souza, Ana Lúcia; da Silva, Tiago Ferraz; Engel, Márcia H; Bonatto, Sandro L</p> <p>2018-01-01</p> <p>Genotypes of 10 microsatellite loci of 420 humpback whales from the Southwestern <span class="hlt">Atlantic</span> Ocean population were used to estimate for the first time its contemporary effective (<span class="hlt">Ne</span>) and census (Nc) population sizes and to test the genetic effect of commercial whaling. The results are in agreement with our previous studies that found high genetic diversity for this breeding population. Using an approximate Bayesian computation approach, the scenario of constant <span class="hlt">Ne</span> was significantly supported over scenarios with moderate to strong size changes during the commercial whaling period. The previous generation Nc (<span class="hlt">Ne</span> multiplied by 3.6), which should corresponds to the years between around 1980 and 1990, was estimated between ~2,600 and 6,800 whales (point estimate ~4,000), and is broadly compatible with the recent abundance surveys extrapolated to the past using a growth rate of 7.4% per annum. The long-term Nc in the constant scenario (point estimate ~15,000) was broadly compatible (considering the confidence interval) with pre-whaling catch records estimates (point estimate ~25,000). Overall, our results shown that the Southwestern <span class="hlt">Atlantic</span> Ocean humpback whale population is genetically very diverse and resisted well to the strong population reduction during commercial whaling.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1914311H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1914311H"><span>Reinterpretation of the tectonics and formation of the Pernambuco Plateau <span class="hlt">Basin</span>, <span class="hlt">NE</span> Brazil.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hoggett, Murray; Jones, Stephen M.; Dunkley Jones, Tom; Reston, Timothy; Barbosa, Antonio; Biondo, Vanessa; Mort, Haydon P.</p> <p>2017-04-01</p> <p>The continental margin from Alagoas to Natal represents arguably the most frontier region for exploration on the Brazillian margin. High quality seismic data was not collected in the region for many decades as it was believed that only a few kilometers of sediment existed, and thus there was no exploration potential. Here we present the results of work done as part of an IODP virtual site survey. The work has resulted in a total reinterpretation of the <span class="hlt">basin</span> structure and tectonics, including finding sediment filled half grabens holding up to 8km thick stratigraphic sections. The two deepest grabens likely represent rift jumps during breakup, which may imply different age sediments in the different grabens. The <span class="hlt">basin</span> is also found to contain a sizable salt accumulation, previously uninterpreted due to hard overlying carbonates hampering seismic imaging. This salt can be seen to have been highly mobile in the past, and has developed into kilometer scale diapirs flanked by typical rollover anticlines. For the first time we show the <span class="hlt">basin</span> has all the elements needed for a working petroleum system, with the exception a source rock - which cannot be speculated on further as the <span class="hlt">basin</span> is undrilled. However source rock sequences are present in the Alagoas <span class="hlt">basin</span> to the south, and recent released seep data show evidence for both biogeneic and thermogenic seeps over the plateau <span class="hlt">basin</span>, which could also signal source rock presence. We present seismic and potential fields data, including forward potential fields models and seismically derived crustal stretching and thinning estimates, to show that the half grabens terminate abruptly at the latitude of the Pernambuco Shear Zone, a major crustal scale Precambrian shear zone. Onshore boreholes, well away from the deep seismically imaged half grabens offshore, find crystalline basement to drop away rapidly across the shearzone, revealing a third graben to terminate at the shear zone. We interpret this as that the preexisting</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EGUGA..14.6489C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EGUGA..14.6489C"><span>Palaeogeographic evolution of the central segment of the South <span class="hlt">Atlantic</span> during Early Cretaceous times: palaeotopographic and geodynamic implications</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chaboureau, A. C.; Guillocheau, F.; Robin, C.; Rohais, S.; Moulin, M.; Aslanian, D.</p> <p>2012-04-01</p> <p>The tectonic and sedimentary evolution of the Early Cretaceous rift of the central segment of the South <span class="hlt">Atlantic</span> Ocean is debated. Our objective is to better constraint the timing of its evolution by drawing palaeogeographic and deformation maps. Eight palaeogeographic and deformations maps were drawn from the Berriasian to the Middle-Late Aptian, based on a biostratigraphic (ostracodes and pollens) chart recalibrated on absolute ages (chemostratigraphy, interstratified volcanics, Re-Os dating of the organic matter). The central segment of the South <span class="hlt">Atlantic</span> is composed of two domains that have a different history in terms of deformation and palaeogeography. The southern domain includes Namibe, Santos and Campos <span class="hlt">Basins</span>. The northern domain extends from Espirito Santo and North Kwanza <span class="hlt">Basins</span>, in the South, to Sergipe-Alagoas and North Gabon <span class="hlt">Basins</span> to the North. Extension started in the northern domain during Late Berriasian (Congo-Camamu <span class="hlt">Basin</span> to Sergipe-Alagoas-North Gabon <span class="hlt">Basins</span>) and migrated southward. At that time, the southern domain was not a subsiding domain. This is time of emplacement of the Parana-Etendeka Trapp (Late Hauterivian-Early Barremian). Extension started in this southern domain during Early Barremian. The brittle extensional period is shorter in the South (5-6 Ma, Barremian to base Aptian) than in the North (19 to 20 Myr, Upper Berriasian to Base Aptian). From Late Berriasian to base Aptian, the northern domain evolves from a deep lake with lateral highs to a shallower one, organic-rich with no more highs. The lake migrates southward in two steps, until Valanginian at the border between the northern and southern domains, until Early Barremian, North of Walvis Ridge. The Sag phase is of Middle to Late Aptian age. In the southern domain, the transition between the brittle rift and the sag phase is continuous. In the northern domain, this transition corresponds to a hiatus of Early to Middle Aptian age, possible period of mantle exhumation. Marine</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005AGUFMGP21A0020C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005AGUFMGP21A0020C"><span>IODP Expedition 303 (North <span class="hlt">Atlantic</span>): Excursions and Reversals in the Brunhes and Matuyama Chrons</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Channell, J. E.; Mazaud, A.; Stoner, J. S.</p> <p>2005-12-01</p> <p>The primary objective of IODP Expedition 303 (Sept.-Nov., 2004) was to recover complete and continuous records of Pliocene-Quaternary millennial-scale environmental and geomagnetic variability, and place these records into high-resolution isotopic and magnetic stratigraphies (including relative paleointensity). Some of the Exp. 303 site locations (Orphan Knoll, Eirik and Gardar Drifts, and DSDP Site 609) have already been instrumental in developing marine records of suborbital climate variability for the last climate cycle, and the goal of Exp. 303 was to extend the records back through the Quaternary and into the Pliocene. High mean sedimentation rates (15-20 cm/ky) at sites located on Orphan Knoll (Site U1302/3), Eirik Drift (Sites U1305 and U1306) and Gardar Drift (Site U1304) have resulted in shipboard records of excursions and reversals in the Brunhes and Matuyama Chrons. Site U1308 (DSDP Site 609) has lower mean sedimentation rate (7.9 cm/kyr) and extends the record into the Gauss Chron to ~3.1 Ma. Initial u-channel magnetic data support the existence of a number of polarity excursions in the Matuyama Chron, but only a single polarity excursion (Iceland <span class="hlt">Basin</span> Event) has so far been observed in the Brunhes Chron. The Matuyama-Brunhes (M-B) polarity reversal yields virtual geomagnetic polar (VGP) paths that are reminiscent of those recovered from the northern Gardar and Bjorn drifts during ODP Leg 162. VGP clusters in the South <span class="hlt">Atlantic</span> and off <span class="hlt">NE</span> Asia accompany a Pacific loop, in what appears to be a repetitive but complex pattern for the M-B transition recorded in 9 holes from three Exp. 303 North <span class="hlt">Atlantic</span> sites.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014Tectp.614...78B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014Tectp.614...78B"><span>Neotectonic reactivation of shear zones and implications for faulting style and geometry in the continental margin of <span class="hlt">NE</span> Brazil</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bezerra, F. H. R.; Rossetti, D. F.; Oliveira, R. G.; Medeiros, W. E.; Neves, B. B. Brito; Balsamo, F.; Nogueira, F. C. C.; Dantas, E. L.; Andrades Filho, C.; Góes, A. M.</p> <p>2014-02-01</p> <p>The eastern continental margin of South America comprises a series of rift <span class="hlt">basins</span> developed during the breakup of Pangea in the Jurassic-Cretaceous. We integrated high resolution aeromagnetic, structural and stratigraphic data in order to evaluate the role of reactivation of ductile, Neoproterozoic shear zones in the deposition and deformation of post-rift sedimentary deposits in one of these <span class="hlt">basins</span>, the Paraíba <span class="hlt">Basin</span> in northeastern Brazil. This <span class="hlt">basin</span> corresponds to the last part of the South American continent to be separated from Africa during the Pangea breakup. Sediment deposition in this <span class="hlt">basin</span> occurred in the Albian-Maastrichtian, Eocene-Miocene, and in the late Quaternary. However, our investigation concentrates on the Miocene-Quaternary, which we consider the neotectonic period because it encompasses the last stress field. This consisted of an E-W-oriented compression and a N-S-oriented extension. The basement of the <span class="hlt">basin</span> forms a slightly seaward-tilted ramp capped by a late Cretaceous to Quaternary sedimentary cover ~ 100-400 m thick. Aeromagnetic lineaments mark the major steeply-dipping, ductile E-W- to <span class="hlt">NE</span>-striking shear zones in this basement. The ductile shear zones mainly reactivated as strike-slip, normal and oblique-slip faults, resulting in a series of Miocene-Quaternary depocenters controlled by <span class="hlt">NE</span>-, E-W-, and a few NW-striking faults. Faulting produced subsidence and uplift that are largely responsible for the present-day morphology of the valleys and tablelands in this margin. We conclude that Precambrian shear zone reactivation controlled geometry and orientation, as well as deformation of sedimentary deposits, until the Neogene-Quaternary.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1913954B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1913954B"><span>Paleogeographic constraints on continental-scale source-to-sink systems: Northern South America and its <span class="hlt">Atlantic</span> margins</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bajolet, Flora; Chardon, Dominique; Rouby, Delphine; Dall'Asta, Massimo; Roig, Jean-Yves; Loparev, Artiom; Coueffe, Renaud</p> <p>2017-04-01</p> <p>Our work aims at setting the evolving boundary conditions of erosion and sediments transfer, transit, and onshore-offshore accumulations on northern South America and along its <span class="hlt">Atlantic</span> margins. Since the Early Mesozoic, the source-to-sink system evolved under the interplay of four main processes, which are (i) volcanism and arc building along the proto-Andes, (ii) long-term dynamics of the Amazon incratonic <span class="hlt">basin</span>, (iii) rifting, relaxation and rejuvenation of the <span class="hlt">Atlantic</span> margins and (iv) building of the Andes. We compiled information available from geological maps and the literature regarding tectonics, plate kinematics, magmatism, stratigraphy, sedimentology (including paleoenvironments and currents) and thermochronology to produce a series of paleogeographic maps showing the tectonic and kinematic framework of continental areas under erosion (sources), by-pass and accumulation (sinks) over the Amazonian craton, its adjacent regions and along its <span class="hlt">Atlantic</span> margins. The maps also allow assessing the relative impact of (i) ongoing Pacific subduction, (ii) <span class="hlt">Atlantic</span> rifting and its aftermath, and (iii) <span class="hlt">Atlantic</span> slab retreat from under the Caribbean domain on the distribution and activity of onshore/offshore sedimentary <span class="hlt">basins</span>. Stratigraphic and thermochronology data are also used to assess denudation / vertical motions due to sediment transfers and lithosphere-asthenosphere interactions. This study ultimately aims at linking the sediment routing system to long-wavelength deformation of northern South America under the influence of mountain building, intracratonic geodynamics, divergent margin systems and mantle dynamics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.P51A2121W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.P51A2121W"><span>Source of Volatiles in Earth's Deep Mantle from Neon Isotope Systematics in the South <span class="hlt">Atlantic</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Williams, C. D.; Mukhopadhyay, S.</p> <p>2016-12-01</p> <p>The noble gases play an important role in understanding Earth's accretion and subsequent evolution. Neon isotopes in particular have the potential to distinguish between distinct sources of Earth's volatiles e.g., acquisition of nebular gas, solar wind implanted materials or chondritic meteorites and their components. The neon isotopic composition of the deep mantle remains subject to debate with the majority of mantle-derived basalts displaying maximum 20<span class="hlt">Ne</span>/22<span class="hlt">Ne</span> ratios less than 12.5, similar to values determined for the convective mantle (20<span class="hlt">Ne</span>/22<span class="hlt">Ne</span> = 12.49 +/- 0.04; [1]). These values are also much lower than those of solar wind (20<span class="hlt">Ne</span>/22<span class="hlt">Ne</span> = 13.8; [2,3]) and estimates of the nebular gas (20<span class="hlt">Ne</span>/22<span class="hlt">Ne</span> = 13.4; [4]) but comparable to solar wind implanted meteoritic materials (20<span class="hlt">Ne</span>/22<span class="hlt">Ne</span> = 12.5-12.7; [5]). Here we determine the neon isotopic composition of mantle-derived materials from the south <span class="hlt">Atlantic</span>. These samples display strong linear correlations in 20<span class="hlt">Ne</span>/22<span class="hlt">Ne</span>-21<span class="hlt">Ne</span>/22<span class="hlt">Ne</span> space with maximum 20<span class="hlt">Ne</span>/22<span class="hlt">Ne</span> ratios that are resolvable from and higher than materials derived from the convecting mantle as well as models of solar wind implantation. These results supplement a growing database of mantle materials characterized by 20<span class="hlt">Ne</span>/22<span class="hlt">Ne</span> ratios greater than 12.5, challenging the notion that the entire mantle acquired volatiles from solar wind implanted meteoritic materials. In this presentation we will explore alternative origins for these volatiles and provide testable predictions for each scenario. [1] G. Holland, C.J. Ballentine.. Nature 441 (2006), 186-191. [2] A. Gimberg et al. GCA 72 (2008), 626-645. [3] V.S. Heber et al. GCA 73 (2009), 7414-7432. [4] V. S. Heber et al. ApJ 759 (2012), 121. [5] R. Wieler in: D. Porcelli, C.J. Ballentine, R. Wieler (Eds.), Reviews in Mineralogy and Geochemistry 47 (2002), 21-70.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_13 --> <div id="page_14" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="261"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016NHESS..16.1967B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016NHESS..16.1967B"><span>New study on the 1941 Gloria Fault earthquake and tsunami</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Baptista, Maria Ana; Miranda, Jorge Miguel; Batlló, Josep; Lisboa, Filipe; Luis, Joaquim; Maciá, Ramon</p> <p>2016-08-01</p> <p>The M ˜ 8.3-8.4 25 November 1941 was one of the largest submarine strike-slip earthquakes ever recorded in the Northeast (<span class="hlt">NE</span>) <span class="hlt">Atlantic</span> <span class="hlt">basin</span>. This event occurred along the Eurasia-Nubia plate boundary between the Azores and the Strait of Gibraltar. After the earthquake, the tide stations in the <span class="hlt">NE</span> <span class="hlt">Atlantic</span> recorded a small tsunami with maximum amplitudes of 40 cm peak to through in the Azores and Madeira islands. In this study, we present a re-evaluation of the earthquake epicentre location using seismological data not included in previous studies. We invert the tsunami travel times to obtain a preliminary tsunami source location using the backward ray tracing (BRT) technique. We invert the tsunami waveforms to infer the initial sea surface displacement using empirical Green's functions, without prior assumptions about the geometry of the source. The results of the BRT simulation locate the tsunami source quite close to the new epicentre. This fact suggests that the co-seismic deformation of the earthquake induced the tsunami. The waveform inversion of tsunami data favours the conclusion that the earthquake ruptured an approximately 160 km segment of the plate boundary, in the eastern section of the Gloria Fault between -20.249 and -18.630° E. The results presented here contribute to the evaluation of tsunami hazard in the Northeast <span class="hlt">Atlantic</span> <span class="hlt">basin</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..1610090K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..1610090K"><span>Active faults and minor plates in <span class="hlt">NE</span> Asia</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kozhurin, Andrey I.; Zelenin, Egor A.</p> <p>2014-05-01</p> <p> portion of the plate northern boundary. With this, we have discovered no active faults or fault zones of the Ulakhan fault strike, which could be the portion of the boundary between the Lankovaya-Omolon zone and either the western margin of the Komandor <span class="hlt">basin</span> or the westernmost Aleutians. We conclude that there is a certain disagreement between active faulting pattern and plate models for <span class="hlt">NE</span> Asia, relating to the extent of the plates and missing portions of the plate boundaries. The research was supported by grant # 110500136-a from the Russian Foundation for Basic Research.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017Tectp.716...21J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017Tectp.716...21J"><span>Crustal structure of the Agulhas Ridge (South <span class="hlt">Atlantic</span> Ocean): Formation above a hotspot?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jokat, Wilfried; Hagen, Claudia</p> <p>2017-10-01</p> <p>The southern South <span class="hlt">Atlantic</span> Ocean contains several features believed to document the traces of hotspot volcanism during the early formation of the ocean <span class="hlt">basin</span>, namely the Agulhas Ridge and the Cape Rise seamounts located in the southeast <span class="hlt">Atlantic</span> between 36°S and 50°S. The Agulhas Ridge parallels the Agulhas-Falkland Fracture Zone, one of the major transform zones of the world. The morphology of the ridge changes dramatically from two parallel segments in the southwest, to the broad plateau-like Agulhas Ridge in the northeast. Because the crustal fabric of the ridge is unknown relating its evolution to hotspots in the southeast <span class="hlt">Atlantic</span> is an open question. During the RV Polarstern cruise ANT-XXIII-5 seismic reflection and refraction data were collected along a 370 km long profile with 8 Ocean Bottom Stations to investigate its crustal fabric. The profile extends in NNE direction from the Agulhas <span class="hlt">Basin</span>, 60 km south of the Agulhas Ridge, and continues into the Cape <span class="hlt">Basin</span> crossing the southernmost of the Cape Rise seamounts. In the Cape <span class="hlt">Basin</span> we found a crustal thickness of 5.5-7.5 km, and a velocity distribution typical for oceanic crust. The Cape Rise seamounts, however, show a higher velocity in comparison to the surrounding oceanic crust and the Agulhas Ridge. Underplated material is evident below the southernmost of the Cape Rise seamounts. It also has a 5-8% higher density compared to the Agulhas Plateau. The seismic velocities of the Agulhas Ridge are lower, the crustal thickness is approximately 14 km, and age dating of dredge samples from its top provides clear evidence of rejuvenated volcanism at around 26 Ma. Seismic data indicate that although the Cape Rise seamounts formed above a mantle thermal anomaly it had a limited areal extent, whereas the hotspot material that formed the Agulhas Ridge likely erupted along a fracture zone.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017DSRII.145....8L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017DSRII.145....8L"><span>Effects of cold-water corals on fish diversity and density (European continental margin: Arctic, <span class="hlt">NE</span> <span class="hlt">Atlantic</span> and Mediterranean Sea): Data from three baited lander systems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Linley, T. D.; Lavaleye, M.; Maiorano, P.; Bergman, M.; Capezzuto, F.; Cousins, N. J.; D'Onghia, G.; Duineveld, G.; Shields, M. A.; Sion, L.; Tursi, A.; Priede, I. G.</p> <p>2017-11-01</p> <p>Autonomous photographic landers are a low-impact survey method for the assessment of mobile fauna in situations where methods such as trawling are not feasible or ethical. Three institutions collaborated through the CoralFISH project, each using differing lander systems, to assess the effects of cold-water corals on fish diversity and density. The Biogenic Reef Ichthyofauna Lander (BRIL, Oceanlab), Autonomous Lander for Biological Experiments (ALBEX, NIOZ) and the Marine Environment MOnitoring system (MEMO, CoNISMa) were deployed in four CoralFISH European study regions covering the Arctic, <span class="hlt">NE</span> <span class="hlt">Atlantic</span> and Mediterranean, namely Northern Norway (275-310 m depth), Belgica Mound Province (686-1025 m depth), the Bay of Biscay (623-936 m depth), and Santa Maria di Leuca (547-670 m depth). A total of 33 deployments were carried out in the different regions. Both the time of first arrival (Tarr) and the maximum observed number of fish (MaxN) were standardised between the different lander systems and compared between coral and reference stations as indicators of local fish density. Fish reached significantly higher MaxN at the coral stations than at the reference stations. Fish were also found to have significantly lower Tarr in the coral areas in data obtained from the BRIL and MEMO landers. All data indicated that fish abundance is higher within the coral areas. Fish species diversity was higher within the coral areas of <span class="hlt">Atlantic</span> Ocean while in Northern Norway and Santa Maria di Leuca coral areas, diversity was similar at coral and reference stations but a single dominant species (Brosme brosme and Conger conger respectively) showed much higher density within the coral areas. Indicating that, while cold-water coral reefs have a positive effect on fish diversity and/or abundance, this effect varies across Europe's reefs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.noaanews.noaa.gov/stories2013/20130411_sandynameretiredt.html','SCIGOVWS'); return false;" href="http://www.noaanews.noaa.gov/stories2013/20130411_sandynameretiredt.html"><span>Sandy retired from list of <span class="hlt">Atlantic</span> <span class="hlt">Basin</span> tropical cyclone names</span></a></p> <p><a target="_blank" href="http://www.science.gov/aboutsearch.html">Science.gov Websites</a></p> <p></p> <p></p> <p>2012 <span class="hlt">Atlantic</span> <em>hurricane</em> season Media Contact Dennis Feltgen 305-229-4404 305-433-1933 (cellular) Share tropical cyclone names April 11, 2013 GOES East image of <em>Hurricane</em> Sandy, Oct. 29, 2012. This NOAA GOES-13 cyclone names by the World Meteorological Organization's <em>hurricane</em> committee because of the extreme</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015ESSD....7..173L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015ESSD....7..173L"><span>Biogeography of jellyfish in the North <span class="hlt">Atlantic</span>, by traditional and genomic methods</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Licandro, P.; Blackett, M.; Fischer, A.; Hosia, A.; Kennedy, J.; Kirby, R. R.; Raab, K.; Stern, R.; Tranter, P.</p> <p>2015-07-01</p> <p>Scientific debate on whether or not the recent increase in reports of jellyfish outbreaks represents a true rise in their abundance has outlined a lack of reliable records of Cnidaria and Ctenophora. Here we describe different jellyfish data sets produced within the EU programme EURO-<span class="hlt">BASIN</span>. These data were assembled with the aim of creating an improved baseline and providing new data that can be used to evaluate the current diversity and standing stocks of jellyfish in the North <span class="hlt">Atlantic</span> region. Using a net adapted to sample gelatinous zooplankton quantitatively, cnidarians and ctenophores were collected from the epipelagic layer during spring-summer 2010-2013, in inshore and offshore waters between lat 59 and 68° N and long 62° W and 5° E. Jellyfish were also identified and counted in samples opportunistically collected by other sampling equipment in the same region and at two coastal stations in the Bay of Biscay and in the Gulf of Cadiz. Continuous Plankton Recorder (CPR) samples collected in 2009-2012 were re-analysed with the aim of identifying the time and location of cnidarian blooms across the North <span class="hlt">Atlantic</span> <span class="hlt">Basin</span>. Overall the data show high variability in jellyfish abundance and diversity, mainly in relation to different water masses and bathymetry. Higher densities were generally recorded on the shelves, where the communities tend to be more diverse due to the presence of meropelagic medusae. Comparison of net records from the G.O. Sars transatlantic cruise shows that information on jellyfish diversity differs significantly depending on the sampling gear utilised. Indeed, the big trawls mostly collect relatively large scyphozoan and hydrozoan species, while small hydrozoans and early stages of Ctenophora are only caught by smaller nets. Based on CPR data from 2009 to 2012, blooms of cnidarians occurred in all seasons across the whole North <span class="hlt">Atlantic</span> <span class="hlt">Basin</span>. Molecular analysis revealed that, contrary to previous hypotheses, the CPR is able to detect</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.A53D2283N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.A53D2283N"><span>The Caspian Sea Catchment influenced by <span class="hlt">Atlantic</span> Teleconnections in CESM1.2.2 and Observations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nandini, S. D.; Prange, M.; Schulz, M.</p> <p>2017-12-01</p> <p>The Caspian Sea (CS) is the world's largest inland sea and located within a closed (endorheic) drainage <span class="hlt">basin</span> [ 37°-47N, 47°-54°E]. It has undergone dynamic variations (>3 m) during the past century with huge impacts on the economy, ecosystem and livelihood of coastal people. The origin of these variations as well as future changes are disputable. Here, we examine the impact of the major seasonal North <span class="hlt">Atlantic</span> teleconnection patterns, the North <span class="hlt">Atlantic</span> Oscillation (NAO) and the East <span class="hlt">Atlantic</span> pattern (EA) on Caspian hydroclimate variability from 1850-2100 CE. Five Numerical experiments at different atmospheric grid resolutions (2° and 1°) and atmospheric model versions (CAM4 and CAM5) are carried out with the coupled Community Earth System Model (CESM1.2.2). Results reveal the 1° CESM1.2.2 CAM5 captures DJF NAO (46.5%) and EA (13.4%), agreeing well with observational data (1850-2000). The DJF NAO has a strong influence on the DJF temperature, rainfall and evaporation minus precipitation (E-P) over the Caspian sub-<span class="hlt">basins</span> (Volga, Ural, Terek and Kura). Furthermore, 1° model climate projections (2020-2100 CE) are performed with different Representative Concentration Pathways (RCP4.5 and RCP8.5) to examine likely changes in the NAO and EA and their influence on the Caspian catchment. The NAO under the RCP4.5 and RCP8.5 scenarios remains the leading mode with the highest variance and influences E-P with increased precipitation over the Volga <span class="hlt">basin</span> and increased evaporation over the Caspian Sea. The above canceling effects act on the hydroclimate variability in the Caspian sub-<span class="hlt">basins</span>. Moreover, it is indicated that no substantial change is predicted in the CSL by the year 2100. Keywords: North <span class="hlt">Atlantic</span> Oscillation (NAO), CESM1.2.2 resolutions, Evaporation minus Precipitation (E-P), RCP4.5, RCP8.5</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.T31C2521H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.T31C2521H"><span>The influence of pre-existing basement structures on salt tectonics in the Upper Silurian Salina Group, Appalachian <span class="hlt">Basin</span>, <span class="hlt">NE</span> Pennsylvania: results from 3D seismic analysis and analogue modelling</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Harding, M. R.; Rowan, C. J.</p> <p>2013-12-01</p> <p>The Upper Silurian Salina Group in Pennsylvania's Appalachian <span class="hlt">basin</span> consists of several hundred feet of highly deformable and mobile salt that was a significant influence on the tectonic and structural development of the Appalachian Mountains during the late Paleozoic. Understanding how halokinesis and décollement thrusting of the Salina Group has contributed to the present-day structure of the Appalachian <span class="hlt">Basin</span> is of intense current interest due to the energy resource potential of the overlying Marcellus Shale and underlying Utica Shale. Seismic data suggest that halokinesis of the Salina Group in the Appalachian <span class="hlt">Basin</span> might be strongly influenced by the presence of preexisting faults in the underlying Neoproterozoic basement, which suggests that these structures may have interacted with the Salina Group or its interior during deformation. We examine these apparent interactions in more detail using high-resolution 3D seismic data from the Appalachian <span class="hlt">Basin</span> of <span class="hlt">NE</span> Pennsylvania to identify and characterize salt tectonic-related structures developed above and within the Salina Group during orogenesis, verify their geographic association with major basement faults, and document how reactivation of these preexisting faults might have influenced later deformation within and above the salt units. We also present the results of sandbox modelling of thin-skinned thrusting in a salt-analogue décollement. Multiple runs in the presence and absence of preexisting basement structures provide insight into how the modern structures observed in the seismic data initiated and evolved during progressively more intense orogenesis, and better constrain the physical processes that control the structural linkage through the Salina décollement.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.T41B2918O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.T41B2918O"><span>Quaternary Activity of the Erciyes Fault Southeast of the Kayseri <span class="hlt">Basin</span>, Turkey</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Okumura, K.; Hayakawa, Y. S.; Kontani, R.; Fikri, K.</p> <p>2016-12-01</p> <p>The Erciyes fault in SE of the Kayseri <span class="hlt">basin</span> is one of the most active Quaternary faults in Central Anatolia. Emre et al. (2011) mapped about 100 km long faults including a section runs across the Erciyes volcano. A M 7+ earthquake from the fault would be a big threat for the 1.5 million people in Kayseri <span class="hlt">basin</span>, but little has been know about its activity and earthquake potential. We studied Plio-Pleistocene volacanics, Quaternary sediments, and UAV-SfM topography in southeast of the Kayseri <span class="hlt">basin</span> and recognized significant dip-slip separation as well as sinistral slip in Late Quaternary. The Incesu ignimbrite (IC) of 2.52±0.49 Ma (Aydar et al., 2012) is a very distinctive densely welded ignimbrite layer in and around Kayseri <span class="hlt">basin</span>. The Plinian pumice fall deposits from the Erciyes in Late Pleistocene (Sen et al. 2003) at Gesi Bagpnar (GBP) is another key-bed. There are two strands and one group of faults. The <span class="hlt">NE</span> strike frontal strand separates the <span class="hlt">basin</span> floor and the upland in SW extending from Kayseri city to more than 50 km <span class="hlt">NE</span>. The Gesi Guney strand runs parallel to the frontal strand at 3 to 4 km away from the <span class="hlt">basin</span> floor for 20 km from Ali Dag. The NS trending fault group is observed both inside and outside of the <span class="hlt">basin</span> under IC. These NS faults are swarm of normal Pliocene faults. The Gesi Guney strand offsets IC around 120 m vertically. There is no information to infer the initiation of its activity, but the normal offset of an alluvial fan and unconsolidated fresh talus deposits indicate Late Quaternary activities. Near the SW end of the frontal strand, IC is vertically offset around 40 m. 15 km <span class="hlt">NE</span> from the SW end, sand and gravel layers that intercalates GBP (0.11-0.14 Ma) are tilted to NW for 30 to 40 m and truncated by a sub-vertical sinistral faults. Most of frontal strand deformation occurred in Late Pleistocene because the offset of IC and GBP are similar. Estimated slip-rate of 0.3 to 0.4 mm/yr is significant for Central Anatolia.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017GeoRL..4412511A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017GeoRL..4412511A"><span>A Midwinter Minimum in North <span class="hlt">Atlantic</span> Storm Track Intensity in Years of a Strong Jet</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Afargan, H.; Kaspi, Y.</p> <p>2017-12-01</p> <p>This study investigates the occurrence of a midwinter suppression in synoptic eddy activity within the North <span class="hlt">Atlantic</span> storm track. It is found that eddy kinetic energy over the <span class="hlt">Atlantic</span> is reduced during winter relative to fall and spring, despite the stronger wintertime jet and enhanced baroclinicity. This behavior is similar to the well-known Pacific midwinter minimum, yet the reduction over the <span class="hlt">Atlantic</span> is smaller and persists for a shorter period. To examine the conditions favorable for this phenomenon, we present an analysis of years with stronger jet intensity versus years of weaker jets over the <span class="hlt">Atlantic</span> and Pacific <span class="hlt">basins</span>. When the wintertime jet is stronger, the midwinter suppression of eddy activity is more pronounced, and the jet is more equatorward. Since the climatological <span class="hlt">Atlantic</span> jet is weaker relative to the Pacific jet, the conditions for a midwinter suppression in the <span class="hlt">Atlantic</span> are generally less favorable, yet a midwinter suppression often occurs in years of a strong jet.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16906489','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16906489"><span>Caladium bicolor (Araceae) and Cyclocephala celata (Coleoptera, Dynastinae): a well-established pollination system in the Northern <span class="hlt">Atlantic</span> rainforest of Pernambuco, Brazil.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Maia, A C D; Schlindwein, C</p> <p>2006-07-01</p> <p>Flowering, pollination ecology, and floral thermogenesis of Caladium bicolor were studied in the <span class="hlt">Atlantic</span> Rainforest of Pernambuco, <span class="hlt">NE</span> Brazil. Inflorescences of this species are adapted to the characteristic pollination syndrome performed by Cyclocephalini beetles. They bear nutritious rewards inside well-developed floral chambers and exhibit a thermogenic cycle which is synchronized to the activity period of visiting beetles. Heating intervals of the spadix were observed during consecutive evenings corresponding to the beginning of the female and male phases of anthesis. Highest temperatures were recorded during the longer-lasting female phase. An intense sweet odour was volatized on both evenings. Beetles of a single species, Cyclocephala celata, were attracted to odoriferous inflorescences of C. bicolor and are reported for the first time as Araceae visitors. All the inflorescences visited by C. celata developed into infructescences, whereas unvisited inflorescences showed no fruit development. Findings of previous studies in the Amazon <span class="hlt">basin</span> of Surinam indicated that Cyclocephala rustica is a likely pollinator of C. bicolor. This leads to the assumption that locally abundant Cyclocephalini species are involved in the pollination of this species.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/15961666','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/15961666"><span>Dilution of the northern North <span class="hlt">Atlantic</span> Ocean in recent decades.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Curry, Ruth; Mauritzen, Cecilie</p> <p>2005-06-17</p> <p>Declining salinities signify that large amounts of fresh water have been added to the northern North <span class="hlt">Atlantic</span> Ocean since the mid-1960s. We estimate that the Nordic Seas and Subpolar <span class="hlt">Basins</span> were diluted by an extra 19,000 +/- 5000 cubic kilometers of freshwater input between 1965 and 1995. Fully half of that additional fresh water-about 10,000 cubic kilometers-infiltrated the system in the late 1960s at an approximate rate of 2000 cubic kilometers per year. Patterns of freshwater accumulation observed in the Nordic Seas suggest a century time scale to reach freshening thresholds critical to that portion of the <span class="hlt">Atlantic</span> meridional overturning circulation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1912941R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1912941R"><span>How predictable are equatorial <span class="hlt">Atlantic</span> surface winds?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Richter, Ingo; Doi, Takeshi; Behera, Swadhin</p> <p>2017-04-01</p> <p>Sensitivity tests with the SINTEX-F general circulation model (GCM) as well as experiments from the Coupled Model Intercomparison Project phase 5 (CMIP5) are used to examine the extent to which sea-surface temperature (SST) anomalies contribute to the variability and predictability of monthly mean surface winds in the equatorial <span class="hlt">Atlantic</span>. In the SINTEX-F experiments, a control experiment with prescribed observed SST for the period 1982-2014 is modified by inserting climatological values in certain regions, thereby eliminating SST anomalies. When SSTs are set to climatology in the tropical <span class="hlt">Atlantic</span> only (30S to 30N), surface wind variability over the equatorial <span class="hlt">Atlantic</span> (5S-5N) decreases by about 40% in April-May-June (AMJ). This suggests that about 60% of surface wind variability is due to either internal atmospheric variability or SSTs anomalies outside the tropical <span class="hlt">Atlantic</span>. A further experiment with climatological SSTs in the equatorial Pacific indicates that another 10% of variability in AMJ may be due to remote influences from that <span class="hlt">basin</span>. Experiments from the CMIP5 archive, in which climatological SSTs are prescribed globally, tend to confirm the results from SINTEX-F but show a wide spread. In some models, the equatorial <span class="hlt">Atlantic</span> surface wind variability decreases by more than 90%, while in others it even increases. Overall, the results suggest that about 50-60% of surface wind variance in AMJ is predictable, while the rest is due to internal atmospheric variability. Other months show significantly lower predictability. The relatively strong internal variability as well as the influence of remote SSTs suggest a limited role for coupled ocean-atmosphere feedbacks in equatorial <span class="hlt">Atlantic</span> variability.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005AGUFM.T53A1416O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005AGUFM.T53A1416O"><span>Tectonic Evolution of the Southern tip of the Parece Vela <span class="hlt">Basin</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Okino, K.; Ohara, Y.; Fujiwara, T.; Lee, S.; Nakamura, Y.; Wu, S.</p> <p>2005-12-01</p> <p>The southern tip of the Parece Vela <span class="hlt">Basin</span> was mapped using state-of-the-art instruments for the first time. The <span class="hlt">basin</span> is known as an extinct backarc <span class="hlt">basin</span> behind the Mariana arc-trench system and has developed from ~26 to 12 Ma. The backarc spreading consists of two stages: early east-west spreading and later <span class="hlt">NE</span>-SW spreading accompanied by several oceanic core complexes. The remnant spreading center, the Parece Vela Rift, seems to connect the Yap Trench at its southern end (~12°N) and is not traceable in the southern tip of the <span class="hlt">basin</span> (9~11°N) west of the Yap Trench. The evolution of the area seems to be linked to the collision of the Caroline Ridge to the Yap Trench, however no systematic mapping had been done before and the tectonics of the area remained enigmatic. New mapping/seismic reflection/dredging results reveal the complex structure of the area, which cannot be seen in northern part of the <span class="hlt">basin</span>. Relatively continuous N-S fabrics are found in the northern part of the studied area and these fabrics develops within a V-shaped triangle zone. The short NW-SE abyssal hills offset by the <span class="hlt">NE</span>-SW fracture zones are recognized in the very narrow area just east of the V-shaped area of N-S fabrics. These fabrics indicate the southward propagation of the N-S trending ridge and following <span class="hlt">NE</span>-SW opening as same as seen in the northern part of the <span class="hlt">basin</span>, although the eastern wing of the <span class="hlt">basin</span> was lost. The western part of the area is completely different from the other part of the <span class="hlt">basin</span>. The most prominent morphology is en echelon, curved deeps near the Kyushu-Palau Ridge. Two deeps are crescent-shaped and curve towards northward. The northern deep is ~6100 m and the abyssal hills seem approximately perpendicular to the deep. The southwestern extension of the northern deep is a narrow curved rift trending 030° and the rift develops within a topographic high. The southern deep is characterized with voluminous dome, which consists of branched topographic highs. The</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1995PalOc..10..197S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1995PalOc..10..197S"><span>Late Quaternary surface circulation in the east equatorial South <span class="hlt">Atlantic</span>: Evidence from Alkenone sea surface temperatures</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schneider, Ralph R.; Müller, Peter J.; Ruhland, GöTz</p> <p>1995-04-01</p> <p>Angola <span class="hlt">Basin</span> and Walvis Ridge records of past sea surface temperatures (SST) derived from the alkenone Uk37 index are used to reconstruct the surface circulation in the east equatorial South <span class="hlt">Atlantic</span> for the last 200,000 years. Comparison of SST estimates from surface sediments between 5° and 20°S with modern SST data suggests that the alkenone temperatures represent annual mean values of the surface mixed layer. Alkenone-derived temperatures for the warm climatic maxima of the Holocene and the penultimate interglacial are 1 to 4°C higher than latest Holocene values. All records show glacial to interglacial differences of about 3.5°C in annual mean SST, which is about 1.5°C greater than the difference estimated by CLIMAP (1981) for the eastern Angola <span class="hlt">Basin</span>. At the Walvis Ridge, significant SST variance is observed at all of the Earth's orbital periodicities. SST records from the Angola <span class="hlt">Basin</span> vary predominantly at 23- and 100-kyr periodicities. For the precessional cycle, SST changes at the Walvis Ridge correspond to variations of boreal summer insolation over Africa and lead ice volume changes, suggesting that the east equatorial South <span class="hlt">Atlantic</span> is sensitive to African monsoon intensity via trade-wind zonality. Angola <span class="hlt">Basin</span> SST records lag those from the Walvis Ridge and the equatorial <span class="hlt">Atlantic</span> by about 3 kyr. The comparison of Angola <span class="hlt">Basin</span> and Walvis Ridge SST records implies that the Angola-Benguela Front (ABF) (currently at about 14-16°S) has remained fairly stationary between 12° and 20°S (the limits of our cores) during the last two glacial-interglacial cycles. The temperature contrast associated with the ABF exhibits a periodic 23-kyr variability which is coherent with changes in boreal summer insolation over Africa. These observations suggest that surface waters north of the present ABF have not directly responded to monsoon-modulated changes in the trade-wind vector, that the central field of zonally directed trades in the southern hemisphere was not</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017GeCoA.210..267D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017GeCoA.210..267D"><span>Fingerprinting Northeast <span class="hlt">Atlantic</span> water masses using neodymium isotopes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dubois-Dauphin, Quentin; Colin, Christophe; Bonneau, Lucile; Montagna, Paolo; Wu, Qiong; Van Rooij, David; Reverdin, Gilles; Douville, Eric; Thil, François; Waldner, Astrid; Frank, Norbert</p> <p>2017-08-01</p> <p>Dissolved neodymium (Nd) isotopic composition (expressed as εNd) has been analysed for 82 seawater samples collected from 13 stations stretching from the Alboran Sea to the Iceland <span class="hlt">Basin</span>. The distribution of the εNd values of water masses was thus investigated for the first time along the western European margin in order to explore whether the water masses flowing in the eastern subpolar and subtropical <span class="hlt">Atlantic</span> reveal distinct isotopic patterns. The Modified <span class="hlt">Atlantic</span> Water (MAW) in the Alboran Sea displays εNd values (between -9.2 ± 0.2 and -8.9 ± 0.2) that are significantly more radiogenic than those reported in previous studies (-10.8 ± 0.2 to -9.7 ± 0.2), suggesting temporal variations in the Nd isotopic composition of the water that enters the Mediterranean Sea from the Strait of Gibraltar. The εNd value of the underlying modified Winter Intermediate Water (WIW) has been established for the first time (-9.8 ± 0.3) and is compatible with a Nd signature acquired from the sinking of MAW in the northwestern Mediterranean Sea. Within the Gulf of Cádiz, southern Mediterranean Sea Water (MSW) (-10.6 ± 0.2) differs slightly from the northern MSW (-9.9 ± 0.4) owing to a significant contribution of modified East Antarctic Intermediate Water (EAAIW) (-10.9 ± 0.2). In the northeast <span class="hlt">Atlantic</span>, the North <span class="hlt">Atlantic</span> Current surface water located in the inter-gyre region (north of 46°N) displays εNd values of between -14.0 ± 0.3 and -15.1 ± 0.3, reflecting the subpolar gyre signature. Along the western European margin, εNd values of surface water decrease toward the north (from -10.4 ± 1.6 to -13.7 ± 1.0) in agreement with the gradual mixing between subtropical and subpolar water. At intermediate depth, εNd values decrease from -9.9 ± 0.4 within the Gulf of Cádiz to -12.1 ± 0.2 within the Porcupine Seabight, indicating a strong dilution of the MSW with subpolar water. Within the Rockall Trough and the Iceland <span class="hlt">Basin</span>, the more negative εNd values at mid</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.1619G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.1619G"><span><span class="hlt">Atlantic</span> Water transformation in the Nordic Seas and its influence on the export rate of the Overflow Waters</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Garcia Quintana, Yarisbel; Wiesner, Pia; Hu, Xianmin; Myers, Paul</p> <p>2017-04-01</p> <p>The Nordic Seas (NS) are the main gateway between the Arctic and the <span class="hlt">Atlantic</span> Oceans. The <span class="hlt">basin</span> can be considered as the headwaters for the Meridional Overturning Circulation (MOC), for it is there that the Denmark Strait Overflow Water (DSOW) and the Iceland-Scotland Overflow Water (ISOW) acquire their properties. Their inflow into the North <span class="hlt">Atlantic</span> Ocean occurs across the Greenland-Scotland ridge. Together with Labrador Sea Water, DSOW and ISOW are the main components of the North <span class="hlt">Atlantic</span> Deep Water (NADW), which ventilates the lower limb of the <span class="hlt">Atlantic</span> MOC. In spite recent studies exploring the export rate and later pathways of the overflows, the question about what drives them, remains. Here we explore the transformation of the <span class="hlt">Atlantic</span> Water (AW) as it enters the NS through Denmark Strait, Iceland Faroe Ridge and Faroe Schotland Channel, as well as its pathways within the <span class="hlt">basin</span>. To do so, we use an eddy-permitting ocean general circulation model run over the period 2002 to 2015. Two different approaches are used to track the AW transformation in the NS: the well-tested off-line Lagrangian tool ARIANE and on-line passive tracers. In both cases we use the same definition of AW to tag its inflow through the three entering sections. The overflows directly impact circulation and water properties in much of the deep <span class="hlt">Atlantic</span> Ocean, thus a better understanding of the physical processes behind their variability is crucial a asset.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70017169','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70017169"><span>Late Cretaceous to Miocene phosphatic sediments in the Georges Bank <span class="hlt">Basin</span>, U.S. North <span class="hlt">Atlantic</span> outer continental shelf</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Poppe, L.J.; Manheim, F. T.; Popenoe, P.</p> <p>1992-01-01</p> <p>Phosphorite and phosphatic sediments are present in the Georges Bank <span class="hlt">Basin</span> in marine, Late Cretaceous to Miocene strata equivalent to the Dawson Canyon Formation and Banquereau Formation of offshore Nova Scotia. The Late Cretaceous to Paleocene phosphorite occurs predominantely as sand- and gravel-sized pellets and as cement in conglomeratic aggregates. The Eocene and Miocene phosphate occurs mainly as fine-very fine sand-size spheroidal-avoidal pellets in unconsolidated clayey silts. The older phosphorites form intraformational conglomerates that are the result of a winnowed finer-grained matrix, leaving lag deposits of phosphorite. We present evidence that most of the Eocene and Miocene phosphate is primary and formed during marine trangressions. Our observations extend the geographic and temporal limits of the major phosphogenic system of the Western North <span class="hlt">Atlantic</span> northward and through time. However, compared to the well-known phosphorite deposits along the southeastern margin of the U.S.A., these northern deposits are not of commercial scale due to a high terrigenous input and the lack of a mechanism capable of driving persistant upwelling. ?? 1992.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013ExG....44..251E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013ExG....44..251E"><span>Structural interpretation of the Ifal <span class="hlt">Basin</span> in north-western Saudi Arabia from aeromagnetic data: hydrogeological and environmental implications</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Elawadi, Eslam; Zaman, Haider; Batayneh, Awni; Mogren, Saad; Laboun, Abdalaziz; Ghrefat, Habes; Zumlot, Taisser</p> <p>2013-09-01</p> <p>The Ifal (Midyan) <span class="hlt">Basin</span> is one of the well defined <span class="hlt">basins</span> along the Red Sea coast, north-western Saudi Arabia. Location, geometry, thick sedimentary cover and structural framework qualify this <span class="hlt">basin</span> for groundwater, oil and mineral occurrences. In spite of being studied by two airborne magnetic surveys during 1962 and 1983, structural interpretation of the area from a magnetic perspective, and its uses for hydrogeological and environmental investigations, has not been attempted. This work thus presents interpretation of the aeromagnetic data for basement depth estimation and tectonic framework delineation, which both have a role in controlling groundwater flow and accumulation in the Ifal <span class="hlt">Basin</span>. A maximum depth of 3.5km is estimated for the basement surface by this study. In addition, several faulted and tilted blocks, perpendicularly dissected by <span class="hlt">NE</span>-trending faults, are delineated within the structural framework of the study area. It is also observed that the studied <span class="hlt">basin</span> is bounded by NW- and <span class="hlt">NE</span>-trending faults. All these multi-directional faults/fracture systems in the Ifal <span class="hlt">Basin</span> could be considered as conduits for groundwater accumulation, but with a possibility of environmental contamination from the surrounding soils and rock bodies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008Geote..42..105S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008Geote..42..105S"><span>Generations of spreading <span class="hlt">basins</span> and stages of breakdown of Wegener's Pangea in the geodynamic evolution of the Arctic Ocean</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shipilov, E. V.</p> <p>2008-03-01</p> <p>Chronological succession in the formation of spreading <span class="hlt">basins</span> is considered in the context of reconstruction of breakdown of Wegener’s Pangea and the development of the geodynamic system of the Arctic Ocean. This study made it possible to indentify three temporally and spatially isolated generations of spreading <span class="hlt">basins</span>: Late Jurassic-Early Cretaceous, Late Cretaceous-Early Cenozoic, and Cenozoic. The first generation is determined by the formation, evolution, and extinction of the spreading center in the Canada <span class="hlt">Basin</span> as a tectonic element of the Amerasia <span class="hlt">Basin</span>. The second generation is connected to the development of the Labrador-Baffin-Makarov spreading branch that ceased to function in the Eocene. The third generation pertains to the formation of the spreading system of interrelated ultraslow Mohna, Knipovich, and Gakkel mid-ocean ridges that has functioned until now in the Norwegian-Greenland and Eurasia <span class="hlt">basins</span>. The interpretation of the available geological and geophysical data shows that after the formation of the Canada <span class="hlt">Basin</span>, the Arctic region escaped the geodynamic influence of the Paleopacific, characterized by spreading, subduction, formation of backarc <span class="hlt">basins</span>, collision-related processes, etc. The origination of the Makarov <span class="hlt">Basin</span> marks the onset of the oceanic regime characteristic of the North <span class="hlt">Atlantic</span> (intercontinental rifting, slow and ultraslow spreading, separation of continental blocks (microcontinents), extinction of spreading centers of primary <span class="hlt">basins</span>, spreading jumps, formation of young spreading ridges and centers, etc., are typical) along with retention of northward propagation of spreading systems both from the Pacific and <span class="hlt">Atlantic</span> sides. The aforesaid indicates that the Arctic Ocean is in fact a hybrid <span class="hlt">basin</span> or, in other words, a composite heterogeneous ocean in respect to its architectonics. The Arctic Ocean was formed as a result of spatial juxtaposition of two geodynamic systems different in age and geodynamic style: the Paleopacific</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_14 --> <div id="page_15" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="281"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JSG...107..132N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JSG...107..132N"><span>Development of cataclastic foliation in deformation bands in feldspar-rich conglomerates of the Rio do Peixe <span class="hlt">Basin</span>, <span class="hlt">NE</span> Brazil</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nicchio, Matheus A.; Nogueira, Francisco C. C.; Balsamo, Fabrizio; Souza, Jorge A. B.; Carvalho, Bruno R. B. M.; Bezerra, Francisco H. R.</p> <p>2018-02-01</p> <p>In this work we describe the deformation mechanisms and processes that occurred during the evolution of cataclastic deformation bands developed in the feldspar-rich conglomerates of the Rio do Peixe <span class="hlt">Basin</span>, <span class="hlt">NE</span> Brazil. We studied bands with different deformation intensities, ranging from single cm-thick tabular bands to more evolved clustering zones. The chemical identification of cataclastic material within deformation bands was performed using compositional mapping in SEM images, EDX and XRD analyses. Deformation processes were identified by microstructural analysis and by the quantification of comminution intensity, performed using digital image processing. The deformation bands are internally non homogeneous and developed during five evolutionary stages: (1) moderate grain size reduction, grain rotation and grain border comminution; (2) intense grain size reduction with preferential feldspar fragmentation; (3) formation of subparallel C-type slip zones; (4) formation of S-type structures, generating S-C-like fabric; and (5) formation of C‧-type slip zones, generating well-developed foliation that resembles S-C-C‧-type structures in a ductile environment. Such deformation fabric is mostly imparted by the preferential alignment of intensely comminuted feldspar fragments along thin slip zones developed within deformation bands. These processes were purely mechanical (i.e., grain crushing and reorientation). No clays or fluids were involved in such processes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JSR...130..248R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JSR...130..248R"><span>Catch and post-release mortalities of deep-water sharks caught by bottom longlines in the Cantabrian Sea (<span class="hlt">NE</span> <span class="hlt">Atlantic</span>)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rodríguez-Cabello, Cristina; Sánchez, Francisco</p> <p>2017-12-01</p> <p>The majority of deep-water fish have very low capacity to survive discarding as fishery bycatch due to their biological characteristics and adaptation to depth. This study explores the catch and post-release mortalities of several deep-water shark species caught by bottom longline in the El Cachucho (Le Danois Bank) MPA in northern Spanish waters (<span class="hlt">NE</span> <span class="hlt">Atlantic</span>). Survivorship was qualitatively evaluated according to health condition and responses of individuals after capture and subsequent release. A total of 15 species were caught, of which the most abundant were leafscale gulper shark Centrophorus squamosus (39%), birdbeak dogfish Deania calcea (39%) and Portuguese dogfish Centroscymnus coelolepis (10%). Catch or at-vessel mortality (AVM) for these species was lower than expected, 1.2%, 8.8% and 4.5%, respectively but 18.9%, 37.4% and 38.6% including both those specimens dead on retrieval and those scored in poor condition). The species with the highest vitality rate was C. squamosus (37.3% in good condition; 43.8% in moderate condition), followed by D. calcea (22.8% in good condition; 39.8% in moderate condition) and C. coelolepis (6.8% and 54.5%). Post-release mortality (PRM) was examined using electronic tags (PSATs, n = 14). Of the nine C. squamosus tagged successfully, three died within 5-10 weeks after release, whereas the other six survived for periods of at least 45-120 days, when tags were programmed to release). In the case of C. coelolepis, two of the four tagged specimens died almost immediately after release, whereas the other two tags indicated that the fish survived immediate release, but data were too limited to gauge survival due to tag failure.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..1613875R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..1613875R"><span>Stone Age settlement and Holocene water level changes of the Baltic Sea in the Torvajoe <span class="hlt">Basin</span> area, Narva-Luga Klint Bay, <span class="hlt">NE</span> Estonia</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Raig, Hanna; Rosentau, Alar; Muru, Merle; Risberg, Jan</p> <p>2014-05-01</p> <p>The Tõrvajõe <span class="hlt">basin</span> is located in <span class="hlt">NE</span> Estonia in the southern part of the Narva-Luga Klint Bay, that is characterized by slow post-glacial isostatic uplift (about 0-1mm/yr) and slowly undulating low topography. Post-glacial changes of the water-level of the Baltic Sea have at times flooded the area, and at times, it has emerged as terrestrial land. In addition to a complex geological development, the surroundings of the Tõrvajõe <span class="hlt">basin</span> are interesting from the archaeological point of view because of abundant archaeological findings in the area, of which the oldest (c 8.1 cal ka BP) from the Mesolithic period and the majority, indicating very intense habitation (c 7.1-5.5 cal ka BP), from the Neolithic period. Development of the Tőrvajőe <span class="hlt">basin</span> area during the period of Stone Age settlement (c 8.1-5.5 cal. ka BP) is studied with multiple geological and archaeological proxies. Sediments are described by lithostratigraphical methods, loss-on-ignition. AMS radiocarbon dates are used to date events and create an age-depth model. Environment is described by pollen analyses and water environment by siliceous microfossil analyses. Palaeogeographical reconstructions for time slices of interest are created to illustrate Stone Age settlement pattern and changes of the coastline and landscape over time. The aim of this interdisciplinary study is to investigate and associate palaeoenvironmental conditions and water-level changes with Stone Age settlement pattern in the Tőrvajőe area. Results show four developmental stages in the post-glacial history of the <span class="hlt">basin</span>: Ancylus Lake lagoon, mire, lagoon during the Litorina Sea and mire. During the Ancylus Lake transgression at about 10.8-10.2 cal. ka BP a spit started to form north of the <span class="hlt">basin</span> and a lagoon evolved behind it. Following the Ancylus Lake regression river activity and formation of palaeosoil and fen peat took place. Due to the Litorina Sea transgression, that was initially slower but accelerated around 7.8-7.6 cal ka</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009Tectp.479..285B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009Tectp.479..285B"><span>Seismic images of an extensional <span class="hlt">basin</span>, generated at the hangingwall of a low-angle normal fault: The case of the Sansepolcro <span class="hlt">basin</span> (Central Italy)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Barchi, Massimiliano R.; Ciaccio, Maria Grazia</p> <p>2009-12-01</p> <p>The study of syntectonic <span class="hlt">basins</span>, generated at the hangingwall of regional low-angle detachments, can help to gain a better knowledge of these important and mechanically controversial extensional structures, constraining their kinematics and timing of activity. Seismic reflection images constrain the geometry and internal structure of the Sansepolcro <span class="hlt">Basin</span> (the northernmost portion of the High Tiber Valley). This <span class="hlt">basin</span> was generated at the hangingwall of the Altotiberina Fault (AtF), an E-dipping low-angle normal fault, active at least since Late Pliocene, affecting the upper crust of this portion of the Northern Apennines. The dataset analysed consists of 5 seismic reflection lines acquired in the 80s' by ENI-Agip for oil exploration and a portion of the NVR deep CROP03 profile. The interpretation of the seismic profiles provides a 3-D reconstruction of the <span class="hlt">basin</span>'s shape and of the sedimentary succession infilling the <span class="hlt">basin</span>. This consisting of up to 1200 m of fluvial and lacustrine sediments: this succession is much thicker and possibly older than previously hypothesised. The seismic data also image the geometry at depth of the faults driving the <span class="hlt">basin</span> onset and evolution. The western flank is bordered by a set of E-dipping normal faults, producing the uplifting and tilting of Early to Middle Pleistocene succession along the Anghiari ridge. Along the eastern flank, the sediments are markedly dragged along the SW-dipping Sansepolcro fault. Both <span class="hlt">NE</span>- and SW-dipping faults splay out from the <span class="hlt">NE</span>-dipping, low-angle Altotiberina fault. Both AtF and its high-angle splays are still active, as suggested by combined geological and geomorphological evidences: the historical seismicity of the area can be reasonably associated to these faults, however the available data do not constrain an unambiguous association between the single structural elements and the major earthquakes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015QSRv..114..126A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015QSRv..114..126A"><span>A review of the MIS 5e highstand deposits from Santa Maria Island (Azores, <span class="hlt">NE</span> <span class="hlt">Atlantic</span>): palaeobiodiversity, palaeoecology and palaeobiogeography</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ávila, Sérgio P.; Melo, Carlos; Silva, Luís; Ramalho, Ricardo S.; Quartau, Rui; Hipólito, Ana; Cordeiro, Ricardo; Rebelo, Ana Cristina; Madeira, Patrícia; Rovere, Alessio; Hearty, Paul J.; Henriques, Diamantino; Silva, Carlos Marques da; Martins, António M. de Frias; Zazo, Caridad</p> <p>2015-04-01</p> <p>The privileged location of Santa Maria Island (Azores archipelago) in the middle of the North <span class="hlt">Atlantic</span> makes the fossiliferous outcrops on this island of utmost importance to gain a better understanding of how coeval living communities relate to the broader evolutionary and biogeographic history of the <span class="hlt">Atlantic</span> <span class="hlt">basin</span> during the late Neogene and the Quaternary. Here we focus on this island's MIS 5e fossil record, offering a comprehensive review on the palaeobiodiversity, palaeoecology and palaeobiogeography of the biota living in the mid North <span class="hlt">Atlantic</span> during this interglacial. Several studies in oceanic islands stress the huge impact of sea level changes on insular communities. Pleistocene sea-level changes occur during the short-time events known as "Terminations" (associated to glacial/interglacial shifts) as well as with the onset of glaciations (associated to interglacial/glacial shifts). Both are responsible for extinctions and local disappearance of species, bottleneck effects and formation of new species, resulting in community structure changes. This work increases the number of fossil marine taxa reported from the Last Interglacial deposits of Santa Maria to 143 species. All the 19 new records are molluscs (13 gastropods and 6 bivalves), thus increasing the number of fossil molluscs to 136 species. Although thermophilic members of the "Senegalese" tropical fauna were found in these deposits, many of the most emblematic species (e.g., Persististrombus latus (=Strombus bubonius), Cymbula safiana, Harpa doris, Cardita senegalensis, Barbatia plicata, Ctena eburnea or Hyotissa hyotis) are absent, suggesting that they did not reach the Azores. Our results indicate that the main differences between the species composition of the MIS 5e and the present-day shallow-water Azorean communities are probably due to the dropping of sea surface temperature associated with the onset of the last glaciation, which had both direct and indirect effects on species ecology. A</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUOSPO54F3316R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUOSPO54F3316R"><span>Causes of Upper-Ocean Temperature Anomalies in the Tropical North <span class="hlt">Atlantic</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rugg, A.; Foltz, G. R.; Perez, R. C.</p> <p>2016-02-01</p> <p>Hurricane activity and regional rainfall are strongly impacted by upper ocean conditions in the tropical North <span class="hlt">Atlantic</span>, defined as the region between the equator and 20°N. A previous study analyzed a strong cold sea surface temperature (SST) anomaly that developed in this region during early 2009 and was recorded by the Pilot Research Array in the Tropical <span class="hlt">Atlantic</span> (PIRATA) moored buoy at 4°N, 23°W (Foltz et al. 2012). The same mooring shows a similar cold anomaly in the spring of 2015 as well as a strong warm anomaly in 2010, offering the opportunity for a more comprehensive analysis of the causes of these events. In this study we examine the main causes of the observed temperature anomalies between 1998 and 2015. <span class="hlt">Basin</span>-scale conditions during these events are analyzed using satellite SST, wind, and rain data, as well as temperature and salinity profiles from the NCEP Global Ocean Data Assimilation System. A more detailed analysis is conducted using ten years of direct measurements from the PIRATA mooring at 4°N, 23°W. Results show that the cooling and warming anomalies were caused primarily by wind-driven changes in surface evaporative cooling, mixed layer depth, and upper-ocean vertical velocity. Anomalies in surface solar radiation acted to damp the wind-driven SST anomalies in the latitude bands of the ITCZ (3°-8°N). <span class="hlt">Basin</span>-scale analyses also suggest a strong connection between the observed SST anomalies and the <span class="hlt">Atlantic</span> Meridional Mode, a well-known pattern of SST and surface wind anomalies spanning the tropical <span class="hlt">Atlantic</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.3871H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.3871H"><span>Latitudinal Trends in Stable Isotope Signatures of Northeast <span class="hlt">Atlantic</span> Rhodoliths</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hofmann, Laurie</p> <p>2017-04-01</p> <p>Rhodoliths are free-living calcifying red algae that form extensive beds in shallow marine benthic environments (< 200 m) that provide important habitats and nurseries for marine organisms and contribute to carbonate sediment accumulation. There is growing concern that these organisms are sensitive to global climate change, which will have important consequences for coastal productivity and stability. Despite their significance and sensitivity, their basic photosynthetic and calcification mechanisms are not well understood. The goal of this study was to determine the plasticity of dissolved inorganic carbon (DIC) uptake mechanisms of rhodoliths along a latitudinal gradient in the Northeast (<span class="hlt">NE</span>) <span class="hlt">Atlantic</span> using natural stable isotope signatures. The delta 13C signature of macroalgae can be used to provide an indication of the preferred inorganic carbon source (CO2 vs. HCO3-). Here we present the total and organic delta 13C signatures of <span class="hlt">NE</span> <span class="hlt">Atlantic</span> rhodoliths with respect to changing temperature and light along the latitudinal gradient from the Canary Islands to Spitsbergen. A decreasing trend in delta 13C signatures with increasing latitude suggests that rhodoliths rely solely on CO2 as an inorganic carbon source at mid latitudes, while those at low latitudes may be able to utilize HCO3-. Polar rhodoliths deviate from this trend, suggesting they may have unique physiological mechanisms related to inorganic carbon acquisition and assimilation, which may have important implications for calcification in an environment undergoing rapid changing ocean chemistry.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JAfES.141...22C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JAfES.141...22C"><span>The Sidi Ifni transect across the rifted margin of Morocco (Central <span class="hlt">Atlantic</span>): Vertical movements constrained by low-temperature thermochronology</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Charton, Rémi; Bertotti, Giovanni; Arantegui, Angel; Bulot, Luc</p> <p>2018-05-01</p> <p>The occurrence of km-scale exhumations during syn- and post-rift stages has been documented along <span class="hlt">Atlantic</span> continental margins, which are also characterised by <span class="hlt">basins</span> undergoing substantial subsidence. The relationship between the exhuming and subsiding domains is poorly understood. In this study, we reconstruct the evolution of a 50 km long transect across the Moroccan rifted margin from the western Anti-Atlas to the <span class="hlt">Atlantic</span> <span class="hlt">basin</span> offshore the city of Sidi Ifni. Low-temperature thermochronology data from the Sidi Ifni area document a ca. 8 km exhumation between the Permian and the Early/Middle Jurassic. The related erosion fed sediments to the subsiding Mesozoic <span class="hlt">basin</span> to the NW. Basement rocks along the transect were subsequently buried by 1-2 km between the Late Jurassic and the Early Cretaceous. From late Early/Late Cretaceous onwards, rocks present along the transect were exhumed to their present-day position.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.S22B..05H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.S22B..05H"><span>Slip Potential of Faults in the Fort Worth <span class="hlt">Basin</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hennings, P.; Osmond, J.; Lund Snee, J. E.; Zoback, M. D.</p> <p>2017-12-01</p> <p>Similar to other areas of the southcentral United States, the Fort Worth <span class="hlt">Basin</span> of <span class="hlt">NE</span> Texas has experienced an increase in the rate of seismicity which has been attributed to injection of waste water in deep saline aquifers. To assess the hazard of induced seismicity in the <span class="hlt">basin</span> we have integrated new data on location and character of previously known and unknown faults, stress state, and pore pressure to produce an assessment of fault slip potential which can be used to investigate prior and ongoing earthquake sequences and for development of mitigation strategies. We have assembled data on faults in the <span class="hlt">basin</span> from published sources, 2D and 3D seismic data, and interpretations provided from petroleum operators to yield a 3D fault model with 292 faults ranging in strike-length from 116 to 0.4 km. The faults have mostly normal geometries, all cut the disposal intervals, and most are presumed to cut into the underlying crystalline and metamorphic basement. Analysis of outcrops along the SW flank of the <span class="hlt">basin</span> assist with geometric characterization of the fault systems. The interpretation of stress state comes from integration of wellbore image and sonic data, reservoir stimulation data, and earthquake focal mechanisms. The orientation of SHmax is generally uniform across the <span class="hlt">basin</span> but stress style changes from being more strike-slip in the <span class="hlt">NE</span> part of the <span class="hlt">basin</span> to normal faulting in the SW part. Estimates of pore pressure come from a <span class="hlt">basin</span>-scale hydrogeologic model as history-matched to injection test data. With these deterministic inputs and appropriate ranges of uncertainty we assess the conditional probability that faults in our 3D model might slip via Mohr-Coulomb reactivation in response to increases in injected-related pore pressure. A key component of the analysis is constraining the uncertainties associated with each of the principal parameters. Many of the faults in the model are interpreted to be critically-stressed within reasonable ranges of uncertainty.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009pcms.confE..37B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009pcms.confE..37B"><span>Reconstructing the Santa Tecla flash flood in the Ondara River (Ebro <span class="hlt">Basin</span>, <span class="hlt">NE</span> Spain)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Balasch, J. C.; Tuset, J.; Ramos, M. C.; Martínez-Casasnovas, J. A.</p> <p>2009-09-01</p> <p>The Santa Tecla flood may be considered the most catastrophic rainfall event in the modern history of Catalonia (<span class="hlt">NE</span> Iberian Peninsula), and one of the most important in the Western Mediterranean <span class="hlt">Basin</span>. This event took place during the night between 22nd and 23rd September 1874, in which torrential convective rainfalls generated significant flash floods in most of the small streams in the southern half of Catalonia (i.e. Ondara, Corb, Francolí and Siurana catchments). More than 570 people died, 150 of which in the town of Tàrrega, by the Ondara River. Despite being one of the last huge floods of the pre-instrumental era and, consequently, without any precipitation or flow data, the event was reconstructed both hydraulically and hydrologically for the Ondara River at Tàrrega (150 km2). Thus, the maximum water level and the temporal evolution of the flood were obtained, respectively, from several epigraphic limnimarks found in Tàrrega and from the event description recorded in historical documents. Additionally, the information from local archaeological sites allowed the reconstruction of the fluvial section at Tàrrega at the end of the 19th century. Finally, some old cellars flooded during the event provided information about sediment concentration at the peak flow. The methodology put into practice for the event reconstruction had two stages. The first stage was the hydraulic modelling, which estimated the peak flow. The input data used were the maximum water level given by the limnimetric marks, a digital terrain model of the river bed shape, and the stream and floodplain roughness and channel slope (which were considered similar to the present ones, according to archaeological data). The hydraulic model used was the unidimensional HEC-RAS (USACE), applied in several cross sections of the Ondara River at Tàrrega. The second stage was the hydrological modelling. The objective of this stage was to derive the event hyetograph from the above calculated peak flow</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24784218','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24784218"><span>North <span class="hlt">Atlantic</span> forcing of tropical Indian Ocean climate.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mohtadi, Mahyar; Prange, Matthias; Oppo, Delia W; De Pol-Holz, Ricardo; Merkel, Ute; Zhang, Xiao; Steinke, Stephan; Lückge, Andreas</p> <p>2014-05-01</p> <p>The response of the tropical climate in the Indian Ocean realm to abrupt climate change events in the North <span class="hlt">Atlantic</span> Ocean is contentious. Repositioning of the intertropical convergence zone is thought to have been responsible for changes in tropical hydroclimate during North <span class="hlt">Atlantic</span> cold spells, but the dearth of high-resolution records outside the monsoon realm in the Indian Ocean precludes a full understanding of this remote relationship and its underlying mechanisms. Here we show that slowdowns of the <span class="hlt">Atlantic</span> meridional overturning circulation during Heinrich stadials and the Younger Dryas stadial affected the tropical Indian Ocean hydroclimate through changes to the Hadley circulation including a southward shift in the rising branch (the intertropical convergence zone) and an overall weakening over the southern Indian Ocean. Our results are based on new, high-resolution sea surface temperature and seawater oxygen isotope records of well-dated sedimentary archives from the tropical eastern Indian Ocean for the past 45,000 years, combined with climate model simulations of <span class="hlt">Atlantic</span> circulation slowdown under Marine Isotope Stages 2 and 3 boundary conditions. Similar conditions in the east and west of the <span class="hlt">basin</span> rule out a zonal dipole structure as the dominant forcing of the tropical Indian Ocean hydroclimate of millennial-scale events. Results from our simulations and proxy data suggest dry conditions in the northern Indian Ocean realm and wet and warm conditions in the southern realm during North <span class="hlt">Atlantic</span> cold spells.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016OcSci..12.1179K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016OcSci..12.1179K"><span>Sub-<span class="hlt">basin</span>-scale sea level budgets from satellite altimetry, Argo floats and satellite gravimetry: a case study in the North <span class="hlt">Atlantic</span> Ocean</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kleinherenbrink, Marcel; Riva, Riccardo; Sun, Yu</p> <p>2016-11-01</p> <p>In this study, for the first time, an attempt is made to close the sea level budget on a sub-<span class="hlt">basin</span> scale in terms of trend and amplitude of the annual cycle. We also compare the residual time series after removing the trend, the semiannual and the annual signals. To obtain errors for altimetry and Argo, full variance-covariance matrices are computed using correlation functions and their errors are fully propagated. For altimetry, we apply a geographically dependent intermission bias [Ablain et al.(2015)], which leads to differences in trends up to 0.8 mm yr-1. Since Argo float measurements are non-homogeneously spaced, steric sea levels are first objectively interpolated onto a grid before averaging. For the Gravity Recovery And Climate Experiment (GRACE), gravity fields full variance-covariance matrices are used to propagate errors and statistically filter the gravity fields. We use four different filtered gravity field solutions and determine which post-processing strategy is best for budget closure. As a reference, the standard 96 degree Dense Decorrelation Kernel-5 (DDK5)-filtered Center for Space Research (CSR) solution is used to compute the mass component (MC). A comparison is made with two anisotropic Wiener-filtered CSR solutions up to degree and order 60 and 96 and a Wiener-filtered 90 degree ITSG solution. Budgets are computed for 10 polygons in the North <span class="hlt">Atlantic</span> Ocean, defined in a way that the error on the trend of the MC plus steric sea level remains within 1 mm yr-1. Using the anisotropic Wiener filter on CSR gravity fields expanded up to spherical harmonic degree 96, it is possible to close the sea level budget in 9 of 10 sub-<span class="hlt">basins</span> in terms of trend. Wiener-filtered Institute of Theoretical geodesy and Satellite Geodesy (ITSG) and the standard DDK5-filtered CSR solutions also close the trend budget if a glacial isostatic adjustment (GIA) correction error of 10-20 % is applied; however, the performance of the DDK5-filtered solution strongly depends</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018ESD.....9...91E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018ESD.....9...91E"><span>The concurrence of atmospheric rivers and explosive cyclogenesis in the North <span class="hlt">Atlantic</span> and North Pacific <span class="hlt">basins</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Eiras-Barca, Jorge; Ramos, Alexandre M.; Pinto, Joaquim G.; Trigo, Ricardo M.; Liberato, Margarida L. R.; Miguez-Macho, Gonzalo</p> <p>2018-01-01</p> <p>The explosive cyclogenesis of extratropical cyclones and the occurrence of atmospheric rivers are characteristic features of a baroclinic atmosphere, and are both closely related to extreme hydrometeorological events in the mid-latitudes, particularly on coastal areas on the western side of the continents. The potential role of atmospheric rivers in the explosive cyclone deepening has been previously analysed for selected case studies, but a general assessment from the climatological perspective is still missing. Using ERA-Interim reanalysis data for 1979-2011, we analyse the concurrence of atmospheric rivers and explosive cyclogenesis over the North <span class="hlt">Atlantic</span> and North Pacific <span class="hlt">basins</span> for the extended winter months (ONDJFM). Atmospheric rivers are identified for almost 80 % of explosive deepening cyclones. For non-explosive cyclones, atmospheric rivers are found only in roughly 40 % of the cases. The analysis of the time evolution of the high values of water vapour flux associated with the atmospheric river during the cyclone development phase leads us to hypothesize that the identified relationship is the fingerprint of a mechanism that raises the odds of an explosive cyclogenesis occurrence and not merely a statistical relationship. These new insights on the relationship between explosive cyclones and atmospheric rivers may be helpful to a better understanding of the associated high-impact weather events.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EGUGA..14.9758Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EGUGA..14.9758Z"><span>Evolution of the Grenada and Tobago <span class="hlt">basins</span> and the onset of the Lesser Antilles subduction zone</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zitter, T. A. C.; Rangin, C.</p> <p>2012-04-01</p> <p>The Lesser Antilles active island arc marks the eastern boundary of the Caribbean plate, where the <span class="hlt">Atlantic</span> oceanic crust is subducted. Geodynamic history of the Grenada and Tobago <span class="hlt">basins</span>, accepted as both the back arc and fore arc <span class="hlt">basins</span> respectively for this convergent zone, is the key for a better understanding of the Antilles arc subduction onset. Still, recent studies propose that these two <span class="hlt">basins</span> formed as a single paleogene depocenter. Analysis of industrial and academical seismic profiling supports this hypothesis, and shows these <span class="hlt">basins</span> are two half-graben filled by 15 kilometers of cenozoic sediments. The seismic profiles across these <span class="hlt">basins</span>, and particularly the Geodinos Bolivar seismic profiles, indicate that the Antilles magmatic arc develops in the midst of the previously-extended Grenada-Tobago <span class="hlt">basin</span> from Miocene time to present. The pre-cenozoic basement of the Grenada-Tobago <span class="hlt">basin</span> can be traced from the Aves ridge to the Tobago Island where cretaceous meta-volcanic rocks are cropping out. Therefore, this large <span class="hlt">basin</span> extension has been initiated in early Paleocene time during stretching or subsidence of the great cretaceous Caribbean arc and long time before the onset of the lesser Antilles volcanic arc. The question arises for the mechanism responsible of this intra-plate extension. The Tobago Ridge consists of the backstop of the Barbados prism. The innermost wedge is particularly well imaged on seismic data along the Darien Ridge, where the isopach paleogene sediments are jointly deformed in latest Oligocene. This deformation is starved with the early miocene piggy-back <span class="hlt">basin</span>. Hence, we conclude the innermost wedge in contact with the butresss is late Oligocene in age and can be considered as the onset of the subduction along the Antilles arc. This 30 Ma subduction onset is also supported by the 750 km long <span class="hlt">Atlantic</span> slab, imaged in tomography, indicating this subduction was active with constant velocity of 2.5 km/yr. Consequently, another</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70025112','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70025112"><span>Controls on facies and sequence stratigraphy of an upper Miocene carbonate ramp and platform, Melilla <span class="hlt">basin</span>, <span class="hlt">NE</span> Morocco</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Cunningham, K.J.; Collins, Luke S.</p> <p>2002-01-01</p> <p>Upwelling of cool seawater, paleoceanographic circulation, paleoclimate, local tectonics and relative sea-level change controlled the lithofacies and sequence stratigraphy of a carbonate ramp and overlying platform that are part of a temporally well constrained carbonate complex in the Melilla <span class="hlt">basin</span>, northeastern Morocco. At Melilla, from oldest to youngest, a third-order depositional sequence within the carbonate complex contains (1) a retrogradational, transgressive, warm temperate-type rhodalgal ramp; (2) an early highstand, progradational, bioclastic platform composed mainly of a temperate-type, bivalve-rich molechfor facies; and (3) late highstand, progradational to downstepping, subtropical/tropical-type chlorozoan fringing Porites reefs. The change from rhodalgal ramp to molechfor platform occurred at 7.0??0.14 Ma near the Tortonian/Messinian boundary. During a late stage in the development of the bioclastic platform a transition from temperate-type molechfor facies to subtropical/tropical-type chlorozoan facies occurred and is bracketed by chron 3An.2n (??? 6.3-6.6 Ma). Comparison to a well-dated carbonate complex in southeastern Spain at Cabo de Gata suggests that upwelling of cool seawater influenced production of temperate-type limestone within the ramp and platform at Melilla during postulated late Tortonian-early Messinian subtropical/tropical paleoclimatic conditions in the western Paleo-Mediterranean region. The upwelling of cool seawater across the bioclastic platform at Melilla could be related to the beginning of 'siphoning' of deep, cold <span class="hlt">Atlantic</span> waters into the Paleo-Mediterranean Sea at 7.17 Ma. The facies change within the bioclastic platform from molechfor to chlorozoan facies may be coincident with a reduction of the siphoning of <span class="hlt">Atlantic</span> waters and the end of upwelling at Melilla during chron 3An.2n. The ramp contains one retrogradational parasequence and the bioclastic platform three progradational parasequences. Minor erosional surfaces</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20120016995&hterms=atlantic+meridional+overturning+circulation&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Datlantic%2Bmeridional%2Boverturning%2Bcirculation','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20120016995&hterms=atlantic+meridional+overturning+circulation&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Datlantic%2Bmeridional%2Boverturning%2Bcirculation"><span>Introduction to: <span class="hlt">Atlantic</span> Meridional Overturning Circulation(AMOC)</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hakkinen, Sirpa; Carton, James A.</p> <p>2011-01-01</p> <p> water formation in the sinking regions. In addition to transporting mass, the AMOC transports roughly half of the total amount of heat carried northward through the northern subtropics (down the temperature-gradient) by the ocean. In contrast in the Southern Hemisphere AMOC transports heat up-gradient from the cool Circumpolar Current to the warm tropics. Paleoevidence suggests that AMOC heat transport in the two hemispheres has varied over time in ways intimately tied to millennial changes in the Earth's climate. In one example, the abrupt Younger Dryas spell of cold weather over the North <span class="hlt">Atlantic</span>, which began 13,000 years ago, has generally been linked to a millennial shutdown of the AMOC as a result of massive freshwater discharge from the North American continent. The current AMOC monitoring array consists of a series of instrumented transects located across key passages (see Cunningham et al., 2010 for a recent review). In the Arctic and sub-Arctic, transects cross Fram Strait, Denmark Strait and the Faroe Channel (connecting Greenland, Iceland, and the United Kingdom), as well as the entrance to the Labrador Sea. Further south and extending outwards from the east coast of North America there are a series of monitoring arrays including arrays of the Canadian <span class="hlt">Atlantic</span> Zone Monitoring Program, deployments of the Rapid Western <span class="hlt">Atlantic</span> Variability Experiment (WAVE), Line W at 39 N, as well as the Rapid-MOC moored array. The latter spans the entire <span class="hlt">Atlantic</span> <span class="hlt">basin</span> along 26.5 N. At tropical latitudes we have the Meridional Overturning Variability Experiment (MOVE) array at 16 N, while in the Southern Hemisphere a corresponding <span class="hlt">basin</span>-spanning transect is being established at the latitude of Cape of Good Hope, complemented by arrays at Drake Passage.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1990JSG....12..601G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1990JSG....12..601G"><span>Formation and inversion of transtensional <span class="hlt">basins</span> in the western part of the Lachlan Fold Belt, Australia, with emphasis on the Cobar <span class="hlt">Basin</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Glen, R. A.</p> <p></p> <p>The Palaeozoic history of the western part of the Lachlan Fold Belt in New South Wales was dominated by strike-slip tectonics. In the latest Silurian to late Early Devonian, an area of crust >25,000 km 2 lying west of the Gilmore Suture underwent regional sinistral transtension, leading to the development of intracratonic successor <span class="hlt">basins</span>, troughs and flanking shelves. The volcaniclastic deep-water Mount Hope Trough and Rast Trough, the siliciclastic Cobar <span class="hlt">Basin</span> and the volcanic-rich Canbelego-Mineral Hill Belt of the Kopyje Shelf all were initiated around the Siluro-Devonian boundary. They all show clear evidence of having evolved by both active syn-rift processes and passive later post-rift (sag-phase) processes. Active syn-rift faulting is best documented for the Cobar <span class="hlt">Basin</span> and Mount Hope Trough. In the former case, the synchronous activity on several fault sets suggests that the <span class="hlt">basin</span> formed by sinistral transtension in response to a direction of maximum extension oriented <span class="hlt">NE</span>-SW. Structures formed during inversion of the Cobar <span class="hlt">Basin</span> and Canbelego-Mineral Hill Belt indicate closure under a dextral transpressive strain regime, with a far-field direction of maximum shortening oriented <span class="hlt">NE</span>-SW. In the Cobar <span class="hlt">Basin</span>, shortening was partitioned into two structural zones. A high-strain zone in the east was developed into a positive half-flower structure by re-activation of early faults and by formation of short-cut thrusts, some with strike-slip movement, above an inferred steep strike-slip fault. Intense subvertical cleavage, a steep extension lineation and variably plunging folds are also present. A lower-strain zone to the west developed by syn-depositional faults being activated as thrusts soling into a gently dipping detachment. A subvertical cleavage and steep extension lineation are locally present, and variably plunging folds are common. Whereas Siluro-Devonian <span class="hlt">basin</span>-opening appeared to be synchronous in the western part of the fold belt, the different period of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018GeoJI.212.1546D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018GeoJI.212.1546D"><span>Crust and uppermost-mantle structure of Greenland and the Northwest <span class="hlt">Atlantic</span> from Rayleigh wave group velocity tomography</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Darbyshire, Fiona A.; Dahl-Jensen, Trine; Larsen, Tine B.; Voss, Peter H.; Joyal, Guillaume</p> <p>2018-03-01</p> <p>The Greenland landmass preserves ˜4 billion years of tectonic history, but much of the continent is inaccessible to geological study due to the extensive inland ice cap. We map out, for the first time, the 3-D crustal structure of Greenland and the NW <span class="hlt">Atlantic</span> ocean, using Rayleigh wave anisotropic group velocity tomography, in the period range 10-80 s, from regional earthquakes and the ongoing GLATIS/GLISN seismograph networks. 1-D inversion gives a pseudo-3-D model of shear wave velocity structure to depths of ˜100 km with a horizontal resolution of ˜200 km. Crustal thickness across mainland Greenland ranges from ˜25 km to over 50 km, and the velocity structure shows considerable heterogeneity. The large sedimentary <span class="hlt">basins</span> on the continental shelf are clearly visible as low velocities in the upper ˜5-15 km. Within the upper continental basement, velocities are systematically lower in northern Greenland than in the south, and exhibit a broadly NW-SE trend. The thinning of the crust at the continental margins is also clearly imaged. Upper-mantle velocities show a clear distinction between typical fast cratonic lithosphere (Vs ≥4.6 km s-1) beneath Greenland and its <span class="hlt">NE</span> margin and anomalously slow oceanic mantle (Vs ˜4.3-4.4 km s-1) beneath the NW <span class="hlt">Atlantic</span>. We do not observe any sign of pervasive lithospheric modification across Greenland in the regions associated with the presumed Iceland hotspot track, though the average crustal velocity in this region is higher than that of areas to the north and south. Crustal anisotropy beneath Greenland is strong and complex, likely reflecting numerous episodes of tectonic deformation. Beneath the North <span class="hlt">Atlantic</span> and Baffin Bay, the dominant anisotropy directions are perpendicular to the active and extinct spreading centres. Anisotropy in the subcontinental lithosphere is weaker than that of the crust, but still significant, consistent with cratonic lithosphere worldwide.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PrOce.138...18D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PrOce.138...18D"><span>Nitrous oxide and methane in <span class="hlt">Atlantic</span> and Mediterranean waters in the Strait of Gibraltar: Air-sea fluxes and inter-<span class="hlt">basin</span> exchange</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>de la Paz, M.; Huertas, I. E.; Flecha, S.; Ríos, A. F.; Pérez, F. F.</p> <p>2015-11-01</p> <p> the circulation pattern in the Strait to a bi-layer scheme, N2O exchange between <span class="hlt">basins</span> was also calculated, and a net export from the Mediterranean Sea to the <span class="hlt">Atlantic</span> Ocean equivalent to 39 μmol m-2 d-1 was found.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015GeoRL..42..871D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015GeoRL..42..871D"><span>Impact of Greenland orography on the <span class="hlt">Atlantic</span> Meridional Overturning Circulation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Davini, P.; Hardenberg, J.; Filippi, L.; Provenzale, A.</p> <p>2015-02-01</p> <p>We show that the absence of the Greenland ice sheet would have important consequences on the North <span class="hlt">Atlantic</span> Ocean circulation, even without taking into account the effect of the freshwater input to the ocean from ice melting. These effects are investigated in a 600year long coupled ocean-atmosphere simulation with the high-resolution global climate model EC-Earth 3.0.1. Once a new equilibrium is established, a cooling of Eurasia and of the North <span class="hlt">Atlantic</span> and a poleward shift of the subtropical jet are observed. These hemispheric changes are ascribed to a weakening of the <span class="hlt">Atlantic</span> Meridional Overturning Circulation (AMOC) by about 12%. We attribute this slowdown to a reduction in salinity of the Arctic <span class="hlt">basin</span> and to the related change of the mass and salt transport through the Fram Strait—a consequence of the new surface wind pattern over the lower orography. This idealized experiment illustrates the sensitivity of the AMOC to local surface winds.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_15 --> <div id="page_16" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="301"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.6400D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.6400D"><span>Impact of Greenland orography on the <span class="hlt">Atlantic</span> Meridional Overturning Circulation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Davini, Paolo; von Hardenberg, Jost; Filippi, Luca; Provenzale, Antonello</p> <p>2015-04-01</p> <p>We show that the absence of the Greenland Ice Sheet would have important consequences on the North <span class="hlt">Atlantic</span> Ocean circulation, even without taking into account the effect of the freshwater input from ice melting. These effects are investigated in a 200-year long coupled ocean-atmosphere simulation with the high-resolution global climate model EC-Earth 3.0.1. Once a new equilibrium is established, cooling of Eurasia and of the North <span class="hlt">Atlantic</span> and poleward shift of the subtropical jet are observed. These hemispheric changes are ascribed to a weakening of the <span class="hlt">Atlantic</span> Meridional Overturning Circulation (AMOC) by about 20%. Such slowdown is associated to the freshening of the Arctic <span class="hlt">basin</span> and to the related reduction in the freshwater export through the Fram Strait, as a result of the new wind pattern generated by the lower orography. This idealized experiment reveals the possibility of decreasing the AMOC by locally changing the surface winds.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.A53D2285R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.A53D2285R"><span>A Skilful Marine Sclerochronological Network Based Reconstruction of North <span class="hlt">Atlantic</span> Subpolar Gyre Dynamics</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Reynolds, D.; Hall, I. R.; Slater, S. M.; Scourse, J. D.; Wanamaker, A. D.; Halloran, P. R.; Garry, F. K.</p> <p>2017-12-01</p> <p>Spatial network analyses of precisely dated, and annually resolved, tree-ring proxy records have facilitated robust reconstructions of past atmospheric climate variability and the associated mechanisms and forcings that drive it. In contrast, a lack of similarly dated marine archives has constrained the use of such techniques in the marine realm, despite the potential for developing a more robust understanding of the role <span class="hlt">basin</span> scale ocean dynamics play in the global climate system. Here we show that a spatial network of marine molluscan sclerochronological oxygen isotope (δ18Oshell) series spanning the North <span class="hlt">Atlantic</span> region provides a skilful reconstruction of <span class="hlt">basin</span> scale North <span class="hlt">Atlantic</span> sea surface temperatures (SSTs). Our analyses demonstrate that the composite marine series (referred to as δ18Oproxy_PC1) is significantly sensitive to inter-annual variability in North <span class="hlt">Atlantic</span> SSTs (R=-0.61 P<0.01) and surface air temperatures (SATs; R=-0.67, P<0.01) over the 20th century. Subpolar gyre (SPG) SSTs dominates variability in the δ18Oproxy_PC1 series at sub-centennial frequencies (R=-0.51, P<0.01). Comparison of the δ18Oproxy_PC1 series against variability in the strength of the European Slope Current and maximum North <span class="hlt">Atlantic</span> meridional overturning circulation derived from numeric climate models (CMIP5), indicates that variability in the SPG region, associated with the strength of the surface currents of the North <span class="hlt">Atlantic</span>, are playing a significant role in shaping the multi-decadal scale SST variability over the industrial era. These analyses demonstrate that spatial networks developed from sclerochronological archives can provide powerful baseline archives of past ocean variability that can facilitate the development of a quantitative understanding for the role the oceans play in the global climate systems and constraining uncertainties in numeric climate models.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JChPh.144c4303K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JChPh.144c4303K"><span>Scattering study of the <span class="hlt">Ne</span> + <span class="hlt">Ne</span>H+(v0 = 0, j0 = 0) → <span class="hlt">Ne</span>H+ + <span class="hlt">Ne</span> reaction on an ab initio based analytical potential energy surface</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Koner, Debasish; Barrios, Lizandra; González-Lezana, Tomás; Panda, Aditya N.</p> <p>2016-01-01</p> <p>Initial state selected dynamics of the <span class="hlt">Ne</span> + <span class="hlt">Ne</span>H+(v0 = 0, j0 = 0) → <span class="hlt">Ne</span>H+ + <span class="hlt">Ne</span> reaction is investigated by quantum and statistical quantum mechanical (SQM) methods on the ground electronic state. The three-body ab initio energies on a set of suitably chosen grid points have been computed at CCSD(T)/aug-cc-PVQZ level and analytically fitted. The fitting of the diatomic potentials, computed at the same level of theory, is performed by spline interpolation. A collinear [<span class="hlt">Ne</span>HNe]+ structure lying 0.72 eV below the <span class="hlt">Ne</span> + <span class="hlt">Ne</span>H+ asymptote is found to be the most stable geometry for this system. Energies of low lying vibrational states have been computed for this stable complex. Reaction probabilities obtained from quantum calculations exhibit dense oscillatory structures, particularly in the low energy region and these get partially washed out in the integral cross section results. SQM predictions are devoid of oscillatory structures and remain close to 0.5 after the rise at the threshold thus giving a crude average description of the quantum probabilities. Statistical cross sections and rate constants are nevertheless in sufficiently good agreement with the quantum results to suggest an important role of a complex-forming dynamics for the title reaction.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PrOce.159..211Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PrOce.159..211Z"><span>Observed and modeled pathways of the Iceland Scotland Overflow Water in the eastern North <span class="hlt">Atlantic</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zou, Sijia; Lozier, Susan; Zenk, Walter; Bower, Amy; Johns, William</p> <p>2017-12-01</p> <p>The spreading of Iceland Scotland Overflow Water (ISOW) in the eastern North <span class="hlt">Atlantic</span> has largely been studied in an Eulerian frame using numerical models or with observations limited to a few locations. No study to date has provided a comprehensive description of the ISOW spreading pathways from both Eulerian and Lagrangian perspectives. In this paper, we use a combination of previously unreported current meter data, hydrographic data, RAFOS float data, and a high resolution (1/12°) numerical ocean model to study the spreading pathways of ISOW from both of these perspectives. We identify three ISOW transport cores in the central Iceland <span class="hlt">Basin</span> (∼59°N), with the major core along the eastern boundary of the Reykjanes Ridge (RR) and the other two in the <span class="hlt">basin</span> interior. Based on trajectories of observed and/or numerical floats seeded along 59°N, we also describe the ISOW spreading pathways and quantify their relative importance. Within 10 years, 7-11% of ISOW from 59°N escapes into the Irminger Sea via gaps in the RR north of the Charlie Gibbs Fracture Zone (CGFZ); the water that moves through these gaps principally originates from the shallower ISOW layer along the RR eastern boundary. 10-13% travels further southward until the CGFZ, where it crosses westward into the western subpolar gyre. 18-21% of ISOW spreads southward along the eastern flank of the Mid-<span class="hlt">Atlantic</span> Ridge into the Western European <span class="hlt">Basin</span> (WEB). Most of the remaining water stays in the Iceland <span class="hlt">Basin</span> over the 10-year period. A model-based investigation provides a first look at the temporal variability of these ISOW pathways. We find that the fraction of southward water exported into the WEB is anti-correlated with the export through the CGFZ, a result assumed to reflect these pathways' interactions with the North <span class="hlt">Atlantic</span> Current in magnitude and/or position shift.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMEP23D3626M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMEP23D3626M"><span>Zinc and Its Isotopes in the Loire River <span class="hlt">Basin</span>, France</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Millot, R.; Desaulty, A. M.; Bourrain, X.</p> <p>2014-12-01</p> <p>The contribution of human activities such as industries, agriculture and domestic inputs, becomes more and more significant in the chemical composition of the dissolved load of rivers. Human factors act as a supplementary key process. Therefore the mass-balance for the budget of catchments and river <span class="hlt">basins</span> include anthropogenic disturbances. The Loire River in central France is approximately 1010 km long and drains an area of 117,800 km2. In the upper <span class="hlt">basin</span>, the bedrock is old plutonic rock overlain by much younger volcanic rocks. The intermediate <span class="hlt">basin</span> includes three major tributaries flowing into the Loire River from the left bank: the Cher, the Indre and the Vienne rivers; the main stream flows westward and its valley stretches toward the <span class="hlt">Atlantic</span> Ocean. Here, the Loire River drains the sedimentary series of the Paris <span class="hlt">Basin</span>, mainly carbonate deposits. The lower Loire <span class="hlt">basin</span> drains pre-Mesozoic basement of the Armorican Massif and its overlying Mesozoic to Cenozoic sedimentary deposits. The Loire River is one of the main European riverine inputs to the <span class="hlt">Atlantic</span> ocean. Here we are reporting concentration and isotope data for Zn in river waters and suspended sediments from the Loire River <span class="hlt">Basin</span>. In addition, we also report concentration and isotope data for the different industrial sources within the Loire <span class="hlt">Basin</span>, as well as data for biota samples such as mussels and oysters from the Bay of Biscay and North Brittany. These organisms are known to be natural accumulators of metal pollutants. Zinc isotopic compositions are rather homogeneous in river waters with δ66Zn values ranging from 0.21 to 0.39‰. This range of variation is very different from anthropogenic signature (industrial and/or agriculture release) that displays δ66Zn values between 0.02 to 0.14‰. This result is in agreement with a geogenic origin and the low Zn concentrations in the Loire River <span class="hlt">Basin</span> (from 0.8 to 6 µg/L).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/of/1980/0268/report.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/of/1980/0268/report.pdf"><span>Geologic and operational summary, COST No. 1 well, Georges Bank area, North <span class="hlt">Atlantic</span> OCS</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Amato, Roger V.; Bebout, John W.</p> <p>1980-01-01</p> <p>The first Continental Offshore Stratigraphic Test (COST) well on the U.S. North <span class="hlt">Atlantic</span> Outer Continental Shelf (OCS) was drilled by Ocean Production Company between April 6 and July 26, 1976, and designated the COST No. G-l. Geological and engineering data obtained from this deep well in the Georges Bank <span class="hlt">Basin</span> were used by the 31 participating companies and the U.S. Geological Survey (USGS) for evaluating the petroleum potential and possible drilling problems in the U.S. North <span class="hlt">Atlantic</span> OCS area in preparation for Lease Sale 42 held on December 18, 1979.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012JGRC..117.5037V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012JGRC..117.5037V"><span>Does the vorticity flux from Agulhas rings control the zonal pathway of NADW across the South <span class="hlt">Atlantic</span>?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>van Sebille, Erik; Johns, William E.; Beal, Lisa M.</p> <p>2012-05-01</p> <p>As part of the global thermohaline circulation, some North <span class="hlt">Atlantic</span> Deep Water (NADW) exits the <span class="hlt">Atlantic</span> <span class="hlt">basin</span> to the south of Africa. Observations have shown that there is a quasi-zonal pathway centered at 25°S carrying NADW eastward, connecting the Deep Western Boundary Current to the Cape <span class="hlt">Basin</span>. However, it has been unclear what sets this pathway. In particular, waters must move southward through the Cape <span class="hlt">Basin</span>, thereby crossing isolines of planetary vorticity, in order to exit the <span class="hlt">basin</span>. Here, we find that an eddy thickness flux induced by Agulhas rings moving northwestward forces a circulation of NADW through the Cape <span class="hlt">Basin</span>. The pathway at 25°S feeds the southeastward flow of this circulation while conserving potential vorticity. Using Lagrangian floats advected for 300 years in a 1/10° resolution ocean model, we show that the most common pathway for NADW in our model lies directly below the Agulhas ring corridor. By analyzing the velocity and density fields in the model, we find that the decay of these rings, and their forward tilt with depth, results in a southward velocity, across isolines of planetary vorticity, of 1 to 2 cm/s in the deep waters. The associated stream function pattern yields a deep circulation transporting 4 Sv of NADW from the Deep Western Boundary Current at 25°S to the southern tip of Africa.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016GGG....17.2336D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016GGG....17.2336D"><span>South <span class="hlt">Atlantic</span> intermediate water advances into the North-east <span class="hlt">Atlantic</span> with reduced <span class="hlt">Atlantic</span> meridional overturning circulation during the last glacial period</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dubois-Dauphin, Quentin; Bonneau, Lucile; Colin, Christophe; Montero-Serrano, Jean-Carlos; Montagna, Paolo; Blamart, Dominique; Hebbeln, Dierk; Van Rooij, David; Pons-Branchu, Edwige; Hemsing, Freya; Wefing, Anne-Marie; Frank, Norbert</p> <p>2016-06-01</p> <p>The Nd isotopic composition (ɛNd) of seawater and cold-water coral (CWC) samples from the Gulf of Cádiz and the Alboran Sea, at a depth of 280-827 m were investigated in order to constrain middepth water mass dynamics within the Gulf of Cádiz over the past 40 ka. ɛNd of glacial and Holocene CWC from the Alboran Sea and the northern Gulf of Cádiz reveals relatively constant values (-8.6 to -9.0 and -9.5 to -10.4, respectively). Such values are similar to those of the surrounding present-day middepth waters from the Mediterranean Outflow Water (MOW; ɛNd ˜ -9.4) and Mediterranean Sea Water (MSW; ɛNd ˜ -9.9). In contrast, glacial ɛNd values for CWC collected at thermocline depth (550-827 m) in the southern Gulf of Cádiz display a higher average value (-8.9 ± 0.4) compared to the present-day value (-11.7 ± 0.3). This implies a higher relative contribution of water masses of Mediterranean (MSW) or South <span class="hlt">Atlantic</span> origin (East Antarctic Intermediate Water, EAAIW). Our study has produced the first evidence of significant radiogenic ɛNd values (˜ -8) at 19, 23-24, and 27 ka, which are coeval with increasing iceberg discharges and a weakening of <span class="hlt">Atlantic</span> Meridional Overturning Circulation (AMOC). Since MOW ɛNd values remained stable during the last glacial period, it is suggested that these radiogenic ɛNd values most likely reflect an enhanced northward propagation of glacial EAAIW into the eastern <span class="hlt">Atlantic</span> <span class="hlt">Basin</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70046695','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70046695"><span>Attributes for MRB_E2RF1 Catchments by Major River <span class="hlt">Basins</span> in the Conterminous United States: <span class="hlt">Basin</span> Characteristics, 2002 Geospatial_Data_Presentation_Form: tabular digital data</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Wieczorek, Michael; LaMotte, Andrew E.</p> <p>2010-01-01</p> <p>This tabular data set represents <span class="hlt">basin</span> characteristics for the year 2002 compiled for every MRB_E2RF1 catchment of selected Major River <span class="hlt">Basins</span> (MRBs, Crawford and others, 2006). These characteristics are reach catchment shape index, stream density, sinuosity, mean elevation, mean slope and number of road-stream crossings. The source data sets are based on a modified version of the U.S. Environmental Protection Agency's (USEPA) RF1_2 and include enhancements to support national and regional-scale surface-water quality modeling (Nolan and others, 2002; Brakebill and others, 2011) and the U.S. Census Bureau's TIGER/Line Files (U.S. Census Bureau,2006). The MRB_E2RF1 catchments are based on a modified version of the U.S. Environmental Protection Agency's (USEPA) ERF1_2 and include enhancements to support national and regional-scale surface-water quality modeling (Nolan and others, 2002; Brakebill and others, 2011). Data were compiled for every MRB_E2RF1 catchment for the conterminous United States covering New England and Mid-<span class="hlt">Atlantic</span> (MRB1), South <span class="hlt">Atlantic</span>-Gulf and Tennessee (MRB2), the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy (MRB3), the Missouri (MRB4), the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf (MRB5), the Rio Grande, Colorado, and the Great <span class="hlt">basin</span> (MRB6), the Pacific Northwest (MRB7) river <span class="hlt">basins</span>, and California (MRB8).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70195226','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70195226"><span>Hydroclimatology of the Missouri River <span class="hlt">basin</span></span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Wise, Erika K.; Woodhouse, Connie A.; McCabe, Gregory; Pederson, Gregory T.; St. Jacques, Jeannine-Marie</p> <p>2018-01-01</p> <p>Despite the importance of the Missouri River for navigation, recreation, habitat, hydroelectric power, and agriculture, relatively little is known about the basic hydroclimatology of the Missouri River <span class="hlt">basin</span> (MRB). This is of particular concern given the droughts and floods that have occurred over the past several decades and the potential future exacerbation of these extremes by climate change. Here, observed and modeled hydroclimatic data and estimated natural flow records in the MRB are used to 1) assess the major source regions of MRB flow, 2) describe the climatic controls on streamflow in the upper and lower <span class="hlt">basins</span> , and 3) investigate trends over the instrumental period. Analyses indicate that 72% of MRB runoff is generated by the headwaters in the upper <span class="hlt">basin</span> and by the lowest portion of the <span class="hlt">basin</span> near the mouth. Spring precipitation and temperature and winter precipitation impacted by changes in zonal versus meridional flow from the Pacific Ocean play key roles in surface water supply variability in the upper <span class="hlt">basin</span>. Lower <span class="hlt">basin</span> flow is significantly correlated with precipitation in late spring and early summer, indicative of <span class="hlt">Atlantic</span>-influenced circulation variability affecting the flow of moisture from the Gulf of Mexico. Although increases in precipitation in the lower <span class="hlt">basin</span> are currently overriding the effects of warming temperatures on total MRB flow, the upper basin’s long-term trend toward decreasing flows, reduction in snow versus rain fraction, and warming spring temperatures suggest that the upper <span class="hlt">basin</span> may less often provide important flow supplements to the lower <span class="hlt">basin</span> in the future.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4464550','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4464550"><span>Between-Habitat Variation of Benthic Cover, Reef Fish Assemblage and Feeding Pressure on the Benthos at the Only Atoll in South <span class="hlt">Atlantic</span>: Rocas Atoll, <span class="hlt">NE</span> Brazil</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Longo, G. O.; Morais, R. A.; Martins, C. D. L.; Mendes, T. C.; Aued, A. W.; Cândido, D. V.; de Oliveira, J. C.; Nunes, L. T.; Fontoura, L.; Sissini, M. N.; Teschima, M. M.; Silva, M. B.; Ramlov, F.; Gouvea, L. P.; Ferreira, C. E. L.; Segal, B.; Horta, P. A.; Floeter, S. R.</p> <p>2015-01-01</p> <p>The Southwestern <span class="hlt">Atlantic</span> harbors unique and relatively understudied reef systems, including the only atoll in South <span class="hlt">Atlantic</span>: Rocas atoll. Located 230 km off the <span class="hlt">NE</span> Brazilian coast, Rocas is formed by coralline red algae and vermetid mollusks, and is potentially one of the most “pristine” areas in Southwestern <span class="hlt">Atlantic</span>. We provide the first comprehensive and integrative description of the fish and benthic communities inhabiting different shallow reef habitats of Rocas. We studied two contrasting tide pool habitats: open pools, which communicate with the open ocean even during low tides, thus more exposed to wave action; and closed pools, which remain isolated during low tide and are comparatively less exposed. Reef fish assemblages, benthic cover, algal turfs and fish feeding pressure on the benthos remarkably varied between open and closed pools. The planktivore Thalassoma noronhanum was the most abundant fish species in both habitats. In terms of biomass, the lemon shark Negaprion brevirostris and the omnivore Melichtys niger were dominant in open pools, while herbivorous fishes (mainly Acanthurus spp.) prevailed in closed pools. Overall benthic cover was dominated by algal turfs, composed of articulated calcareous algae in open pools and non-calcified algae in closed pools. Feeding pressure was dominated by acanthurids and was 10-fold lower in open pools than in closed pools. Besides different wave exposure conditions, such pattern could also be related to the presence of sharks in open pools, prompting herbivorous fish to feed more in closed pools. This might indirectly affect the structure of reef fish assemblages and benthic communities. The macroalgae Digenea simplex, which is uncommon in closed pools and abundant in the reef flat, was highly preferred in herbivory assays, indicating that herbivory by fishes might be shaping this distribution pattern. The variations in benthic and reef fish communities, and feeding pressure on the benthos between open</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26061735','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26061735"><span>Between-Habitat Variation of Benthic Cover, Reef Fish Assemblage and Feeding Pressure on the Benthos at the Only Atoll in South <span class="hlt">Atlantic</span>: Rocas Atoll, <span class="hlt">NE</span> Brazil.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Longo, G O; Morais, R A; Martins, C D L; Mendes, T C; Aued, A W; Cândido, D V; de Oliveira, J C; Nunes, L T; Fontoura, L; Sissini, M N; Teschima, M M; Silva, M B; Ramlov, F; Gouvea, L P; Ferreira, C E L; Segal, B; Horta, P A; Floeter, S R</p> <p>2015-01-01</p> <p>The Southwestern <span class="hlt">Atlantic</span> harbors unique and relatively understudied reef systems, including the only atoll in South <span class="hlt">Atlantic</span>: Rocas atoll. Located 230 km off the <span class="hlt">NE</span> Brazilian coast, Rocas is formed by coralline red algae and vermetid mollusks, and is potentially one of the most "pristine" areas in Southwestern <span class="hlt">Atlantic</span>. We provide the first comprehensive and integrative description of the fish and benthic communities inhabiting different shallow reef habitats of Rocas. We studied two contrasting tide pool habitats: open pools, which communicate with the open ocean even during low tides, thus more exposed to wave action; and closed pools, which remain isolated during low tide and are comparatively less exposed. Reef fish assemblages, benthic cover, algal turfs and fish feeding pressure on the benthos remarkably varied between open and closed pools. The planktivore Thalassoma noronhanum was the most abundant fish species in both habitats. In terms of biomass, the lemon shark Negaprion brevirostris and the omnivore Melichtys niger were dominant in open pools, while herbivorous fishes (mainly Acanthurus spp.) prevailed in closed pools. Overall benthic cover was dominated by algal turfs, composed of articulated calcareous algae in open pools and non-calcified algae in closed pools. Feeding pressure was dominated by acanthurids and was 10-fold lower in open pools than in closed pools. Besides different wave exposure conditions, such pattern could also be related to the presence of sharks in open pools, prompting herbivorous fish to feed more in closed pools. This might indirectly affect the structure of reef fish assemblages and benthic communities. The macroalgae Digenea simplex, which is uncommon in closed pools and abundant in the reef flat, was highly preferred in herbivory assays, indicating that herbivory by fishes might be shaping this distribution pattern. The variations in benthic and reef fish communities, and feeding pressure on the benthos between open and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017DSRII.145...22L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017DSRII.145...22L"><span>Long-term baited lander experiments at a cold-water coral community on Galway Mound (Belgica Mound Province, <span class="hlt">NE</span> <span class="hlt">Atlantic</span>)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lavaleye, Marc; Duineveld, Gerard; Bergman, Magda; van den Beld, Inge</p> <p>2017-11-01</p> <p>A long-term lander employing a baited camera system was developed to study temporal variation in the presence of scavenging fish and invertebrates at a cold-water coral community on Galway Mound (Belgica Mound Province, <span class="hlt">NE</span> <span class="hlt">Atlantic</span>). The camera system was tested during two successful long-term deployments for periods of 6 and 12 months respectively. The baited system, consisting of two separate video cameras with infrared lights and a bait dispenser with 24 bait positions, recorded more than 15,500 clips of 17 s, regularly spread over both periods. New bait, consisting of sardines in oil, was offered at regular time intervals, and attracted scavengers over the whole period of deployment, and especially the crab Chaceon affinis did still eat from it till the end of the deployments. However, the attractiveness for some scavengers, i.e. amphipods, diminished quite quickly. In addition to invertebrate scavengers, namely C. affinis, two other crab species, amphipods, a shrimp and a starfish, also 7 species of fish were recorded near the bait, of which Lepidion eques was by far the most common. Though there was no concrete evidence for seasonal patterns, the observations showed substantial temporal variation in the abundance of several species, especially the crabs C. affinis and Bathynectes maravigna and the fish Phycis blennoides. It is concluded that long-term deployments of such a baited camera system can produce novel data. For instance such a system could be employed for monitoring impacts of disturbances on the deep-sea floor (e.g. mining), as we infer that mobile scavengers will be among the first organisms to show a visible reaction to any chemically and physically (noise, vibrations) alteration of the environment similar to a mine canary.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016NatCC...6..275L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016NatCC...6..275L"><span><span class="hlt">Atlantic</span>-induced pan-tropical climate change over the past three decades</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, Xichen; Xie, Shang-Ping; Gille, Sarah T.; Yoo, Changhyun</p> <p>2016-03-01</p> <p>During the past three decades, tropical sea surface temperature (SST) has shown dipole-like trends, with warming over the tropical <span class="hlt">Atlantic</span> and Indo-western Pacific but cooling over the eastern Pacific. Competing hypotheses relate this cooling, identified as a driver of the global warming hiatus, to the warming trends in either the <span class="hlt">Atlantic</span> or Indian Ocean. However, the mechanisms, the relative importance and the interactions between these teleconnections remain unclear. Using a state-of-the-art climate model, we show that the <span class="hlt">Atlantic</span> plays a key role in initiating the tropical-wide teleconnection, and the <span class="hlt">Atlantic</span>-induced anomalies contribute ~55-75% of the tropical SST and circulation changes during the satellite era. The <span class="hlt">Atlantic</span> warming drives easterly wind anomalies over the Indo-western Pacific as Kelvin waves and westerly anomalies over the eastern Pacific as Rossby waves. The wind changes induce an Indo-western Pacific warming through the wind-evaporation-SST effect, and this warming intensifies the La Niña-type response in the tropical Pacific by enhancing the easterly trade winds and through the Bjerknes ocean dynamical processes. The teleconnection develops into a tropical-wide SST dipole pattern. This mechanism, supported by observations and a hierarchy of climate models, reveals that the tropical ocean <span class="hlt">basins</span> are more tightly connected than previously thought.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015FrEaS...3...22K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015FrEaS...3...22K"><span>Tracing tetraether lipids from source to sink in the Rhô<span class="hlt">ne</span> River system (NW Mediterranean)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kim, Jung-Hyun; Ludwig, Wolfgang; Buscail, Roselyne; Dorhout, Denise; Sinninghe Damste, Jaap</p> <p>2015-06-01</p> <p>In this study, we investigated soils and river suspended particulate matter (SPM) collected in the Rhô<span class="hlt">ne</span> and its tributary <span class="hlt">basins</span> as well as marine surface sediments taken in the Rhô<span class="hlt">ne</span> prodelta (Gulf of Lions, NW Mediterranean). Thereby, we traced the signal of branched glycerol dialkyl glycerol tetraethers (brGDGTs) from the source to sink via the Rhô<span class="hlt">ne</span> River and its tributaries and identified sources of brGDGTs in rivers and marine sediments. Soil pH rather than the mean annual air temperature (MAAT) explains most of the observed variances of the brGDGT distribution in our soil dataset. The observed changes in the distribution of brGDGTs in the river SPM indicate that brGDGTs brought by the river to the sea are primarily derived from the lower Rhô<span class="hlt">ne</span> and its tributary soils, even though in situ production in the river itself cannot be excluded. In marine surface sediments, it appears that the input of riverine brGDGTs is the primary source of brGDGTs in the Rhô<span class="hlt">ne</span> prodelta, although the brGDGT composition may be further modified by the in situ production in the marine environment. More work is required to assess fully whether brGDGTs can be used to reconstruct the terrestrial paleoenvironmental changes using marine sediment cores taken in the Rhô<span class="hlt">ne</span> prodelta close to the river mouth.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMPP21A2267S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMPP21A2267S"><span>Dueling Deglacial Depth Transects: A Synthesis of Isotope Records from the South <span class="hlt">Atlantic</span> and Pacific Oceans Provides Insight into Deglacial Ocean Circulation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sikes, E. L.; Allen, K. A.; Lund, D. C.</p> <p>2016-12-01</p> <p>The end of the last ice age was marked by rapid increases in atmospheric CO2 and changes in ocean circulation and seawater δ13C and Δ14C, suggesting that enhanced ventilation of the deep ocean may have released sequestered CO2 to the atmosphere. Here we compare depth transects of Δ14C and high-resolution Cibicidoides sp. δ13C and δ18O records from the Southwest Pacific and the Southwest <span class="hlt">Atlantic</span> to gain insight into the changing extent and composition of water masses in the Southern Hemisphere. Our vertical transects document that during the Last Glacial Maximum (LGM), water mass properties and boundaries in the Southwest <span class="hlt">Atlantic</span> and Pacific were very different from one another and from their respective modern profiles. The shallow to deep δ13C difference (Δδ13C, 660- 2500 m) in the Pacific was 1.7‰, more than double the Holocene value ( 0.7‰) and a deep watermass boundary was situated above 1600m. LGM Δδ13C in the <span class="hlt">Atlantic</span> was similar to the Pacific, but the deep geochemical front was situated at 2500 m (as observed previously; e.g. Hoffman and Lund, 2012). At the onset of Heinrich Stadial 1 (HS1; 18 - 14.5 ka), changes in the shallow isotope records (< 1500 m) from the two <span class="hlt">basins</span> differed, indicating independent controls on intermediate water composition/formation in these two ocean <span class="hlt">basins</span>. During HS1 in the Pacific, rapid δ13C and Δ14C enrichment above 1600 m coincided with δ13C depletion in <span class="hlt">Atlantic</span> waters between 1500 m and 2500 m. Benthic δ13C below 2500 m in both <span class="hlt">basins</span> and D14C in the Pacific remained depleted until the Antarctic Cold Reversal (ACR; 14.7 to 12.7 ka). During the ACR, Pacific Δ14C below 1600 m increased while both the <span class="hlt">Atlantic</span> and Pacific experienced a rapid increase in δ13C and decrease in δ18O below 2500 m. These simultaneous isotopic shifts in the Pacific and <span class="hlt">Atlantic</span> support the idea of a widespread pulse of deep-water ventilation driven by the resumption of North <span class="hlt">Atlantic</span> Deep Water formation during the ACR. Overall</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20070032937','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20070032937"><span>Shifting Surface Currents in the Northern North <span class="hlt">Atlantic</span> Ocean</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hakkinen, Sirpa; Rhines, Peter B.</p> <p>2007-01-01</p> <p>Analysis of surface drifter tracks in the North <span class="hlt">Atlantic</span> Ocean from the time period 1990 to 2006 provides the first evidence that the Gulf Stream waters can have direct pathways to the Nordic Seas. Prior to 2000, the drifters entering the channels leading to the Nordic Seas originated in the western and central subpolar region. Since 2001 several paths from the western subtropics have been present in the drifter tracks leading to the Rockall Trough through which the most saline North <span class="hlt">Atlantic</span> Waters pass to the Nordic Seas. Eddy kinetic energy from altimetry shows also the increased energy along the same paths as the drifters, These near surface changes have taken effect while the altimetry shows a continual weakening of the subpolar gyre. These findings highlight the changes in the vertical structure of the northern North <span class="hlt">Atlantic</span> Ocean, its dynamics and exchanges with the higher latitudes, and show how pathways of the thermohaline circulation can open up and maintain or increase its intensity even as the <span class="hlt">basin</span>-wide circulation spins down.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018SolE....9..341K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018SolE....9..341K"><span>Middle to Late Devonian-Carboniferous collapse <span class="hlt">basins</span> on the Finnmark Platform and in the southwesternmost Nordkapp <span class="hlt">basin</span>, SW Barents Sea</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Koehl, Jean-Baptiste P.; Bergh, Steffen G.; Henningsen, Tormod; Faleide, Jan Inge</p> <p>2018-03-01</p> <p>The SW Barents Sea margin experienced a pulse of extensional deformation in the Middle-Late Devonian through the Carboniferous, after the Caledonian Orogeny terminated. These events marked the initial stages of formation of major offshore <span class="hlt">basins</span> such as the Hammerfest and Nordkapp <span class="hlt">basins</span>. We mapped and analyzed three major fault complexes, (i) the Måsøy Fault Complex, (ii) the Rolvsøya fault, and (iii) the Troms-Finnmark Fault Complex. We discuss the formation of the Måsøy Fault Complex as a possible extensional splay of an overall <span class="hlt">NE</span>-SW-trending, NW-dipping, basement-seated Caledonian shear zone, the Sørøya-Ingøya shear zone, which was partly inverted during the collapse of the Caledonides and accommodated top-NW normal displacement in Middle to Late Devonian-Carboniferous times. The Troms-Finnmark Fault Complex displays a zigzag-shaped pattern of NNE-SSW- and ENE-WSW-trending extensional faults before it terminates to the north as a WNW-ESE-trending, <span class="hlt">NE</span>-dipping normal fault that separates the southwesternmost Nordkapp <span class="hlt">basin</span> in the northeast from the western Finnmark Platform and the Gjesvær Low in the southwest. The WNW-ESE-trending, margin-oblique segment of the Troms-Finnmark Fault Complex is considered to represent the offshore prolongation of a major Neoproterozoic fault complex, the Trollfjorden-Komagelva Fault Zone, which is made of WNW-ESE-trending, subvertical faults that crop out on the island of Magerøya in NW Finnmark. Our results suggest that the Trollfjorden-Komagelva Fault Zone dies out to the northwest before reaching the western Finnmark Platform. We propose an alternative model for the origin of the WNW-ESE-trending segment of the Troms-Finnmark Fault Complex as a possible hard-linked, accommodation cross fault that developed along the Sørøy-Ingøya shear zone. This brittle fault decoupled the western Finnmark Platform from the southwesternmost Nordkapp <span class="hlt">basin</span> and merged with the Måsøy Fault Complex in Carboniferous times. Seismic</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70046930','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70046930"><span>Attributes for NHDPlus Catchments (Version 1.1): <span class="hlt">Basin</span> Characteristics, 2002</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Wieczorek, Michael; LaMotte, Andrew E.</p> <p>2010-01-01</p> <p>This data set represents <span class="hlt">basin</span> characteristics, compiled for every catchment in NHDPlus for the conterminous United States. These characteristics are <span class="hlt">basin</span> shape index, stream density, sinuosity, mean elevation, mean slope, and number of road-stream crossings. The source data sets are the U.S. Environmental Protection Agency's NHDPlus and the U.S. Census Bureau's TIGER/Line Files. The NHDPlus Version 1.1 is an integrated suite of application-ready geospatial datasets that incorporates many of the best features of the National Hydrography Dataset (NHD) and the National Elevation Dataset (NED). The NHDPlus includes a stream network (based on the 1:100,00-scale NHD), improved networking, naming, and value-added attributes (VAAs). NHDPlus also includes elevation-derived catchments (drainage areas) produced using a drainage enforcement technique first widely used in New England, and thus referred to as "the New England Method." This technique involves "burning in" the 1:100,000-scale NHD and when available building "walls" using the National Watershed Boundary Dataset (WBD). The resulting modified digital elevation model (HydroDEM) is used to produce hydrologic derivatives that agree with the NHD and WBD. Over the past two years, an interdisciplinary team from the U.S. Geological Survey (USGS), and the U.S. Environmental Protection Agency (USEPA), and contractors, found that this method produces the best quality NHD catchments using an automated process (USEPA, 2007). The NHDPlus dataset is organized by 18 Production Units that cover the conterminous United States. The NHDPlus version 1.1 data are grouped by the U.S. Geologic Survey's Major River <span class="hlt">Basins</span> (MRBs, Crawford and others, 2006). MRB1, covering the New England and Mid-<span class="hlt">Atlantic</span> River <span class="hlt">basins</span>, contains NHDPlus Production Units 1 and 2. MRB2, covering the South <span class="hlt">Atlantic</span>-Gulf and Tennessee River <span class="hlt">basins</span>, contains NHDPlus Production Units 3 and 6. MRB3, covering the Great Lakes, Ohio, Upper Mississippi, and Souris</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFM.H31B1109M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFM.H31B1109M"><span>Pb-Zn-Cd-Hg multi isotopic characterization of the Loire River <span class="hlt">Basin</span>, France</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Millot, R.; Widory, D.; Innocent, C.; Guerrot, C.; Bourrain, X.; Johnson, T. M.</p> <p>2012-12-01</p> <p>The contribution of human activities such as industries, agriculture and domestic inputs, becomes more and more significant in the chemical composition (major ions and pollutants such as metals) of the dissolved load of rivers. Furthermore, this influence can also be evidenced in the suspended solid matter known to play an important role in the transport of heavy metals through river systems. Human factors act as a supplementary key process. Therefore the mass-balance for the budget of catchments and river <span class="hlt">basins</span> include anthropogenic disturbances. The Loire River in central France is approximately 1010 km long and drains an area of 117,800 km2. Initially, the Loire upstream flows in a south to north direction originating in the Massif Central, and continues up to the city of Orléans, 650 km from the source. In the upper <span class="hlt">basin</span>, the bedrock is old plutonic rock overlain by much younger volcanic rocks. The Loire River then follows a general east to west direction to the <span class="hlt">Atlantic</span> Ocean. The intermediate <span class="hlt">basin</span> includes three major tributaries flowing into the Loire River from the left bank: the Cher, the Indre and the Vienne rivers; the main stream flows westward and its valley stretches toward the <span class="hlt">Atlantic</span> Ocean. Here, the Loire River drains the sedimentary series of the Paris <span class="hlt">Basin</span>, mainly carbonate deposits. The lower Loire <span class="hlt">basin</span> drains pre-Mesozoic basement of the Armorican Massif and its overlying Mesozoic to Cenozoic sedimentary deposits. The Loire River is one of the main European riverine inputs to the <span class="hlt">Atlantic</span> ocean. Here we are reporting concentration and isotope data for heavy metals Zn-Cd-Pb-Hg in river waters and suspended sediments from the Loire River <span class="hlt">Basin</span>. In addition, we also report concentration and isotope data for these metals for the different industrial sources within the Loire <span class="hlt">Basin</span>, as well as data for biota samples such as mussels and oysters from the Bay of Biscay and North Brittany. These organisms are known to be natural accumulators of</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_16 --> <div id="page_17" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="321"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.H32F..03D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.H32F..03D"><span>Forecasting Total Water Storage Changes in the Amazon <span class="hlt">basin</span> using <span class="hlt">Atlantic</span> and Pacific Sea Surface Temperatures</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>De Linage, C.; Famiglietti, J. S.; Randerson, J. T.</p> <p>2013-12-01</p> <p>Floods and droughts frequently affect the Amazon River <span class="hlt">basin</span>, impacting the transportation, river navigation, agriculture, economy and the carbon balance and biodiversity of several South American countries. The present study aims to find the main variables controlling the natural interannual variability of terrestrial water storage in the Amazon region and to propose a modeling framework for flood and drought forecasting. We propose three simple empirical models using a linear combination of lagged spatial averages of central Pacific (Niño 4 index) and tropical North <span class="hlt">Atlantic</span> (TNAI index) sea surface temperatures (SST) to predict a decade-long record of 3°, monthly terrestrial water storage anomalies (TWSA) observed by the Gravity Recovery And Climate Experiment (GRACE) mission. In addition to a SST forcing term, the models included a relaxation term to simulate the memory of water storage anomalies in response to external variability in forcing. Model parameters were spatially-variable and individually optimized for each 3° grid cell. We also investigated the evolution of the predictive capability of our models with increasing minimum lead times for TWSA forecasts. TNAI was the primary external forcing for the central and western regions of the southern Amazon (35% of variance explained with a 3-month forecast), whereas Niño 4 was dominant in the northeastern part of the <span class="hlt">basin</span> (61% of variance explained with a 3-month forecast). Forcing the model with a combination of the two indices improved the fit significantly (p<0.05) for at least 64% of the grid cells, compared to models forced solely with Niño 4 or TNAI. The combined model was able to explain 43% of the variance in the Amazon <span class="hlt">basin</span> as a whole with a 3-month lead time. While 66% of the observed variance was explained in the northeastern Amazon, only 39% of the variance was captured by the combined model in the central and western regions, suggesting that other, more local, forcing sources were</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003AGUFM.C31B0402J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003AGUFM.C31B0402J"><span>Aerogeophysical evidence for complex subglacial geology below the Rutford drainage <span class="hlt">basin</span>,WestAntarctica</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jones, P.; Ferraccioli, F.; Corr, H.; Smith, A. M.; King, E.; Vaughan, D.</p> <p>2003-12-01</p> <p>A significant part of the West Antarctic Ice Sheet appears to be imposed upon a complex and still largely unknown continental rift system, perhaps featuring sedimentary <span class="hlt">basins</span>, thin crust and high heat flow. Subglacial geology has been postulated to strongly modulate the dynamics and stability of the ice sheet itself. Specifically, recent aerogeophysics collected over central West Antarctica at edge of the Whitmore Mountains crustal block show that narrow subglacial rift <span class="hlt">basins</span> with thick sedimentary infill may control the onsets and lateral margins of ice streams. The British Antarctic Survey flew an aerogeophysical survey during the 2001-02 field season: the main aim was to investigate what factors control the location and dynamics of the onset region of the Rutford Ice stream. Airborne radar, aerogravity and aeromagnetic data were simultaneously collected over the drainage <span class="hlt">basin</span> of the Rutford Ice Stream. The new bedrock elevation grid for the area shows that the Rutford Ice Stream is constrained by a deep bedrock trough with a N-S to <span class="hlt">NE</span>-SW trend. The onset region appears however to lie within an E-W bedrock trough at the edge of the Ellsworth Mountains crustal block. Bouguer gravity maps do not reveal typical signatures for a coincident deep rift <span class="hlt">basin</span> at this location. However, a sharp <span class="hlt">NE</span>-SW trending gradient, likely separating crustal blocks with contrasting crustal thickness is revealed. Aeromagnetic data image <span class="hlt">NE</span>-SW trends north of the Rutford Ice Stream. In the onset region, these trends appear to be truncated by a NNW-SSE trend, lying on strike with the Ellsworth Mountains. Hence, the new aerogeophysical data suggests greater complexity in the subglacial geology and structure of an onset region of an ice stream compared to previous investigations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/FR-2011-04-04/pdf/2011-7947.pdf','FEDREG'); return false;" href="https://www.gpo.gov/fdsys/pkg/FR-2011-04-04/pdf/2011-7947.pdf"><span>76 FR 18504 - <span class="hlt">Atlantic</span> Highly Migratory Species; <span class="hlt">Atlantic</span> Bluefin Tuna Quotas and <span class="hlt">Atlantic</span> Tuna Fisheries...</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collection.action?collectionCode=FR">Federal Register 2010, 2011, 2012, 2013, 2014</a></p> <p></p> <p>2011-04-04</p> <p>...-BA65 <span class="hlt">Atlantic</span> Highly Migratory Species; <span class="hlt">Atlantic</span> Bluefin Tuna Quotas and <span class="hlt">Atlantic</span> Tuna Fisheries..., 2011, NMFS published a proposed rule to modify <span class="hlt">Atlantic</span> bluefin tuna (BFT) base quotas for all domestic...); amend the <span class="hlt">Atlantic</span> tunas possession at sea and landing regulations to allow removal of <span class="hlt">Atlantic</span> tunas...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.A54C..01C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.A54C..01C"><span><span class="hlt">Basin</span>-scale observations of isoprene and monoterpenes in the Arctic and <span class="hlt">Atlantic</span> Oceans</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Carpenter, L.; Hackenberg, S.; Andrews, S.; Minaeian, J.; Chance, R.; Arnold, S.; Spracklen, D. V.; Walker, H.; Brewin, R. J.; Tarran, G.; Tilstone, G.; Small, A.; Bouman, H. A.</p> <p>2016-12-01</p> <p>We report surface ocean concentrations, atmospheric mixing ratios and calculated sea-to-air fluxes of isoprene and six monoterpenes (α- and β-pinene, myrcene, Δ 3-carene, ocimene, and limonene) spanning approximately 130 degrees of latitude (80 °N- 50 °S) in the Arctic and <span class="hlt">Atlantic</span> Oceans. Oceanic isoprene concentrations showed covariance with a number of concurrently monitored biological parameters, and these relationships were dependent on sea surface temperatures. Parameterisations of isoprene seawater concentrations based on linear regression analyses of these relationships perform well for Arctic and <span class="hlt">Atlantic</span> data. Levels of all monoterpenes were generally low, with oceanic concentrations ranging from below the detection limit of <1 pmol L-1 to 5 pmol L-1 . In air, monoterpene mixing ratios varied from below the detection limit ( 1 pptv) to 5 pptv, after careful filtering for ship-related contamination. Unlike in previous studies, no clear trends or relationships of the monoterpenes with biological data were found. Limonene showed generally the highest levels in water (up to 84 pmol L-1 in the <span class="hlt">Atlantic</span> Ocean) and air; however this was attributed mostly to shipborne contamination. We calculate global sea-air fluxes of isoprene and monoterpenes based on this data and compare to previous estimates.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AGUFMPP52A..05B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AGUFMPP52A..05B"><span>Seasonality in the tropical <span class="hlt">Atlantic</span>: an 800-year record of seasonally-representative Mg/Ca data from the Cariaco <span class="hlt">Basin</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Black, D. E.; Rahman, S.; Wurtzel, J.; Thunell, R.; Mauer, B.; Tappa, E. J.</p> <p>2009-12-01</p> <p>The Cariaco <span class="hlt">Basin</span>, Venezuela is well-positioned to record a detailed history of surface ocean changes along the southern margin of the Caribbean and the tropical <span class="hlt">Atlantic</span>. Varved, high deposition rate sediments deposited under anoxic conditions and an abundance of well-preserved microfossils result in one of the few marine records capable of preserving evidence of interannual- to decadal-scale climate variability in the tropical <span class="hlt">Atlantic</span>. Boreal winter/spring sea surface temperatures (SST) spanning the last eight centuries have previously been reconstructed using Mg/Ca measurements on the planktic foraminifer Globigerina bulloides. Here we present the complementary record using Globigerinoides ruber (pink), a summer/fall indicator. Globigerinoides ruber Mg/Ca values are generally greater than those of G. bulloides from the same sample, reflecting warmer calcification temperatures. Both species’ records display similar long-term trends, yet there are some distinctive differences. The Medieval Warm Period (MWP) and Little Ice Age (LIA) as distinctly separate climate events are more apparent in the G. ruber record than that of G. bulloides. Additionally, greater variability in the G. ruber data may indicate a stronger than expected bias from productivity during the local upwelling season. As G. bulloides and pink G. ruber are thought to be winter/spring and summer/fall SST indicators, respectively (albeit with the potential upwelling season bias), the intersample differences between the two records can potentially be interpreted as a record of seasonality. Our seasonality reconstruction shows a distinctive oscillation of 4 °C with a period of approximately 200 years. The proxy seasonality is slightly less than what has been instrumentally measured (5 to 6 °C) over the last 15 years, and does not appear related to or affected by the MWP or LIA events.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018ClDy...50.2951B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018ClDy...50.2951B"><span>Nonlinear interactions between the Amazon River <span class="hlt">basin</span> and the Tropical North <span class="hlt">Atlantic</span> at interannual timescales</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Builes-Jaramillo, Alejandro; Marwan, Norbert; Poveda, Germán; Kurths, Jürgen</p> <p>2018-04-01</p> <p>We study the physical processes involved in the potential influence of Amazon (AM) hydroclimatology over the Tropical North <span class="hlt">Atlantic</span> (TNA) Sea Surface Temperatures (SST) at interannual timescales, by analyzing time series of the precipitation index (P-E) over AM, as well as the surface atmospheric pressure gradient between both regions, and TNA SSTs. We use a recurrence joint probability based analysis that accounts for the lagged nonlinear dependency between time series, which also allows quantifying the statistical significance, based on a twin surrogates technique of the recurrence analysis. By means of such nonlinear dependence analysis we find that at interannual timescales AM hydrology influences future states of the TNA SSTs from 0 to 2 months later with a 90-95% statistical confidence. It also unveils the existence of two-way feedback mechanisms between the variables involved in the processes: (1) precipitation over AM leads the atmospheric pressure gradient between TNA and AM from 0 to 2 month lags, (2) the pressure gradient leads the trade zonal winds over the TNA from 0 to 3 months and from 7 to 12 months, (3) the zonal winds lead the SSTs from 0 to 3 months, and (4) the SSTs lead precipitation over AM by 1 month lag. The analyses were made for time series spanning from 1979 to 2008, and for extreme precipitation events in the AM during the years 1999, 2005, 2009 and 2010. We also evaluated the monthly mean conditions of the relevant variables during the extreme AM droughts of 1963, 1980, 1983, 1997, 1998, 2005, and 2010, and also during the floods of 1989, 1999, and 2009. Our results confirm that the Amazon River <span class="hlt">basin</span> acts as a land surface-atmosphere bridge that links the Tropical Pacific and TNA SSTs at interannual timescales. The identified mutual interactions between TNA and AM are of paramount importance for a deeper understanding of AM hydroclimatology but also of a suite of oceanic and atmospheric phenomena over the TNA, including recently</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009EnGeo..58.1407R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009EnGeo..58.1407R"><span>Morphometric and landsliding analyses in chain domain: the Roccella <span class="hlt">basin</span>, <span class="hlt">NE</span> Sicily, Italy</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rapisarda, Francesco</p> <p>2009-10-01</p> <p>The dynamic interaction of endogenic and exogenic processes in active geodynamic context leads to the deterioration of the physico-mechanical characteristics of the rocks, inducing slopes instability. In such context, the morphometric parameters and the analysis of landslide distribution contribute to appraise the evolutive state of hydrographic <span class="hlt">basins</span>. The aim of the study is the morphometric characterization of the Roccella Torrent <span class="hlt">basin</span> (Rtb) located in South Italy. Landsliding and tectonic structure dynamically interact with the drainage pattern that records these effects and permits the definition of the evolutive geomorphic stage of the <span class="hlt">basin</span>. The Air Photograph Investigation and field surveys permitted to draw the main geomorphic features, the drainage pattern of the Rtb, to calculate the morphometric parameters and to delimit the landslides’ bodies. Detailed analysis about the landslide distribution within a test site 17 km2 wide were carried out to elaborate indicative indexes of the landslides type and to single out the lithotypes that are more involved in slope instability phenomena. The morphometric parameters indicate the rejuvenation state within the Rtb where the stream reaches show the effects of increased energy relief in agreement with the geological settings of this sector of the Apennine-Maghrebian Chain.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/publication/?seqNo115=243025','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/publication/?seqNo115=243025"><span>The Choptank <span class="hlt">Basin</span> in transition: intensifying agriculture, slow urbanization, and estuarine eutrophication</span></a></p> <p><a target="_blank" href="https://www.ars.usda.gov/research/publications/find-a-publication/">USDA-ARS?s Scientific Manuscript database</a></p> <p></p> <p></p> <p>The Choptank <span class="hlt">basin</span> and estuary are located on the Mid-<span class="hlt">Atlantic</span> coastal plain on the Delmarva Peninsula. The regional hydrology is characterized by nearly uniform rainfall, but large seasonal variations in temperature and evapotranspiration (maximum in summer) drive large seasonal changes in groundwa...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AGUSMPP31A..02V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AGUSMPP31A..02V"><span>Reconstruction of Sea/Lake-Level Changes in an Active Strike-Slip <span class="hlt">Basin</span> (Gulf of Cariaco, <span class="hlt">NE</span> Venezuela)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>van Daele, M.; Audemard, F.; Beck, C.; de Batist, M.; van Welden, A.; Moernaut, J.; 2006 Shipboard Party, G.</p> <p>2008-05-01</p> <p>. According to this age model, our seismic stratigraphy reaches back to MIS6, and the average sedimentation rate in the central parts of the gulf since MIS5e is 0.92 mm/y. Our data show that reconstructed lake levels in the Gulf of Cariaco, which represent a proxy for climate in <span class="hlt">NE</span>- Venezuela, are very strongly coupled to the global stadials and interstadials of the last glacial period. Also the Younger Dryas is recognised in the sedimentary record of the Gulf of Cariaco as lowstand deposit resulting from an (almost) complete desiccation. Our data reveal that the stratigraphy of the Gulf of Cariaco holds a very accurate, complete and promising record of eustasy and climate change, at least since the penultimate glacial maximum. The quality of this record and the vicinity to the iconic Cariaco <span class="hlt">Basin</span> make the Gulf of Cariaco an ideal target for future ocean drilling (or long coring).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017E%26PSL.462...76W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017E%26PSL.462...76W"><span>Sedimentary and crustal thicknesses and Poisson's ratios for the <span class="hlt">NE</span> Tibetan Plateau and its adjacent regions based on dense seismic arrays</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Weilai; Wu, Jianping; Fang, Lihua; Lai, Guijuan; Cai, Yan</p> <p>2017-03-01</p> <p>The sedimentary and crustal thicknesses and Poisson's ratios of the <span class="hlt">NE</span> Tibetan Plateau and its adjacent regions are estimated by the h- κ stacking and CCP image of receiver functions from the data of 1,317 stations. The horizontal resolution of the obtained results is as high as 0.5° × 0.5°, which can be used for further high resolution model construction in the region. The crustal thicknesses from Airy's equilibrium are smaller than our results in the Sichuan <span class="hlt">Basin</span>, Qilian tectonic belt, northern Alxa block and Qaidam <span class="hlt">Basin</span>, which is consistent with the high densities in the mantle lithosphere and may indicate that the high-density lithosphere drags crust down overall. High Poisson's ratios and low velocity zones are found in the mid- and lower crust beneath eastern Qilian tectonic belt and the boundary areas of the Ordos block, indicating that partial melting may exist in these regions. Low Poisson's ratios and low-velocity anomalies are observed in the crust in the <span class="hlt">NE</span> Tibetan Plateau, implying that the mafic lower crust is thinning or missing and that the mid- and lower crust does not exhibit melting or partial melting in the <span class="hlt">NE</span> Tibetan Plateau, and weak flow layers are not likely to exist in this region.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70016665','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70016665"><span>Sedimentary facies and depositional environments of early Mesozoic Newark Supergroup <span class="hlt">basins</span>, eastern North America</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Smoot, J.P.</p> <p>1991-01-01</p> <p>The early Mesozoic Newark Supergroup consists of continental sedimentary rocks and basalt flows that occupy a <span class="hlt">NE</span>-trending belt of elongate <span class="hlt">basins</span> exposed in eastern North America. The <span class="hlt">basins</span> were filled over a period of 30-40 m.y. spanning the Late Triassic to Early Jurassic, prior to the opening of the north <span class="hlt">Atlantic</span> Ocean. The sedimentary rocks are here divided into four principal lithofacies. The alluvial-fan facies includes deposits dominated by: (1) debris flows; (2) shallow braided streams; (3) deeper braided streams (with trough crossbeds); or (4) intense bioturbation or hyperconcentrated flows (tabular, unstratified muddy sandstone). The fluvial facies include deposits of: (1) shallow, ephemeral braided streams; (2) deeper, flashflooding, braided streams (with poor sorting and crossbeds); (3) perennial braided rivers; (4) meandering rivers; (5) meandering streams (with high suspended loads); (6) overbank areas or local flood-plain lakes; or (7) local streams and/or colluvium. The lacustrine facies includes deposits of: (1) deep perennial lakes; (2) shallow perennial lakes; (3) shallow ephemeral lakes; (4) playa dry mudflats; (5) salt-encrusted saline mudflats; or (6) vegetated mudflats. The lake margin clastic facies includes deposits of: (1) birdfoot deltas; (2) stacked Gilbert-type deltas; (3) sheet deltas; (4) wave-reworked alluvial fans; or (5) wave-sorted sand sheets. Coal deposits are present in the lake margin clastic and the lacustrine facies of Carnian age (Late Triassic) only in <span class="hlt">basins</span> of south-central Virginia and North and South Carolina. Eolian deposits are known only from the <span class="hlt">basins</span> in Nova Scotia and Connecticut. Evaporites (and their pseudomorphs) occur mainly in the northern <span class="hlt">basins</span> as deposits of saline soils and less commonly of saline lakes, and some evaporite and alkaline minerals present in the Mesozoic rocks may be a result of later diagenesis. These relationships suggest climatic variations across paleolatitudes, more humid to the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19760064740&hterms=Pepper&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DPepper','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19760064740&hterms=Pepper&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DPepper"><span>Production of <span class="hlt">Ne</span> Auger electrons by <span class="hlt">Ne</span>/+/ bombardment of Mg and Al surfaces</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ferrante, J.; Pepper, S. V.</p> <p>1976-01-01</p> <p>A description is given of experiments which provide evidence for the production of an inner shell vacancy in the <span class="hlt">Ne</span> by the asymmetric <span class="hlt">Ne</span>-Mg and <span class="hlt">Ne</span>-Al collision. In addition, autoionization states of neutral <span class="hlt">Ne</span> have been observed. These states are to be distinguished from the more usual case in Auger electron spectroscopy of de-excitation of an ion with a core vacancy. The experiments involved the bombardment of Mg and Al surfaces with <span class="hlt">Ne</span>(+) ions. A LEED-Auger system equipped with an ion gun and a four-grid retarding potential analyzer operated in the usual dN(E)/dE mode was used.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014PhDT........47N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014PhDT........47N"><span>Hydroclimatology of Extreme Precipitation and Floods Originating from the North <span class="hlt">Atlantic</span> Ocean</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nakamura, Jennifer</p> <p></p> <p>This study explores seasonal patterns and structures of moisture transport pathways from the North <span class="hlt">Atlantic</span> Ocean and the Gulf of Mexico that lead to extreme large-scale precipitation and floods over land. Storm tracks, such as the tropical cyclone tracks in the Northern <span class="hlt">Atlantic</span> Ocean, are an example of moisture transport pathways. In the first part, North <span class="hlt">Atlantic</span> cyclone tracks are clustered by the moments to identify common traits in genesis locations, track shapes, intensities, life spans, landfalls, seasonal patterns, and trends. The clustering results of part one show the dynamical behavior differences of tropical cyclones born in different parts of the <span class="hlt">basin</span>. Drawing on these conclusions, in the second part, statistical track segment model is developed for simulation of tracks to improve reliability of tropical cyclone risk probabilities. Moisture transport pathways from the North <span class="hlt">Atlantic</span> Ocean are also explored though the specific regional flood dynamics of the U.S. Midwest and the United Kingdom in part three of the dissertation. Part I. Classifying North <span class="hlt">Atlantic</span> Tropical Cyclones Tracks by Mass Moments. A new method for classifying tropical cyclones or similar features is introduced. The cyclone track is considered as an open spatial curve, with the wind speed or power information along the curve considered as a mass attribute. The first and second moments of the resulting object are computed and then used to classify the historical tracks using standard clustering algorithms. Mass moments allow the whole track shape, length and location to be incorporated into the clustering methodology. Tropical cyclones in the North <span class="hlt">Atlantic</span> <span class="hlt">basin</span> are clustered with K-means by mass moments producing an optimum of six clusters with differing genesis locations, track shapes, intensities, life spans, landfalls, seasonality, and trends. Even variables that are not directly clustered show distinct separation between clusters. A trend analysis confirms recent conclusions</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19940030956','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19940030956"><span>Noachian and Hesperian modification of the original Chryse impact <span class="hlt">basin</span> topography</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Stockman, Stephanie; Frey, Herbert</p> <p>1994-01-01</p> <p>We propose a new center (35.5 W, 32.5 N) and ring assignment for the original Chryse impact <span class="hlt">basin</span> based on photogeologic mapping and re-examination of the published geology. Noachian features in the Chryse Planitia area are the best indicators of the original ancient multiringed impact structure. While other workers have centered the Chryse impact on the topographic low associated with Hesperian volcanic and fluvial deposits, we suggest that the center of the original Noachian-age excavation cavity was located 800 km farther <span class="hlt">NE</span>, and the <span class="hlt">basin</span> topography was significantly modified over time.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017Tecto..36.1072M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017Tecto..36.1072M"><span>Deformation style and controlling geodynamic processes at the eastern Guadalquivir foreland <span class="hlt">basin</span> (Southern Spain)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Marín-Lechado, C.; Pedrera, A.; Peláez, J. A.; Ruiz-Constán, A.; González-Ramón, A.; Henares, J.</p> <p>2017-06-01</p> <p>The tectonic structure of the Guadalquivir foreland <span class="hlt">basin</span> becomes complex eastward evolving from a single depocenter to a compartmented <span class="hlt">basin</span>. The deformation pattern within the eastern Guadalquivir foreland <span class="hlt">basin</span> has been characterized by combining seismic reflection profiles, boreholes, and structural field data to output a 3-D model. High-dipping NNE-SSW to <span class="hlt">NE</span>-SW trending normal and reverse fault arrays deform the Variscan basement of the <span class="hlt">basin</span>. These faults generally affect Tortonian sediments, which show syntectonic features sealed by the latest Miocene units. Curved and S-shaped fault traces are abundant and caused by the linkage of nearby fault segments during lateral fault propagation. Preexisting faults were reactivated either as normal or reverse faults depending on their position within the foreland. At Tortonian time, reverse faults deformed the <span class="hlt">basin</span> forebulge, while normal faults predominated within the backbulge. Along-strike variation of the Betic foreland <span class="hlt">basin</span> geometry is supported by an increasing mechanical coupling of the two plates (Alborán Domain and Variscan basement) toward the eastern part of the cordillera. Thus, subduction would have progressed in the western Betics, while it would have failed in the eastern one. There, the initially subducted Iberian paleomargin (Nevado-Filábride Complex) was incorporated into the upper plate promoting the transmission of collision-related compressional stresses into the foreland since the middle Miocene. Nowadays, compression is still active and produces low-magnitude earthquakes likely linked to NNE-SSW to <span class="hlt">NE</span>-SW preexiting faults reactivated with reverse oblique-slip kinematics. Seismicity is mostly concentrated around fault tips that are frequently curved in overstepping zones.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19930029692&hterms=Organic+matter&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DOrganic%2Bmatter','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19930029692&hterms=Organic+matter&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DOrganic%2Bmatter"><span>Meridional fluxes of dissolved organic matter in the North <span class="hlt">Atlantic</span> Ocean</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Walsh, John J.; Carder, Kendall L.; Mueller-Karger, Frank E.</p> <p>1992-01-01</p> <p>Biooptical estimates of gelbstoff and a few platinum measurements of dissolved organic carbon (DOCpt) are used to construct a budget of the meridional flux of DOC and dissolved organic nitrogen (DON) across 36 deg 25 min N in the North <span class="hlt">Atlantic</span> from previous inverse models of water and element transport. Distinct southward subsurface fluxes of dissolved organic matter within subducted shelf water, cabelled slope water, and overturned <span class="hlt">basin</span> water are inferred. Within two cases of a positive gradient of DOCpt between terrestrial/shelf and offshore stocks, the net equatorward exports of O2 and DOCpt from the northern North <span class="hlt">Atlantic</span> yield molar ratios of 2.1 to 9.1, compared to the expected Redfield O2/C ratio of 1.3. It is concluded that some shelf export of DOC, with a positive gradient between coastal and oceanic stocks, as well as falling particles, are required to balance carbon, nitrogen, and oxygen budgets of the North <span class="hlt">Atlantic</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA036616','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA036616"><span>North <span class="hlt">Atlantic</span> Regional Water Resources Study. Main Report</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>1972-06-01</p> <p>Areas of the Rgion are found in Annex 1 to this Report. These Area Programs have The NAR is presently growing at a slower rate been reformu!ld into...Physical Characteristics of The Region double to 86.2 million by the year 2020. The rate of growth is about 80 percent of that The North <span class="hlt">Atlantic</span> Region...Use of 141 and Delaware River <span class="hlt">Basin</span> (Area 15). wells and of waste water intakes, while small, is growing at an increased rate . Publicly supplied and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014E%26PSL.392..143H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014E%26PSL.392..143H"><span>The origin of the asymmetry in the Iceland hotspot along the Mid-<span class="hlt">Atlantic</span> Ridge from continental breakup to present-day</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Howell, Samuel M.; Ito, Garrett; Breivik, Asbjørn J.; Rai, Abhishek; Mjelde, Rolf; Hanan, Barry; Sayit, Kaan; Vogt, Peter</p> <p>2014-04-01</p> <p>The Iceland hotspot has profoundly influenced the creation of oceanic crust throughout the North <span class="hlt">Atlantic</span> <span class="hlt">basin</span>. Enigmatically, the geographic extent of the hotspot influence along the Mid-<span class="hlt">Atlantic</span> Ridge has been asymmetric for most of the spreading history. This asymmetry is evident in crustal thickness along the present-day ridge system and anomalously shallow seafloor of ages ∼49-25 Ma created at the Reykjanes Ridge (RR), SSW of the hotspot center, compared to deeper seafloor created by the now-extinct Aegir Ridge (AR) the same distance <span class="hlt">NE</span> of the hotspot center. The cause of this asymmetry is explored with 3-D numerical models that simulate a mantle plume interacting with the ridge system using realistic ridge geometries and spreading rates that evolve from continental breakup to present-day. The models predict plume-influence to be symmetric at continental breakup, then to rapidly contract along the ridges, resulting in widely influenced margins next to uninfluenced oceanic crust. After this initial stage, varying degrees of asymmetry along the mature ridge segments are predicted. Models in which the lithosphere is created by the stiffening of the mantle due to the extraction of water near the base of the melting zone predict a moderate amount of asymmetry; the plume expands <span class="hlt">NE</span> along the AR ∼70-80% as far as it expands SSW along the RR. Without dehydration stiffening, the lithosphere corresponds to the near-surface, cool, thermal boundary layer; in these cases, the plume is predicted to be even more asymmetric, expanding only 40-50% as far along the AR as it does along the RR. Estimates of asymmetry and seismically measured crustal thicknesses are best explained by model predictions of an Iceland plume volume flux of ∼100-200 m/s, and a lithosphere controlled by a rheology in which dehydration stiffens the mantle, but to a lesser degree than simulated here. The asymmetry of influence along the present-day ridge system is predicted to be a transient</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://archives.datapages.com/data/specpubs/oversiz2/data/a189/a189/0001/0050/0081.htm','USGSPUBS'); return false;" href="http://archives.datapages.com/data/specpubs/oversiz2/data/a189/a189/0001/0050/0081.htm"><span>Passive margins: U.S. Geological Survey Line 19 across the Georges Bank <span class="hlt">basin</span></span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Klitgord, Kim D.; Schlee, John S.; Grow, John A.; Bally, A.W.</p> <p>1987-01-01</p> <p>Georges Bank is a shallow part of the <span class="hlt">Atlantic</span> continental shelf southeast of New England (Emery and Uchupi, 1972, 1984). This bank, however, is merely the upper surface of several sedimentary <span class="hlt">basins</span> overlying a block-faulted basement of igneous and metamorphic crystalline rock. Sedimentary rock forms a seaward-thickening cover that has accumulated in one main depocenter and several ancillary depressions, adjacent to shallow basement platforms of paleozoic and older crystalline rock. Georges Bank <span class="hlt">basin</span> contains a thickness of sedimentary rock greater than 10 km, whereas the basement platforms that flank the <span class="hlt">basin</span> are areas of thin sediment accumulation (less than 5 km).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016GeoRL..43.7625K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016GeoRL..43.7625K"><span>Impact of slowdown of <span class="hlt">Atlantic</span> overturning circulation on heat and freshwater transports</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kelly, Kathryn A.; Drushka, Kyla; Thompson, LuAnne; Le Bars, Dewi; McDonagh, Elaine L.</p> <p>2016-07-01</p> <p>Recent measurements of the strength of the <span class="hlt">Atlantic</span> overturning circulation at 26°N show a 1 year drop and partial recovery amid a gradual weakening. To examine the extent and impact of the slowdown on <span class="hlt">basin</span> wide heat and freshwater transports for 2004-2012, a box model that assimilates hydrographic and satellite observations is used to estimate heat transport and freshwater convergence as residuals of the heat and freshwater budgets. Using an independent transport estimate, convergences are converted to transports, which show a high level of spatial coherence. The similarity between <span class="hlt">Atlantic</span> heat transport and the Agulhas Leakage suggests that it is the source of the surface heat transport anomalies. The freshwater budget in the North <span class="hlt">Atlantic</span> is dominated by a decrease in freshwater flux. The increasing salinity during the slowdown supports modeling studies that show that heat, not freshwater, drives trends in the overturning circulation in a warming climate.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_17 --> <div id="page_18" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="341"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.T51E2956W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.T51E2956W"><span><span class="hlt">Basin</span>-mountain structures and hydrocarbon exploration potential of west Junggar orogen in China</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wu, X.; Qi, X.; Zheng, M.</p> <p>2015-12-01</p> <p>Situated in northern Xinjiang, China, in <span class="hlt">NE</span>-SW trend, West Junggar Orogen is adjacent to Altai fold belt on the north with the Ertix Fault as the boundary, North Tianshan fold belt on the south with the Ebinur Lake Strike-slip Fault as the boundary, and the Junggar <span class="hlt">Basin</span> on the southeast with Zaire-Genghis Khan-Hala'alat fold belt as the boundary. Covering an area of about 10×104 km2 in China, there are medium and small intermontane <span class="hlt">basins</span>, Burqin-Fuhai, Tacheng, Hefeng and Hoxtolgay, distributing inside the orogen. Tectonically West Junggar Orogen lies in the middle section of the Palaeo-Asian tectonic domain where the Siberia, Kazakhstan and Tarim Plates converge, and is the only orogen trending <span class="hlt">NE</span>-SW in the Palaeo-Asian tectonic domain. Since the Paleozoic, the orogen experienced pre-Permian plate tectonic evolution and post-Permian intra-plate <span class="hlt">basin</span> evolution. Complex tectonic evolution and multi-stage structural superimposition not only give rise to long term controversial over the <span class="hlt">basin</span> basement property but also complex <span class="hlt">basin</span>-mountain coupling relations, structures and <span class="hlt">basin</span> superimposition modes. According to analysis of several kinds of geological and geophysical data, the orogen was dominated by compressive folding and thrust napping from the Siberia plate in the north since the Late Paleozoic. Compressive stress weakened from north to south, corresponding to subdued vertical movement and enhanced horizontal movement of crustal surface from north to south, and finally faded in the overthrust-nappe belt at the northwest margin of the Junggar <span class="hlt">Basin</span>. The variation in compressive stress is consistent with the surface relief of the orogen, which is high in the north and low in the south. There are two kinds of <span class="hlt">basin</span>-mountain coupling relationships, i.e. high angle thrusting and overthrusting and napping, and two kinds of <span class="hlt">basin</span> superimposition modes, i.e. inherited and progressive, and migrating and convulsionary modes. West Junggar orogen has rich oil and gas</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1914241S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1914241S"><span>Contrasting <span class="hlt">basin</span> architecture and rifting style of the Vøring <span class="hlt">Basin</span>, offshore mid-Norway and the Faroe-Shetland <span class="hlt">Basin</span>, offshore United Kingdom</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schöpfer, Kateřina; Hinsch, Ralph</p> <p>2017-04-01</p> <p>The Vøring and the Faroe-Shetland <span class="hlt">basins</span> are offshore deep sedimentary <span class="hlt">basins</span> which are situated on the outer continental margin of the northeast <span class="hlt">Atlantic</span> Ocean. Both <span class="hlt">basins</span> are underlain by thinned continental crust whose structure is still debated. In particular the nature of the lower continental crust and the origin of high velocity bodies located at the base of the lower crust are a subject of discussion in recent literature. Regional interpretation of 2D and 3D seismic reflection data, combined with well data, suggest that both <span class="hlt">basins</span> share several common features: (i) Pre-Cretaceous faults that are distributed across the entire <span class="hlt">basin</span> width. (ii) Geometries of pre-Jurassic strata reflecting at least two extensional phases. (iii) Three common rift phases, Late Jurassic, Campanian-Maastrichtian and Palaeocene. (iv) Large pre-Cretaceous fault blocks that are buried by several kilometres of Cretaceous and Cenozoic strata. (iii). (v) Latest Cretaceous/Palaeocene inversion. (vi) Occurrence of partial mantle serpentinization during Early Cretaceous times, as proposed by other studies, seems improbable. The detailed analysis of the data, however, revealed significant differences between the two <span class="hlt">basins</span>: (i) The Faroe-Shetland <span class="hlt">Basin</span> was a fault-controlled <span class="hlt">basin</span> during the Late Jurassic but also the Late Cretaceous extensional phase. In contrast, the Vøring <span class="hlt">Basin</span> is dominated by the late Jurassic rifting and subsequent thermal subsidence. It exhibits only minor Late Cretaceous faults that are localised above intra-<span class="hlt">basinal</span> and marginal highs. In addition, the Cretaceous strata in the Vøring <span class="hlt">Basin</span> are folded. (ii) In the Vøring <span class="hlt">Basin</span>, the locus of Late Cretaceous rifting shifted westwards, affecting mainly the western <span class="hlt">basin</span> margin, whereas in the Faroe-Shetland <span class="hlt">Basin</span> Late Cretaceous rifting was localised in the same area as the Late Jurassic phase, hence masking the original Jurassic geometries. (iii) Devono-Carboniferous and Aptian/Albian to Cenomanian rift phases</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1998JGR...10324737F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1998JGR...10324737F"><span>South <span class="hlt">Atlantic</span> Ocean circulation: Simulation experiments with a quasi-geostrophic model and assimilation of TOPEX/POSEIDON and ERS 1 altimeter data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Florenchie, P.; Verron, J.</p> <p>1998-10-01</p> <p>Simulation experiments of South <span class="hlt">Atlantic</span> Ocean circulations are conducted with a 1/6°, four-layered, quasi-geostrophic model. By means of a simple nudging data assimilation procedure along satellite tracks, TOPEX/POSEIDON and ERS 1 altimeter measurements are introduced into the model to control the simulation of the <span class="hlt">basin</span>-scale circulation for the period from October 1992 to September 1994. The model circulation appears to be strongly influenced by the introduction of altimeter data, offering a consistent picture of South <span class="hlt">Atlantic</span> Ocean circulations. Comparisons with observations show that the assimilating model successfully simulates the kinematic behavior of a large number of surface circulation components. The assimilation procedure enables us to produce schematic diagrams of South <span class="hlt">Atlantic</span> circulation in which patterns ranging from <span class="hlt">basin</span>-scale currents to mesoscale eddies are portrayed in a realistic way, with respect to their complexity. The major features of the South <span class="hlt">Atlantic</span> circulation are described and analyzed, with special emphasis on the Brazil-Malvinas Confluence region, the Subtropical Gyre with the formation of frontal structures, and the Agulhas Retroflection. The Agulhas eddy-shedding process has been studied extensively. Fourteen eddies appear to be shed during the 2-year experiment. Because of their strong surface topographic signature, Agulhas eddies have been tracked continuously during the assimilation experiment as they cross the South <span class="hlt">Atlantic</span> <span class="hlt">basin</span> westward. Other effects of the assimilation procedure are shown, such as the intensification of the Subtropical Gyre, the appearance of a strong seasonal cycle in the Brazil Current transport, and the increase of the mean Brazil Current transport. This last result, combined with the westward oriention of the Agulhas eddies' trajectories, leads to a southward transport of mean eddy kinetic energy across 30°S.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70036495','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70036495"><span>Chapter 43: Assessment of <span class="hlt">NE</span> Greenland: Prototype for development of Circum-ArcticResource Appraisal methodology</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Gautier, D.L.; Stemmerik, L.; Christiansen, F.G.; Sorensen, K.; Bidstrup, T.; Bojesen-Koefoed, J. A.; Bird, K.J.; Charpentier, R.R.; Houseknecht, D.W.; Klett, T.R.; Schenk, C.J.; Tennyson, Marilyn E.</p> <p>2011-01-01</p> <p>Geological features of <span class="hlt">NE</span> Greenland suggest large petroleum potential, as well as high uncertainty and risk. The area was the prototype for development of methodology used in the US Geological Survey (USGS) Circum-Arctic Resource Appraisal (CARA), and was the first area evaluated. In collaboration with the Geological Survey of Denmark and Greenland (GEUS), eight "assessment units" (AU) were defined, six of which were probabilistically assessed. The most prospective areas are offshore in the Danmarkshavn <span class="hlt">Basin</span>. This study supersedes a previous USGS assessment, from which it differs in several important respects: oil estimates are reduced and natural gas estimates are increased to reflect revised understanding of offshore geology. Despite the reduced estimates, the CARA indicates that <span class="hlt">NE</span> Greenland may be an important future petroleum province. ?? 2011 The Geological Society of London.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUOSPO21B..07H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUOSPO21B..07H"><span>Coupled ocean-shelf ecosystem modelling of northern North <span class="hlt">Atlantic</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Harle, J.; Holt, J. T.; Butenschön, M.; Allen, J. I.</p> <p>2016-02-01</p> <p>The biogeochemistry and ecosystems of the open-ocean and shelf seas are intimately connected. For example Northwest European continental shelf receives a substantial fraction of its nutrients from the wider North <span class="hlt">Atlantic</span> and exports carbon at depth, sequestering it from atmospheric exchange. In the EC FP7 Euro<span class="hlt">Basin</span> project (Holt et al 2014) we have developed a 1/12 degree <span class="hlt">basin</span>-scale NEMO-ERSEM model with specific features relevant to shelf seas (e.g. tides and advanced vertical mixing schemes). This model is eddy resolving in the open-ocean, and resolves barotropic scales on-shelf. We use this model to explore the interaction between finely resolved physical processes and the ecosystem. Here we focus on shelf-sea processes and the connection between the shelf seas and open-ocean, and compare results with a 1/4 degree (eddy permitting) model that does not include shelf sea processes. We find tidal mixing fronts and river plume are well represented in the 1/12 degree model. Using approaches developed for the NW Shelf (Holt et al 2012), we provide estimates of across-shelf break nutrient fluxes to the seas surrounding this <span class="hlt">basin</span>, and relate these fluxes and their interannual variability to the physical processes driving ocean-shelf exchange. Holt, J., et al, 2012. Oceanic controls on the primary production of the northwest European continental shelf: model experiments under recent past conditions and a potential future scenario. Biogeosciences 9, 97-117. Holt, J., et al, 2014. Challenges in integrative approaches to modelling the marine ecosystems of the North <span class="hlt">Atlantic</span>: Physics to Fish and Coasts to Ocean. Progress in Oceanography doi:10.1016/j.pocean.2014.04.024.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016DSRI..111...73B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016DSRI..111...73B"><span>Chemotaxonomic phytoplankton patterns on the eastern boundary of the <span class="hlt">Atlantic</span> Ocean</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Barlow, R.; Gibberd, M.-J.; Lamont, T.; Aiken, J.; Holligan, P.</p> <p>2016-05-01</p> <p>Surface pigment data from a transect along the eastern boundary of the <span class="hlt">Atlantic</span> Ocean was analysed using CHEMTAX to yield more detailed information on the composition of phytoplankton communities. Total chlorophyll a concentrations varied from 0.03 mg m-3 in a northern oligotrophic region to 30.3 mg m-3 in the Benguela ecosystem. Diatoms dominated the Benguela, while both diatoms and haptophytes were the major groups in the Canary ecosystem and the temperate <span class="hlt">NE</span> <span class="hlt">Atlantic</span>. Prochlorococcus was the most prominent group in the southern oligotrophic region (15.5°S-15°N) although haptophytes were also a significant component of the population. In contrast, haptophytes dominated the northern oligotrophic region (21°-40°N). Photo-pigment indices indicated that chlorophyll b was mainly associated with prasinophytes and chlorophyll c with diatoms. Elevated photosynthetic carotenoids were due to increased proportions of haptophytes, but also linked with diatoms and dinoflagellates. Photoprotective carotenoids were more prominently associated with Prochlorococcus and to a lesser extent to Synechococcus.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUOSPO14E2862V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUOSPO14E2862V"><span>Intense Mixing and Recirculations of Intermediate and Deep Water in the Northwest Argentine <span class="hlt">Basin</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Valla, D.; Piola, A. R.</p> <p>2016-02-01</p> <p>The sources of the South <span class="hlt">Atlantic</span> upper and intermediate waters that form the upper layer flow needed to maintain mass balance due the export of North <span class="hlt">Atlantic</span> Deep Water from the North <span class="hlt">Atlantic</span> are still under debate. The "cold path" scheme postulates that intermediate waters are injected into the South <span class="hlt">Atlantic</span> from the Pacific through the Drake Passage, advected north by the Malvinas Current up to the Brazil/Malvinas Confluence (BMC) and circulated around the <span class="hlt">basin</span> following the path of the subtropical gyre. We report high-quality hydrographic observations collected in the South <span class="hlt">Atlantic</span> western boundary at 34.5 °S during 7 hydrographic cruises as part of the SAMOC project. We focus on the flow and characteristics of Antarctic Intermediate Water (AAIW) and Upper Circumpolar Deep Water (UCDW). The water mass analysis indicates the presence of "young" (fresh and highly oxygenated) varieties of AAIW (S<34.2, O2>6 ml·l-1) which must be derived from south of the SAMOC array. This suggests an alternative pathway for intermediate waters that involves a short circuit beneath the BMC. Simultaneous full-depth velocity measurements using lowered acoustic Doppler current profilers confirm this hypothesis. The flow direction across the SAMOC array in the UCDW range inferred from dissolved oxygen measurements also indicate the presence of UCDW (O2<4.2 ml·l-1) derived from farther south. However, the wider range of oxygen concentrations suggests strong recirculations of both water masses within the northwestern Argentine <span class="hlt">Basin</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018OcSci..14...53M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018OcSci..14...53M"><span>South <span class="hlt">Atlantic</span> meridional transports from NEMO-based simulations and reanalyses</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mignac, Davi; Ferreira, David; Haines, Keith</p> <p>2018-02-01</p> <p>The meridional heat transport (MHT) of the South <span class="hlt">Atlantic</span> plays a key role in the global heat budget: it is the only equatorward <span class="hlt">basin</span>-scale ocean heat transport and it sets the northward direction of the global cross-equatorial transport. Its strength and variability, however, are not well known. The South <span class="hlt">Atlantic</span> transports are evaluated for four state-of-the-art global ocean reanalyses (ORAs) and two free-running models (FRMs) in the period 1997-2010. All products employ the Nucleus for European Modelling of the Oceans (NEMO) model, and the ORAs share very similar configurations. Very few previous works have looked at ocean circulation patterns in reanalysis products, but here we show that the ORA <span class="hlt">basin</span> interior transports are consistently improved by the assimilated in situ and satellite observations relative to the FRMs, especially in the Argo period. The ORAs also exhibit systematically higher meridional transports than the FRMs, which is in closer agreement with observational estimates at 35 and 11° S. However, the data assimilation impact on the meridional transports still greatly varies among the ORAs, leading to differences up to ˜ 8 Sv and 0.4 PW in the South <span class="hlt">Atlantic</span> Meridional Overturning Circulation and the MHTs, respectively. We narrow this down to large inter-product discrepancies in the western boundary currents (WBCs) at both upper and deep levels explaining up to ˜ 85 % of the inter-product differences in MHT. We show that meridional velocity differences, rather than temperature differences, in the WBCs drive ˜ 83 % of this MHT spread. These findings show that the present ocean observation network and data assimilation schemes can be used to consistently constrain the South <span class="hlt">Atlantic</span> interior circulation but not the overturning component, which is dominated by the narrow western boundary currents. This will likely limit the effectiveness of ORA products for climate or decadal prediction studies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.8103B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.8103B"><span>Overflow Water Pathways in the Subpolar North <span class="hlt">Atlantic</span> Observed with Deep Floats</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bower, Amy; Furey, Heather; Lozier, Susan</p> <p>2017-04-01</p> <p>As part of the Overturning in the Subpolar North <span class="hlt">Atlantic</span> Program (OSNAP), a total of 135 acoustically tracked RAFOS floats have been deployed in the deep boundary currents of the Iceland, Irminger and Labrador <span class="hlt">Basins</span>, and in the Charlie-Gibbs Fracture Zone, to investigate the pathways of Iceland-Scotland Overflow Water (ISOW) and Denmark Strait Overflow Water (DSOW). Floats were released annually in 2014, 2015 and 2016 at depths between 1800 and 2800 m for two-year missions. The array of sound sources used for tracking was expanded from 10 to 13 moorings in 2016 when it was discovered that wintertime surface roughness was negatively impacting acoustic ranges. The floats from the first setting reveal several examples of persistent , deep coherent eddy motion, including a cyclonic eddy spinning off the tip of Eirik Ridge (southwest of Cape Farewell), a cyclonic eddy in the northeastern Labrador <span class="hlt">Basin</span> near where anticyclonic Irminger Rings are formed, and an anticyclonic eddy under the North <span class="hlt">Atlantic</span> Current (NAC) in the central Iceland <span class="hlt">Basin</span>. A consistent region of boundary-interior exchange was observed near Hamilton Bank on the western boundary of the Labrador Sea. Deep cyclonic recirculation gyres are revealed in all three <span class="hlt">basins</span>. Floats released in the southward-flowing deep boundary current over the eastern flank of the Reykjanes Ridge show that shallower layers of ISOW peel off to the west and cross the Ridge into the Irminger <span class="hlt">Basin</span> through various gaps south of 60°N, including the Bight Fracture Zone. These floats tend to turn northward and continue along the slope in the Irminger <span class="hlt">Basin</span>. Interestingly, floats released at the ISOW level in the CGFZ did not turn into the Irminger <span class="hlt">Basin</span> as often depicted in deep circulation schematics, but rather drifted west-northwestward toward the Labrador Sea, or eddied around west of the CGFZ and (in some cases) turned southward. This result is consistent with some previous hydrographic and high-resolution model results</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16.5470L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16.5470L"><span>Impact of the Indonesian Throughflow on the <span class="hlt">Atlantic</span> Meridional Overturning Circulation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Le Bars, Dewi; Dijkstra, Henk</p> <p>2014-05-01</p> <p>Understanding the mechanisms controlling the strength and variability of the <span class="hlt">Atlantic</span> Meridional Overturning Circulation (AMOC) is one of the main topics of climate science and in particular physical oceanography. Current simple representations of the global ocean overturning separates the surface return flow to the <span class="hlt">Atlantic</span> <span class="hlt">basin</span> into a cold water path through the Drake Passage and a warm water path through the Indonesian Throughflow and Agulhas leakage. The relative importance of these two paths has been investigated in non-eddying ocean models. In these models the Agulhas retroflection cannot be modelled properly, which leads to an important overestimation of the Agulhas leakage. Furthermore, it seems that the in these models the relation between the meridional density gradient and the overturning strength is greatly simplified and changes significantly when eddies are resolved (Den Toom et al. 2013). As a result, the impact of the Pacific-Indian Oceans exchange through the Indonesian Throughflow on the AMOC is still unknown. To investigate this question we run a state-of-the-art ocean model, the Parallel Ocean Program (POP), globally, at eddy resolving resolution (0.1º). Using climatological forcing from the CORE dataset we perform two simulations of 110 years, a control experiment with realistic coastlines and one in which the Indonesian Passages are closed. Results show that, for a closed Indonesian Throughflow, the Indian Ocean cools down but its salinity increases. The Agulhas leakage reduces also by 3Sv (Le Bars et al. 2013) and the net effect on the south <span class="hlt">Atlantic</span> is a cooling down and decrease salinity. The anomalies propagate slowly northward and a significant decrease of the AMOC is found at 26ºN after 50 years. This decrease AMOC also leads to reduced northward heat flux in the <span class="hlt">Atlantic</span>. These processes are investigated with a detailed analysis of the heat and freshwater balances in the <span class="hlt">Atlantic</span>-Arctic region and in the region south of 34ºS where</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AIPC.1666d0004D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AIPC.1666d0004D"><span>KM3<span class="hlt">Ne</span>T</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>de Jong, M.</p> <p>2015-07-01</p> <p>KM3<span class="hlt">Ne</span>T is a large research infrastructure, that will consist of a network of deep-sea neutrino telescopes in the Mediterranean Sea. The main objective of KM3<span class="hlt">Ne</span>T is the discovery and subsequent observation of high-energy neutrino sources in the Universe. A further physics perspective is the measurement of the mass hierarchy of neutrinos. A corresponding study, ORCA, is ongoing within KM3<span class="hlt">Ne</span>T. A cost effective technology for (very) large water Cherenkov detectors has been developed based on a new generation of low price 3-inch photo-multiplier tubes. Following the successful deployment and operation of two prototypes, the construction of the KM3<span class="hlt">Ne</span>T research infrastructure has started. The prospects of the different phases of the implementation of KM3<span class="hlt">Ne</span>T are summarised.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMPP44B..08W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMPP44B..08W"><span>Latest Cretaceous Climatic and Environmental Change in the South <span class="hlt">Atlantic</span> Region</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Woelders, L.; Vellekoop, J.; Smit, J.; Kroon, D.; Casadío, S.; Prámparo, M.; Dinarès-turell, J.; Peterse, F.; Sluijs, A.; Speijer, R. P.</p> <p>2016-12-01</p> <p>It is generally assumed that the Chicxulub impact resulted in the Cretaceous-Paleogene (K-Pg) boundary mass extinction ( 66 Ma). However, there is continuing debate about the contribution of latest Maastrichtian climate changes, possibly caused by Deccan volcanism, to this mass extinction event. This debate is complicated because of the lack of high quality latest Maastrichtian climatological and ecological reconstructions. Here we present an astronomically tuned late Maastrichtian - early Danian record of bulk carbonate δ18O, a proxy record of sea surface temperature (SST), from Southern <span class="hlt">Atlantic</span> Ocean Drilling Program Site 1262 (Walvis Ridge) and a late Maastrichtian TEX86 sea surface temperature record from the Bajada del Jagüel site in the Neuquén <span class="hlt">Basin</span> (Argentina). The combination of these inferred temperature records with foraminiferal and organic-walled dinoflagellate cyst (dinocyst) data from Bajada del Jagüel allows to reconstruct environmental changes across this time interval in a mid-latitude, Southern <span class="hlt">Atlantic</span> setting. Our results show that latest Maastrichtian warming of 2.5-4°C started gradually around 66.7 Ma, culminating in the interval between 450 to 150 kyr before the K-Pg boundary. Highest temperatures occurred 200 kyr before the K-Pg boundary. During the last 150 kyr of the Maastrichtian, the temperature trend reversed again at both sites. Benthic foraminiferal and dinocyst assemblage changes indicate that late Maastrichtian warming resulted in more humid climate conditions in the Neuquén <span class="hlt">basin</span>, causing enhanced runoff and stratification of the water column. Vice versa, the subsequent cooling induced again a drier climate in the <span class="hlt">basin</span>, resulting in reduced salinity stratification and better ventilation of the <span class="hlt">basin</span>. We conclude that late Maastrichtian climate and sea level change caused distinct environmental perturbations in the Neuquén <span class="hlt">basin</span>, although it remains uncertain to which extent late Maastrichtian climatological changes</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014E%26PSL.407....9R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014E%26PSL.407....9R"><span>The isotopic composition of authigenic chromium in anoxic marine sediments: A case study from the Cariaco <span class="hlt">Basin</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Reinhard, Christopher T.; Planavsky, Noah J.; Wang, Xiangli; Fischer, Woodward W.; Johnson, Thomas M.; Lyons, Timothy W.</p> <p>2014-12-01</p> <p>Chromium (Cr) isotopes are an emerging proxy for tracking redox processes at the Earth's surface. However, there has been limited exploration of the Cr isotope record of modern and recent marine sediments. The basic inorganic chemistry of Cr suggests that anoxic marine <span class="hlt">basins</span> should factor prominently in the global Cr cycle and that sediments deposited within anoxic <span class="hlt">basins</span> may offer a valuable Cr isotope archive throughout Earth's history. Here, we present δ53Cr data from sediments of the Cariaco <span class="hlt">Basin</span>, Venezuela-a 'type' environment for large, perennially anoxic <span class="hlt">basins</span> with a relatively strong hydrological connection to the global oceans. We document a marked positive shift in bulk δ53Cr values following the termination of the Last Glacial Maximum, followed by relative stasis. Based on a suite of independent redox proxies, this transition marks a switch from oxic to persistently anoxic and sulfidic (euxinic) depositional conditions within the <span class="hlt">basin</span>. We find good agreement between two independent approaches toward estimating the δ53Cr composition of authigenic Cr in euxinic Cariaco <span class="hlt">Basin</span> sediments and that these estimates are very similar to the δ53Cr composition of modern open <span class="hlt">Atlantic</span> Ocean seawater. These data, together with considerations of reaction kinetics and mass balance within the Cariaco <span class="hlt">Basin</span>, are consistent with the hypothesis that anoxic marine settings can serve as a chemical archive of first-order trends in seawater δ53Cr composition. Additionally, the Cariaco <span class="hlt">Basin</span> data suggest that there has been secular stability in the average δ53Cr value of <span class="hlt">Atlantic</span> seawater over the last ∼15 kyr.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70033379','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70033379"><span>Population genetic structure in <span class="hlt">Atlantic</span> and Pacific Ocean common murres (Uria aalge): Natural replicate tests of post-Pleistocene evolution</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Morris-Pocock, J. A.; Taylor, S.A.; Birt, T.P.; Damus, M.; Piatt, John F.; Warheit, K.I.; Friesen, Vicki L.</p> <p>2008-01-01</p> <p>Understanding the factors that influence population differentiation in temperate taxa can be difficult because the signatures of both historic and contemporary demographics are often reflected in population genetic patterns. Fortunately, analyses based on coalescent theory can help untangle the relative influence of these historic and contemporary factors. Common murres (Uria aalge) are vagile seabirds that breed in the boreal and low arctic waters of the Northern Hemisphere. Previous analyses revealed that <span class="hlt">Atlantic</span> and Pacific populations are genetically distinct; however, less is known about population genetic structure within ocean <span class="hlt">basins</span>. We employed the mitochondrial control region, four microsatellite loci and four intron loci to investigate population genetic structure throughout the range of common murres. As in previous studies, we found that <span class="hlt">Atlantic</span> and Pacific populations diverged during the Pleistocene and do not currently exchange migrants. Therefore, <span class="hlt">Atlantic</span> and Pacific murre populations can be used as natural replicates to test mechanisms of population differentiation. While we found little population genetic structure within the Pacific, we detected significant east-west structuring among <span class="hlt">Atlantic</span> colonies. The degree that population genetic structure reflected contemporary population demographics also differed between ocean <span class="hlt">basins</span>. Specifically, while the low levels of population differentiation in the Pacific are at least partially due to high levels of contemporary gene flow, the east-west structuring of populations within the <span class="hlt">Atlantic</span> appears to be the result of historic fragmentation of populations rather than restricted contemporary gene flow. The contrasting results in the <span class="hlt">Atlantic</span> and Pacific Oceans highlight the necessity of carefully considering multilocus nonequilibrium population genetic approaches when reconstructing the demographic history of temperate Northern Hemisphere taxa. ?? 2008 The Authors.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMPP34B..05G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMPP34B..05G"><span>Meridional Transect of <span class="hlt">Atlantic</span> Overturning Circulation across the Mid-Pleistocene Transition</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Goldstein, S. L.; Pena, L. D.; Seguí, M. J.; Kim, J.; Yehudai, M.; Farmer, J. R.; Ford, H. L.; Haynes, L.; Hoenisch, B.; Raymo, M. E.; Ferretti, P.; Bickert, T.</p> <p>2016-12-01</p> <p>The Mid-Pleistocene Transition (MPT) marked a major transition in glacial-interglacial periodicity from dominantly 41 kyr to 100 kyr cycles between 1.3-0.7 Ma. From Nd isotope records in the South <span class="hlt">Atlantic</span>, Pena and Goldstein (Science, 2014) concluded that the <span class="hlt">Atlantic</span> overturning circulation circulation experienced major weakening between 950-850 ka (MIS 25-21), which generated the climatic conditions that intensified cold periods, prolonged their duration, and stabilized 100 kyr cycles. Such weakening would provide a mechanism for decreased atmospheric CO2 (Hönisch et al., Science, 2009) by allowing for additional atmospheric CO2 to be stored in the deep ocean. We present a summary of work in-progress to generate two dimensional representations of the <span class="hlt">Atlantic</span> meridional overturning circulation, from the north <span class="hlt">Atlantic</span> to the Southern Ocean, at different time slices over the past 2Ma, including the MPT, based on Nd isotope ratios measured on Fe-Mn-oxide encrusted foraminifera and fish debris. Thus far we are analyzing samples from DSDP/ODP Sites 607, 1063 from the North <span class="hlt">Atlantic</span>, 926 from the Equatorial <span class="hlt">Atlantic</span>, 1264, 1267, 1088, 1090 in the South <span class="hlt">Atlantic</span>, and 1094 from the Southern Ocean. Our data generated thus far support important changes in the overturning circulation during the MPT, and greater glacial-interglacial variability in the 100 kyr world compared with the 40 kyr world. In addition, the data indicate a North <span class="hlt">Atlantic</span>-sourced origin for the ocean circulation disruption during the MPT. Comparison with ɛNd records in different ocean <span class="hlt">basins</span> and with benthic foraminiferal δ13C and B/Ca ratios will also allow us to understand the links between deep ocean circulation changes and the global carbon cycle.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017GBioC..31.1608M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017GBioC..31.1608M"><span>Tropical Dominance of N2 Fixation in the North <span class="hlt">Atlantic</span> Ocean</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Marconi, Dario; Sigman, Daniel M.; Casciotti, Karen L.; Campbell, Ethan C.; Alexandra Weigand, M.; Fawcett, Sarah E.; Knapp, Angela N.; Rafter, Patrick A.; Ward, Bess B.; Haug, Gerald H.</p> <p>2017-10-01</p> <p>To investigate the controls on N2 fixation and the role of the <span class="hlt">Atlantic</span> in the global ocean's fixed nitrogen (N) budget, <span class="hlt">Atlantic</span> N2 fixation is calculated by combining meridional nitrate fluxes across World Ocean Circulation Experiment sections with observed nitrate 15N/14N differences between northward and southward transported nitrate. N2 fixation inputs of 27.1 ± 4.3 Tg N/yr and 3.0 ± 0.5 Tg N/yr are estimated north of 11°S and 24°N, respectively. That is, 90% of the N2 fixation in the <span class="hlt">Atlantic</span> north of 11°S occurs south of 24°N in a region with upwelling that imports phosphorus (P) in excess of N relative to phytoplankton requirements. This suggests that, under the modern iron-rich conditions of the equatorial and North <span class="hlt">Atlantic</span>, N2 fixation occurs predominantly in response to P-bearing, N-poor conditions. We estimate a N2 fixation rate of 30.5 ± 4.9 Tg N/yr north of 30°S, implying only 3 Tg N/yr between 30° and 11°S, despite evidence of P-bearing, N-poor surface waters in this region as well; this is consistent with iron limitation of N2 fixation in the South <span class="hlt">Atlantic</span>. Since the ocean flows through the <span class="hlt">Atlantic</span> surface in <2,500 years, similar to the residence time of oceanic fixed N, <span class="hlt">Atlantic</span> N2 fixation can stabilize the N-to-P ratio of the global ocean. However, the calculated rate of <span class="hlt">Atlantic</span> N2 fixation is a small fraction of global ocean estimates for either N2 fixation or fixed N loss. This suggests that, in the modern ocean, an approximate balance between N loss and N2 fixation is achieved within the combined Indian and Pacific <span class="hlt">basins</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18..268M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18..268M"><span>Bottom melting of Arctic Sea Ice in the Nansen <span class="hlt">Basin</span> due to <span class="hlt">Atlantic</span> Water influence</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Muilwijk, Morven; Smedsrud, Lars H.; Meyer, Amelie</p> <p>2016-04-01</p> <p>Our global climate is warming, and a shrinking Arctic sea ice cover remains one of the most visible signs of this warming. Sea Ice loss is now visible for all months in all regions of the Arctic. Hydrographic and current observations from a region north of Svalbard collected during the Norwegian Young Sea Ice Cruise (N-ICE2015) are presented here. Comparison with historical data shows that the new observations from January through June fill major gaps in available observations, and help describing important processes linking changes in regional <span class="hlt">Atlantic</span> Water (AW) heat transport and sea ice. Warm and salty AW originating in the North <span class="hlt">Atlantic</span> enters the Arctic Ocean through the Fram Strait and is present below the Arctic Sea Ice cover throughout the Arctic. However, the depth of AW varies by region and over time. In the region north of Svalbard, we assume that depth could be governed primarily by local processes, by upstream conditions of the ice cover (Northwards), or by upstream conditions of the AW (Southwards). AW carries heat corresponding to the volume transport of approximately 9 SV through Fram Strait, varying seasonally from 28 TW in winter to 46 TW in summer. Some heat is recirculated, but the net annual heat flux into the Arctic Ocean from AW is estimated to be around 40 TW. The <span class="hlt">Atlantic</span> Water layer temperature at intermediate depths (150-900m) has increased in recent years. Until recently, maximum temperatures have been found to be 2-3 C in the Nansen <span class="hlt">Basin</span>. Studies have shown that for example, in the West Spitsbergen Current the upper 50-200m shows an overall AW warming of 1.1 C since 1979. In general we expect efficient melting when AW is close to the surface. Previously the AW entering through Fram Strait has been considered as less important because changes in the sea ice cover have been connected to greater inflow of Pacific Water through Bering Strait and atmospheric forcing. Conversely it is now suggested that AW has direct impact on melting of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFMGC51G0812C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFMGC51G0812C"><span>A 320-year AMM+SOI Index Reconstruction from Historical <span class="hlt">Atlantic</span> Tropical Cyclone Records</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chenoweth, M.; Divine, D.</p> <p>2010-12-01</p> <p>Trends in the frequency of North <span class="hlt">Atlantic</span> tropical cyclones, including major hurricanes, are dominated by those originating in the deep tropics. In addition, these tropical cyclones are stronger when making landfall and their total power dissipation is higher than storms forming elsewhere in the <span class="hlt">Atlantic</span> <span class="hlt">basin</span>. Both the <span class="hlt">Atlantic</span> Meridional Mode (AMM) and El Nino-Southern Oscillation (ENSO) are the leading modes of coupled air-sea interaction in the <span class="hlt">Atlantic</span> and Pacific, respectively, and have well-established relationships with <span class="hlt">Atlantic</span> hurricane variability. Here we use a 320-year record of tropical cyclone activity in the Lesser Antilles region of the North <span class="hlt">Atlantic</span> from historical manuscript and newspaper records to reconstruct a normalized seasonal (July-October) index combining the Southern Oscillation Index (SOI) and AMM employing both the modern analog technique and back-propagation artificial neural networks. Our results indicate that the AMM+SOI index since 1690 shows no long-term trend but is dominated by both short-term (<10 years) and long-term (quasi-decadal to bi-decadal) variations. The decadal-scale variation is consistent with both instrumental and proxy records elsewhere from the global tropics. Distinct periods of high and low index values, corresponding to high and low tropical cyclone frequency, are regularly-appearing features in the record and provides further evidence that natural decadal -scale variability in <span class="hlt">Atlantic</span> tropical cyclone frequency must be accounted for when determining trends in records and attribution of climate change.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EOSTr..95...53A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EOSTr..95...53A"><span><span class="hlt">Basin</span>-Wide Oceanographic Array Bridges the South <span class="hlt">Atlantic</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ansorge, I. J.; Baringer, M. O.; Campos, E. J. D.; Dong, S.; Fine, R. A.; Garzoli, S. L.; Goni, G.; Meinen, C. S.; Perez, R. C.; Piola, A. R.; Roberts, M. J.; Speich, S.; Sprintall, J.; Terre, T.; Van den Berg, M. A.</p> <p>2014-02-01</p> <p>The meridional overturning circulation (MOC) is a global system of surface, intermediate, and deep ocean currents. The MOC connects the surface layer of the ocean and the atmosphere with the huge reservoir of the deep sea and is the primary mechanism for transporting heat, freshwater, and carbon between ocean <span class="hlt">basins</span>. Climate models show that past changes in the strength of the MOC were linked to historical climate variations. Further research suggests that the MOC will continue to modulate climate change scenarios on time scales ranging from decades to centuries [Latif et al., 2006].</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMPP11C1047T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMPP11C1047T"><span>Recent Increase in North <span class="hlt">Atlantic</span> Jet Variability Emerges from Three-Century Long Context</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Trouet, V.; Babst, F.; Meko, M. D.</p> <p>2017-12-01</p> <p>The position and strength of the Northern Hemisphere polar jet stream are important modulators of mid-latitude weather extremes and their societal, ecosystem, and economic impacts. A recent increase in mid-latitude extreme events highlights the need for long-term records of jet stream variability to put recent trends in a historical perspective and to investigate non-linear relationships between jet stream variability, mid-latitude extreme weather events, and anthropogenic climate change. In Europe, anomalies of the North <span class="hlt">Atlantic</span> Jet (NAJ) create a summer temperature seesaw between the British Isles (BRIT) and the northeastern Mediterranean (NEMED). We combined summer temperature-sensitive tree-ring records from BRIT and NEMED to reconstruct inter-annual variability in the latitudinal position of the August NAJ back to 1725 CE. The two temperature proxies BRIT and NEMED counter-correlate significantly over their period of overlap, thus illustrate the temperature dipole generated by anomalous NAJ positions, and combined explain close to 40% of the variance in the August NAJ target (Fig. 1). The NAJ reconstruction is dominated by sub-decadal variability and no significant long-term poleward or equatorward trends were detected. However, the NAJ time series shows a steep and unprecedented increase in variance starting in the late 1960s. Enhanced late 20th century variance has also been detected in climate and ecosystem dynamics in the Central and Northeast Pacific, which are associated with the latitudinal position of the North Pacific Jet. Our combined results suggest a late 20th century increase in jet stream latitudinal variance in the North <span class="hlt">Atlantic</span> and the North Pacific <span class="hlt">Basin</span> that can be indicative of enhanced jet stream waviness and that coincides with a recent increase in quasi-resonant amplification (QRA). Our results show a late 20th century amplification of meridional flow in both the North Pacific and the North <span class="hlt">Atlantic</span> <span class="hlt">Basin</span> and support more sinuous jet</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_18 --> <div id="page_19" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="361"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19980021260','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19980021260"><span>Chemical Characteristics of Continental Outflow Over the Tropical South <span class="hlt">Atlantic</span> Ocean from Brazil and Africa</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Talbot, R. W.; Bradshaw, J. D.; Sandholm, S. T.; Smyth, S.; Blake, D. R.; Blake, N. R.; Sachse, G. W.; Collins, J. E.; Heikes, B. G.; Anderson, B. E.; <a style="text-decoration: none; " href="javascript:void(0); " onClick="displayelement('author_19980021260'); toggleEditAbsImage('author_19980021260_show'); toggleEditAbsImage('author_19980021260_hide'); "> <img style="display:inline; width:12px; height:12px; " src="images/arrow-up.gif" width="12" height="12" border="0" alt="hide" id="author_19980021260_show"> <img style="width:12px; height:12px; display:none; " src="images/arrow-down.gif" width="12" height="12" border="0" alt="hide" id="author_19980021260_hide"></p> <p>1996-01-01</p> <p>The chemical characteristics of air parcels over the tropical South <span class="hlt">Atlantic</span> during September - October 1992 are summarized by analysis of aged marine and continental outflow classifications. Positive correlations between CO and CH3CL and minimal enhancements of C2CL40, and various ChloroFluoroCarbon (CFC) species in air parcels recently advected over the South <span class="hlt">Atlantic</span> <span class="hlt">basin</span> strongly suggest an impact on tropospheric chemistry from biomass burning on adjacent continental areas of Brazil and Africa. Comparison of the composition of aged Pacific air with aged marine air over the South <span class="hlt">Atlantic</span> <span class="hlt">basin</span> from 0.3 to 12.5 km altitude indicates potential accumulation of long-lived species during the local dry season. This may amount to enhancements of up to two-fold for C2H6, 30% for CO, and 10% for CH3Cl. Nitric oxide and NO(x) were significantly enhanced (up to approx. 1 part per billion by volume (ppbv)) above 10 km altitude and poorly correlated with CO and CH3Cl. In addition, median mixing ratios of NO and NO(x) were essentially identical in aged marine and continental outflow air masses. It appears that in addition to biomass burning, lightning or recycled reactive nitrogen may be an important source of NO(x) to the upper troposphere. Methane exhibited a monotonic increase with altitude from approx. 1690 to 1720 ppbv in both aged marine and continental outflow air masses. The largest mixing ratios in the upper troposphere were often anticorrelated with CO, CH3Cl, and CO2, suggesting CH, contributions from natural sources. We also argue, based on CH4/CO ratios and relationships with various hydrocarbon and CFC species, that inputs from biomass burning and the northern hemisphere are unlikely to be the dominant sources of CO, CH4 and C2H6 in aged marine air. Emissions from urban areas would seem to be necessary to account for the distribution of at least CH4 and C2H6. Over the African and South American continents an efficient mechanism of convective vertical transport</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70118064','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70118064"><span>Insights from a synthesis of old and new climate-proxy data from the Pyramid and Winnemucca lake <span class="hlt">basins</span> for the period 48 to 11.5 cal ka</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Benson, Larry; Smoot, J.P.; Lund, S.P.; Mensing, S.A.; Foit, F.F.; Rye, R.O.</p> <p>2013-01-01</p> <p>A synthesis of old and new paleoclimatic data from the Pyramid and Winnemucca lake <span class="hlt">basins</span> indicates that, between 48.0 and 11.5·103 calibrated years BP (hereafter ka), the climate of the western Great <span class="hlt">Basin</span> was, to a degree, linked with the climate of the North <span class="hlt">Atlantic</span>. Paleomagnetic secular variation (PSV) records from Pyramid Lake core PLC08-1 were tied to the GISP2 ice-core record via PSV matches to North <span class="hlt">Atlantic</span> sediment cores whose isotopic and(or) carbonate records could be linked to the GISP2 δ18O record. Relatively dry intervals in the western Great <span class="hlt">Basin</span> were associated with cold Heinrich events and relatively wet intervals were associated with warm Dansgaard-Oeschger (DO) oscillations. The association of western Great <span class="hlt">Basin</span> dry events with North <span class="hlt">Atlantic</span> cold events (and vice versa) switched sometime after the Laurentide Ice Sheet (LIS) reached its maximum extent. For example, the Lahontan highstand, which culminated at 15.5 ka, and a period of elevated lake level between 13.1 and 11.7 ka were associated with cold North <span class="hlt">Atlantic</span> conditions, the latter period with the Youngest Dryas event. Relatively dry periods were associated with the Bølling and Allerød warm events. A large percentage of the LIS may have been lost to the North <span class="hlt">Atlantic</span> during Heinrich events 1 and 2 and may have resulted in the repositioning of the Polar Jet Stream over North America. The Trego Hot Springs, Wono, Carson Sink, and Marble Bluff tephras found in core PLC08-1 have been assigned GISP2 calendar ages of respectively, 29.9, 33.7, 34.1, and 43.2 ka. Given its unique trace-element chemistry, the Carson Sink Bed is the same as Wilson Creek Ash 15 in the Mono Lake <span class="hlt">Basin</span>. This implies that the Mono Lake magnetic excursion occurred at approximately 34 ka and it is not the Laschamp magnetic excursion. The entrance of the First Americans into the northern Great <span class="hlt">Basin</span> is dated to approximately 14.4 ka, a time when the climate was relatively dry. Evidence for human occupation of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19880012242','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19880012242"><span>Mass, heat and nutrient fluxes in the <span class="hlt">Atlantic</span> Ocean determined by inverse methods. Ph.D. Thesis</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Rintoul, Stephen Rich</p> <p>1988-01-01</p> <p>Inverse methods are applied to historical hydrographic data to address two aspects of the general circulation of the <span class="hlt">Atlantic</span> Ocean. The method allows conservation statements for mass and other properties, along with a variety of other constraints, to be combined in a dynamically consistent way to estimate the absolute velocity field and associated property transports. The method was first used to examine the exchange of mass and heat between the South <span class="hlt">Atlantic</span> and the neighboring ocean <span class="hlt">basins</span>. The second problem addressed concerns the circulation and property fluxes across the 24 and 36 deg N in the subtropical North <span class="hlt">Atlantic</span>. Conservation statements are considered for the nutrients as well as mass, and the nutrients are found to contribute significant information independent of temperature and salinity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMEP23B0962P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMEP23B0962P"><span>Linking North <span class="hlt">Atlantic</span> Teleconnections to Latitudinal Variability of Wave Climate Along the North American <span class="hlt">Atlantic</span> Coast</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Provancha, C.; Adams, P. N.; Hegermiller, C.; Storlazzi, C. D.</p> <p>2015-12-01</p> <p>Shoreline change via coastal erosion and accretion is largely influenced by variations in ocean wave climate. Identifying the sources of these variations is challenging because the timing of wave energy delivery varies over multiple timescales within ocean <span class="hlt">basins</span>. We present the results of an investigation of USACE Wave Information Studies hindcast hourly wave heights, periods, and directions along the North American <span class="hlt">Atlantic</span> coast from 1980-2012, designed to explore links between wave climate and teleconnection patterns. Trends in median and extreme significant wave heights (SWHs) demonstrate that mean monthly SWHs increased from 1 to 5 cm/yr along the roughly 3000 km reach of study area, with changes in hurricane season waves appearing to be most influential in producing the overall trends. Distributions of SWHs categorized by North <span class="hlt">Atlantic</span> Oscillation (NAO) phase, show that positive-period NAO SWHs are greater than negative-period NAO SWHs along the entire eastern seaboard (25°N to 45°N). The most prominent wave direction off Cape Cod, MA during positive-period NAO is approximately 105°, as compared to approximately 75° during negative-period NAO. Prominent wave directions between Cape Canaveral, FL, and Savannah, GA exhibit a similar shift but during opposite phases of the NAO. The results of this analysis suggest that the atmosphere-ocean interactions associated with contrasting NAO phases can significantly change the wave climate observed offshore along the North American <span class="hlt">Atlantic</span> coast, altering alongshore wave energy fluxes and sediment transport patterns along the coast.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/publication/?seqNo115=303545','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/publication/?seqNo115=303545"><span>Sampling techniques and detection methods for developing risk assessments for root-knot nematode (Meloidogyne incognita) on lima bean (Phaseolus lunatus) in the Mid-<span class="hlt">Atlantic</span> region</span></a></p> <p><a target="_blank" href="https://www.ars.usda.gov/research/publications/find-a-publication/">USDA-ARS?s Scientific Manuscript database</a></p> <p></p> <p></p> <p>Lima bean, Phaseolus lunatus, is a cornerstone crop in the Mid-<span class="hlt">Atlantic</span> region and Meloidogyne incognita, the southern root knot nematode (RKN), causes significant yield loss. The RKN has become more pervasive as toxic nematicides have been removed from the market, and risk evaluation research is <span class="hlt">ne</span>...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFMPP32B..02M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFMPP32B..02M"><span>A century of Amazon burning driven by <span class="hlt">Atlantic</span> climate</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Makou, M.; Thompson, L. G.; Davis, M. E.; Eglinton, T. I.</p> <p>2011-12-01</p> <p>Very little is known about annual burning trends in the Amazon <span class="hlt">Basin</span> prior to remote sensing of fires beginning in the late 1970's. Fires reduce Amazon forest biomass and species richness, release pollutant aerosols, and impact the carbon cycle, compelling further investigation of fire-climate dynamics. We measured organic compounds derived from vegetation burning in ice core samples from the Quelccaya Ice Cap in Peru at better than annual resolution to reconstruct wet and dry season burning throughout the Twentieth Century. Variations in the abundance of methyl hexadecanoate, which is produced by thermal alteration of vascular plant alkanoic acids, were used as a proxy for past fire activity. Concentrations of this compound in Quelccaya ice varied strongly on seasonal, interannual, and decadal time scales over the last 100 years, with high-amplitude dry season variability and muted, decadal-scale changes in wet season fire activity. Decade-long periods of repeatedly enhanced burning occurred during the 1930's and 1960's when dry season precipitation was perpetually reduced, as evidenced by low stages of the Rio Negro. These decadal trends suggest that changes in dry season precipitation drive fire activity in the western Amazon and highlight the potential of Amazon forests to undergo repeated strong burning. Fires occurred during years when sea surface temperatures (SSTs) in the north tropical <span class="hlt">Atlantic</span> were elevated and the north-south tropical <span class="hlt">Atlantic</span> SST gradient was enhanced; this SST pattern likely displaced the intertropical convergence zone northward, driving subsidence and drought in the western and southern Amazon <span class="hlt">basin</span>. Thus, our novel ice core record suggests that Amazon forest fire activity during the Twentieth Century was driven primarily by <span class="hlt">Atlantic</span> climate processes, and future forest health will depend heavily on the evolution of tropical climate.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19860017310','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19860017310"><span>Objective analysis of tidal fields in the <span class="hlt">Atlantic</span> and Indian Oceans</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Sanchez, B. V.; Rao, D. B.; Steenrod, S. D.</p> <p>1986-01-01</p> <p>An objective analysis technique has been developed to extrapolate tidal amplitudes and phases over entire ocean <span class="hlt">basins</span> using existing gauge data and the altimetric measurements which are now beginning to be provided by satellite oceanography. The technique was previously tested in the Lake Superior <span class="hlt">basin</span>. The method has now been developed and applied in the <span class="hlt">Atlantic</span>-Indian ocean <span class="hlt">basins</span> using a 6 deg x 6 deg grid to test its essential features. The functions used in the interpolation are the eigenfunctions of the velocity potential (Proudman functions) which are computed numerically from a knowledge of the <span class="hlt">basin</span>'s bottom topography, the horizontal plan form and the necessary boundary conditions. These functions are characteristic of the particular <span class="hlt">basin</span>. The gravitational normal modes of the <span class="hlt">basin</span> are computed as part of the investigation, they are used to obtain the theoretical forced solutions for the tidal constituents, the latter provide the simulated data for the testing of the method and serve as a guide in choosing the most energetic modes for the objective analysis. The results of the objective analysis of the M2 and K1 tidal constituents indicate the possibility of recovering the tidal signal with a degree of accuracy well within the error bounds of present day satellite techniques.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140000834','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140000834"><span>On the Current Trend of Tropical Cyclone Activity and the Lengthening of the Tropical Cyclone Season in the North <span class="hlt">Atlantic</span> <span class="hlt">Basin</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wilson, Robert M.</p> <p>2013-01-01</p> <p>In this TP, the trend in North <span class="hlt">Atlantic</span> <span class="hlt">basin</span> TC activity, especially as related to the determination of the length of season (LOS) and its possible association with warming surface-air and sea-surface temperature, is revisited. In particular, examined are: (1) the trend in TC activity for the yearly intervals 1945-1965, 1966-1994, and 1995-2012 for TCs having duration NSD greater or equal to 0.25 day, less than 2 days, greater than or equal to 2 days, greater than or equal to 4 days, and greater than or equal to 8 days; (2) the latitudinal and longitudinal genesis locations of the short-lived TC (defined herein as those TCs having duration NSD less than 2 days) for the three yearly intervals; (3) the first storm day (FSD), last storm day (LSD), and LOS based on TCs having duration NSD greater than or equal to 0.25 day and NSD greater than or equal to 2 days; (4) the relationship between FSD, LSD, and LOS for TCs having duration NSD greater than or equal to 0.25 day and NSD greater than or equal to 2 days; (5) the surface-air and sea-surface temperature, wind, and North <span class="hlt">Atlantic</span> Oscillation (NAO) during the interval 1945-2012; (6) the relationship of FSD, LSD, and LOS against surface-air and sea-surface temperature, wind, and the NAO; (7) the relationship of TC activity against surface-air and sea-surface temperature, wind, and the NAO; and (8) the relationship of TC activity against FSD and LOS. This TP represents an update to an earlier study by Wilson concerning the length of the yearly hurricane season.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1997BAMS...78.1917J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1997BAMS...78.1917J"><span>The Fronts and <span class="hlt">Atlantic</span> Storm-Track Experiment (FASTEX): Scientific Objectives and Experimental Design.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Joly, Alain; Jorgensen, Dave; Shapiro, Melvyn A.; Thorpe, Alan; Bessemoulin, Pierre; Browning, Keith A.; Cammas, Jean-Pierre; Chalon, Jean-Pierre; Clough, Sidney A.; Emanuel, Kerry A.; Eymard, Laurence; Gall, Robert; Hildebrand, Peter H.; Langland, Rolf H.; Lemaître, Yvon; Lynch, Peter; Moore, James A.; Persson, P. Ola G.; Snyder, Chris; Wakimoto, Roger M.</p> <p>1997-09-01</p> <p>The Fronts and <span class="hlt">Atlantic</span> Storm-Track Experiment (FASTEX) will address the life cycle of cyclones evolving over the North <span class="hlt">Atlantic</span> Ocean in January and February 1997. The objectives of FASTEX are to improve the forecasts of end-of-storm-track cyclogenesis (primarily in the eastern <span class="hlt">Atlantic</span> but with applicability to the Pacific) in the range 24 to 72 h, to enable the testing of theoretical ideas on cyclone formation and development, and to document the vertical and the mesoscale structure of cloud systems in mature cyclones and their relation to the dynamics. The observing system includes ships that will remain in the vicinity of the main baroclinic zone in the central <span class="hlt">Atlantic</span> Ocean, jet aircraft that will fly and drop sondes off the east coast of North America or over the central <span class="hlt">Atlantic</span> Ocean, turboprop aircraft that will survey mature cyclones off Ireland with dropsondes, and airborne Doppler radars, including ASTRAIA/ELDORA. Radiosounding frequency around the North <span class="hlt">Atlantic</span> <span class="hlt">basin</span> will be increased, as well as the number of drifting buoys. These facilities will be activated during multiple-day intensive observing periods in order to observe the same meteorological systems at several stages of their life cycle. A central archive will be developed in quasi-real time in Toulouse, France, thus allowing data to be made widely available to the scientific community.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22490635-km3net','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22490635-km3net"><span>KM3<span class="hlt">Ne</span>T</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Jong, M. de; Leiden Institute of Physics, Leiden University, Leiden; Collaboration: KM3NeT Collaboration</p> <p>2015-07-15</p> <p>KM3<span class="hlt">Ne</span>T is a large research infrastructure, that will consist of a network of deep-sea neutrino telescopes in the Mediterranean Sea. The main objective of KM3<span class="hlt">Ne</span>T is the discovery and subsequent observation of high-energy neutrino sources in the Universe. A further physics perspective is the measurement of the mass hierarchy of neutrinos. A corresponding study, ORCA, is ongoing within KM3<span class="hlt">Ne</span>T. A cost effective technology for (very) large water Cherenkov detectors has been developed based on a new generation of low price 3-inch photo-multiplier tubes. Following the successful deployment and operation of two prototypes, the construction of the KM3<span class="hlt">Ne</span>T research infrastructure hasmore » started. The prospects of the different phases of the implementation of KM3<span class="hlt">Ne</span>T are summarised.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AGUFM.V51G..07T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AGUFM.V51G..07T"><span>Contrasting geochemical trends in the fertile and refractory parts of the <span class="hlt">NE</span> <span class="hlt">Atlantic</span> mantle source</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tronnes, R. G.; Debaille, V.; Brandon, A. D.; Waight, T. E.; Graham, D. W.; Williams, A.; Lee, C. A.</p> <p>2008-12-01</p> <p>Primitive alkaline basalts from the Icelandic off-rift volcanic zones and Jan Mayen represent low-degree melts from the fertile parts of the <span class="hlt">NE</span> <span class="hlt">Atlantic</span> mantle. Olivine tholeiites and picrites from the Icelandic rift zones and nearby oceanic spreading ridges are formed by protracted decompressional melting. The V-shaped ridges along the Reykjanes, Kolbeinsey and Aegir ridges indicate that ascending source material is supplied by a pulsating plume and deflected laterally for distances of about 1000 km from Iceland (Jones et al. GGG 2002; Breivik et al. JGR 2006). Plume material deflected in the direction of the rift zones and spreading ridges undergoes extensive melting at shallow level, whereas material deflected in other directions flows laterally at deeper levels and remains largely unmelted and more fertile. The comparison of a sample suite of primitive off-rift basalts from Iceland and Jan Mayen (Debaille et al., in prep.) with olivine tholeiites and picrites from the Icelandic rift zones (mainly Brandon et al. GCA 2007) demonstrate opposing geochemical trends. The degree of source enrichment, expressed by the La/Sm-ratio, is positively and negatively correlated with 87/86Sr and 143/144Nd throughout the entire range of depleted rift zone tholeiites and enriched off-rift basalts. In the rift zone tholeiites the La/Sm-ratio has negative correlations with Mg# and Mg-content and positive correlations with 187/188Os and 3/4He. These four trends have opposite equivalents for the off-rift basalts. The most enriched and alkaline basalts from Jan Mayen and Snæfellsnes have the lowest 3/4He of 6-9*Ra and 187/188Os of 0.12-0.13. The trends seem to require a source component with ancient melt depletion and subsequent enrichment. A subcontinental lithospheric mantle keel (SCLM) is the most likely origin for the enriched component with high LILE, La/Sm and 87/86Sr and low 143/144Nd, 3/4He and 187/188Os. The most enriched alkaline basalts have notably higher Mg# and Mg and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016E%26PSL.434...18W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016E%26PSL.434...18W"><span>Deep circulation changes in the South <span class="hlt">Atlantic</span> since the Last Glacial Maximum from Nd isotope and multi-proxy records</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wei, R.; Abouchami, W.; Zahn, R.; Masque, P.</p> <p>2016-01-01</p> <p>We report down-core sedimentary Nd isotope (εNd) records from two South <span class="hlt">Atlantic</span> sediment cores, MD02-2594 and GeoB3603-2, located on the western South African continental margin. The core sites are positioned downstream of the present-day flow path of North <span class="hlt">Atlantic</span> Deep Water (NADW) and close to the Southern Ocean, which makes them suitable for reconstructing past variability in NADW circulation over the last glacial cycle. The Fe-Mn leachates εNd records show a coherent decreasing trend from glacial radiogenic values towards less radiogenic values during the Holocene. This trend is confirmed by εNd in fish debris and mixed planktonic foraminifera, albeit with an offset during the Holocene to lower values relative to the leachates, matching the present-day composition of NADW in the Cape <span class="hlt">Basin</span>. We interpret the εNd changes as reflecting the glacial shoaling of Southern Ocean waters to shallower depths combined with the admixing of southward flowing Northern Component Water (NCW). A compilation of <span class="hlt">Atlantic</span> εNd records reveals increasing radiogenic isotope signatures towards the south and with increasing depth. This signal is most prominent during the Last Glacial Maximum (LGM) and of similar amplitude across the <span class="hlt">Atlantic</span> <span class="hlt">basin</span>, suggesting continuous deep water production in the North <span class="hlt">Atlantic</span> and export to the South <span class="hlt">Atlantic</span> and the Southern Ocean. The amplitude of the εNd change from the LGM to Holocene is largest in the southernmost cores, implying a greater sensitivity to the deglacial strengthening of NADW at these sites. This signal impacted most prominently the South <span class="hlt">Atlantic</span> deep and bottom water layers that were particularly deprived of NCW during the LGM. The εNd variations correlate with changes in 231Pa/230Th ratios and benthic δ13C across the deglacial transition. Together with the contrasting 231Pa/230Th: εNd pattern of the North and South <span class="hlt">Atlantic</span>, this indicates a progressive reorganization of the AMOC to full strength during the Holocene.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.V33C4895C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.V33C4895C"><span>Whole Rock and Mineral Chemistry from the Central <span class="hlt">Atlantic</span> Magmatic Province (CAMP)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chau, K. X.; Draper, G.; Sen, G.</p> <p>2014-12-01</p> <p>The Central <span class="hlt">Atlantic</span> Magmatic Province (CAMP) was a large igneous province (LIP) emplaced approximately 200 million years ago during the rifting of Pangaea, shortly before the opening of the <span class="hlt">Atlantic</span> Ocean. Although a comparatively small amount of the original province remains today, the locations of the existing outcrops on four continents (North America, South America, Africa, and Europe) show the extensive reach of igneous activity and indicate that the CAMP was likely one of the biggest LIPs known. Because of the geologic and global significance of this episode, a knowledge of the conditions that generated and emplaced such a large volume of magma would help better understand mantle and tectonic processes. In this study, we compare whole rock and mineral chemistry data from three of the North American outcrops: the Palisades Sill of the Newark <span class="hlt">Basin</span> in eastern New York and New Jersey, the Centreville Sheet of the Culpeper <span class="hlt">Basin</span> in northern Virginia, and the York Haven pluton of the Gettysburg <span class="hlt">Basin</span> in southeastern Pennsylvania. The diabases are quartz-normative theoleiites; their chemistries are indicate high degrees of internal differentiation and thermal disequilbirum, consistent with magma bodies cooling as a closed or near-closed system. The trace element data shows that, although there is evidence to support a deep mantle source for CAMP melts, there is also a shallower component influencing the chemistries of the samples. We interpret this as the signal of an ancient subducted slab through which CAMP melts passed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.2083B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.2083B"><span>Paleostress Reconstruction from 3D seismic, Natural Fracture and Calcite Twin Analyses: Structural Insights into the Otway <span class="hlt">Basin</span>, Australia</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Burgin, Hugo; Amrouch, Khalid; Holford, Simon</p> <p>2017-04-01</p> <p>The Otway <span class="hlt">Basin</span>, Australia, is of particular interest due to its significance as an Australian hydrocarbon producing province and a major global CO2 burial project. Structural data was collected in the form of natural fractures from wellbore image logs and outcrop in addition to calcite twin analyses, within formations from the mid cretaceous from both on and offshore. Evidence for four structural events within the study area have been identified including <span class="hlt">NE</span>-SW and NW-SE orientated extension, in addition to a NW-SE compressive event. Natural fracture data also reveals a previously "un-detected" <span class="hlt">NE</span>-SW compression within the Otway <span class="hlt">Basin</span>. This study presents the first investigation of paleostress environments within the region from micro, meso and macro scale tectonic data in both onshore and offshore in addition to the first quantification of differential paleostresses. This work highlights the importance of a comprehensive understanding of four dimensional stress evolution within the sedimentary <span class="hlt">basins</span> of Australia's southern margin.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5056707','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5056707"><span>Accuracy of Assignment of <span class="hlt">Atlantic</span> Salmon (Salmo salar L.) to Rivers and Regions in Scotland and Northeast England Based on Single Nucleotide Polymorphism (SNP) Markers</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Gilbey, John; Cauwelier, Eef; Coulson, Mark W.; Stradmeyer, Lee; Sampayo, James N.; Armstrong, Anja; Verspoor, Eric; Corrigan, Laura; Shelley, Jonathan; Middlemas, Stuart</p> <p>2016-01-01</p> <p>Understanding the habitat use patterns of migratory fish, such as <span class="hlt">Atlantic</span> salmon (Salmo salar L.), and the natural and anthropogenic impacts on them, is aided by the ability to identify individuals to their stock of origin. Presented here are the results of an analysis of informative single nucleotide polymorphic (SNP) markers for detecting genetic structuring in <span class="hlt">Atlantic</span> salmon in Scotland and <span class="hlt">NE</span> England and their ability to allow accurate genetic stock identification. 3,787 fish from 147 sites covering 27 rivers were screened at 5,568 SNP markers. In order to identify a cost-effective subset of SNPs, they were ranked according to their ability to differentiate between fish from different rivers. A panel of 288 SNPs was used to examine both individual assignments and mixed stock fisheries and eighteen assignment units were defined. The results improved greatly on previously available methods and, for the first time, fish caught in the marine environment can be confidently assigned to geographically coherent units within Scotland and <span class="hlt">NE</span> England, including individual rivers. As such, this SNP panel has the potential to aid understanding of the various influences acting upon <span class="hlt">Atlantic</span> salmon on their marine migrations, be they natural environmental variations and/or anthropogenic impacts, such as mixed stock fisheries and interactions with marine power generation installations. PMID:27723810</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70196052','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70196052"><span><span class="hlt">Atlantic</span> continental margin of the United States</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Grow, John A.; Sheridan, Robert E.; Palmer, A.R.</p> <p>1982-01-01</p> <p>The objective of this Decade of North American Geology (D-NAG) volume will be to focus on the Mesozoic and Cenozoic evolution of the U.S. <span class="hlt">Atlantic</span> continental margin, including the onshore coastal plain, related onshore Triassic-Jurassic rift grabens, and the offshore <span class="hlt">basins</span> and platforms. Following multiple compressional tectonic episodes between Africa and North America during the Paleozoic Era that formed the Appalachian Mountains, the Mesozoic and Cenozoic Eras were dominated by tensional tectonic processes that separated Africa and North America. Extensional rifting during Triassic and Early Jurassic times resulted in numerous tensional grabens both onshore and offshore, which filled with nonmarine continental red beds, lacustrine deposits, and volcanic flows and debris. The final stage of this breakup between Africa and North America occurred beneath the present outer continental shelf and continental slope during Early or Middle Jurassic time when sea-floor spreading began to form new oceanic crust and lithosophere between the two continents as they drifted apart. Postrift subsidence of the marginal <span class="hlt">basins</span> continued in response to cooling of the lithosphere and sedimentary loading.Geophysical surveys and oil-exploration drilling along the U.S. <span class="hlt">Atlantic</span> continental margin during the past 5 years are beginning to answer many questions concerning its deep structure and stratigraphy and how it evolved during the rifting and early sea-floor-spreading stages of the separation of this region from Africa. Earlier geophysical studies of the U.S. continental margin used marine refraction and submarine gravity measurements. Single-channel seismic-reflection, marine magnetic, aeromagnetic, and continuous gravity measurements became available during the 1960s.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4934859','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4934859"><span><span class="hlt">Atlantic</span> Sturgeon Spatial and Temporal Distribution in Minas Passage, Nova Scotia, Canada, a Region of Future Tidal Energy Extraction</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Stokesbury, Michael J. W.; Logan-Chesney, Laura M.; McLean, Montana F.; Buhariwalla, Colin F.; Redden, Anna M.; Beardsall, Jeffrey W.; Broome, Jeremy E.; Dadswell, Michael J.</p> <p>2016-01-01</p> <p>In the Bay of Fundy, <span class="hlt">Atlantic</span> sturgeon from endangered and threatened populations in the USA and Canada migrate through Minas Passage to enter and leave Minas <span class="hlt">Basin</span>. A total of 132 sub-adult and adult <span class="hlt">Atlantic</span> sturgeon were tagged in Minas <span class="hlt">Basin</span> during the summers of 2010–2014 using pressure measuring, uniquely coded, acoustic transmitters with a four or eight year life span. The aim of this study was to examine spatial and seasonal distribution of sturgeon in Minas Passage during 2010–2014 and test the hypothesis that, when present, <span class="hlt">Atlantic</span> sturgeon were evenly distributed from north to south across Minas Passage. This information is important as tidal energy extraction using in-stream, hydrokinetic turbines is planned for only the northern portion of Minas Passage. Electronic tracking data from a total of 740 sturgeon days over four years demonstrated that <span class="hlt">Atlantic</span> sturgeon used the southern portion of Minas Passage significantly more than the northern portion. Sturgeon moved through Minas Passage at depths mostly between 15 and 45 m (n = 10,116; mean = 31.47 m; SD = 14.88). Sturgeon mean swimming depth was not significantly related to bottom depth and in deeper regions they swam pelagically. Sturgeon predominately migrated inward through Minas Passage during spring, and outward during late summer-autumn. Sturgeon were not observed in Minas Passage during winter 2012–2013 when monitoring receivers were present. This information will enable the estimation of encounters of <span class="hlt">Atlantic</span> sturgeon with in-stream hydrokinetic turbines. PMID:27383274</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22493664-scattering-study-ne-neh-sup-sub-sub-neh-sup-ne-reaction-ab-initio-based-analytical-potential-energy-surface','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22493664-scattering-study-ne-neh-sup-sub-sub-neh-sup-ne-reaction-ab-initio-based-analytical-potential-energy-surface"><span>Scattering study of the <span class="hlt">Ne</span> + <span class="hlt">Ne</span>H{sup +}(v{sub 0} = 0, j{sub 0} = 0) → <span class="hlt">Ne</span>H{sup +} + <span class="hlt">Ne</span> reaction on an ab initio based analytical potential energy surface</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Koner, Debasish; Panda, Aditya N., E-mail: adi07@iitg.ernet.in; Barrios, Lizandra</p> <p>2016-01-21</p> <p>Initial state selected dynamics of the <span class="hlt">Ne</span> + <span class="hlt">Ne</span>H{sup +}(v{sub 0} = 0, j{sub 0} = 0) → <span class="hlt">Ne</span>H{sup +} + <span class="hlt">Ne</span> reaction is investigated by quantum and statistical quantum mechanical (SQM) methods on the ground electronic state. The three-body ab initio energies on a set of suitably chosen grid points have been computed at CCSD(T)/aug-cc-PVQZ level and analytically fitted. The fitting of the diatomic potentials, computed at the same level of theory, is performed by spline interpolation. A collinear [<span class="hlt">Ne</span>HNe]{sup +} structure lying 0.72 eV below the <span class="hlt">Ne</span> + <span class="hlt">Ne</span>H{sup +} asymptote is found to be the most stablemore » geometry for this system. Energies of low lying vibrational states have been computed for this stable complex. Reaction probabilities obtained from quantum calculations exhibit dense oscillatory structures, particularly in the low energy region and these get partially washed out in the integral cross section results. SQM predictions are devoid of oscillatory structures and remain close to 0.5 after the rise at the threshold thus giving a crude average description of the quantum probabilities. Statistical cross sections and rate constants are nevertheless in sufficiently good agreement with the quantum results to suggest an important role of a complex-forming dynamics for the title reaction.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/FR-2011-03-21/pdf/2011-6563.pdf','FEDREG'); return false;" href="https://www.gpo.gov/fdsys/pkg/FR-2011-03-21/pdf/2011-6563.pdf"><span>76 FR 15276 - <span class="hlt">Atlantic</span> Highly Migratory Species; <span class="hlt">Atlantic</span> Bluefin Tuna Quotas and <span class="hlt">Atlantic</span> Tuna Fisheries...</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collection.action?collectionCode=FR">Federal Register 2010, 2011, 2012, 2013, 2014</a></p> <p></p> <p>2011-03-21</p> <p>.... 110210132-1133-01] RIN 0648-BA65 <span class="hlt">Atlantic</span> Highly Migratory Species; <span class="hlt">Atlantic</span> Bluefin Tuna Quotas and <span class="hlt">Atlantic</span> Tuna Fisheries Management Measures; Correction AGENCY: National Marine Fisheries Service (NMFS... 14, 2011, NMFS published a proposed rule to modify <span class="hlt">Atlantic</span> bluefin tuna (BFT) base quotas for all...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMNH51A0110B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMNH51A0110B"><span>Future Changes in Cyclonic Wave Climate in the North <span class="hlt">Atlantic</span>, with a Focus on the French West Indies</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Belmadani, A.; Palany, P.; Dalphinet, A.; Pilon, R.; Chauvin, F.</p> <p>2017-12-01</p> <p>Tropical cyclones (TCs) are a major environmental hazard in numerous small islands such as the French West Indies (Guadeloupe, Martinique, St-Martin, St-Barthélémy). The intense associated winds, which can reach 300 km/h or more, can cause serious damage in the islands and their coastlines. In particular, the combined action of waves, currents and low atmospheric pressure leads to severe storm surge and coastal flooding. Here we report on future changes in cyclonic wave climate for the North <span class="hlt">Atlantic</span> <span class="hlt">basin</span>, as a preliminary step for downscaled projections over the French West Indies at sub-kilometer-scale resolution. A new configuration of the Météo-France ARPEGE atmospheric general circulation model on a stretched grid with increased resolution in the tropical North <span class="hlt">Atlantic</span> ( 15 km) is able to reproduce the observed distribution of maximum surface winds, including extreme events corresponding to Category 5 hurricanes. Ensemble historical simulations (1985-2014, 5 members) and future projections with the IPCC (Intergovernmental Panel on Climate Change) RCP8.5 scenario (2051-2080, 5 members) are used to drive the MFWAM (Météo-France Wave Action Model) over the North <span class="hlt">Atlantic</span> <span class="hlt">basin</span>. A lower 50-km resolution grid is used to propagate distant mid-latitude swells into a higher 10-km resolution grid over the cyclonic <span class="hlt">basin</span>. Wave model performance is evaluated over a few TC case studies including the Sep-Oct 2016 Category 5 Hurricane Matthew, using an operational version of ARPEGE at similar resolution to force MFWAM together with wave buoy data. The latter are also used to compute multi-year wave statistics, which then allow assessing the realism of the MFWAM historical runs. For each climate scenario and ensemble member, a simulation of the cyclonic season (July to mid-November) is performed every year. The simulated sea states over the North <span class="hlt">Atlantic</span> cyclonic <span class="hlt">basin</span> over 150 historical simulations are compared to their counterparts over 150 future simulations</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_19 --> <div id="page_20" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="381"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012GGG....13.7003J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012GGG....13.7003J"><span>The thermal environment of Cascadia <span class="hlt">Basin</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Johnson, H. Paul; Hautala, Susan L.; Bjorklund, Tor A.</p> <p>2012-07-01</p> <p>Located adjacent to the <span class="hlt">NE</span> Pacific convergent boundary, Cascadia <span class="hlt">Basin</span> has a global impact well beyond its small geographic size. Composed of young oceanic crust formed at the Juan de Fuca Ridge, igneous rocks underlying the <span class="hlt">basin</span> are partially insulated from cooling of their initial heat of formation by a thick layer of pelagic and turbidite sediments derived from the adjacent North American margin. The igneous seafloor is eventually consumed at the Cascadia subduction zone, where interactions between the approaching oceanic crust and the North American continental margin are partially controlled by the thermal environment. Within Cascadia <span class="hlt">Basin</span>, basement topographic relief varies dramatically, and sediments have a wide range of thickness and physical properties. This variation produces regional differences in heat flow and basement temperatures for seafloor even of similar age. Previous studies proposed a north-south thermal gradient within Cascadia <span class="hlt">Basin</span>, with high geothermal flux and crustal temperatures measured in the heavily sedimented northern portion near Vancouver Island and lower than average heat flux and basement temperatures predicted for the central and southern portions of the <span class="hlt">basin</span>. If confirmed, this prediction has implications for processes associated with the Cascadia subduction zone, including the location of the "locked zone" of the megathrust fault. Although existing archival geophysical data in the central and southern <span class="hlt">basin</span> are sparse, nonuniformly distributed, and derived from a wide range of historical sources, a substantial N-S geothermal gradient appears to be confirmed by our present compilation of combined water column and heat flow measurements.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFMPP13B1512V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFMPP13B1512V"><span>Tropical-Subpolar Linkages in the North <span class="hlt">Atlantic</span> during the last Glacial Period</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vautravers, M. J.; Hodell, D. A.</p> <p>2010-12-01</p> <p>We studied millennial-scale changes in planktonic foraminifera assemblages from the last glacial period in a high-resolution core (KN166-14-JPC13) recovered from the southern part of the Gardar Drift in the subpolar North <span class="hlt">Atlantic</span>. Similar to recent findings reported by Jonkers et al. (2010), we also found that the sub-polar North <span class="hlt">Atlantic</span> Ocean experienced some seasonal warming during each of the Heinrich Events (HEs). In addition, increasing abundances of tropical species are found just prior to the IRD event marking the end of each Bond cycle, suggesting that summer warming may have been involved in triggering Heinrich events. We suggest that tropical-subtropical water transported via the Gulf Stream and North <span class="hlt">Atlantic</span> Drift may have triggered the collapse of large NH ice-shelves. Sharp decreases in polar species are tied to abrupt warming following Heinrich Events as documented in Greenland Ice cores and other marine records in the North <span class="hlt">Atlantic</span>. The record bears a strong resemblance to the tropical record of Cariaco <span class="hlt">basin</span> (Peterson et al., 2000), suggesting strong tropical-subpolar linkages in the glacial North <span class="hlt">Atlantic</span>. Enhanced spring productivity, possibly related to eddy activity along the Subpolar Front, is recorded by increased shell size, high δ13C in G. bulloides and other biological indices early during the transition from HE stadials to the following interstadial.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JSR...100...91V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JSR...100...91V"><span>Lost fishing gear and litter at Gorringe Bank (<span class="hlt">NE</span> <span class="hlt">Atlantic</span>)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vieira, Rui P.; Raposo, Isabel P.; Sobral, Paula; Gonçalves, Jorge M. S.; Bell, Katherine L. C.; Cunha, Marina R.</p> <p>2015-06-01</p> <p>Studies concerning marine litter have received great attention over the last several years by the scientific community mainly due to their ecological and economic impacts in marine ecosystems, from coastal waters to the deep ocean seafloor. The distribution, type and abundance of marine litter in Ormonde and Gettysburg, the two seamounts of Gorringe Bank, were analyzed from photo and video imagery obtained during ROV-based surveys carried out at 60-3015 m depths during the E/V Nautilus cruise NA017. Located approximately 125 nm southwest of Portugal, Gorringe Bank lays at the crossroad between the <span class="hlt">Atlantic</span> and the Mediterranean and is therefore characterized by an intense maritime traffic and fishing activities. The high frequency of lost or discarded fishing gear, such as cables, longlines and nets, observed on Gorringe Bank suggests an origin mostly from fishing activities, with a clear turnover in the type of litter (mostly metal, glass and to a much lesser extent, plastic) with increasing depth. Litter was more abundant at the summit of Gorringe Bank (ca. 4 items·km- 1), decreasing to less than 1 item·km- 1 at the flanks and to ca. 2 items·km- 1 at greater depths. Nevertheless, litter abundance appeared to be lower than in continental margin areas. The results presented herein are a contribution to support further actions for the conservation of vulnerable habitats on Gorringe Bank so that they can continue contributing to fishery productivity in the surrounding region.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/15295596','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/15295596"><span>Vigorous exchange between the Indian and <span class="hlt">Atlantic</span> oceans at the end of the past five glacial periods.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Peeters, Frank J C; Acheson, Ruth; Brummer, Geert-Jan A; De Ruijter, Wilhelmus P M; Schneider, Ralph R; Ganssen, Gerald M; Ufkes, Els; Kroon, Dick</p> <p>2004-08-05</p> <p>The magnitude of heat and salt transfer between the Indian and <span class="hlt">Atlantic</span> oceans through 'Agulhas leakage' is considered important for balancing the global thermohaline circulation. Increases or reductions of this leakage lead to strengthening or weakening of the <span class="hlt">Atlantic</span> meridional overturning and associated variation of North <span class="hlt">Atlantic</span> Deep Water formation. Here we show that modern Agulhas waters, which migrate into the south <span class="hlt">Atlantic</span> Ocean in the form of an Agulhas ring, contain a characteristic assemblage of planktic foraminifera. We use this assemblage as a modern analogue to investigate the Agulhas leakage history over the past 550,000 years from a sediment record in the Cape <span class="hlt">basin</span>. Our reconstruction indicates that Indian-<span class="hlt">Atlantic</span> water exchange was highly variable: enhanced during present and past interglacials and largely reduced during glacial intervals. Coherent variability of Agulhas leakage with northern summer insolation suggests a teleconnection to the monsoon system. The onset of increased Agulhas leakage during late glacial conditions took place when glacial ice volume was maximal, suggesting a crucial role for Agulhas leakage in glacial terminations, timing of interhemispheric climate change and the resulting resumption of the <span class="hlt">Atlantic</span> meridional overturning circulation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.usgs.gov/of/2012/1266/pdf/ofr20121266_v2.pdf','USGSPUBS'); return false;" href="http://pubs.usgs.gov/of/2012/1266/pdf/ofr20121266_v2.pdf"><span>Bathymetric terrain model of the <span class="hlt">Atlantic</span> margin for marine geological investigations</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Andrews, Brian D.; Chaytor, Jason D.; ten Brink, Uri S.; Brothers, Daniel S.; Gardner, James V.; Lobecker, Elizabeth A.; Calder, Brian R.</p> <p>2016-01-01</p> <p>A bathymetric terrain model of the <span class="hlt">Atlantic</span> margin covering almost 725,000 square kilometers of seafloor from the New England Seamounts in the north to the Blake <span class="hlt">Basin</span> in the south is compiled from existing multibeam bathymetric data for marine geological investigations. Although other terrain models of the same area are extant, they are produced from either satellite-derived bathymetry at coarse resolution (ETOPO1), or use older bathymetric data collected by using a combination of single beam and multibeam sonars (Coastal Relief Model). The new multibeam data used to produce this terrain model have been edited by using hydrographic data processing software to maximize the quality, usability, and cartographic presentation of the combined 100-meter resolution grid. The final grid provides the largest high-resolution, seamless terrain model of the <span class="hlt">Atlantic</span> margin..</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018ClDy..tmp.2388F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018ClDy..tmp.2388F"><span>Interdecadal modulation of the <span class="hlt">Atlantic</span> Multi-decadal Oscillation (AMO) on southwest China's temperature over the past 250 years</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fang, Keyan; Guo, Zhengtang; Chen, Deliang; Wang, Lei; Dong, Zhipeng; Zhou, Feifei; Zhao, Yan; Li, Jinbao; Li, Yingjun; Cao, Xinguang</p> <p>2018-05-01</p> <p>The temperature gradient between southwestern China and Indian Ocean is one key driver of the Indian Summer Monsoon, suggesting the necessity to understand temperature variability in southwestern China. Contrary to the general warming experienced in most of China, a few regions in southwestern China have undergone a cooling trend since the 1950s. To place this cooling trend in a historical context, this study develops an Abies fabri tree-ring width chronology in the Sichuan <span class="hlt">Basin</span>, the most populated region in southwest China. The chronology spans from 1590 to 2012, with its reliable portion from 1758 to 2012, by far the longest in the Sichuan <span class="hlt">Basin</span>. To better extract regional climate signals encoded in tree rings with strong local disturbances, we incorporate climate signals of nearby tree-ring chronologies to generate a large-scale tree-ring chronology (LSC). The LSC shows higher correlations with temperature near the sampling site on Mount Emei and sea surface temperatures of the northern <span class="hlt">Atlantic</span> Ocean than chronologies developed using traditional methods. The highest correlations between the LSC and temperature are found from current February to July in the Sichuan <span class="hlt">Basin</span> for the period 1901-1950 (r = 0.70), with a sharp decrease afterwards. Interdecadal variations of the LSC match well with <span class="hlt">Atlantic</span> Multi-decadal Oscillation reconstructions, except for the late nineteenth century and after 1980s. This study provides evidence that southwest China is a transitional region both affected by the interdecadal temperature variations of the northern <span class="hlt">Atlantic</span> and Asian areas, although their influences weakened in recent possible due to enhanced human activities.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA083439','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA083439"><span>Deep Drilling Results in the <span class="hlt">Atlantic</span> Ocean: Continental Margins and Paleoenvironment</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>1979-01-01</p> <p>nannoplankton, a sparse to rich DITIBTO OF HORIZO C I foraminiferal fauna (simple arenaceous foramin - 5S SSftB / ifera, lagenids, epistominids, and primitive...Deep Sea Pessagno, E.A., Jr., Mesozoic Planctonic Foramin - DrillingP , 11, Washington (U.S. Govern- vera and Radiolaria, in Ewing, M., Worzel, L.J. ment...Strati- B.,er, W.H., Foramin ooze: solution at graphic Micropaleontology of <span class="hlt">Atlantic</span> <span class="hlt">Basins</span> depths, Science, 156, 383-385, 1967. and Borderlands</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018GBioC..32...78T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018GBioC..32...78T"><span>Limited Carbonate Dissolution by Boring Microflora at Two Volcanically Acidified Temperate Sites: Ischia (Italy, Mediterranean Sea) and Faial (Azores, <span class="hlt">NE</span> <span class="hlt">Atlantic</span> Ocean)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tribollet, A.; Grange, J. S.; Parra, H.; Rodolfo-Metalpa, R.; Carreiro-Silva, M.</p> <p>2018-01-01</p> <p>In situ effects of ocean acidification on carbonate dissolution by microboring flora, also called biogenic dissolution, have only been studied once in tropical environments. Naturally acidified seawaters due to CO2 vents offer a perfect setting to study these effects in temperate systems. Three sites were selected at Ischia (Italy, Mediterranean Sea) with one experiencing ambient pH and the two others a mean pHT of 7.2 and 7.5. At Faial (Azores, <span class="hlt">NE</span> <span class="hlt">Atlantic</span>), one site with ambient pH and one acidified site with a mean pHT of 7.4 were selected. Experiments were carried out during 1.5 months and 6 months in Azores and Ischia, respectively, to determine the effects of OA on microboring communities in various carbonate substrates. Low pH influenced negatively boring microflora development by limiting their depth of penetration and abundance in substrates. Biogenic dissolution was thus reduced by a factor 3 to 7 depending on sites and substrate types. At sites with ambient pH in Faial, biogenic dissolution contributed up to 23% to the total weight loss, while it contributed less than 1% to the total weight loss of substrates at the acidified sites. Most of the dissolution at these sites was due to chemical dissolution (often Ω ≤ 1). Such conditions maintained microboring communities at a pioneer stage with a limited depth of penetration in substrates. Our results, together with previous findings that showed an increase of biogenic dissolution at pH > 7.7, suggest that there is a pH tipping point below which microborer development and thus carbonate biogenic dissolution is strongly limited.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4064999','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4064999"><span>The Influence of Physical Factors on Kelp and Sea Urchin Distribution in Previously and Still Grazed Areas in the <span class="hlt">NE</span> <span class="hlt">Atlantic</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Rinde, Eli; Christie, Hartvig; Fagerli, Camilla W.; Bekkby, Trine; Gundersen, Hege; Norderhaug, Kjell Magnus; Hjermann, Dag Ø.</p> <p>2014-01-01</p> <p>The spatial distribution of kelp (Laminaria hyperborea) and sea urchins (Strongylocentrotus droebachiensis) in the <span class="hlt">NE</span> <span class="hlt">Atlantic</span> are highly related to physical factors and to temporal changes in temperature. On a large scale, we identified borders for kelp recovery and sea urchin persistence along the north-south gradient. Sea urchin persistence was also related to the coast-ocean gradient. The southern border corresponds to summer temperatures exceeding about 10°C, a threshold value known to be critical for sea urchin recruitment and development. The outer border along the coast-ocean gradient is related to temperature, wave exposure and salinity. On a finer scale, kelp recovery occurs mainly at ridges in outer, wave exposed, saline and warm areas whereas sea urchins still dominate in inner, shallow and cold areas, particularly in areas with optimal current speed for sea urchin foraging. In contrast to other studies in Europe, we here show a positive influence of climate change to presence of a long-lived climax canopy-forming kelp. The extent of the coast-ocean gradient varies within the study area, and is especially wide in the southern part where the presence of islands and skerries increases the area of the shallow coastal zone. This creates a large area with intermediate physical conditions for the two species and a mosaic of kelp and sea urchin dominated patches. The statistical models (GAM and BRT) show high performance and indicate recovery of kelp in 45–60% of the study area. The study shows the value of combining a traditional (GAM) and a more complex (BRT) modeling approach to gain insight into complex spatial patterns of species or habitats. The results, methods and approaches are of general ecological relevance regardless of ecosystems and species, although they are particularly relevant for understanding and exploring the corresponding changes between algae and grazers in different coastal areas. PMID:24949954</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24949954','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24949954"><span>The influence of physical factors on kelp and sea urchin distribution in previously and still grazed areas in the <span class="hlt">NE</span> <span class="hlt">Atlantic</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Rinde, Eli; Christie, Hartvig; Fagerli, Camilla W; Bekkby, Trine; Gundersen, Hege; Norderhaug, Kjell Magnus; Hjermann, Dag Ø</p> <p>2014-01-01</p> <p>The spatial distribution of kelp (Laminaria hyperborea) and sea urchins (Strongylocentrotus droebachiensis) in the <span class="hlt">NE</span> <span class="hlt">Atlantic</span> are highly related to physical factors and to temporal changes in temperature. On a large scale, we identified borders for kelp recovery and sea urchin persistence along the north-south gradient. Sea urchin persistence was also related to the coast-ocean gradient. The southern border corresponds to summer temperatures exceeding about 10°C, a threshold value known to be critical for sea urchin recruitment and development. The outer border along the coast-ocean gradient is related to temperature, wave exposure and salinity. On a finer scale, kelp recovery occurs mainly at ridges in outer, wave exposed, saline and warm areas whereas sea urchins still dominate in inner, shallow and cold areas, particularly in areas with optimal current speed for sea urchin foraging. In contrast to other studies in Europe, we here show a positive influence of climate change to presence of a long-lived climax canopy-forming kelp. The extent of the coast-ocean gradient varies within the study area, and is especially wide in the southern part where the presence of islands and skerries increases the area of the shallow coastal zone. This creates a large area with intermediate physical conditions for the two species and a mosaic of kelp and sea urchin dominated patches. The statistical models (GAM and BRT) show high performance and indicate recovery of kelp in 45-60% of the study area. The study shows the value of combining a traditional (GAM) and a more complex (BRT) modeling approach to gain insight into complex spatial patterns of species or habitats. The results, methods and approaches are of general ecological relevance regardless of ecosystems and species, although they are particularly relevant for understanding and exploring the corresponding changes between algae and grazers in different coastal areas.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018DSRII.148...35B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018DSRII.148...35B"><span>Composition of abyssal macrofauna along the Vema Fracture Zone and the hadal Puerto Rico Trench, northern tropical <span class="hlt">Atlantic</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Brandt, A.; Frutos, I.; Bober, S.; Brix, S.; Brenke, N.; Guggolz, T.; Heitland, N.; Malyutina, M.; Minzlaff, U.; Riehl, T.; Schwabe, E.; Zinkann, A.-C.; Linse, K.</p> <p>2018-02-01</p> <p>We analyzed composition and variations in benthic macrofaunal communities along a transect of the entire length of the Vema-Fracture Zone on board of RV Sonne (SO-237) between December 2014 and January 2015 in order to test whether the Mid-<span class="hlt">Atlantic</span> Ridge serves as a barrier limiting benthic taxon distribution in the abyssal <span class="hlt">basins</span> on both sides of the ridge or whether the fracture zone permits the migration of species between the western and eastern abyssal <span class="hlt">Atlantic</span> <span class="hlt">basins</span>. The Puerto Rico Trench, much deeper than the surrounding abyssal West <span class="hlt">Atlantic</span>, was sampled to determine whether the biodiversity of its hadal macrofauna differs from that of the abyssal <span class="hlt">Atlantic</span>. The composition of the macrofauna from the epibenthic sledge catches yielded a total of 21,332 invertebrates. Crustacea occurred most frequently (59%) with 12,538 individuals followed by Annelida (mostly Polychaeta) (26%) with 5491 individuals, Mollusca (7%) with 1458 individuals, Echinodermata (4%) with 778 individuals, Nematoda (2%) with 502 individuals and Chaetognatha (1%) with 152 and Porifera (1%) with 131 individuals. All other taxa occurred with overall less than ten individuals (Hemichordata, Phoronida, Priapulida, Brachiopoda, invertebrate Chordata, Echiurida, Foraminifera (here refereed to macrofaunal Komokiacea only), Chelicerata, Platyhelminthes). Within the Crustacea, Peracarida (62.6%) with 7848 individuals and Copepoda (36.1%) with 44,526 individuals were the most abundant taxa. Along the abyssal Vema-Fracture Zone macrofaunal abundances (ind./1000 m2) were generally higher on the eastern side, while the highest normalized abundance value was reported in the Puerto Rico Trench at abyssal station 14-1 2313 individuals/1000 m2. The lowest abundance was reported at station 11-4 with 120 ind./1000 m2 located at the western side of the Vema-Fracture Zone. The number of major macrofaunal taxa (phylum, class) ranged between five (stations 12-5, 13-4 and 13-5 at hadal depths in the Puerto Rico</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMPP51E1175B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMPP51E1175B"><span>Cenozoic Circulation History of the North <span class="hlt">Atlantic</span> Ocean From Seismic Stratigraphy of the Newfoundland Ridge Drift Complex</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Boyle, P. R.; Romans, B.; Norris, R. D.; Tucholke, B. E.; Swift, S. A.; Sexton, P. F.</p> <p>2014-12-01</p> <p>In the North <span class="hlt">Atlantic</span> Ocean, contour-following bottom currents have eroded regional unconformities and deposited contourite drifts that exceed two km in thickness and extend for 100s of km. The character of deep-water masses that are conveyed through ocean <span class="hlt">basins</span> by such currents influence global heat transfer and ocean-atmosphere partitioning of CO2. The Newfoundland Ridge Drift Complex lies directly under the modern Deep Western Boundary Current southeast of Newfoundland, close to the site of overturning in the northwest <span class="hlt">Atlantic</span> Ocean and at the intersection of the warm Gulf Stream and cool Labrador surface currents. To the south are regions of the western North <span class="hlt">Atlantic</span> <span class="hlt">basin</span> that are influenced by southern- as well as northern-sourced bottom waters. Here, we document the evolution of North <span class="hlt">Atlantic</span> deep-water circulation by seismic-stratigraphic analysis of the long-lived and areally extensive Newfoundland Ridge Drift Complex. IODP Expedition 342 boreholes provide age control on seismic units, allowing sedimentation patterns to be placed in a temporal framework. We find three major phases of sedimentation: pre-contourite drift (~115-50 Ma), active contourite drift (~50-2.6 Ma), and late-contourite drift (~2.6-0 Ma). Bottom-current-controlled deposition of terrigenous-rich sediment began at ~50 Ma, which correlates to the onset of a long-term global cooling trend. A further change in deep circulation near the Eocene-Oligocene transition (~30 Ma) is indicated by more focused drift sedimentation with greatly increased accumulation rates and stratal architecture dominated by mud waves. At ~2.6 Ma to present the axis of drift accumulation shifted markedly towards shallower water depths, corresponding with the onset of Northern Hemisphere ice sheets. We discuss how these reorganizations of deep circulation correlate with results of other North <span class="hlt">Atlantic</span> seismic stratigraphic studies to the north and south.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JSAES..84..351L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JSAES..84..351L"><span>Imaging exhumed lower continental crust in the distal Jequitinhonha <span class="hlt">basin</span>, Brazil</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Loureiro, A.; Schnürle, P.; Klingelhöfer, F.; Afilhado, A.; Pinheiro, J.; Evain, M.; Gallais, F.; Dias, N. A.; Rabineau, M.; Baltzer, A.; Benabdellouahed, M.; Soares, J.; Fuck, R.; Cupertino, J. A.; Viana, A.; Matias, L.; Moulin, M.; Aslanian, D.; Vinicius Aparecido Gomes de Lima, M.; Morvan, L.; Mazé, J. P.; Pierre, D.; Roudaut-Pitel, M.; Rio, I.; Alves, D.; Barros Junior, P.; Biari, Y.; Corela, C.; Crozon, J.; Duarte, J. L.; Ducatel, C.; Falcão, C.; Fernagu, P.; Le Piver, D.; Mokeddem, Z.; Pelleau, P.; Rigoti, C.; Roest, W.; Roudaut, M.; Salsa Team</p> <p>2018-07-01</p> <p>Twelve combined wide-angle refraction and coincident multi-channel seismic profiles were acquired in the Jequitinhonha-Camamu-Almada, Jacuípe, and Sergipe-Alagoas <span class="hlt">basins</span>, <span class="hlt">NE</span> Brazil, during the SALSA experiment in 2014. Profiles SL11 and SL12 image the Jequitinhonha <span class="hlt">basin</span>, perpendicularly to the coast, with 15 and 11 four-channel ocean-bottom seismometers, respectively. Profile SL10 runs parallel to the coast, crossing profiles SL11 and SL12, imaging the proximal Jequitinhonha and Almada <span class="hlt">basins</span> with 17 ocean-bottom seismometers. Forward modelling, combined with pre-stack depth migration to increase the horizontal resolution of the velocity models, indicates that sediment thickness varies between 3.3 km and 6.2 km in the distal <span class="hlt">basin</span>. Crustal thickness at the western edge of the profiles is of around 20 km, with velocity gradients indicating a continental origin. It decreases to less than 5 km in the distal <span class="hlt">basin</span>, with high seismic velocities and gradients, not compatible with normal oceanic crust nor exhumed upper mantle. Typical oceanic crust is never imaged along these about 200 km-long profiles and we propose that the transitional crust in the Jequitinhonha <span class="hlt">basin</span> is a made of exhumed lower continental crust.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..1610396V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..1610396V"><span>Nd and Pb isotopic Mediterranean overflow water signature in the Gulf of Cadiz over the Mio-Pliocene boundary.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>van der Schee, Marlies; Gutjahr, Marcus; Sierro, Francisco Javier; Flecker, Rachel; Jiménez Espejo, Francisco; Hodell, David; Abel Flores, Jose</p> <p>2014-05-01</p> <p>Marine gateways play a major role in ocean circulation and therefore climate. Currently, it is thought that there was no significant Mediterranean Overflow Water (MOW) in the Gulf of Cadiz during the Messinian Salinity Crisis (MSC) in the Late Miocene. However, a connection has supplied the Mediterranean with enough salt to precipitate the extensive evaporates preserved across the <span class="hlt">basin</span>. After the MSC, the Mediterranean overflow was re-established through the Straits of Gibraltar. Today, MOW follows the continental slope of the Iberian Peninsula at a depth of 500-800 m in the Gulf of Cadiz northwards. In this study, lead and neodymium isotopes are used as water mass tracers for Mio-Pliocene MOW and <span class="hlt">NE</span> <span class="hlt">Atlantic</span> water in the Gulf of Cadiz. Complementary biostratigraphic data, carbon and oxygen isotopes and trace elements are presented alongside to corroborate our findings. Here we present a detailed authigenic Fe-Mn oxyhydroxide-derived Pb and Nd isotope records extracted from ~5.85 - 4.0 million year old bulk sediments recovered in IODP Core U1387C in the Gulf of Cadiz (current water depth 559 m). MOW and <span class="hlt">NE</span> <span class="hlt">Atlantic</span> waters have different Nd and Pb isotopic characteristics allowing for the identification of bottom water mass provenance changes and mixing proportions at the core site. The properties of the water bodies during the given time period are defined by Fe-Mn crust and marine sediment signatures. We also examine the natural variability within a single precession cycle. In order to confirm that the bulk sediment data indeed reliably reflects the primary composition of the bottom water masses, several bulk sediment samples are compared to foraminifera-derived Nd isotopic compositions. Results from the Messinian show a trend from isotope compositions that are more typical for MOW towards compositions more typical for the <span class="hlt">NE</span> <span class="hlt">Atlantic</span>. Subsequently, this trend reverses. After this, around 5.6 Ma an abrupt shift from MOW to more <span class="hlt">NE</span> <span class="hlt">Atlantic</span> characteristics is</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009EGUGA..11.6417J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009EGUGA..11.6417J"><span>Marine magnetic anomalies in the <span class="hlt">NE</span> Indian Ocean: the Wharton and Central Indian <span class="hlt">basins</span> revisited</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jacob, J.; Dyment, J.; Yatheesh, V.; Bhattacharya, G. C.</p> <p>2009-04-01</p> <p>The North-eastern Indian Ocean has recently received a renewed interest. The disastrous earthquakes and tsunamis of Dec. 2004 off Sumatra have triggered a large international effort including several oceanographic cruises. The Ninetyeast Ridge, a long submarine ridge which extends NS on more than 4000 km, has been the focus of a recent cruise aiming to study the interaction of a hotspot with the oceanic lithosphere and spreading centres. Both the study of the seismogenic zone under Sumatra and the Ninetyeast Ridge formation require accurate determination of the age and structure of the oceanic lithosphere in the Wharton and Central Indian <span class="hlt">Basins</span>. First we delineate tectonic elements such as the Sunda Trench, the Ninetyeast Ridge, and the fracture zones of the Wharton and Central Indian <span class="hlt">basins</span> from a recent version of the free-air gravity anomaly deduced from satellite altimetry and available multibeam bathymetric data. We use all available magnetic data to identify magnetic anomalies and depict seafloor spreading isochrons in order to build a tectonic map of the Wharton <span class="hlt">Basin</span>. To do so, we apply the analytic signal method to unambiguously determine the location of the magnetic picks. The new tectonic map shows more refinements than previous ones, as expected from a larger data set. The fossil ridge in the Wharton <span class="hlt">Basin</span> is clearly defined; spreading ceased at anomaly 18 young (38.5 Ma), and, perhaps, as late as anomaly 15 (35 Ma). Symmetric anomalies are observed on both flanks of the fossil ridge up to anomaly 24 (54 Ma), preceded by a slight reorganization of the spreading compartments between anomalies 28 and 25 (64 - 56 Ma) and a more stable phase of spreading between anomalies 34 and 29 (83 - 64 Ma). Earlier, a major change of spreading direction is clearly seen in the bending fracture zones; interpolating in the Cretaceous Quiet Zone between anomaly 34 in the Wharton <span class="hlt">Basin</span> and anomaly M0 off Australia leads to an age of ~100 Ma for this reorganization</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017IJEaS.tmp..234B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017IJEaS.tmp..234B"><span>The evolution of a Late Cretaceous-Cenozoic intraplate <span class="hlt">basin</span> (Duaringa <span class="hlt">Basin</span>), eastern Australia: evidence for the negative inversion of a pre-existing fold-thrust belt</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Babaahmadi, Abbas; Sliwa, Renate; Esterle, Joan; Rosenbaum, Gideon</p> <p>2017-12-01</p> <p>The Duaringa <span class="hlt">Basin</span> in eastern Australia is a Late Cretaceous?-early Cenozoic sedimentary <span class="hlt">basin</span> that developed simultaneously with the opening of the Tasman and Coral Seas. The <span class="hlt">basin</span> occurs on the top of an earlier (Permian-Triassic) fold-thrust belt, but the negative inversion of this fold-thrust belt, and its contribution to the development of the Duaringa <span class="hlt">Basin</span>, are not well understood. Here, we present geophysical datasets, including recently surveyed 2D seismic reflection lines, aeromagnetic and Bouguer gravity data. These data provide new insights into the structural style in the Duaringa <span class="hlt">Basin</span>, showing that the NNW-striking, <span class="hlt">NE</span>-dipping, deep-seated Duaringa Fault is the main boundary fault that controlled sedimentation in the Duaringa <span class="hlt">Basin</span>. The major activity of the Duaringa Fault is observed in the southern part of the <span class="hlt">basin</span>, where it has undergone the highest amount of displacement, resulting in the deepest and oldest depocentre. The results reveal that the Duaringa <span class="hlt">Basin</span> developed in response to the partial negative inversion of the pre-existing Permian-Triassic fold-thrust belt, which has similar orientation to the extensional faults. The Duaringa Fault is the negative inverted part of a single Triassic thrust, known as the Banana Thrust. Furthermore, small syn-depositional normal faults at the base of the <span class="hlt">basin</span> likely developed due to the reactivation of pre-existing foliations, accommodation faults, and joints associated with Permian-Triassic folds. In contrast to equivalent offshore <span class="hlt">basins</span>, the Duaringa <span class="hlt">Basin</span> lacks a complex structural style and thick syn-rift sediments, possibly because of the weakening of extensional stresses away from the developing Tasman Sea.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70015503','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70015503"><span>Petroleum geology of the mid-<span class="hlt">Atlantic</span> continental margin, offshore Virginia</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Bayer, K.C.; Milici, R.C.</p> <p>1989-01-01</p> <p>The Baltimore Canyon Trough, a major sedimentary <span class="hlt">basin</span> on the <span class="hlt">Atlantic</span> continental shelf, contains up to 18 km of Mesozoic and Cenozoic strata. The <span class="hlt">basin</span> has been studied extensively by multichannel common depth point (CDP) seismic reflection profiles and has been tested by drilling for hydrocarbon resources in several places. The Mesozoic and Cenozoic strata contained in the <span class="hlt">basin</span> were deposited in littoral to bathyal depositional settings and contain immature to marginally mature oil-prone and gas-prone kerogen. The more deeply buried strata of Early Mesozoic age are more likely to be thermally mature than are the younger strata with respect to hydrocarbon generation, but contain terrestrially derived coaly organic matter that would be prone to yield gas, rather than oil. An analysis of available CDP seismic reflection data has indicated that there are several potential hydrocarbon plays in the area offshore of Virginia. These include: (1) Lower Mesozoic synrift <span class="hlt">basins</span> that appear similar to those exposed in the Appalachian Piedmont, (2) a stratigraphic updip pinchout of strata of Early Mesozoic age in the offshore region near the coast, (3) a deeply buried paleoshelf edge, where seismic reflectors dip sharply seaward; and (4) a Cretaceous/Jurassic shelf edge beneath the present continental rise. Of these, the synrift <span class="hlt">basins</span> and Cretaceous/Jurassic shelf edge are considered to be the best targets for exploration. ?? 1989.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70043086','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70043086"><span>The Holocene history of Nares Strait: Transition from glacial bay to Arctic-<span class="hlt">Atlantic</span> throughflow</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Jennings, Anne E.; Sheldon, Christina; Cronin, Thomas M.; Francus, Pierre; Stoner, Joseph; Andrews, John</p> <p>2011-01-01</p> <p>Retreat of glacier ice from Nares Strait and other straits in the Canadian Arctic Archipelago after the end of the last Ice Age initiated an important connection between the Arctic and the North <span class="hlt">Atlantic</span> Oceans, allowing development of modern ocean circulation in Baffin Bay and the Labrador Sea. As low-salinity, nutrient-rich Arctic Water began to enter Baffin Bay, it contributed to the Baffin and Labrador currents flowing southward. This enhanced freshwater inflow must have influenced the sea ice regime and likely is responsible for poor calcium carbonate preservation that characterizes the Baffin Island margin today. Sedimentologic and paleoceanographic data from radiocarbon-dated core HLY03-05GC, Hall <span class="hlt">Basin</span>, northern Nares Strait, document the timing and paleoenvironments surrounding the retreat of waning ice sheets from Nares Strait and opening of this connection between the Arctic Ocean and Baffin Bay. Hall <span class="hlt">Basin</span> was deglaciated soon before 10,300 cal BP (calibrated years before present) and records ice-distal sedimentation in a glacial bay facing the Arctic Ocean until about 9,000 cal BP. <span class="hlt">Atlantic</span> Water was present in Hall <span class="hlt">Basin</span> during deglaciation, suggesting that it may have promoted ice retreat. A transitional unit with high ice-rafted debris content records the opening of Nares Strait at approximately 9,000 cal BP. High productivity in Hall <span class="hlt">Basin</span> between 9,000 and 6,000 cal BP reflects reduced sea ice cover and duration as well as throughflow of nutrient-rich Pacific Water. The later Holocene is poorly resolved in the core, but slow sedimentation rates and heavier carbon isotope values support an interpretation of increased sea ice cover and decreased productivity during the Neoglacial period.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.A51L..02D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.A51L..02D"><span>Role of the North <span class="hlt">Atlantic</span> Ocean in Low Frequency Climate Variability</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Danabasoglu, G.; Yeager, S. G.; Kim, W. M.; Castruccio, F. S.</p> <p>2017-12-01</p> <p>The <span class="hlt">Atlantic</span> Ocean is a unique <span class="hlt">basin</span> with its extensive, North - South overturning circulation, referred to as the <span class="hlt">Atlantic</span> meridional overturning circulation (AMOC). AMOC is thought to represent the dynamical memory of the climate system, playing an important role in decadal and longer time scale climate variability as well as prediction of the earth's future climate on these time scales via its large heat and salt transports. This oceanic memory is communicated to the atmosphere primarily through the influence of persistent sea surface temperature (SST) variations. Indeed, many modeling studies suggest that ocean circulation, i.e., AMOC, is largely responsible for the creation of coherent SST variability in the North <span class="hlt">Atlantic</span>, referred to as <span class="hlt">Atlantic</span> Multidecadal Variability (AMV). AMV has been linked to many (multi)decadal climate variations in, e.g., Sahel and Brazilian rainfall, <span class="hlt">Atlantic</span> hurricane activity, and Arctic sea-ice extent. In the absence of long, continuous observations, much of the evidence for the ocean's role in (multi)decadal variability comes from model simulations. Although models tend to agree on the role of the North <span class="hlt">Atlantic</span> Oscillation in creating the density anomalies that proceed the changes in ocean circulation, model fidelity in representing variability characteristics, mechanisms, and air-sea interactions remains a serious concern. In particular, there is increasing evidence that models significantly underestimate low frequency variability in the North <span class="hlt">Atlantic</span> compared to available observations. Such model deficiencies can amplify the relative influence of external or stochastic atmospheric forcing in generating (multi)decadal variability, i.e., AMV, at the expense of ocean dynamics. Here, a succinct overview of the current understanding of the (North) <span class="hlt">Atlantic</span> Ocean's role on the regional and global climate, including some outstanding questions, will be presented. In addition, a few examples of the climate impacts of the AMV via</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015LPICo1856.5054N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015LPICo1856.5054N"><span>"Normal Planetary" <span class="hlt">Ne</span>-Q in Chelyabinsk and Mars</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nyquist, L. E.; Park, J.; Nagao, K.; Haba, M. K.; Mikouchi, T.; Kusakabe, M.; Shih, C.-Y.; Herzog, G. F.</p> <p>2015-07-01</p> <p>Chelyabinsk contains “Q”-noble gases. Martian shergottite Dhofar 378 contains trapped 20<span class="hlt">Ne</span>/22<span class="hlt">Ne</span> = 7.3±0.3, derivable from Q-<span class="hlt">Ne</span> with 20<span class="hlt">Ne</span>/22<span class="hlt">Ne</span> = 10.67 via fractionation by solar wind induced sputtering. Martian juvenile <span class="hlt">Ne</span> is suggested to be Q-<span class="hlt">Ne</span>.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_20 --> <div id="page_21" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="401"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ApWS....7.3767P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ApWS....7.3767P"><span>Morphotectonics of the Jamini River <span class="hlt">basin</span>, Bundelkhand Craton, Central India; using remote sensing and GIS technique</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Prakash, K.; Mohanty, T.; Pati, J. K.; Singh, S.; Chaubey, K.</p> <p>2017-11-01</p> <p>Morphological and morphotectonic analyses have been used to obtain information that influence hydrographic <span class="hlt">basins</span>, predominantly these are modifications of tectonic elements and the quantitative description of landforms. Discrimination of morphotectonic indices of active tectonics of the Jamini river <span class="hlt">basin</span> consists the analyses of asymmetry factor, ruggedness number, <span class="hlt">basin</span> relief, gradient, <span class="hlt">basin</span> elongation ratio, drainage density analysis, and drainage pattern analysis, which have been completed for each drainage <span class="hlt">basin</span> using remote sensing and GIS techniques. The Jamini river is one of the major tributaries of the Betwa river in central India. The Jamini river <span class="hlt">basin</span> is divided into five subwatersheds viz. Jamrar, Onri, Sainam, Shahzad and Baragl subwatershed. The quantitative approach of watershed development of the Jamini river <span class="hlt">basin</span>, and its four sixth (SW1-SW4) and one fifth (SW5) order subwatersheds, was carried out using Survey of India toposheets (parts of 54I, 54K, 54L, 54O, and 54P), Landsat 7 ETM+, ASTER (GDEM) data, and field data. The Jamini river has low bifurcation index which is a positive marker of tectonic imprint on the hydrographic network. The analyses show that the geomorphological progression of the study area was robustly influenced by tectonics. The analysis demonstrates to extensional tectonics system with the following alignments: <span class="hlt">NE</span>-SW, NW-SE, NNE-SSW, ENE-WSW, E-W, and N-S. Three major trends are followed by lower order streams viz. <span class="hlt">NE</span>-SW, NW-SE, and E-W directions which advocate that these tectonic trends were active at least up to the Late Pleistocene. The assessment of morphotectonic indices may be used to evaluate the control of active faults on the hydrographic system. The analysis points out westward tilting of the drainage <span class="hlt">basins</span> with strong asymmetry in some reaches, marked elongation ratio of subwatersheds, and lower order streams having close alignment with lineaments (active faults). The study facilitated to considerate the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013SedG..296...86G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013SedG..296...86G"><span>The beginning of the Buntsandstein cycle (Early-Middle Triassic) in the Catalan Ranges, <span class="hlt">NE</span> Spain: Sedimentary and palaeogeographic implications</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Galán-Abellán, Belén; López-Gómez, José; Barrenechea, José F.; Marzo, Mariano; De la Horra, Raúl; Arche, Alfredo</p> <p>2013-10-01</p> <p>The Early-Middle Triassic siliciclastic deposits of the Catalan Ranges, <span class="hlt">NE</span> Spain, are dominated by aeolian sediments indicating a predominance of arid climate during this time span, in sharp contrast with the coeval fluvial sediments found in the Castilian Branch of the Iberian Ranges, 300 km to the SW. The <span class="hlt">NE</span>-SW-oriented Catalan <span class="hlt">Basin</span> evolved during the Middle-Late Permian as the result of widespread extension in the Iberian plate. This rift <span class="hlt">basin</span> was bounded by the Pyrenees, Ebro and Montalbán-Oropesa highs. The Permian-Early Triassic-age sediments of the Catalan <span class="hlt">Basin</span> were deposited in three isolated subbasins (Montseny, Garraf, Prades), separated by intrabasinal highs, but linked by transversal NW-SE oriented faults. The three subbasins show evidence of diachronic evolution with different subsidence rates and differences in their sedimentary records. The Buntsandstein sedimentary cycle started in the late Early Triassic (Smithian-Spathian) in the central and southern domains (Garraf and Prades), with conglomerates of alluvial fan origin followed by fluvial and aeolian sandstones. Source area of the fluvial sediments was nearby Paleozoic highs to the north and west, in contrast with the far-away source areas of the fluvial sediments in the Iberian Ranges, to the SW. These fluvial systems were interacting with migrating aeolian dune fields located towards the S, which developed in the shadow areas behind the barriers formed by the Paleozoic highs. These highs were separating the subbasins under arid and semi-arid climate conditions. The dominating winds came from the east where the westernmost coast of the Tethys Sea was located, and periods of water run-off and fields of aeolian dunes development alternated. Some of the fluvial systems were probably evaporating as they were mixed into the interdune areas, never reaching the sea. From the end of the Smithian to the Spathian, the Catalan <span class="hlt">Basin</span> and neighbour peri-Tethys <span class="hlt">basins</span> of the present-day southern France</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012PalOc..27.3222P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012PalOc..27.3222P"><span>Impact of restriction of the <span class="hlt">Atlantic</span>-Mediterranean gateway on the Mediterranean Outflow Water and eastern <span class="hlt">Atlantic</span> circulation during the Messinian</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>PéRez-Asensio, J. N.; Aguirre, J.; Schmiedl, G.; Civis, J.</p> <p>2012-09-01</p> <p>Messinian foraminiferal stable oxygen and carbon isotopes of the Montemayor-1 core (Guadalquivir <span class="hlt">Basin</span>, SW Spain) have been investigated. This record is exceptional to study the Mediterranean Outflow Water (MOW) impact on the <span class="hlt">Atlantic</span> meridional overturning circulation (AMOC) and global climate during the Messinian because the core is near the Guadalhorce Corridor, the last Betic gateway to be closed during the early Messinian. Our results allow dating accurately its closure at 6.18 Ma. Constant benthicδ18O values, high difference between benthic and planktonic δ18O, and low sedimentation rates before 6.18 Ma indicate the presence of a two-layer water column, with bottom winnowing due to an enhanced Mediterranean outflow current. The enhanced contribution of dense MOW to the North <span class="hlt">Atlantic</span> Ocean likely fostered the formation of North <span class="hlt">Atlantic</span> Deep Water (NADW). After 6.18 Ma, benthicδ18O values parallel that of the global glacioeustatic curve, the difference between benthic and planktonic δ18O is low, and sedimentation rates considerably increased. This indicates a good vertical mixing of the water column, interruption of the MOW, and a dominant glacioeustatic control on the isotopic signatures. According to the role of MOW in the modern <span class="hlt">Atlantic</span> thermohaline circulation, the reduction of the MOW after the closure of the Guadalhorce Corridor might have resulted in a decreased NADW formation rate between 6.0 and 5.5 Ma weakening the AMOC and promoting northern hemisphere cooling. After the Gibraltar Strait opening, the restoration of the MOW and related salt export from the Mediterranean could have promoted an enhanced NADW formation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1915206P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1915206P"><span>The Minorca <span class="hlt">Basin</span>: a buffer zone between the Valencia and Liguro-Provençal <span class="hlt">Basins</span> (NW Mediterranean Sea)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pellen, Romain; Aslanian, Daniel; Rabineau, Marina; Leroux, Estelle; Gorini, Christian; Silenziario, Carmine; Blanpied, Christian; Rubino, Jean-Loup</p> <p>2017-04-01</p> <p> <span class="hlt">NE</span>-SW Neogene blocks rotation proposed in earlier studies are therefore questioned (Pellen et al., 2016). A better kinematic understanding of the NW Mediterranean area is possible through the study of the South Balearic margin and Algerian <span class="hlt">basins</span>. Pellen, R., Aslanian, D., Rabineau, M., Leroux, E., Gorini, C., Silenzario, C., Blanpied, C., Rubino J-L., 2016. The Minorca <span class="hlt">Basin</span>: a buffer zone between Valencia and Provençal <span class="hlt">Basins</span>, Terra Nova. doi: 10.1111/ter.12215</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/15616560','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/15616560"><span>Break-up of the <span class="hlt">Atlantic</span> deep western boundary current into eddies at 8 degrees S.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Dengler, M; Schott, F A; Eden, C; Brandt, P; Fischer, J; Zantopp, R J</p> <p>2004-12-23</p> <p>The existence in the ocean of deep western boundary currents, which connect the high-latitude regions where deep water is formed with upwelling regions as part of the global ocean circulation, was postulated more than 40 years ago. These ocean currents have been found adjacent to the continental slopes of all ocean <span class="hlt">basins</span>, and have core depths between 1,500 and 4,000 m. In the <span class="hlt">Atlantic</span> Ocean, the deep western boundary current is estimated to carry (10-40) x 10(6) m3 s(-1) of water, transporting North <span class="hlt">Atlantic</span> Deep Water--from the overflow regions between Greenland and Scotland and from the Labrador Sea--into the South <span class="hlt">Atlantic</span> and the Antarctic circumpolar current. Here we present direct velocity and water mass observations obtained in the period 2000 to 2003, as well as results from a numerical ocean circulation model, showing that the <span class="hlt">Atlantic</span> deep western boundary current breaks up at 8 degrees S. Southward of this latitude, the transport of North <span class="hlt">Atlantic</span> Deep Water into the South <span class="hlt">Atlantic</span> Ocean is accomplished by migrating eddies, rather than by a continuous flow. Our model simulation indicates that the deep western boundary current breaks up into eddies at the present intensity of meridional overturning circulation. For weaker overturning, continuation as a stable, laminar boundary flow seems possible.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/FR-2010-06-02/pdf/2010-13204.pdf','FEDREG'); return false;" href="https://www.gpo.gov/fdsys/pkg/FR-2010-06-02/pdf/2010-13204.pdf"><span>75 FR 30730 - <span class="hlt">Atlantic</span> Highly Migratory Species; <span class="hlt">Atlantic</span> Bluefin Tuna Fisheries</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collection.action?collectionCode=FR">Federal Register 2010, 2011, 2012, 2013, 2014</a></p> <p></p> <p>2010-06-02</p> <p>...-XW54 <span class="hlt">Atlantic</span> Highly Migratory Species; <span class="hlt">Atlantic</span> Bluefin Tuna Fisheries AGENCY: National Marine... <span class="hlt">Atlantic</span> tunas General category daily <span class="hlt">Atlantic</span> bluefin tuna (BFT) retention limit should be adjusted for... criteria regarding inseason adjustments. This action applies to <span class="hlt">Atlantic</span> tunas General category permitted...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29550607','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29550607"><span>Plastic pollution in islands of the <span class="hlt">Atlantic</span> Ocean.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Monteiro, Raqueline C P; Ivar do Sul, Juliana A; Costa, Monica F</p> <p>2018-07-01</p> <p>Marine plastic pollution is present in all oceans, including remote oceanic islands. Despite the increasing number of articles on plastic pollution in the last years, there is still a lack of studies in islands, that are biodiversity hotspots when compared to the surrounding ocean, and even other recognized highly biodiverse marine environments. Articles published in the peer reviewed literature (N = 20) were analysed according to the presence of macro (>5 mm) and microplastics (<5 mm) on beaches and the marine habitats immediately adjacent to 31 islands of the <span class="hlt">Atlantic</span> Ocean and Caribbean Sea. The first articles date from the 1980s, but most were published in the 2000s. Articles on macroplastics were predominant in this review (N = 12). Beaches were the most studied environment, possibly due to easy access. The main focus of most articles was the spatial distribution of plastics associated with variables such as position of the beach in relation to wind and currents. Very few studies have analysed plastics colonization by organisms or the identification of persistent organic pollutants (POPs). Islands of the North/South <span class="hlt">Atlantic</span> and Caribbean Sea were influenced by different sources of macroplastics, being marine-based sources (i.e., fishing activities) predominant in the <span class="hlt">Atlantic</span> Ocean <span class="hlt">basin</span>. On the other hand, in the Caribbean Sea, land-based sources were more common. Copyright © 2018 Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25081159','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25081159"><span>Two new species of Aulospongus Norman, 1878 with a key to the <span class="hlt">Atlantic</span> species (Poecilosclerida; Demospongiae; Porifera).</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Cavalcanti, Thaynã; Santos, George Garcia; Pinheiro, Ulisses</p> <p>2014-07-03</p> <p>We describe two new species: Aulospongus trirhabdostylus sp. nov. and Aulospongus mandela sp. nov. from Potiguar <span class="hlt">Basin</span> (Rio Grande do Norte State, Northeastern Brazil). Both species were compared with their congeners and an identification key for the <span class="hlt">Atlantic</span> species of Aulospongus is provided. The genus Aulospongus now contains 16 species.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014ERL.....9l4007C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014ERL.....9l4007C"><span>The extreme 2014 flood in south-western Amazon <span class="hlt">basin</span>: the role of tropical-subtropical South <span class="hlt">Atlantic</span> SST gradient</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Carlo Espinoza, Jhan; Marengo, José Antonio; Ronchail, Josyane; Molina Carpio, Jorge; Noriega Flores, Luís; Loup Guyot, Jean</p> <p>2014-12-01</p> <p>Unprecedented wet conditions are reported in the 2014 summer (December-March) in South-western Amazon, with rainfall about 100% above normal. Discharge in the Madeira River (the main southern Amazon tributary) has been 74% higher than normal (58 000 m3 s-1) at Porto Velho and 380% (25 000 m3 s-1) at Rurrenabaque, at the exit of the Andes in summer, while levels of the Rio Negro at Manaus were 29.47 m in June 2014, corresponding to the fifth highest record during the 113 years record of the Rio Negro. While previous floods in Amazonia have been related to La Niña and/or warmer than normal tropical South <span class="hlt">Atlantic</span>, the 2014 rainfall and flood anomalies are associated with warm condition in the western Pacific-Indian Ocean and with an exceptionally warm Subtropical South <span class="hlt">Atlantic</span>. Our results suggest that the tropical and subtropical South <span class="hlt">Atlantic</span> SST gradient is a main driver for moisture transport from the <span class="hlt">Atlantic</span> toward south-western Amazon, and this became exceptionally intense during summer of 2014.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1163146','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1163146"><span>Sterile Neutrino Searches in MiniBoo<span class="hlt">NE</span> and MicroBoo<span class="hlt">NE</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Ignarra, Christina M.</p> <p></p> <p>Tension among recent short baseline neutrino experiments has pointed toward the possible need for the addition of one or more sterile (non-interacting) neutrino states into the existing neutrino oscillation framework. This thesis fi rst presents the motivation for sterile neutrino models by describing the short-baseline anomalies that can be addressed with them. This is followed by a discussion of the phenomenology of these models. The MiniBoo<span class="hlt">NE</span> experiment and results are then described in detail, particularly the most recent antineutrino analysis. This will be followed by a discussion of global fits to world data, including the anomalous data sets. Lastly, futuremore » experiments will be addressed, especially focusing on the MicroBoo<span class="hlt">NE</span> experiment and light collection studies. In particular, understanding the degradation source of TPB, designing the TPB-coated plates for MicroBoo<span class="hlt">NE</span> and developing lightguide collection systems will be discussed. We find an excess of events in the MiniBoo<span class="hlt">NE</span> antineutrino mode results consistent with the LSND anomaly, but one that has a di fferent energy dependence than the low-energy excess reported in neutrino mode. This disagreement creates tension within global fi ts which include up to three sterile neutrinos. The low-energy excess will be addressed by the MicroBoo<span class="hlt">NE</span> experiment, which is expected to start taking data in early 2015. Tension among existing experiments calls for additional, more decisive future experiments.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010E%26PSL.297..355L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010E%26PSL.297..355L"><span>An alternative early opening scenario for the Central <span class="hlt">Atlantic</span> Ocean</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Labails, Cinthia; Olivet, Jean-Louis; Aslanian, Daniel; Roest, Walter R.</p> <p>2010-09-01</p> <p>The opening of the Central <span class="hlt">Atlantic</span> Ocean <span class="hlt">basin</span> that separated North America from northwest Africa is well documented and assumed to have started during the Late Jurassic. However, the early evolution and the initial breakup history of Pangaea are still debated: most of the existing models are based on one or multiple ridge jumps at the Middle Jurassic leaving the oldest crust on the American side, between the East Coast Magnetic Anomaly (ECMA) and the Blake Spur Magnetic Anomaly (BSMA). According to these hypotheses, the BSMA represents the limit of the initial <span class="hlt">basin</span> and the footprint subsequent to the ridge jump. Consequently, the evolution of the northwest African margin is widely different from the northeast American margin. However, this setting is in contradiction with the existing observations. In this paper, we propose an alternative scenario for the continental breakup and the Mesozoic spreading history of the Central <span class="hlt">Atlantic</span> Ocean. The new model is based on an analysis of geophysical data (including new seismic lines, an interpretation of the newly compiled magnetic data, and satellite derived gravimetry) and recently published results which demonstrate that the opening of the Central <span class="hlt">Atlantic</span> Ocean started already during the Late Sinemurian (190 Ma), based on a new identification of the African conjugate to the ECMA and on the extent of salt provinces off Morocco and Nova Scotia. The identification of an African conjugate magnetic anomaly to BSMA, the African Blake Spur Magnetic Anomaly (ABSMA), together with the significant change in basement topography, are in good agreement with that initial reconstruction. The early opening history for the Central <span class="hlt">Atlantic</span> Ocean is described in four distinct phases. During the first 20 Myr after the initial breakup (190-170 Ma, from Late Sinemurian to early Bajocian), oceanic accretion was extremely slow (˜ 0.8 cm/y). At the time of Blake Spur (170 Ma, early Bajocian), a drastic change occurred both in the relative</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFMPP23A1823W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFMPP23A1823W"><span>A Tropical View of <span class="hlt">Atlantic</span> Multidecadal SST Variability over the Last Two Millennia</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wurtzel, J. B.; Black, D. E.; Thunell, R.; Peterson, L. C.; Tappa, E. J.; Rahman, S.</p> <p>2011-12-01</p> <p>Instrumental and proxy-reconstructions show the existence of a 60-80 year periodicity in <span class="hlt">Atlantic</span> sea surface temperature (SST), known as the <span class="hlt">Atlantic</span> Multidecadal Oscillation (AMO). The AMO is correlated with circum-tropical <span class="hlt">Atlantic</span> climate phenomena such as Sahel and Nordeste rainfall, as well as <span class="hlt">Atlantic</span> hurricane patterns. Though it has been suggested that the AMO is controlled by thermohaline circulation, much debate exists as to whether the SST fluctuations are a result of anthropogenic forcing or natural climate variability. Our ability to address this issue has been limited by instrumental SST records that rarely extend back more than 50-100 years and proxy reconstructions that are largely terrestrial-based. Here we present a high-resolution marine sediment-derived reconstruction of seasonal tropical <span class="hlt">Atlantic</span> SSTs from the Cariaco <span class="hlt">Basin</span> spanning the past two millennia that is correlated with instrumental SSTs and the AMO for the period of overlap. The full record demonstrates that seasonality is largely controlled by variations in winter/spring SST. Wavelet analysis of the proxy data suggest that variability in the 60-80 year band evolved 250 years ago, while 40-60 year periodicities dominate earlier parts of the record. At least over the last millennia, multidecadal- and centennial- scale SST variability in the tropical <span class="hlt">Atlantic</span> appears related to <span class="hlt">Atlantic</span> meridional overturning circulation (AMOC) fluctuations and its associated northward heat transport that in turn may be driven by solar variability. An inverse correlation between the tropical proxy annual average SST record and Δ14C indicates that the tropics experienced positive SST anomalies during times of reduced solar activity, possibly as a result of decreased AMOC strength (Figure 1).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26975331','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26975331"><span>The absence of an <span class="hlt">Atlantic</span> imprint on the multidecadal variability of wintertime European temperature.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yamamoto, Ayako; Palter, Jaime B</p> <p>2016-03-15</p> <p>Northern Hemisphere climate responds sensitively to multidecadal variability in North <span class="hlt">Atlantic</span> sea surface temperature (SST). It is therefore surprising that an imprint of such variability is conspicuously absent in wintertime western European temperature, despite that Europe's climate is strongly influenced by its neighbouring ocean, where multidecadal variability in <span class="hlt">basin</span>-average SST persists in all seasons. Here we trace the cause of this missing imprint to a dynamic anomaly of the atmospheric circulation that masks its thermodynamic response to SST anomalies. Specifically, differences in the pathways Lagrangian particles take to Europe during anomalous SST winters suppress the expected fluctuations in air-sea heat exchange accumulated along those trajectories. Because decadal variability in North <span class="hlt">Atlantic</span>-average SST may be driven partly by the <span class="hlt">Atlantic</span> Meridional Overturning Circulation (AMOC), the atmosphere's dynamical adjustment to this mode of variability may have important implications for the European wintertime temperature response to a projected twenty-first century AMOC decline.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4796317','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4796317"><span>The absence of an <span class="hlt">Atlantic</span> imprint on the multidecadal variability of wintertime European temperature</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Yamamoto, Ayako; Palter, Jaime B.</p> <p>2016-01-01</p> <p>Northern Hemisphere climate responds sensitively to multidecadal variability in North <span class="hlt">Atlantic</span> sea surface temperature (SST). It is therefore surprising that an imprint of such variability is conspicuously absent in wintertime western European temperature, despite that Europe's climate is strongly influenced by its neighbouring ocean, where multidecadal variability in <span class="hlt">basin</span>-average SST persists in all seasons. Here we trace the cause of this missing imprint to a dynamic anomaly of the atmospheric circulation that masks its thermodynamic response to SST anomalies. Specifically, differences in the pathways Lagrangian particles take to Europe during anomalous SST winters suppress the expected fluctuations in air–sea heat exchange accumulated along those trajectories. Because decadal variability in North <span class="hlt">Atlantic</span>-average SST may be driven partly by the <span class="hlt">Atlantic</span> Meridional Overturning Circulation (AMOC), the atmosphere's dynamical adjustment to this mode of variability may have important implications for the European wintertime temperature response to a projected twenty-first century AMOC decline. PMID:26975331</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMPP21A2272M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMPP21A2272M"><span>Western Tropical <span class="hlt">Atlantic</span> Hydrologic change during the last 130,000 years</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>McGrath, S. M.; Lavoie, N.; Oppo, D.</p> <p>2016-12-01</p> <p>Abrupt climate changes in the North <span class="hlt">Atlantic</span> during the last 130,000 years are associated with hydrologic changes in the western tropical <span class="hlt">Atlantic</span> Ocean. Previous studies on marine sediment cores from between 4°S and the equator have documented pulses of terrigenous sediment recording increased precipitation and weathering on the Brazilian Nordeste associated with Heinrich events. We worked on cores KNR197-3-11CDH (7°40'N, 53°49'W, water depth 550 m) and KNR 197-3-46CDH (7°50.1621'N, 53°39.8051'W, 947m water depth) located farther north along the South American continental slope, where sediment derives from the Amazon river <span class="hlt">basin</span> and is transported by the North Brazilian Current. Preliminary stratigraphy based on magnetic susceptibility shows a possible correlation with the Greenland ice core δ18O stratigraphy. We use sediment elemental composition, determined by x-ray fluorescence (XRF) to evaluate variations in terrigenous sediment runoff and δ18O of the planktonic foraminifers Globierinoides ruber to evaluate variations in western tropical North <span class="hlt">Atlantic</span> surface hydrography across North <span class="hlt">Atlantic</span> abrupt climate events. Similarities and differences among our records and the records from the more southerly cores will help understand the mechanisms of hydrologic changes in the regions on abrupt climate time scales.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.9591B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.9591B"><span>Multiphased extension along continental margins: a case study of the Porcupine <span class="hlt">Basin</span>, offshore Ireland</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bulois, Cédric; Shannon, Patrick, M.; Manuel, Pubellier; Nicolas, Chamot-Rooke; Louise, Watremez; Jacques, Deverchère</p> <p>2017-04-01</p> <p>Mesozoic faulting has been recognised in several Irish sedimentary <span class="hlt">basins</span> as part of the northward propagation of the <span class="hlt">Atlantic</span> rift system. However, the contribution of older structural elements remains poorly constrained. The present study documents the succession of extensional phases in the northern part of the Porcupine <span class="hlt">Basin</span> sensu largo, offshore west of Ireland, in which structural inheritance and fault reactivation is commonly observed. The correlation of 2D and 3D seismic lines with exploration wells enables the precise definition of four overprinted extensional systems that link to specific tectonic stages identified along the Irish margin. The Porcupine <span class="hlt">Basin</span> opened through a thickened continental crust that evolved during the Palaeozoic with the Caledonian and Variscan orogenic cycles. Extension initiated during the Carboniferous by reactivation of old structures, resulting in the migration of depocentres bounded by E-W, <span class="hlt">NE</span>-SW and N-S structural trends. Subsequent episodic rifting occurred during several discrete events. The first rift episode, of Late Triassic to Early Jurassic age, is restricted to the North Porcupine <span class="hlt">Basin</span> and most likely reactivated E-W structures of Caledonian age. Synrift sediments were generally deposited in a littoral setting that progressively deepened through time. The second episode, much more pronounced, occurred during the Upper Jurassic to lowermost Cretaceous (Neocomian). It resulted in shallow to deep marine deposition controlled by structural directions recognised in Caledonian and Variscan terranes. A third rift phase, evidenced by thick clastic deposition, locally occurred during the Aptian and finally died out with the opening of the Bay of Biscay located to the south of the region. A series of extensional megacycles are recognised from seismic unconformities and faulting geometries. Initial extension strongly followed the structural architecture of the continental crust (i.e. ancient folds, thrusts or orogenic fronts</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1996MNRAS.279..859J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1996MNRAS.279..859J"><span>Continuous opacity from <span class="hlt">Ne</span>^-</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>John, T. L.</p> <p>1996-04-01</p> <p>Free-free absorption coefficients of the negative neon ion are calculated by the phase-shift approximation based on multiconfiguration Hartree-Fock continuum wave functions. These wave functions accurately account for electron-neon correlation and polarization, and yield scattering cross-sections in excellent agreement with the latest experimental values. The coefficients are expected to give the best current estimates of <span class="hlt">Ne</span>^- continuous absorption. We find that <span class="hlt">Ne</span>^- makes only a small contribution (less than 0.3 per cent) to stellar opacities, including hydrogen-deficient stars with enhanced <span class="hlt">Ne</span> abundances.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.T51C0488B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.T51C0488B"><span>The Sedimentary Architecture of the Hatton <span class="hlt">Basin</span> from New 2D Seismic Reflection and Gravity Data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bérdi, L.; Prada, M.; O'Reilly, B.; Haughton, P.; Shannon, P.; Martínez-Loriente, S.</p> <p>2017-12-01</p> <p>The Hatton <span class="hlt">Basin</span> is located at the western European <span class="hlt">Atlantic</span> Margin, approximately 600 km west of Scotland and Ireland. It is bounded by the Rockall Bank to the east and by the Hatton High to the west. Little is known about its structure and evolution within the context of the North <span class="hlt">Atlantic</span> opening. Here we present a preliminary interpretation of the large-scale sedimentary structure of the Hatton <span class="hlt">basin</span> from new 2D regional long-streamer seismic reflection data and DSDP information. Gravity data and previous knowledge on the crustal structure of the <span class="hlt">basin</span> are used to investigate its formation processes.First interpretations of the seismic data suggest the presence of three megasequences referred to as Ha (Early Pliocene to Holocene), Hb (Late Eocene to Late Miocene) and Hc (Paleocene to middle Eocene), which are bounded by regional unconformities C10 (intra-Early Pliocene), C30 (intra-Late Eocene) and C40 (base Cenozoic) respectively. The C20 (intra-Early Miocene) surface is absent in the <span class="hlt">basin</span> but is locally identified to the south of the study area. The mapped regional reflectors are recognized throughout the European North <span class="hlt">Atlantic</span>.Below the Cenozoic succession, the presence of Mesozoic and/or older rocks in the <span class="hlt">basin</span> is proposed based on the seismic character of the reflectors and the apparent rotated fault blocks. In the lowest Cenozoic megasequence (Hc), a prograding sedimentary wedge system was identified at the <span class="hlt">basin</span> margins that implies a relative sea level fall during this period. In Late Paleocene‒Early Eocene times, the <span class="hlt">basin</span> was affected by extensive magmatism that resulted in the emplacement of volcanic intrusives and extrusives of basaltic origin. The deposition of megasequence Hb was controlled by strong bottom current activity as a consequence of rapid subsidence and deep marine conditions. The transition from sequence Hb to Ha is marked by the C10 unconformity, which records the late Cenozoic uplift and erosion of Ireland and Britain</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..1713892A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..1713892A"><span>Overview of Petroleum Settings in Deep Waters of the Brazilian South <span class="hlt">Atlantic</span> Margin</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Anjos, Sylvia; Penteado, Henrique; Oliveira, Carlos M. M.</p> <p>2015-04-01</p> <p>The objective of this work is to present an overall view of the tectonic and stratigraphic evolution of the western South <span class="hlt">Atlantic</span> with focus on the Brazilian marginal <span class="hlt">basins</span>. It includes the structural evolution, stratigraphic sequences, depositional environments and petroleum systems model along the Brazilian marginal <span class="hlt">basins</span>. In addition, a description of the main petroleum provinces and selected plays including the pre-salt carbonates and post-salt turbidite reservoirs is presented. Source-rock ages and types, trap styles, main reservoir characteristics, petroleum compositions, and recent exploration results are discussed. Finally, an outlook and general assessment of the impact of the large pre-salt discoveries on the present-day and future production curves are given.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009JPhCS.194i2004B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009JPhCS.194i2004B"><span>Alignment relaxation of <span class="hlt">Ne</span>*(2pi [J = 1]) atoms in He-<span class="hlt">Ne</span>* glow discharges</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bahrim, Cristian; Khadilkar, Vaibhav; Matsukuma, Hiraku; Hasuo, Masahiro</p> <p>2009-11-01</p> <p>Alignment relaxation of the <span class="hlt">Ne</span>*(2p5 3p; 2pi [J = 1]) atoms (where i = 2, 5, 7 or 10) induced by collisions with He atoms in glow discharges at 77 K < T < 1,000 K are reported. Close-coupling many-channel quantum calculations using a model potential for the <span class="hlt">Ne</span>*(2p5 3p) - He system are compared with measurements of the alignment relaxation using the LIFS technique and the Hanle effect. The addition of the dipole polarization potential of the <span class="hlt">Ne</span>*(2pi [J = 1]) atoms to the spin-orbit coupling and the electrostatic interaction between <span class="hlt">Ne</span>* and He atoms leads to good agreement between theory and experiment.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_21 --> <div id="page_22" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="421"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70174971','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70174971"><span>Comparative diets of subyearling <span class="hlt">Atlantic</span> salmon and subyearling coho salmon in Lake Ontario tributaries</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Johnson, James H.; Ringler, Neil H.</p> <p>2016-01-01</p> <p>Restoration of <span class="hlt">Atlantic</span> salmon (Salmo salar) in Lake Ontario could potentially be negatively affected by the presence of non-native salmonids that are naturalized in the <span class="hlt">basin</span>. Coho salmon (Oncorhynchus kisutch) have been spawning successfully in Lake Ontario tributaries for over 40 years and their juveniles will reside in streams with juvenile <span class="hlt">Atlantic</span> salmon for one year. This study sought to examine interspecific diet associations between these species, and to compare diets to the composition of the benthos and drift in three Lake Ontario tributaries. Aquatic insects, mainly ephemeropterans and chironomids were the major prey consumed by subyearling <span class="hlt">Atlantic</span> salmon whereas terrestrial invertebrates made up only 3.7% of the diet. Ephemeropterans and chironomids were the primary aquatic taxa consumed by subyearling coho salmon but, as a group, terrestrial invertebrates (41.8%) were the major prey. In sympatry, <span class="hlt">Atlantic</span> salmon fed more actively from the benthos whereas the diet of coho salmon was more similar to the drift. The different feeding pattern of each species resulted in low interspecific diet similarity. There is likely little competition between these species for food in Lake Ontario tributaries as juveniles.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1998QSRv...17..243D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1998QSRv...17..243D"><span>Glacimarine Sedimentary Processes and Facies on the Polar North <span class="hlt">Atlantic</span> Margins</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dowdeswell, J. A.; Elverhfi, A.; Spielhagen, R.</p> <p></p> <p>Major contrasts in the glaciological, oceanic and atmospheric parameters affecting the Polar North <span class="hlt">Atlantic</span>, both over space between its eastern and western margins, and through time from full glacial to interglacial conditions, have lead to the deposition of a wide variety of sedimentary facies in these ice-influenced seas. The dynamics of the glaciers and ice sheets on the hinterlands surrounding the Polar North <span class="hlt">Atlantic</span> have exterted a major influence on the processes, rates and patterns of sedimentation on the continental margins of the Norwegian and Greenland seas over the Late Cenozoic. The western margin is influenced by the cold East Greenland Current and the Svalbard margin by the northernmost extent of the warm North <span class="hlt">Atlantic</span> Drift and the passage of relatively warm cyclonic air masses. In the fjords of Spitsbergen and the northwestern Barents Sea, glacial meltwater is dominant in delivering sediments. In the fjords of East Greenland the large numbers of icebergs produced from fast-flowing outlets of the Greenland Ice Sheet play a more significant role in sedimentation. During full glacials, sediments are delivered to the shelf break from fast-flowing ice streams, which drain huge <span class="hlt">basins</span> within the parent ice sheet. Large prograding fans located on the continental slope offshore of these ice streams are made up of stacked debris flows. Large-scale mass failures, turbidity currents, and gas-escape structures also rework debris in continental slope and shelf settings. Even during interglacials, both the margins and the deep ocean <span class="hlt">basins</span> beyond them retain a glacimarine overprint derived from debris in far-travelled icebergs and sea ice. Under full glacial conditions, the glacier influence is correspondingly stronger, and this is reflected in the glacial and glacimarine facies deposited at these times.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70046748','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70046748"><span>Attributes for MRB_E2RF1 Catchments in Selected Major River <span class="hlt">Basins</span>: Population Density, 2000</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Wieczorek, Michael; LaMotte, Andrew E.</p> <p>2010-01-01</p> <p>This data set represents the average population density, in number of people per square kilometer multiplied by 10 for the year 2000, compiled for every MRB_E2RF1 catchment of selected Major River <span class="hlt">Basins</span> (MRBs, Crawford and others, 2006). The source data set is the 2000 Population Density by Block Group for the Conterminous United States (Hitt, 2003). The MRB_E2RF1 catchments are based on a modified version of the U.S. Environmental Protection Agency's (USEPA) RF1_2 and include enhancements to support national and regional-scale surface-water quality modeling (Nolan and others, 2002; Brakebill and others, 2011). Data were compiled for every MRB_E2RF1 catchment for the conterminous United States covering covering New England and Mid-<span class="hlt">Atlantic</span> (MRB1), South <span class="hlt">Atlantic</span>-Gulf and Tennessee (MRB2), the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy (MRB3), the Missouri (MRB4), the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf (MRB5), the Rio Grande, Colorado, and the Great <span class="hlt">basin</span> (MRB6), the Pacific Northwest (MRB7) river <span class="hlt">basins</span>, and California (MRB8).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1818338J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1818338J"><span>Episodes of subsidence and uplift of the conjugate margins of Greenland and Norway after opening of the <span class="hlt">NE</span> <span class="hlt">Atlantic</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Japsen, Peter; Green, Paul F.; Bonow, Johan M.; Chalmers, James A.</p> <p>2016-04-01</p> <p>We have undertaken a regional study of the thermo-tectonic development of East Greenland (68-75°N; Bonow et al. 2014; Japsen et al. 2014) and of southern Norway (58-64°N) based on integration of apatite fission-track analysis (AFTA), stratigraphic landscape analysis and the geological record onshore and offshore. Volcanic and sedimentary rocks accumulated on the subsiding, East Greenland margin during and following breakup and then began to be exhumed during late Eocene uplift that preceded a major, early Oligocene plate reorganization in the <span class="hlt">NE</span> <span class="hlt">Atlantic</span>. The Norwegian margin also experienced Eocene subsidence and burial; there are hemipelagic, deep-marine sediments of Eocene age along the coast of southern Norway. End-Eocene uplift of the NW European margin led to the formation of a major unconformity along the entire margin and to progradation of clastic wedges from Norway towards the south. Our AFTA data from East Greenland and southern Norway reveal a long history of Mesozoic burial and exhumation across the region, with a number of broadly synchronous events being recorded on both margins. AFTA data from East Greenland show clear evidence for uplift at the Eocene-Oligocene transition whereas the data from Norway do not resolve any effects of exhumation related to this event. AFTA data from the East Greenland margin show evidence of two Neogene events of uplift and incision of the in the late Miocene and Pliocene whereas results from southern Norway define Neogene uplift and erosion which began in the early Miocene. A Pliocene uplift phase in southern Norway is evident from the stratigraphic landscape analysis and from the sedimentary sequences offshore. In East Greenland, a late Eocene phase of uplift led to formation of a regional erosion surface near sea level (the Upper Planation Surface, UPS). Uplift of the UPS in the late Miocene led to formation of the Lower Planation Surface (LPS) by incision below the uplifted UPS, and a Pliocene phase led to</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3810891','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3810891"><span>Threats and knowledge gaps for ecosystem services provided by kelp forests: a northeast <span class="hlt">Atlantic</span> perspective</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Smale, Dan A; Burrows, Michael T; Moore, Pippa; O'Connor, Nessa; Hawkins, Stephen J</p> <p>2013-01-01</p> <p>Kelp forests along temperate and polar coastlines represent some of most diverse and productive habitats on the Earth. Here, we synthesize information from >60 years of research on the structure and functioning of kelp forest habitats in European waters, with particular emphasis on the coasts of UK and Ireland, which represents an important biogeographic transition zone that is subjected to multiple threats and stressors. We collated existing data on kelp distribution and abundance and reanalyzed these data to describe the structure of kelp forests along a spatial gradient spanning more than 10° of latitude. We then examined ecological goods and services provided by kelp forests, including elevated secondary production, nutrient cycling, energy capture and flow, coastal defense, direct applications, and biodiversity repositories, before discussing current and future threats posed to kelp forests and identifying key knowledge gaps. Recent evidence unequivocally demonstrates that the structure of kelp forests in the <span class="hlt">NE</span> <span class="hlt">Atlantic</span> is changing in response to climate- and non-climate-related stressors, which will have major implications for the structure and functioning of coastal ecosystems. However, kelp-dominated habitats along much of the <span class="hlt">NE</span> <span class="hlt">Atlantic</span> coastline have been chronically understudied over recent decades in comparison with other regions such as Australasia and North America. The paucity of field-based research currently impedes our ability to conserve and manage these important ecosystems. Targeted observational and experimental research conducted over large spatial and temporal scales is urgently needed to address these knowledge gaps. PMID:24198956</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24198956','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24198956"><span>Threats and knowledge gaps for ecosystem services provided by kelp forests: a northeast <span class="hlt">Atlantic</span> perspective.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Smale, Dan A; Burrows, Michael T; Moore, Pippa; O'Connor, Nessa; Hawkins, Stephen J</p> <p>2013-10-01</p> <p>Kelp forests along temperate and polar coastlines represent some of most diverse and productive habitats on the Earth. Here, we synthesize information from >60 years of research on the structure and functioning of kelp forest habitats in European waters, with particular emphasis on the coasts of UK and Ireland, which represents an important biogeographic transition zone that is subjected to multiple threats and stressors. We collated existing data on kelp distribution and abundance and reanalyzed these data to describe the structure of kelp forests along a spatial gradient spanning more than 10° of latitude. We then examined ecological goods and services provided by kelp forests, including elevated secondary production, nutrient cycling, energy capture and flow, coastal defense, direct applications, and biodiversity repositories, before discussing current and future threats posed to kelp forests and identifying key knowledge gaps. Recent evidence unequivocally demonstrates that the structure of kelp forests in the <span class="hlt">NE</span> <span class="hlt">Atlantic</span> is changing in response to climate- and non-climate-related stressors, which will have major implications for the structure and functioning of coastal ecosystems. However, kelp-dominated habitats along much of the <span class="hlt">NE</span> <span class="hlt">Atlantic</span> coastline have been chronically understudied over recent decades in comparison with other regions such as Australasia and North America. The paucity of field-based research currently impedes our ability to conserve and manage these important ecosystems. Targeted observational and experimental research conducted over large spatial and temporal scales is urgently needed to address these knowledge gaps.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/wri/2000/4112/report.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/wri/2000/4112/report.pdf"><span>Hydrologic aspects of the 1998-99 drought in the Delaware River <span class="hlt">basin</span></span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Paulachok, Gary N.; Krejmas, Bruce E.; Soden, Heidi L.</p> <p>2000-01-01</p> <p>A notable drought in the Delaware River <span class="hlt">Basin</span> during late 1998 and most of 1999 had a major effect on surface and subsurface components of the hydrologic system. The drought conditions resulted from anomalous patterns in the general atmospheric circulation that diverted Gulf and subtropical <span class="hlt">Atlantic</span> moisture away from the <span class="hlt">basin</span>. From September 1998 to August 1999, the accumulated precipitation deficiency was greater than 12 inches in the part of the <span class="hlt">basin</span> above Trenton, N.J. Flows in some streams, mainly in the middle and lower parts of the <span class="hlt">basin</span>, decreased to levels near or less than those measured during the drought of the 1960's, the most severe drought of record in the <span class="hlt">basin</span>. On several dates in August 1999, combined storage in three New York City water-supply reservoirs in the upper Delaware River <span class="hlt">Basin</span> decreased by more than 2 billion gallons per day. The drought had a pronounced effect on ground-water levels, as the combination of below-normal recharge and elevated rates of evapotranspiration produced abnormal water-level declines and record low water levels in much of the <span class="hlt">basin</span>. The drought was broken in mid-September 1999 when the remnants of Tropical Storm Floyd delivered drenching rains throughout the <span class="hlt">basin</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70032069','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70032069"><span>Summer temperature variation and implications for juvenile <span class="hlt">Atlantic</span> salmon</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Mather, M. E.; Parrish, D.L.; Campbell, C.A.; McMenemy, J.R.; Smith, Joseph M.</p> <p>2008-01-01</p> <p>Temperature is important to fish in determining their geographic distribution. For cool- and cold-water fish, thermal regimes are especially critical at the southern end of a species' range. Although temperature is an easy variable to measure, biological interpretation is difficult. Thus, how to determine what temperatures are meaningful to fish in the field is a challenge. Herein, we used the Connecticut River as a model system and <span class="hlt">Atlantic</span> salmon (Salmo salar) as a model species with which to assess the effects of summer temperatures on the density of age 0 parr. Specifically, we asked: (1) What are the spatial and temporal temperature patterns in the Connecticut River during summer? (2) What metrics might detect effects of high temperatures? and (3) How is temperature variability related to density of <span class="hlt">Atlantic</span> salmon during their first summer? Although the most southern site was the warmest, some northern sites were also warm, and some southern sites were moderately cool. This suggests localized, within <span class="hlt">basin</span> variation in temperature. Daily and hourly means showed extreme values not apparent in the seasonal means. We observed significant relationships between age 0 parr density and days at potentially stressful, warm temperatures (???23??C). Based on these results, we propose that useful field reference points need to incorporate the synergistic effect of other stressors that fish encounter in the field as well as the complexity associated with cycling temperatures and thermal refuges. Understanding the effects of temperature may aid conservation efforts for <span class="hlt">Atlantic</span> salmon in the Connecticut River and other North <span class="hlt">Atlantic</span> systems. ?? 2008 Springer Science+Business Media B.V.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018DSRII.148...91B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018DSRII.148...91B"><span>Does the Mid-<span class="hlt">Atlantic</span> Ridge affect the distribution of abyssal benthic crustaceans across the <span class="hlt">Atlantic</span> Ocean?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bober, Simon; Brix, Saskia; Riehl, Torben; Schwentner, Martin; Brandt, Angelika</p> <p>2018-02-01</p> <p>A trans-<span class="hlt">Atlantic</span> transect along the Vema Fracture Zone was sampled during the Vema-TRANSIT expedition in 2014/15. The aim of the cruise was to investigate whether the Mid-<span class="hlt">Atlantic</span> Ridge (MAR) isolates the abyssal fauna of the western and eastern abyssal <span class="hlt">basins</span>. Based on two genetic datasets of Macrostylidae and Desmosomatidae/Nannoniscidae studied by Riehl et al. and Brix et al. in this issue we found that most of the therein-delimitated species were found at only one side of the MAR. We analysed those species of Macrostylidae and Desmosomatidae that were sampled across the MAR and complemented these with one species of a third family: Munnopsidae. With these datasets we were further able to consider the effect of different niche adaptations: Macrostylidae are infaunal (burrowing), Munnopsidae are considered epifaunal with pronounced swimming capabilities and Desmosomatidae and Nannoniscidae are partly able to swim, but are not as well adapted to swimming as Munnopsidae. We concluded that the MAR seems to be a dispersal barrier for the non-swimming Macrostylidae as well as weakly-swimming Desmosomatidae and Nannoniscidae. However, four species of Macrostylidae and Desmosomatidae did cross the MAR, but evidence for regular unrestricted gene flow is still lacking. For the swimming Munnopsidae we were able to detect persistent gene flow across the MAR.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017GeCoA.204..286B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017GeCoA.204..286B"><span>Barium isotopes reveal role of ocean circulation on barium cycling in the <span class="hlt">Atlantic</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bates, Stephanie L.; Hendry, Katharine R.; Pryer, Helena V.; Kinsley, Christopher W.; Pyle, Kimberley M.; Woodward, E. Malcolm S.; Horner, Tristan J.</p> <p>2017-05-01</p> <p>We diagnose the relative influences of local-scale biogeochemical cycling and regional-scale ocean circulation on <span class="hlt">Atlantic</span> barium cycling by analysing four new depth profiles of dissolved Ba concentrations and isotope compositions from the South and tropical North <span class="hlt">Atlantic</span>. These new profiles exhibit systematic vertical, zonal and meridional variations that reflect the influence of both local-scale barite cycling and large-scale ocean circulation. Epipelagic decoupling of dissolved Ba and Si reported previously in the tropics is also found to be associated with significant Ba isotope heterogeneity. As such, we contend that this decoupling originates from the depth segregation of opal and barite formation but is exacerbated by weak vertical mixing. Zonal influence from isotopically-'heavy' water masses in the western North <span class="hlt">Atlantic</span> evidence the advective inflow of Ba-depleted Upper Labrador Sea Water, which is not seen in the eastern <span class="hlt">basin</span> or the South <span class="hlt">Atlantic</span>. Meridional variations in <span class="hlt">Atlantic</span> Ba isotope systematics below 2000 m appear entirely controlled by conservative mixing. Using an inverse isotopic mixing model, we calculate the Ba isotope composition of the Ba-poor northern end-member as +0.45 ‰ and the Ba-rich southern end-member +0.26 ‰, relative to NIST SRM 3104a. The near-conservative behaviour of Ba below 2000 m indicates that Ba isotopes can serve as an independent tracer of the provenance of northern- versus southern-sourced water masses in the deep <span class="hlt">Atlantic</span> Ocean. This finding may prove useful in palaeoceanographic studies, should appropriate sedimentary archives be identified, and offers new insights into the processes that cycle Ba in seawater.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70036328','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70036328"><span>Chapter 19: Geology and petroleum potential of the east Barents Sea <span class="hlt">Basins</span> and Admiralty Arch</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Klett, T.R.; Pitman, Janet K.</p> <p>2011-01-01</p> <p>The US Geological Survey (USGS) recently assessed the potential for undiscovered oil and gas resources of the East Barents <span class="hlt">Basins</span> and Novaya Zemlya <span class="hlt">Basins</span> and Admiralty Arch Provinces as part of the USGS Circum-Arctic Resource Appraisal. These two provinces are located <span class="hlt">NE</span> of Scandinavia and the northwestern Russian Federation, on the Barents Sea Shelf between Novaya Zemlya to the east and the Barents Platform to the west. Three assessment units (AUs) were defined in the East Barents <span class="hlt">Basins</span> for this study - Kolguyev Terrace Assessment Unit (AU), South Barents <span class="hlt">Basin</span> and Ludlov Saddle AU, and North Barents <span class="hlt">Basin</span> AU. A fourth, defined as Novaya Zemlya <span class="hlt">Basins</span> and Admiralty Arch AU, is coincident with the Novaya Zemlya <span class="hlt">basins</span> and Admiralty Arch Province. These AUs, all lying north of the Arctic Circle, were assessed for undiscovered, technically recoverable resources resulting in total estimated mean volumes of approximately 7.4 billion barrels of crude oil, 318 trillion cubic feet of natural gas and 1.4 billion barrels of natural gas liquids. ?? 2011 The Geological Society of London.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUOS.A24C2588S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUOS.A24C2588S"><span>Natural Surfactant Enrichments in the <span class="hlt">Atlantic</span> Ocean Between 50°N and 50°S: Data from the <span class="hlt">Atlantic</span> Meridional Transect, Oct-Nov 2014</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sabbaghzadeh, B.; Upstill-Goddard, R. C.; Nightingale, P. D.; Beale, R.</p> <p>2016-02-01</p> <p>Surfactants that decrease air-sea gas exchange by suppressing the gas transfer velocity (kw) show variable enrichments in the sea surface microlayer (SML) relative to the underlying water. This reflects variability in the rates of surfactant production and consumption. Total surfactant activity (SA: equivalent to Triton-X-100, mgL -1) was determined daily between the UK and the Falkland Islands, during cruise 24 of the <span class="hlt">Atlantic</span> Meridional Transect programme (AMT 24). Samples were simultaneously obtained from the SML (Garrett screen), from the ship's underway system (inlet at 7m) and in hydrocasts to 500m. SA analysis was by hanging mercury drop electrode polarography (Metrohm 797 VA Computrace). SA enrichment factors (EF: SML SA / underlying water SA) >1 were observed at most locations, showing the SML to be consistently SA-enriched along the entire cruise transect. The persistence of these enrichments up to wind speeds 12m s-¹ support previous conclusions regarding the stability of the SML under high winds. More specifically, SA in the SML was up to four-fold higher in the <span class="hlt">Atlantic</span> Northern Hemisphere than in the <span class="hlt">Atlantic</span> Southern Hemisphere. Even so, EF values were not significantly different between the two hemispheres (p >0.05). These various findings have potentially important implications for kw variability across ocean <span class="hlt">basin</span> scales.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/14967226','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/14967226"><span>Evaluation of double formalin--Lugol's fixation in assessing number and biomass of ciliates: an example of estimations at mesoscale in <span class="hlt">NE</span> <span class="hlt">Atlantic</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Karayanni, Hera; Christaki, Urania; Van Wambeke, France; Dalby, Andrew P</p> <p>2004-03-01</p> <p>Ciliated protozoa are potential grazers of primary and bacterial production and act as intermediaries between picoplankton and copepods and other large suspension feeders. Accurate determination of ciliate abundance and feeding mode is crucial in oceanic carbon budget estimations. However, the impact of different fixatives on the abundance and cell volume of ciliates has been investigated in only a few studies using either laboratory cultures or natural populations. Lugol's solution and formalin are the most commonly used fixatives for the preservation of ciliates samples. In the present study, the aim was to compare 0.4% Lugol's solution and 2% borated-formalin fixation and evaluate the need of counting duplicate samples each using a different fixative. For this, a large number of samples (n = 110) from the <span class="hlt">NE</span> <span class="hlt">Atlantic</span> was analyzed in the frame of POMME program (Multidisciplinary Mesoscale Ocean Program). We established a statistically significant relationship (p < 0.0001) between Lugol's and formalin fixed samples for both abundance (r2 = 0.50) and biomass (r2 = 0.76) of aloricate ciliates which showed that counts were higher in Lugol's solution by a factor of 2 and a non-taxon specific cell-loss in formalin. However, loricate ciliate abundance in our samples which were represented primarily by Tintinnus spp. did not show any difference between the two treatments. Abundance and biomass of mixotrophic ciliates (chloroplast-bearing cells) were for various reasons underestimated in both treatments. Our results show that unique fixation by formalin may severely underestimate ciliates abundance and biomass although their population may not alter. For this reason, Lugol's solution is best for the estimation of their abundance and biomass. However, for counts of mixotrophs and the evaluation of the ecological role of ciliates in carbon flux, double fixation is essential. Compromises regarding the fixatives have lead to severe underestimations of mixotrophs in studies</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007AGUFMPP34A..02B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007AGUFMPP34A..02B"><span>An Eight-Century High-Resolution Paleoclimate Record From the Cariaco <span class="hlt">Basin</span>: Baseline Variability and the 20th Century</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Black, D. E.; Thunell, R. C.; Kaplan, A.; Tappa, E. J.; Peterson, L. C.</p> <p>2007-12-01</p> <p>The Cariaco <span class="hlt">Basin</span>, Venezuela is well-positioned to record a detailed history of surface ocean changes along the southern margin of the Caribbean and the tropical <span class="hlt">Atlantic</span>. Varved, high deposition rate sediments deposited under anoxic conditions and an abundance of well-preserved microfossils result in one of the few marine records capable of preserving evidence of interannual- to decadal-scale climate variability in the tropical <span class="hlt">Atlantic</span>. Here we present Mg/Ca and stable oxygen isotope data with sub-decadal resolution derived from sediments deposited over the last 800 years. Mg/Ca measured on the planktic foraminifer Globigerina bulloides from a Cariaco <span class="hlt">Basin</span> sediment core strongly correlates with spring (March-May) instrumental SSTs between AD 1870 and 1990. The long-term record displays a surprising amount of variability for a tropical location. The temperature swings are not necessarily related to local upwelling variability, but instead represent wider conditions in the Caribbean and western tropical <span class="hlt">Atlantic</span>. The Mg/Ca-SST record also captures the decadal and multidecadal variability observed in global land and sea surface temperature anomalies, and correlates with <span class="hlt">Atlantic</span> tropical storm and hurricane frequency over the late-19th and 20th centuries. On average, 20th century temperatures are not the warmest in the entire record, but they do show the largest increase in magnitude and fastest rate of SST change over the last eight hundred years. Stable oxygen isotope data also correlate well with instrumental SSTs, but not over the full instrumental record. Poor correlations with early instrumental SST data suggest a salinity overprint. However, reconstructing δ- water variability using combined Mg/Ca and δ18O data is not straightforward as the δ- water/salinity relationship varies seasonally in the Cariaco <span class="hlt">Basin</span>. Comparisons with percent titanium data suggest intervals of both local and regional surface salinity changes over the length of the record.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018IzAOP..54...65I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018IzAOP..54...65I"><span>The Effect of Seasonal Variability of <span class="hlt">Atlantic</span> Water on the Arctic Sea Ice Cover</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ivanov, V. V.; Repina, I. A.</p> <p>2018-01-01</p> <p>Under the influence of global warming, the sea ice in the Arctic Ocean (AO) is expected to reduce with a transition toward a seasonal ice cover by the end of this century. A comparison of climate-model predictions with measurements shows that the actual rate of ice cover decay in the AO is higher than the predicted one. This paper argues that the rapid shrinking of the Arctic summer ice cover is due to its increased seasonality, while seasonal oscillations of the <span class="hlt">Atlantic</span> origin water temperature create favorable conditions for the formation of negative anomalies in the ice-cover area in winter. The basis for this hypothesis is the fundamental possibility of the activation of positive feedback provided by a specific feature of the seasonal cycle of the inflowing <span class="hlt">Atlantic</span> origin water and the peaking of temperature in the Nansen <span class="hlt">Basin</span> in midwinter. The recently accelerated reduction in the summer ice cover in the AO leads to an increased accumulation of heat in the upper ocean layer during the summer season. The extra heat content of the upper ocean layer favors prerequisite conditions for winter thermohaline convection and the transfer of heat from the <span class="hlt">Atlantic</span> water (AW) layer to the ice cover. This, in turn, contributes to further ice thinning and a decrease in ice concentration, accelerated melting in summer, and a greater accumulation of heat in the ocean by the end of the following summer. An important role is played by the seasonal variability of the temperature of AW, which forms on the border between the North European and Arctic <span class="hlt">basins</span>. The phase of seasonal oscillation changes while the AW is moving through the Nansen <span class="hlt">Basin</span>. As a result, the timing of temperature peak shifts from summer to winter, additionally contributing to enhanced ice melting in winter. The formulated theoretical concept is substantiated by a simplified mathematical model and comparison with observations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JAfES.134..174B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JAfES.134..174B"><span>Structural evolution of Cenozoic <span class="hlt">basins</span> in northeastern Tunisia, in response to sinistral strike-slip movement on the El Alia-Teboursouk Fault</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bejaoui, Hamida; Aïfa, Tahar; Melki, Fetheddine; Zargouni, Fouad</p> <p>2017-10-01</p> <p>This paper resolves the structural complexity of Cenozoic sedimentary <span class="hlt">basins</span> in northeastern Tunisia. These <span class="hlt">basins</span> trend <span class="hlt">NE</span>-SW to ∼ E-W, and are bordered by old fracture networks. Detailed descriptions of the structural features in outcrop and in subsurface data suggest that the El Alia-Teboursouk Fault zone in the Bizerte area evolved through a series of tectonic events. Cross sections, lithostratigraphic correlations, and interpretation of seismic profiles through the <span class="hlt">basins</span> show evidence for: (i) a Triassic until Jurassic-Early Cretaceous rifting phase that induced lateral variations of facies and strata thicknesses; (ii) a set of faults oriented <span class="hlt">NE</span>-SW, NW-SE, N-S, and E-W that guided sediment accumulation in pull-apart <span class="hlt">basins</span>, which were subject to compressive and transpressive deformation during Eocene (Lutetian-Priabonian), Miocene (Tortonian), and Pliocene-Quaternary; and (iii) NNW-SSE to NS contractional events that occurred during the Late Pliocene. Part of the latest phase has been the formation of different synsedimentary folded structures with significant subsidence inversion. Such events have been responsible for the reactivation of inherited faults, and the intrusion of Triassic evaporites, ensuring the role of a slip layer. The combined effects of the different paleoconstraints and halokinetic movements are at the origin of the evolution of these pull-apart <span class="hlt">basins</span>. The subsurface data suggest that an important fault displacement occurred during the Mesozoic-Cenozoic. The patterns of sediment accumulation in the different <span class="hlt">basins</span> reflect a high activity of deep ancient faults.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70046761','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70046761"><span>Attributes for MRB_E2RF1 Catchments by Major River <span class="hlt">Basins</span> in the Conterminous United States: Surficial Geology</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Wieczorek, Michael; LaMotte, Andrew E.</p> <p>2010-01-01</p> <p>This tabular data set represents the area of surficial geology types in square meters compiled for every MRB_E2RF1 catchment of selected Major River <span class="hlt">Basins</span> (MRBs, Crawford and others, 2006). The source data set is the "Digital data set describing surficial geology in the conterminous US" (Clawges and Price, 1999).The MRB_E2RF1 catchments are based on a modified version of the U.S. Environmental Protection Agency's (USEPA) ERF1_2 and include enhancements to support national and regional-scale surface-water quality modeling (Nolan and others, 2002; Brakebill and others, 2008). Data were compiled for every MRB_E2RF1 catchment for the conterminous United States covering New England and Mid-<span class="hlt">Atlantic</span> (MRB1), South <span class="hlt">Atlantic</span>-Gulf and Tennessee (MRB2), the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy (MRB3), the Missouri (MRB4), the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf (MRB5), the Rio Grande, Colorado, and the Great <span class="hlt">basin</span> (MRB6), the Pacific Northwest (MRB7) river <span class="hlt">basins</span>, and California (MRB8).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004AGUFMGP41B..03L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004AGUFMGP41B..03L"><span>Field Geometry During the Iceland <span class="hlt">Basin</span> Event Observed from the North <span class="hlt">Atlantic</span> Ocean, North Pacific Ocean and the South China Sea</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Laj, C.; Kissel, C.; Roberts, A. P.; Hillaire-Marcel, C.; Cortijo, E.</p> <p>2004-12-01</p> <p>The Iceland <span class="hlt">Basin</span> event (IBE), which is named for a record from ODP Site 983 in the North <span class="hlt">Atlantic</span> Ocean (60.5°N), is a focus of growing interest in our community. This geomagnetic excursion is coeval with the marine oxygen isotope (MIS) stage 7/6 boundary at about 190 ka according to the orbitally tuned SPECMAP time scale. We have detailed new records of this excursion at two new sites from the North <span class="hlt">Atlantic</span> (core MD99-2247; lat. 59°N, long. 31°W and core MD99-2242; lat. 59°N, long. 47°W), at one site from the North Pacific (ODP Site 884; lat. 51.5°N, long. 168.3°E), and in two others from the South China Sea (ODP Site 1146; lat. 19.5°N, long. 116.3°E and ODP Site 1145; lat. 19.6°N; long. 117.6°E). For all five sites, the event is identified at the MIS 7/6 boundary, which confirms its potential as a precise stratigraphic marker. The average sedimentation rate for this portion of the cores is 7.5, 10 and 15 cm/kyr in North <span class="hlt">Atlantic</span>, North Pacific and South China sea cores, respectively, which allows high-resolution studies in this time interval. The event is characterized by a marked minimum in the relative paleointensity (sometimes with a double feature) and by large swings in inclination and declination. The VGP latitudes reach 78°S and 45°S for ODP sites 1146 and 1145, respectively, 37°S for ODP Site 884, and 74°S and 41°S for cores MD99-2247 and MD99-2242, respectively. The VGP paths for the four records from the North <span class="hlt">Atlantic</span> and South China Sea cores are highly similar. For the most detailed of these records, the poles first pass over Africa, then they proceed to Antarctica and return northward over Australia. The paths are less well resolved for ODP Site 1145 and core MD99-2242, for which the poles cross the southern Indian Ocean rather than reaching Antarctica. The VGP paths for the two most detailed records (ODP Site 1146 and MD99-2247) are highly similar and are also similar to the path for ODP Site 983, which also has a high</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EGUGA..12.6852M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EGUGA..12.6852M"><span>Structural features of phosphate accumulations in the Gantour <span class="hlt">basin</span> - Morocco : Application of GIS</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mohamed, Laadraoui; El Hassane, Boumaggard; Essaid, Jourani</p> <p>2010-05-01</p> <p>The Moroccan <span class="hlt">Atlantic</span> margin raises a lot of interest because of its potential resources in phosphates. It also holds in its Mesetien part one of the largest phosphatic deposit in the world. The authors present the results of their researches on structural environments of the phosphatic sedimentary sequences in the Gantour deposit in western Morocco. These investigations are mainly based on field data, data recorded from work done by the OCP (Office Chérifien des Phosphates) group, the interpretation of industrial seismic profiles and the application of GIS. Our aim are devoted to the apprehension of the geometry and the cinematic of these <span class="hlt">basins</span> which are contemporaneous to the Central <span class="hlt">Atlantic</span> Rifting, as well as the determination of the list of factors liable to the genesis of these phosphatic <span class="hlt">basins</span>. Other data of field observations (cartography, study of structural features,...) permit to identify the general structure of the prospect. Sedimentation of phosphated deposits is strained by the presence of two wrench faulting systems oriented N20¬40E, N80¬120E and N140¬160E.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1354863','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1354863"><span>MicroBoo<span class="hlt">NE</span>: The Search For The MiniBoo<span class="hlt">NE</span> Low Energy Excess</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Kaleko, David</p> <p></p> <p>This thesis describes work towards the search for a low energy excess in MicroBoo<span class="hlt">NE</span>. What MicroBoo<span class="hlt">NE</span> is, what the low energy excess is, and how one searches for the latter in the former will be described in detail.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_22 --> <div id="page_23" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="441"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16..305J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16..305J"><span>Tectonic constraints on the development and individualization of the intermontane Ronda <span class="hlt">basin</span> (external Betics, southern Spain): a structural and geomorphologic approach.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jiménez-Bonilla, Alejandro; Balanyá, Juan Carlos; Expósito, Inmaculada; Díaz-Azpiroz, Manuel; Barcos, Leticia</p> <p>2014-05-01</p> <p>As a result of progressive shortening and orogenic wedge thickening, marine foreland <span class="hlt">basins</span> tend to emerge and divide. We have analyzed possible recent tectonic activity within the late evolution stage of the Ronda <span class="hlt">basin</span>, an intermontane <span class="hlt">basin</span> located in the external wedge of the Gibraltar Arc, formerly connected with the Betic foreland <span class="hlt">basin</span> and infilled by marine Upper-Miocene sediments. We analyze (1) the structures responsible for the basinward relief drop along the arc strike and the different topography of their boundaries; (2) qualitative and quantitative geomorphologic indices to asses which structures could present recent activity; and 3) the structures causing the division of the former Betic foreland <span class="hlt">basin</span> and the isolation of the Ronda <span class="hlt">basin</span>. Within the deformational history of the Ronda <span class="hlt">basin</span>, late structures that control high topographic gradients and generate remarkable fault scarps group into three main types: (a) Extensional structures represented by NW-SE striking normal faults, clustered close to the current SW and <span class="hlt">NE</span> boundaries of the <span class="hlt">basin</span>. They usually dip towards the <span class="hlt">basin</span> and their vertical displacement is maximum up to 1,5 km. These structures partially affect the basal unconformity of the Upper Miocene <span class="hlt">basin</span> infill and are scarcely developed inside the <span class="hlt">basin</span> infill. (b) Shortening structures developed both in the <span class="hlt">basin</span> infill and in the outcropping basement near the Northeastern and Southwestern <span class="hlt">basin</span> boundaries. They are represented by <span class="hlt">NE</span>-SW directed plurikilometric box-folds and reverse faults, responsible for the alternation of sierras (altitudes 1000-1500 m) and valleys. (c) Strike-slip dominated structural associations where WSW-ENE lateral faults combined with folds and normal and reverse faults defined a <span class="hlt">NE</span>-SW directed deformation band constituting the NW <span class="hlt">basin</span> boundary. This band includes some sierras up to 1.100 m. Regarding the relief of the Ronda <span class="hlt">basin</span> area, the abrupt slopes of the outcropping basement (heights between 500</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018GPC...165...44G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018GPC...165...44G"><span>Palaeohydrological evolution of the late Cenozoic saline lake in the Qaidam <span class="hlt">Basin</span>, <span class="hlt">NE</span> Tibetan Plateau: Tectonic vs. climatic control</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Guo, Pei; Liu, Chiyang; Huang, Lei; Yu, Mengli; Wang, Peng; Zhang, Guoqing</p> <p>2018-06-01</p> <p>As the largest Cenozoic terrestrial intermountain <span class="hlt">basin</span> on the Tibetan Plateau, the Qaidam <span class="hlt">Basin</span> is an ideal setting to understand the coupled controls of tectonics and climate on hydrological evolution. In this study, we used 47,846 data of carbonate and chloride contents from 146 boreholes to reconstruct the Neogene-Quaternary <span class="hlt">basin</span>-wide hydrological evolution of the Qaidam <span class="hlt">Basin</span>. Our results show that during the early Miocene (22-15 Ma), the palaeolake in the Qaidam <span class="hlt">Basin</span> was mainly situated in the southwestern part of the <span class="hlt">basin</span>, and its water was mostly brackish. From then on, this palaeolake progressively migrated southeastward, and its salinity increased from late Miocene saline water to Quaternary brines. This generally increasing trend of the water palaeosalinity during the late Cenozoic corresponded with regional and global climate changes at that time, suggesting the dominance of climatic control. However, the paces of the salinity increase from sediments in front of the three <span class="hlt">basin</span>-bounding ranges were not the same, indicating that extra tectonic controls occurred. Sediments in front of the Eastern Kunlun Shan to the southwest and the Altyn Shan to the northwest showed an abrupt, dramatic increase in salinity at 15 Ma and 8 Ma, respectively; sediments in front of the Qilian Shan to the northeast showed steady increase without prominent, abrupt changes, indicating the occurrence of asynchronous tectonic controls from the <span class="hlt">basin</span>-bounding ranges. The late Miocene depocentre migration was synchronous with the hydrological changes in front of the Altyn Shan, while the more significant migration during the Quaternary was consistent with the pulsing, intense extrabasinal and intrabasinal tectonic movements along the Tibetan Plateau.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/1332076-transfer-reaction-relation-process-abundances','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/1332076-transfer-reaction-relation-process-abundances"><span>The 20<span class="hlt">Ne</span>(d,p) 21<span class="hlt">Ne</span> Transfer Reaction in Relation to the s-Process Abundances</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Nsangu, C. T.; Laird, A. M.; Parikh, A.</p> <p>2016-01-01</p> <p>A study of the <span class="hlt">Ne</span>-20(d,p)<span class="hlt">Ne</span>-21 transfer reaction was performed using the Quadrupole Dipole Dipole Dipole (Q3D) magnetic spectrograph in Garching, Germany. The experiment probed excitation energies in <span class="hlt">Ne</span>-21 ranging from 6.9 MeV to 8.5 MeV. The aim was to investigate the spectroscopic information of <span class="hlt">Ne</span>-21 within the Gamow window of core helium burning in massive stars. Further information in this region will help reduce the uncertainties on the extrapolation down to Gamow window cross sections of the O-17(alpha,gamma)<span class="hlt">Ne</span>-21 reaction. In low metallicity stars, this reaction has a direct impact on s-process abundances by determining the fate of O-16 as eithermore » a neutron poison or a neutron absorber. The experiment used a 22-MeV deuteron beam, with intensities varying from 0.5-1 mu A, and an implanted target of <span class="hlt">Ne</span>-20 of 7 mu g/cm(2) in 40 mu g/cm(2) carbon foils. Sixteen <span class="hlt">Ne</span>-21 peaks have been identified in the E-x = 6.9-8.5 MeV range, of which only thirteen peaks correspond to known states. Only the previously-known E-x = 7.960 MeV state was observed within the Gamow window.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFM.V31G..07F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFM.V31G..07F"><span>Geochronometry and thermochronometry using nucleogenic 21<span class="hlt">Ne</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Farley, K. A.; Flowers, R. M.; Vasconcelos, P. M.</p> <p>2011-12-01</p> <p>Nucleogenic 21<span class="hlt">Ne</span> is produced by the interaction of α particles with 18O. While the cross section for this reaction is small (about 1 α in 25 million participates), 21<span class="hlt">Ne</span> excesses can be measured in a variety of minerals, forming the basis of (U-Th)/<span class="hlt">Ne</span> chronometry. Previous work focused on thermochronometry of U, Th rich trace minerals. For example, Gautheron et al. (2005) studied nucleogenic <span class="hlt">Ne</span> in zircon and inferred a closure temperature of ~400 C. Our preliminary <span class="hlt">Ne</span> diffusion data on Durango apatite suggests Tc ~280 C. The method can also be applied to phases with much lower U and Th contents in which the 21<span class="hlt">Ne</span> is measurable on old and/or large specimens. We have obtained (U-Th)/<span class="hlt">Ne</span> ages on ~50 mg samples of iron oxides with ppm-level U and Th and <span class="hlt">Ne</span> ages of 50-500 Ma. For example, hematites from the Neoproterozoic (?) Urucum BIF yield a 21<span class="hlt">Ne</span> age of 470 ± 15 Ma and post-depositional hydrothermal hematite in the Redwall Limestone in the Grand Canyon yields an age of 251 ± 11 Ma. In both cases (U-Th)/He ages are more than 100 Myr younger. Outstanding issues with this method are 1) the diffusivity of <span class="hlt">Ne</span> - are we measuring cooling ages or formation ages?, 2) how well known is the production rate?, and 3) in what minerals is the air component sufficiently small to permit precision measurements of 21<span class="hlt">Ne</span> excesses?</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001PhDT........19R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001PhDT........19R"><span>Interannual-to-decadal air-sea interactions in the tropical <span class="hlt">Atlantic</span> region</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ruiz-Barradas, Alfredo</p> <p>2001-09-01</p> <p>The present research identifies modes of atmosphere-ocean interaction in the tropical <span class="hlt">Atlantic</span> region and the mechanisms by which air-sea interactions influence the regional climate. Novelties of the present work are (1)the use of relevant ocean and atmosphere variables important to identity coupled variability in the system. (2)The use of new data sets, including realistic diabatic heating. (3)The study of interactions between ocean and atmosphere relevant at interannual-to-decadal time scales. Two tropical modes of variability are identified during the period 1958-1993, the <span class="hlt">Atlantic</span> Niño mode and the Interhemispheric mode. Those modes have defined structures in both ocean and atmosphere. Anomalous sea surface temperatures and winds are associated to anomalous placement of the Intertropical Convergence Zone (ITCZ). They develop maximum amplitude during boreal summer and spring, respectively. The anomalous positioning of the ITCZ produces anomalous precipitation in some places like Nordeste, Brazil and the Caribbean region. Through the use of a diagnostic primitive equation model, it is found that the most important terms controlling local anomalous surface winds over the ocean are boundary layer temperature gradients and diabatic heating anomalies at low levels (below 780 mb). The latter is of particular importance in the deep tropics in producing the anomalous meridional response to the surface circulation. Simulated latent heat anomalies indicate that a thermodynamic feedback establishes positive feedbacks at both sides of the equator and west of 20°W in the deep tropics and a negative feedback in front of the north west coast of Africa for the Interhemispheric mode. This thermodynamic feedback only establishes negative feedbacks for the <span class="hlt">Atlantic</span> Niño mode. Transients establish some connection between the tropical <span class="hlt">Atlantic</span> and other <span class="hlt">basins</span>. Interhemispheric gradients of surface temperature in the tropical <span class="hlt">Atlantic</span> influence winds in the midlatitude North</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1816782G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1816782G"><span>New insights into Gondwana paleography based on palinological data from Morro do Chaves Formation (Sergipe-Alagoas <span class="hlt">Basin</span>, Brazil)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gonçalves Garcia, Gustavo; Vasconcellos Garcia, Antônio Jorge; Henriques, Maria Helena</p> <p>2016-04-01</p> <p>The Sergipe-Alagoas <span class="hlt">basin</span> (<span class="hlt">NE</span> Brazil) has been widely studied in the frame of oil exploration, because it displays the most complete exposition of the stratigraphic sequences from the <span class="hlt">basins</span> of the Brazilian continental margin. In this context, the aim of this workis to present the results of the bio-stratigraphic and paleo-environmental analysis of Morro do Chaves Formation (Lower Cretaceous), in Alagoas Sub-<span class="hlt">basin</span>, part of the transitional section situated between the rift phase and restricted marine environment associated with the South <span class="hlt">Atlantic</span> ocean opening. The material was analyzed from the palynological point of view and was collected in the InterCement quarry, located in São Miguel dos Campos, State of Alagoas. From 17 outcrop rock samples collected, nine had palynological content; among these only six were considered for biostratigraphic analysis purposes. In addition to outcrop samples, 28 samples were processed from four core drill. The paleoenvironmental analysis was based on the palynological content of the collected samples and on the paleontological and geological information available. The studied sedimentary package corresponds to carbonate and fine siliciclastic deposits, with approximately 70.0 m in thickness. The unit in question is formed by carbonatic "coquinóides" rocks interspersed with shale levels of dark green color. Palinofloristic assemblages were recuperated between 5.0 m and 70.0 m of the outcropping section. In the recovered material it was possible to identify 9 kinds of spores and 8 kinds of pollen grains, and two genera of fungi. Due to the degree of preservation of the material, age was established by the occurrence of Dicheiropollis etruscus specimens, which has enabled the recognition of the Dicheiropollis etruscus palinozone (upper Barremian). In microscopic observations under fluorescent light some algalic vesicles components were also recognized and classified as possible algae of the Prasinophyceae class, indicating</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013SedG..284...76J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013SedG..284...76J"><span>Proximate environmental forcing in fine-scale geochemical records of calcareous couplets (Upper Cretaceous and Palaeocene of the Basque-Cantabrian <span class="hlt">Basin</span>, eastern North <span class="hlt">Atlantic</span>)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jiménez Berrocoso, Álvaro; Elorza, Javier; MacLeod, Kenneth G.</p> <p>2013-02-01</p> <p>Calcareous couplets are key elements in reconstructing the evolution of a sedimentary <span class="hlt">basin</span> due to the influence of forcing mechanisms such as climate, sea level and tectonism on their depositional patterns. Proposed forcing mechanisms, however, are often not mutually exclusive and even constraining the relative importance of different processes is problematic. Added to the question of discriminating forcing mechanisms, a major challenge is to produce high-sampling density so that observations lie within temporal resolutions equal to or finer than the timescales on which different forcing operates. Here, we show fine-scale (1 sample/~ 2 cm) CaCO3, δ18O and δ13C records and sedimentological observations from three different sites (Isla de Castro, Sopelana-Ma, and Sopelana-Da) with calcareous couplets in the Basque Cantabrian <span class="hlt">Basin</span> (eastern North <span class="hlt">Atlantic</span>) to illustrate the potential of fine-sampling strategies to help distinguish proximate environmental forcing. Partial redistribution of carbonate during burial diagenesis has been proposed for these sediments. Our CaCO3, δ18O and δ13C data could thus be dismissed as diagenetic signals if only one sample was collected from each bed. Detailed observations of the fine-scale geochemical records, however, challenge purely diagenetic explanations. Combined with sedimentology, the CaCO3, δ18O and δ13C values, partially altered by diagenesis, are interpreted to have resulted from alternating climates. The proximate forcing through which alternating climates caused the geochemical patterns, though, was different in each section, due to their specific palaeogeographic positions in the <span class="hlt">basin</span> and the properties of the seawater masses. The proximity of continental areas of high relief to the Isla de Castro section supported a high continental influence during its deposition. The Sopelana-Ma sediments are assigned to a transgressive system tract, a condition that is interpreted to have promoted a high influence of oceanic</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29891855','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29891855"><span>Water Vapor Transfer and Near-Surface Salinity Contrasts in the North <span class="hlt">Atlantic</span> Ocean.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Reagan, James; Seidov, Dan; Boyer, Tim</p> <p>2018-06-11</p> <p>Maintaining North <span class="hlt">Atlantic</span> (NA) intra-<span class="hlt">basin</span> near-surface salinity (NSS) contrast between the high NSS (>37.0) in the subtropical NA (STNA) and low NSS (<35.0) in the subpolar NA (SPNA) has been shown to be important in sustaining the strength of the <span class="hlt">Atlantic</span> Meridional Overturning Circulation. Evaporation (E) exceeding precipitation (P) in the STNA is primarily responsible for the high NSS there, whereas P dominating E in the SPNA contributes to its low NSS. With a basic understanding of NA intra-<span class="hlt">basin</span> moisture transport, a correlation analysis was conducted between E-P/NSS over the NA subpolar gyre (SPG) and E-P across the rest of the NA over the 1985-2012 time period. Significant anti-correlations exist between E-P/NSS over the NA SPG and E-P over the central/northern STNA. This suggests that during times of high E over the central/northern STNA there is high (low) precipitation (NSS) over the SPG demonstrating a relationship likely exists between E over the STNA and NSS over the SPG. The maximum anti-correlated area is poleward of the maximum E-P location in the STNA, which is examined. These results provide a first step to ultimately utilizing NSS in the NA as a proxy for estimating changes in the hydrological cycle.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EGUGA..12.6504L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EGUGA..12.6504L"><span>Uplifting of the Jiamusi Block in the eastern Central Asian Orogenic Belt, <span class="hlt">NE</span> China: evidence from <span class="hlt">basin</span> provenance and geochronology</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liu, Yongjiang; Wen, Quanbo; Han, Guoqing; Li, Wei</p> <p>2010-05-01</p> <p>The main part of Jiamusi Block, named as Huanan-Uplift, is located in the northeastern Heilongjiang, China. The Huanan-Uplift is surrounded by many relatively small Mesozoic-Cenozoic <span class="hlt">basins</span>, e.g. Sanjiang <span class="hlt">Basin</span>, Hulin <span class="hlt">Basin</span>, Boli <span class="hlt">Basin</span>, Jixi <span class="hlt">Basin</span>, Shuangyashan <span class="hlt">Basin</span> and Shuanghua <span class="hlt">Basin</span>. However previous research works were mainly focused on stratigraphy and palaeontology of the <span class="hlt">basins</span>, therefore, the coupling relation between the uplift and the surrounding <span class="hlt">basins</span> have not been clear. Based on the field investigations, conglomerate provenance studies of the Houshigou Formation in Boli <span class="hlt">Basin</span>, geochronology of the Huanan-Uplift basement, we have been studied the relationships between Huanan-Uplift and the surrounding <span class="hlt">basins</span>. The regional stratigraphic correlations indicates that the isolated <span class="hlt">basins</span> in the area experienced the same evolution during the period of the Chengzihe and the Muling Formations (the Early Cretaceous). The paleogeography reconstructions suggest that the area had been a large-scale <span class="hlt">basin</span> as a whole during the Early Cretaceous. The Huanan-Uplift did not exist. The paleocurrent directions, sandstone and conglomerate provenance analyses show that the Huanan-Uplift started to be the source area of the surrounding <span class="hlt">basins</span> during the period of Houshigou Formation (early Late Cretaceous), therefore, it suggests that the Jiamusi Block commenced uplift in the early Late Cretaceous. The granitic gneisses in Huanan-Uplift give 494-415 Ma monazite U-Th-total Pb ages, 262-259 Ma biotite and 246-241 Ma K-feldspar 40Ar/39Ar ages. The cooling rates of 1-2 ℃/Ma from 500-260 Ma and 10-11 ℃/Ma from 260-240 Ma have been calculated based on the ages. This suggests that the Jiamusi Block had a rapid exhumation during late Permian, which should be related to the closure of the Paleo-Asian Ocean between the Siberian and North China continents. It is concluded that during the late Paleozoic the Jiamusi Block was stable with a very slow uplifting. With the closure of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.5593H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.5593H"><span>Transport Structure and Energetic of the North <span class="hlt">Atlantic</span> Current in Subpolar Gyre from Observations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Houpert, Loïc; Inall, Mark; Dumont, Estelle; Gary, Stefan; Porter, Marie; Johns, William; Cunningham, Stuart</p> <p>2017-04-01</p> <p>We present the first 2 years of UK-OSNAP glider missions on the Rockall Plateau in the North <span class="hlt">Atlantic</span> subpolar gyre. From July 2014 to August 2016, 20 gliders sections were realized along 58°N, between 22°W and 15°W. Depth-averaged currents estimated from gliders show very strong values (up to 45cm.s-1) associated with meso-scale variability, due particularly to eddies and subpolar mode water formation. The variability of the flow on the eastern slope of the Iceland <span class="hlt">basin</span> and on the Rockall Plateau is presented. Meridional absolute geostrophic transports are calculated from the glider data, and we discuss the vertical structure of the absolute meridional transport, especially the part associated with the North <span class="hlt">Atlantic</span> Current.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011ACP....1112567D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011ACP....1112567D"><span>A statistical analysis of North East <span class="hlt">Atlantic</span> (submicron) aerosol size distributions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dall'Osto, M.; Monahan, C.; Greaney, R.; Beddows, D. C. S.; Harrison, R. M.; Ceburnis, D.; O'Dowd, C. D.</p> <p>2011-12-01</p> <p>The Global Atmospheric Watch research station at Mace Head (Ireland) offers the possibility to sample some of the cleanest air masses being imported into Europe as well as some of the most polluted being exported out of Europe. We present a statistical cluster analysis of the physical characteristics of aerosol size distributions in air ranging from the cleanest to the most polluted for the year 2008. Data coverage achieved was 75% throughout the year. By applying the Hartigan-Wong k-Means method, 12 clusters were identified as systematically occurring. These 12 clusters could be further combined into 4 categories with similar characteristics, namely: coastal nucleation category (occurring 21.3 % of the time), open ocean nucleation category (occurring 32.6% of the time), background clean marine category (occurring 26.1% of the time) and anthropogenic category (occurring 20% of the time) aerosol size distributions. The coastal nucleation category is characterised by a clear and dominant nucleation mode at sizes less than 10 nm while the open ocean nucleation category is characterised by a dominant Aitken mode between 15 nm and 50 nm. The background clean marine aerosol exhibited a clear bimodality in the sub-micron size distribution, with although it should be noted that either the Aitken mode or the accumulation mode may dominate the number concentration. However, peculiar background clean marine size distributions with coarser accumulation modes are also observed during winter months. By contrast, the continentally-influenced size distributions are generally more monomodal (accumulation), albeit with traces of bimodality. The open ocean category occurs more often during May, June and July, corresponding with the North East (<span class="hlt">NE</span>) <span class="hlt">Atlantic</span> high biological period. Combined with the relatively high percentage frequency of occurrence (32.6%), this suggests that the marine biota is an important source of new nano aerosol particles in <span class="hlt">NE</span> <span class="hlt">Atlantic</span> Air.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.5054P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.5054P"><span>Why different gas flux velocity parameterizations result in so similar flux results in the North <span class="hlt">Atlantic</span>?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Piskozub, Jacek; Wróbel, Iwona</p> <p>2016-04-01</p> <p>The North <span class="hlt">Atlantic</span> is a crucial region for both ocean circulation and the carbon cycle. Most of ocean deep waters are produced in the <span class="hlt">basin</span> making it a large CO2 sink. The region, close to the major oceanographic centres has been well covered with cruises. This is why we have performed a study of net CO2 flux dependence upon the choice of gas transfer velocity k parameterization for this very region: the North <span class="hlt">Atlantic</span> including European Arctic Seas. The study has been a part of a ESA funded OceanFlux GHG Evolution project and, at the same time, a PhD thesis (of I.W) funded by Centre of Polar Studies "POLAR-KNOW" (a project of the Polish Ministry of Science). Early results have been presented last year at EGU 2015 as a PICO presentation EGU2015-11206-1. We have used FluxEngine, a tool created within an earlier ESA funded project (OceanFlux Greenhouse Gases) to calculate the North <span class="hlt">Atlantic</span> and global fluxes with different gas transfer velocity formulas. During the processing of the data, we have noticed that the North <span class="hlt">Atlantic</span> results for different k formulas are more similar (in the sense of relative error) that global ones. This was true both for parameterizations using the same power of wind speed and when comparing wind squared and wind cubed parameterizations. This result was interesting because North <span class="hlt">Atlantic</span> winds are stronger than the global average ones. Was the flux result similarity caused by the fact that the parameterizations were tuned to the North <span class="hlt">Atlantic</span> area where many of the early cruises measuring CO2 fugacities were performed? A closer look at the parameterizations and their history showed that not all of them were based on North <span class="hlt">Atlantic</span> data. Some of them were tuned to the South Ocean with even stronger winds while some were based on global budgets of 14C. However we have found two reasons, not reported before in the literature, for North <span class="hlt">Atlantic</span> fluxes being more similar than global ones for different gas transfer velocity parametrizations</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.V11B2783L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.V11B2783L"><span>Elevated helium isotope ratios in the northern Lau and north Fiji <span class="hlt">basins</span>: Intrusion of the Samoan hotspot or another OIB component?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lupton, J. E.; Price, A. A.; Jackson, M. G.; Arculus, R. J.; Nebel, O.</p> <p>2016-12-01</p> <p>The submarine volcanic rocks of the northern Lau <span class="hlt">Basin</span> exhibit a complex pattern in helium and radiogenic isotope ratios attributed to the interplay of depleted upper mantle, arc, and hotspot components. The seafloor lavas of the NW Lau Spreading Center (NWLSC) and Rochambeau Rifts have elevated 3He/4He ratios (12 - 28 Ra) indicating that a mantle plume component, possibly from Samoa, has influenced this extensional zone (Lupton et al., 2009). However, this hotspot helium is absent in the <span class="hlt">NE</span> Lau <span class="hlt">Basin</span>, which has MOR-type helium ( 8 Ra). We have analyzed helium isotope ratios in 40 additional submarine samples collected on the 2012 cruise of the R/V Southern Surveyor which extend the geographic coverage farther west into the Fiji <span class="hlt">Basin</span>. To the west of the NWLSC, several samples from the Futuna Volcanic Zone and the Futuna Spreading Center have elevated 3He/4He in the range of 12 - 20.9 Ra, presumably related to the same OIB influence detected along the nearby NW Lau backarc spreading system. Surprisingly, the <span class="hlt">NE</span> Fiji Triple Junction 1000 km to the west of the NWLSC, also has elevated 3He/4He up to 14.4 Ra. When radiogenic isotopes (Sr, Nd, Hf) are added to the picture, samples from the Futuna Volcanic Zone and from the <span class="hlt">NE</span> Fiji Triple Junction fall on a mixing trend between depleted MORB mantle and FOZO, as do samples from the Rochambeau Rifts and NWLSC. However, this trend is distinct from that of Samoa proper, suggesting that only a restricted (FOZO) portion of the Samoan plume is responsible for the elevated 3He/4He in the northern Lau and Fiji <span class="hlt">basins</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70046768','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70046768"><span>Attributes for MRB_E2RF1 Catchments by Major River <span class="hlt">Basins</span> in the Conterminous United States: Average Daily Maximum Temperature, 2002</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Wieczorek, Michael; LaMotte, Andrew E.</p> <p>2010-01-01</p> <p>The MRB_E2RF1 catchments are based on a modified version of the Environmental Protection Agency's (USEPA) ERF1_2 and include enhancements to support national and regional-scale surface-water quality modeling (Nolan and others, 2002; Brakebill and others, 2008). Data were compiled for every MRB_E2RF1 catchment for the conterminous United States covering New England and Mid-<span class="hlt">Atlantic</span> (MRB1), South <span class="hlt">Atlantic</span>-Gulf and Tennessee (MRB2), the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy (MRB3), the Missouri (MRB4), the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf (MRB5), the Rio Grande, Colorado, and the Great <span class="hlt">basin</span> (MRB6), the Pacific Northwest (MRB7) river <span class="hlt">basins</span>, and California (MRB8).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70046784','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70046784"><span>Attributes for MRB_E2RF1 Catchments by Major River <span class="hlt">Basins</span> in the Conterminous United States: Average Daily Minimum Temperature, 2002</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Wieczorek, Michael; LaMotte, Andrew E.</p> <p>2010-01-01</p> <p>The MRB_E2RF1 catchments are based on a modified version of the Environmental Protection Agency's (USEPA) ERF1_2 and include enhancements to support national and regional-scale surface-water quality modeling (Nolan and others, 2002; Brakebill and others, 2011). Data were compiled for every MRB_E2RF1 catchment for the conterminous United States covering New England and Mid-<span class="hlt">Atlantic</span> (MRB1), South <span class="hlt">Atlantic</span>-Gulf and Tennessee (MRB2), the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy (MRB3), the Missouri (MRB4), the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf (MRB5), the Rio Grande, Colorado, and the Great <span class="hlt">basin</span> (MRB6), the Pacific Northwest (MRB7) river <span class="hlt">basins</span>, and California (MRB8).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUOSAH53A..04R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUOSAH53A..04R"><span>Multidecadal Increase in North <span class="hlt">Atlantic</span> Coccolithophores and Potential Role of Increasing CO2</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rivero-Calle, S.; Gnanadesikan, A.; del Castillo, C. E.; Balch, W. M.; Guikema, S.</p> <p>2016-02-01</p> <p>As anthropogenic CO2 emissions acidify the oceans, calcifiers are expected to be negatively impacted. Using data from the Continuous Plankton Recorder, we show that coccolithophore occurrence in the North <span class="hlt">Atlantic</span> has increased from 2 to over 20% from 1965 through 2010. We used Random Forest models to examine more than 20 possible environmental drivers of this change. CO2 and the <span class="hlt">Atlantic</span> Multidecadal Oscillation were the best predictors. Since coccolithophore photosynthesis is strongly carbon-limited, we hypothesize that higher CO2 levels might be encouraging growth. A compilation of 41 independent laboratory studies supports our hypothesis. Our study shows a long-term <span class="hlt">basin</span>-scale increase in coccolithophores and suggests that increasing pCO2 and temperature accelerated the growth rate of a key phytoplankton group for carbon cycling.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24555308','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24555308"><span>Does Arctic sea ice reduction foster shelf-<span class="hlt">basin</span> exchange?</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ivanov, Vladimir; Watanabe, Eiji</p> <p>2013-12-01</p> <p>The recent shift in Arctic ice conditions from prevailing multi-year ice to first-year ice will presumably intensify fall-winter sea ice freezing and the associated salt flux to the underlying water column. Here, we conduct a dual modeling study whose results suggest that the predicted catastrophic consequences for the global thermohaline circulation (THC), as a result of the disappearance of Arctic sea ice, may not necessarily occur. In a warmer climate, the substantial fraction of dense water feeding the Greenland-Scotland overflow may form on Arctic shelves and cascade to the deep <span class="hlt">basin</span>, thus replenishing dense water, which currently forms through open ocean convection in the sub-Arctic seas. We have used a simplified model for estimating how increased ice production influences shelf-<span class="hlt">basin</span> exchange associated with dense water cascading. We have carried out case studies in two regions of the Arctic Ocean where cascading was observed in the past. The baseline range of buoyancy-forcing derived from the columnar ice formation was calculated as part of a 30-year experiment of the pan-Arctic coupled ice-ocean general circulation model (GCM). The GCM results indicate that mechanical sea ice divergence associated with lateral advection accounts for a significant part of the interannual variations in sea ice thermal production in the coastal polynya regions. This forcing was then rectified by taking into account sub-grid processes and used in a regional model with analytically prescribed bottom topography and vertical stratification in order to examine specific cascading conditions in the Pacific and <span class="hlt">Atlantic</span> sectors of the Arctic Ocean. Our results demonstrate that the consequences of enhanced ice formation depend on geographical location and shelf-<span class="hlt">basin</span> bathymetry. In the Pacific sector, strong density stratification in slope waters impedes noticeable deepening of shelf-origin water, even for the strongest forcing applied. In the <span class="hlt">Atlantic</span> sector, a 1.5x increase of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PrOce.142...30D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PrOce.142...30D"><span>Habitat suitability of the <span class="hlt">Atlantic</span> bluefin tuna by size class: An ecological niche approach</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Druon, Jean-Noël; Fromentin, Jean-Marc; Hanke, Alex R.; Arrizabalaga, Haritz; Damalas, Dimitrios; Tičina, Vjekoslav; Quílez-Badia, Gemma; Ramirez, Karina; Arregui, Igor; Tserpes, George; Reglero, Patricia; Deflorio, Michele; Oray, Isik; Saadet Karakulak, F.; Megalofonou, Persefoni; Ceyhan, Tevfik; Grubišić, Leon; MacKenzie, Brian R.; Lamkin, John; Afonso, Pedro; Addis, Piero</p> <p>2016-03-01</p> <p>An ecological niche modelling (ENM) approach was used to predict the potential feeding and spawning habitats of small (5-25 kg, only feeding) and large (>25 kg) <span class="hlt">Atlantic</span> bluefin tuna (ABFT), Thunnus thynnus, in the Mediterranean Sea, the North <span class="hlt">Atlantic</span> and the Gulf of Mexico. The ENM was built bridging knowledge on ecological traits of ABFT (e.g. temperature tolerance, mobility, feeding and spawning strategy) with patterns of selected environmental variables (chlorophyll-a fronts and concentration, sea surface current and temperature, sea surface height anomaly) that were identified using an extensive set of precisely geo-located presence data. The results highlight a wider temperature tolerance for larger fish allowing them to feed in the northern - high chlorophyll levels - latitudes up to the Norwegian Sea in the eastern <span class="hlt">Atlantic</span> and to the Gulf of Saint Lawrence in the western <span class="hlt">basin</span>. Permanent suitable feeding habitat for small ABFT was predicted to be mostly located in temperate latitudes in the North <span class="hlt">Atlantic</span> and in the Mediterranean Sea, as well as in subtropical waters off north-west Africa, while summer potential habitat in the Gulf of Mexico was found to be unsuitable for both small and large ABFTs. Potential spawning grounds were found to occur in the Gulf of Mexico from March-April in the south-east to April-May in the north, while favourable conditions evolve in the Mediterranean Sea from mid-May in the eastern to mid-July in the western <span class="hlt">basin</span>. Other secondary potential spawning grounds not supported by observations were predicted in the Azores area and off Morocco to Senegal during July and August when extrapolating the model settings from the Gulf of Mexico into the North <span class="hlt">Atlantic</span>. The presence of large ABFT off Florida and the Bahamas in spring was not explained by the model as is, however the environmental variables other than the sea surface height anomaly appeared to be favourable for spawning in part of this area. Defining key spatial and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.8729C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.8729C"><span>Control of hyper-extended passive margin architecture on subduction initiation with application to the Alps and present-day North <span class="hlt">Atlantic</span> ocean</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Candioti, Lorenzo; Bauville, Arthur; Picazo, Suzanne; Mohn, Geoffroy; Kaus, Boris</p> <p>2016-04-01</p> <p>Hyper-extended magma-poor margins are characterized by extremely thinned crust and partially serpentinized mantle exhumation. As this can act as a zone of weakness during a subsequent compression event, a hyper-extended margin can thus potentially facilitate subduction initiation. Hyper-extended margins are also found today as passive margins fringing the <span class="hlt">Atlantic</span> and North <span class="hlt">Atlantic</span> ocean, e.g. Iberia and New Foundland margins [1] and Porcupine, Rockwall and Hatton <span class="hlt">basins</span>. It has been proposed in the literature that hyper-extension in the Alpine Tethys does not exceed ~600 km in width [2]. The geodynamical evolution of the Alpine and <span class="hlt">Atlantic</span> passive margins are distinct: no subduction is yet initiated in the North <span class="hlt">Atlantic</span>, whereas the Alpine Tethys <span class="hlt">basin</span> has undergone subduction. Here, we investigate the control of the presence of a hyper-extended margin on subduction initiation. We perform high resolution 2D simulations considering realistic rheologies and temperature profiles for these locations. We systematically vary the length and thickness of the hyper-extended crust and serpentinized mantle, to better understand the conditions for subduction initiation. References: [1] G. Manatschal. New models for evolution of magma-poor rifted margins based on a review of data and concepts from West Iberia and the Alps. Int J Earth Sci (Geol Rundsch) (2004); 432-466. [2] G. Mohn, G. Manatschal, M. Beltrando, I. Haupert. The role of rift-inherited hyper-extension in alpine-type orogens. Terra Nova (2014); 347-353.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..1712353I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..1712353I"><span>North <span class="hlt">Atlantic</span> teleconnection patterns signature on sea level from satellite altimetry</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Iglesias, Isabel; Lázaro, Clara; Joana Fernandes, M.; Bastos, Luísa</p> <p>2015-04-01</p> <p>Presently, satellite altimetry record is long enough to appropriately study inter-annual signals in sea level anomaly and ocean surface circulation, allowing the association of teleconnection patterns of low-frequency variability with the response of sea level. The variability of the <span class="hlt">Atlantic</span> Ocean at <span class="hlt">basin</span>-scale is known to be complex in space and time, with the dominant mode occurring on annual timescales. However, interannual and decadal variability have already been documented in sea surface temperature. Both modes are believed to be linked and are known to influence sea level along coastal regions. The analysis of the sea level multiannual variability is thus essential to understand the present climate and its long-term variability. While in the open-ocean sea level anomaly from satellite altimetry currently possesses centimetre-level accuracy, satellite altimetry measurements become invalid or of lower accuracy along the coast due to the invalidity of the wet tropospheric correction (WTC) derived from on-board microwave radiometers. In order to adequately analyse long-term changes in sea level in the coastal regions, satellite altimetry measurements can be recovered by using an improved WTC computed from recent algorithms that combine wet path delays from all available observations (remote sensing scanning imaging radiometers, GNSS stations, microwave radiometers on-board satellite altimetry missions and numerical weather models). In this study, a 20-year (1993-2013) time series of multi-mission satellite altimetry (TOPEX/Poseidon, Jason-1, OSTM/Jason-2, ERS-1/2, ENVISAT, CryoSat-2 and SARAL), are used to characterize the North <span class="hlt">Atlantic</span> (NA) long-term variability on sea level at <span class="hlt">basin</span>-scale and analyse its response to several atmospheric teleconnections known to operate on the NA. The altimetry record was generated using an improved coastal WTC computed from either the GNSS-derived path Delay or the Data Combination methodologies developed by University of</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_23 --> <div id="page_24" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="461"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PrOce.132..273W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PrOce.132..273W"><span>Variability of sea surface height and circulation in the North <span class="hlt">Atlantic</span>: Forcing mechanisms and linkages</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Zeliang; Lu, Youyu; Dupont, Frederic; W. Loder, John; Hannah, Charles; G. Wright, Daniel</p> <p>2015-03-01</p> <p>Simulations with a coarse-resolution global ocean model during 1958-2004 are analyzed to understand the inter-annual and decadal variability of the North <span class="hlt">Atlantic</span>. Analyses of Empirical Orthogonal Functions (EOFs) suggest relationships among <span class="hlt">basin</span>-scale variations of sea surface height (SSH) and depth-integrated circulation, and the winter North <span class="hlt">Atlantic</span> Oscillation (NAO) or the East <span class="hlt">Atlantic</span> Pattern (EAP) indices. The linkages between the atmospheric indices and ocean variables are shown to be related to the different roles played by surface momentum and heat fluxes in driving ocean variability. In the subpolar region, variations of the gyre strength, SSH in the central Labrador Sea and the NAO index are highly correlated. Surface heat flux is important in driving variations of SSH and circulation in the upper ocean and decadal variations of the <span class="hlt">Atlantic</span> Meridional Overturning Circulation (AMOC). Surface momentum flux drives a significant barotropic component of flow and makes a noticeable contribution to the AMOC. In the subtropical region, momentum flux plays a dominant role in driving variations of the gyre circulation and AMOC; there is a strong correlation between gyre strength and SSH at Bermuda.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012PalOc..27.3221X','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012PalOc..27.3221X"><span>Deglacial variability of Antarctic Intermediate Water penetration into the North <span class="hlt">Atlantic</span> from authigenic neodymium isotope ratios</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Xie, Ruifang C.; Marcantonio, Franco; Schmidt, Matthew W.</p> <p>2012-09-01</p> <p>Understanding intermediate water circulation across the last deglacial is critical in assessing the role of oceanic heat transport associated with <span class="hlt">Atlantic</span> Meridional Overturning Circulation variability across abrupt climate events. However, the links between intermediate water circulation and abrupt climate events such as the Younger Dryas (YD) and Heinrich Event 1 (H1) are still poorly constrained. Here, we reconstruct changes in Antarctic Intermediate Water (AAIW) circulation in the subtropical North <span class="hlt">Atlantic</span> over the past 25 kyr by measuring authigenic neodymium isotope ratios in sediments from two sites in the Florida Straits. Our authigenic Nd isotope records suggest that there was little to no penetration of AAIW into the subtropical North <span class="hlt">Atlantic</span> during the YD and H1. Variations in the northward penetration of AAIW into the Florida Straits documented in our authigenic Nd isotope record are synchronous with multiple climatic archives, including the Greenland ice core δ18O record, the Cariaco <span class="hlt">Basin</span> atmosphere Δ14C reconstruction, the Bermuda Rise sedimentary Pa/Th record, and nutrient and stable isotope data from the tropical North <span class="hlt">Atlantic</span>. The synchroneity of our Nd records with multiple climatic archives suggests a tight connection between AAIW variability and high-latitude North <span class="hlt">Atlantic</span> climate change.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2000APS..DNP.AS046M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2000APS..DNP.AS046M"><span>Boo<span class="hlt">NE</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>McKenney, S.; Smith, D.; Koutsoliotas, S.; Church, E.; Stancu, I.; Vandalen, G. J.; Johnson, R. A.; Bugel, L.; Conrad, J. M.; Formaggio, J.; Shaevitz, M. H.; Tamminga, B.; Zimmerman, E.; Bhat, C.; Brown, B. C.; Ford, R.; Kasper, P.; Kourbanis, I.; Malensek, A.; Marsh, W.; Martin, P.; Mills, F.; Moore, C.; Russell, A.; Stefanski, R.; Eitel, K.; Garvey, G. T.; Hawker, E.; Louis, W. C.; Mills, G. B.; Sandberg, V.; Sapp, B.; Tayloe, R.; White, D. H.; Imlay, R.; Kim, H. J.; Malik, A.; Metcalf, W.; Sung, M.; Azemoon, T.; Ball, R.; Berbeco, R.; Riles, K.; Roe, B. P.; Wadia, N.; Yamamoto, J.; Bazarko, A. O.; Meyers, P. D.; Shoemaker, F. C.</p> <p>2000-10-01</p> <p>The phenomenon of neutrino oscillations, where a neutrino of one type spontaneously transforms into a neutrino of another type, has important and far-reaching consequences for particle physics and cosmology. For this phenomenon to occur, at least one neutrino must be massive and the heretofore observed lepton flavor conservation law must be violated. There are, at present, several results that indicate neutrino oscillations and it is not clear how and if these experimental results are indicative of the situation that actually obtains in Nature. There is evidence for a deficit of electrons neutrinos observed emanating from the sun. There is evidence for a deficit of electron neutrinos compared to muon neutrinos created in the upper atmosphere. And, there is an excess of electron antineutrinos observed in a beam of muon antineutrinos by the LSND experiment. The Booster Neutrino Experiment (Boo<span class="hlt">NE</span>) will focus on the final observation by definitely testing the LSND result. Boo<span class="hlt">NE</span> has been approved to run at Fermilab and is currently under construction. If the LSND result is due to oscillations, the first stage of the experiment (miniBoo<span class="hlt">NE</span>) will observe approximately 1000 oscillation events in the first calendar year of operation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013Ocgy...53..432T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013Ocgy...53..432T"><span>Transport of Antarctic Bottom Water through passages in the East Azores Ridge (37° N) in the East <span class="hlt">Atlantic</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tarakanov, R. Yu.; Morozov, E. G.; Gritsenko, A. M.; Demidova, T. A.; Makarenko, N. I.</p> <p>2013-07-01</p> <p>The structure of northerly overflow of Antarctic Bottom Water (AABW) through passages in the East Azores Ridge (37° N) in the East <span class="hlt">Atlantic</span> from the Madeira <span class="hlt">Basin</span> to the Iberian <span class="hlt">Basin</span> is studied on the basis of hydrographic measurements carried out by the Institute of Oceanology, Russian Academy of Sciences (RAS) in October 2011, historical World Ocean Data Base 2009, and recent data on the bottom topography. The overflow of the coldest layers of this water occurs through two passages with close depths at 16° W (Discovery Gap) and at 19°30' W (nameless Western Gap). It is shown that it is likely that the role of the latter passage in water transport was underestimated in earlier publications because the water (2.01°C) found in the region north of the Western Gap was cooler than in the region north of the Discovery Gap (2.03°C). In 2011, we found a decrease of 0.01°C in the AABW temperature near the bottom compared to previous measurements in 1982 (from 2.011°C to 2.002°C). Analysis of the historical database shows that this decrease is most likely caused by the cooling trend in the abyssal waters in the East <span class="hlt">Atlantic</span> <span class="hlt">basins</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/wsp/1899i/report.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/wsp/1899i/report.pdf"><span>Streamflow from the United States into the <span class="hlt">Atlantic</span> Ocean during 1931-1960</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Bue, Conrad D.</p> <p>1970-01-01</p> <p>Streamflow from the United States into the <span class="hlt">Atlantic</span> Ocean, between the international stream St. Croix River, inclusive, and Cape Sable, Fla., averaged about 355,000 cfs (cubic feet per second) during the 30-year period 1931-60, or roughly 20 percent of the water that, on the average flows out of the conterminous United States. The area drained by streams flowing into the <span class="hlt">Atlantic</span> Ocean is about 288,000 square miles, including the Canadian part of the St. Croix and Connecticut River <span class="hlt">basins</span>, or a little less than 10 percent of the area of the conterminous United States. Hence, the average streamflow into the <span class="hlt">Atlantic</span> Ocean, in terms of cubic feet per second per square mile, is about twice the national average of the flow that leaves the conterminous United States. Flow from about three-fourths of the area draining into the <span class="hlt">Atlantic</span> Ocean is gaged at streamflow measuring stations of the U.S. Geological Survey. The remaining one-fourth of the drainage area consists mostly of low-lying coastal areas from which the flow was estimated, largely on the basis of nearby gaging stations. Streamflow, in terms of cubic feet per second per square mile, decreases rather progressively from north to south. It averages nearly 2 cfs along the Maine coast, about 1 cfs along the North Carolina coast, and about 0.9 cfs along the Florida coast.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29397009','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29397009"><span>speed-<span class="hlt">ne</span>: Software to simulate and estimate genetic effective population size (<span class="hlt">Ne</span> ) from linkage disequilibrium observed in single samples.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hamilton, Matthew B; Tartakovsky, Maria; Battocletti, Amy</p> <p>2018-05-01</p> <p>The genetic effective population size, N e , can be estimated from the average gametic disequilibrium (r2^) between pairs of loci, but such estimates require evaluation of assumptions and currently have few methods to estimate confidence intervals. speed-<span class="hlt">ne</span> is a suite of matlab computer code functions to estimate <span class="hlt">Ne</span>^ from r2^ with a graphical user interface and a rich set of outputs that aid in understanding data patterns and comparing multiple estimators. speed-<span class="hlt">ne</span> includes functions to either generate or input simulated genotype data to facilitate comparative studies of <span class="hlt">Ne</span>^ estimators under various population genetic scenarios. speed-<span class="hlt">ne</span> was validated with data simulated under both time-forward and time-backward coalescent models of genetic drift. Three classes of estimators were compared with simulated data to examine several general questions: what are the impacts of microsatellite null alleles on <span class="hlt">Ne</span>^, how should missing data be treated, and does disequilibrium contributed by reduced recombination among some loci in a sample impact <span class="hlt">Ne</span>^. Estimators differed greatly in precision in the scenarios examined, and a widely employed <span class="hlt">Ne</span>^ estimator exhibited the largest variances among replicate data sets. speed-<span class="hlt">ne</span> implements several jackknife approaches to estimate confidence intervals, and simulated data showed that jackknifing over loci and jackknifing over individuals provided ~95% confidence interval coverage for some estimators and should be useful for empirical studies. speed-<span class="hlt">ne</span> provides an open-source extensible tool for estimation of <span class="hlt">Ne</span>^ from empirical genotype data and to conduct simulations of both microsatellite and single nucleotide polymorphism (SNP) data types to develop expectations and to compare <span class="hlt">Ne</span>^ estimators. © 2018 John Wiley & Sons Ltd.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/FR-2011-09-16/pdf/2011-23877.pdf','FEDREG'); return false;" href="https://www.gpo.gov/fdsys/pkg/FR-2011-09-16/pdf/2011-23877.pdf"><span>76 FR 57709 - <span class="hlt">Atlantic</span> Highly Migratory Species; <span class="hlt">Atlantic</span> Shark Management Measures</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collection.action?collectionCode=FR">Federal Register 2010, 2011, 2012, 2013, 2014</a></p> <p></p> <p>2011-09-16</p> <p>...-BA17.e <span class="hlt">Atlantic</span> Highly Migratory Species; <span class="hlt">Atlantic</span> Shark Management Measures AGENCY: National Marine... of Intent; control date for <span class="hlt">Atlantic</span> shark landings; request for comments. SUMMARY: This notice... would consider catch shares for the <span class="hlt">Atlantic</span> shark fisheries. NMFS published an Advanced Notice of...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003JAESc..21..543B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003JAESc..21..543B"><span>Regional tectonic framework of the Pranhita Godavari <span class="hlt">basin</span>, India</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Biswas, S. K.</p> <p>2003-03-01</p> <p>The Pranhita-Godavari Gondwana rift (PGR) has a co-genetic relationship with Permo-Triassic reactivation of the Narmada-Son Geofracture (NSG). The Satpura Gondwana <span class="hlt">basin</span> represents the terminal depocentre against the NSG, which restricted the northwestward propagation of the PGR. The <span class="hlt">NE</span>-SW tensional stress responsible for the NW-SE trending PGR could not propagate beyond the ramp formed by uplift along the NSG and transformed kinetically into an ENE directed horizontal shear along the NSG, inducing large scale strike-slip movements. The latter dynamics were responsible for ENE extension of the Satpura rift as a pull-apart <span class="hlt">basin</span>. The PGR extends up to the present east coast of India, where it is apparently terminated by the <span class="hlt">NE</span>-SW trending Bapatla ridge along the Eastern Ghat Rift (EGR). The subsurface data, however, shows that the PGR extends across the Bapatla ridge and continues beneath the Cretaceous-Tertiary sediments of the Krishna-Godavari <span class="hlt">basin</span> (KG) in the EGR. Thus, the Permo-Triassic PGR appears to have continued in the Indo-Antarctic plate before the Cretaceous break up. The EGR, during break up of the continents, cuts across the PGR and the KG <span class="hlt">basin</span> was superimposed on it. The PGR site is located on a paleo-suture between the Dharwar and Bastar proto-cratons. The master faults developed bordering the rift, and the intra-rift higher order faults followed the pre-existing fabric. The transverse transfer zones manifested as basement ridges, divide the rift into segments of tectono-sedimentary domains. The major domains are the Chintalapudi, Godavari, and Chandrapur sub-<span class="hlt">basins</span>, each of which subsided differentially. The central Godavari sub-<span class="hlt">basin</span> subsided most and shows maximum structural complexity and sediment accommodation. The rifting started with initial half-graben faulting along the northeastern master fault and expanded by successive half graben faulting. This gave rise to intra-<span class="hlt">basinal</span> horsts and grabens, which exercised control on the syn</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUOSHE13A..03L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUOSHE13A..03L"><span>What Drives the Variability of the <span class="hlt">Atlantic</span> Water Circulation in the Arctic Ocean?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lique, C.; Johnson, H. L.</p> <p>2016-02-01</p> <p>The <span class="hlt">Atlantic</span> Water (AW) layer in the Arctic <span class="hlt">Basin</span> is isolated from the atmosphere by the overlaying surface layer; yet observations of the AW pan-Arctic boundary current have revealed that the velocities in this layer exhibit significant variations on all timescales. Here, analysis of a global ocean/sea ice model hindcast, complemented by experiments performed with an idealized process model, are used to investigate what controls the variability of AW circulation, with a focus on the role of wind forcing. The AW circulation carries the imprint of wind variations, both remotely over the Nordic and Barents seas where they force variability on the AW inflow to the Arctic <span class="hlt">Basin</span>, and locally over the Arctic <span class="hlt">Basin</span> through the forcing of the wind-driven Beaufort gyre, which modulates and transfers the wind variability to the AW layer. Our results further suggest that understanding variability in the large amount of heat contained within the AW layer requires a better understanding of the circulation within both AW and surface layers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018NatCC...8..493M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018NatCC...8..493M"><span>Model tropical <span class="hlt">Atlantic</span> biases underpin diminished Pacific decadal variability</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>McGregor, Shayne; Stuecker, Malte F.; Kajtar, Jules B.; England, Matthew H.; Collins, Mat</p> <p>2018-06-01</p> <p>Pacific trade winds have displayed unprecedented strengthening in recent decades1. This strengthening has been associated with east Pacific sea surface cooling2 and the early twenty-first-century slowdown in global surface warming2,3, amongst a host of other substantial impacts4-9. Although some climate models produce the timing of these recently observed trends10, they all fail to produce the trend magnitude2,11,12. This may in part be related to the apparent model underrepresentation of low-frequency Pacific Ocean variability and decadal wind trends2,11-13 or be due to a misrepresentation of a forced response1,14-16 or a combination of both. An increasingly prominent connection between the Pacific and <span class="hlt">Atlantic</span> <span class="hlt">basins</span> has been identified as a key driver of this strengthening of the Pacific trade winds12,17-20. Here we use targeted climate model experiments to show that combining the recent <span class="hlt">Atlantic</span> warming trend with the typical climate model bias leads to a substantially underestimated response for the Pacific Ocean wind and surface temperature. The underestimation largely stems from a reduction and eastward shift of the atmospheric heating response to the tropical <span class="hlt">Atlantic</span> warming trend. This result suggests that the recent Pacific trends and model decadal variability may be better captured by models with improved mean-state climatologies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70046731','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70046731"><span>Attributes for MRB_E2RF1 Catchments by Major River <span class="hlt">Basins</span> in the Conterminous United States: Level 3 Ecoregions</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Wieczorek, Michael; LaMotte, Andrew E.</p> <p>2010-01-01</p> <p>This tabular data set represents the estimated area of level 3 ecological landscape regions (ecoregions), as defined by Omernik (1987), compiled for every MRB_E2RF1 catchment of the Major River <span class="hlt">Basins</span> (MRBs, Crawford and others, 2006). The source data set is Level III Ecoregions of the Continental United States (U.S. Environmental Protection Agency, 2003). The MRB_E2RF1 catchments are based on a modified version of the U.S. Environmental Protection Agency's (USEPA) ERF1_2 and include enhancements to support national and regional-scale surface-water quality modeling (Nolan and others, 2002; Brakebill and others, 2011). Data were compiled for every MRB_E2RF1 catchment for the conterminous United States covering New England and Mid-<span class="hlt">Atlantic</span> (MRB1), South <span class="hlt">Atlantic</span>-Gulf and Tennessee (MRB2), the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy (MRB3), the Missouri (MRB4), the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf (MRB5), the Rio Grande, Colorado, and the Great <span class="hlt">basin</span> (MRB6), the Pacific Northwest (MRB7) river <span class="hlt">basins</span>, and California (MRB8).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFMPP41B1762N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFMPP41B1762N"><span>Paleohydrology of tropical South America and paleoceanography of the tropical <span class="hlt">Atlantic</span> as deduced from two new sediment cores on the Brazilian continental slope</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nace, T.; Baker, P. A.; Dwyer, G. S.; Silva, C. G.; Hollander, D. J.; Rigsby, C. A.; Giosan, L.; Burns, S. J.</p> <p>2011-12-01</p> <p>Paleoclimate/paleoceanographic reconstructions of the Amazon <span class="hlt">Basin</span>, Brazilian Nordeste, and western equatorial <span class="hlt">Atlantic</span> have been undertaken on two new sediment cores located on the Brazilian continental slope (Core CDH-5 at 1708 mbsl, 4N, 48W, 32m long, ~30 ka record; Core CDH-86 at 3708 mbsl, 0N/S, 44W, 30m long, ~100ka record). High-resolution XRF analyses of Fe, Ti, and Ca are used to define the paleohydrologic history of the adjacent continent at both sites. Large and abrupt excursions of Ti/Ca ratios are observed in both cores, but are significantly better defined in the southern core, representative of Nordeste conditions. In this core there are a total of 9 Ti/Ca excursions, the oldest recovered dating to ~98ka. These excursions correlate well with Heinrich events from the North <span class="hlt">Atlantic</span>. High-resolution stable oxygen isotopic analysis and Mg/Ca paleothermometry undertaken on the near-surface-dwelling planktic foraminiferal species Globierinoides ruber provide a picture of paleoceanographic forcings in the western equatorial <span class="hlt">Atlantic</span>. The northern and southern cores respectively exhibit rapid warming of ~3C and ~3.5C between the last glacial maximum and the early Holocene. Furthermore, in almost all cases, during the last glacial stage, there was a 0.5C to 2C warming of the western equatorial <span class="hlt">Atlantic</span> during the periods of high Ti/Ca ratios that correlate with Heinrich events. Thus, as observed in some previous studies, the western equatorial <span class="hlt">Atlantic</span> was warm and the adjacent southern tropical continent was wet at the same time that the high-latitude North <span class="hlt">Atlantic</span> was cold. The largely accepted paradigm is that Northern hemisphere cold events result in a southward migration of the Intertropical Convergence Zone (ITCZ), contributing to drier conditions at the northern extent of the ITCZ annual range (Cariaco <span class="hlt">Basin</span>) and increased precipitation in the southern tropics of South America. The ITCZ appears to have been influenced by millennial variability of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PrOce.158..203G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PrOce.158..203G"><span>Ecological dispersal barrier across the equatorial <span class="hlt">Atlantic</span> in a migratory planktonic copepod</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Goetze, Erica; Hüdepohl, Patricia T.; Chang, Chantel; Van Woudenberg, Lauren; Iacchei, Matthew; Peijnenburg, Katja T. C. A.</p> <p>2017-11-01</p> <p>Resolving the large-scale genetic structure of plankton populations is important to understanding their responses to climate change. However, few studies have reported on the presence and geographic extent of genetically distinct populations of marine zooplankton at ocean-<span class="hlt">basin</span> scales. Using mitochondrial sequence data (mtCOI, 718 animals) from 18 sites across a <span class="hlt">basin</span>-scale <span class="hlt">Atlantic</span> transect (39°N-40°S), we show that populations of the dominant migratory copepod, Pleuromamma xiphias, are genetically subdivided across subtropical and tropical waters (global FST = 0.15, global ΦST = 0.21, both P < 0.00001), with a major genetic break observed in the equatorial <span class="hlt">Atlantic</span> (between gyre FCT and ΦCT = 0.23, P < 0.005). This equatorial region of strong genetic transition coincides with an area of low abundance for the species. Transitional regions between the subtropical gyres and the equatorial province also harbor a distinct mitochondrial clade (clade 2), have higher haplotype and nucleotide diversities relative to the northern and/or southern subtropical gyres (e.g., mean h = 0.831 EQ, 0.742 North, 0.594 South, F2,11 = 20.53, P < 0.001), and are genetically differentiated from the majority of sites in the central gyre and temperate zones of the same hemisphere (significant pairwise ΦST 0.038-0.267, 79% significant). Our observations support the hypothesis that regions of low abundance within species mark areas of suboptimal habitat that serve as dispersal barriers for marine plankton, and we suggest that this may be a dominant mechanism driving the large-scale genetic structure of zooplankton species. Our results also demonstrate the potential importance of the <span class="hlt">Atlantic</span> equatorial province as a region of evolutionary novelty for the holoplankton.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUOSPC53A..07L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUOSPC53A..07L"><span><span class="hlt">Atlantic</span> Induced Pan-tropical Climate Variability in the Upper-ocean and Atmosphere</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, X.; Xie, S. P.; Gille, S. T.; Yoo, C.</p> <p>2016-02-01</p> <p>During the last three decades, tropical sea surface temperature (SST) exhibited dipole-like trends, with warming over the tropical <span class="hlt">Atlantic</span> and Indo-Western Pacific but cooling over the Eastern Pacific. The Eastern Pacific cooling has recently been identified as a driver of the global warming hiatus. Previous studies revealed atmospheric bridges between the tropical Pacific, <span class="hlt">Atlantic</span>, and Indian Ocean, which could potentially contribute to this zonally asymmetric SST pattern. However, the mechanisms and the interactions between these teleconnections remain unclear. To investigate these questions, we performed a `pacemaker' simulation by restoring the tropical <span class="hlt">Atlantic</span> SST changes in a state-of-the-art climate model - the CESM1. Results show that the <span class="hlt">Atlantic</span> plays a key role in initiating the tropical-wide teleconnections, and the <span class="hlt">Atlantic</span>-induced anomalies contribute 55%-75% of the total tropical SST and circulation changes during the satellite era. A hierarchy of oceanic and atmospheric models are then used to investigate the physical mechanisms of these teleconnections: the <span class="hlt">Atlantic</span> warming enhances atmospheric deep convection, drives easterly wind anomalies over the Indo-Western Pacific through the Kelvin wave, and westerly anomalies over the eastern Pacific as Rossby waves, in line with Gill's solution (Fig1a). These wind changes induce an Indo-Western Pacific warming via the wind-evaporation-SST effect, and this warming intensifies the La Niña-type response in the upper Pacific Ocean by enhancing the easterly trade winds and through the Bjerknes ocean-dynamical processes (Fig1b). The teleconnection finally develops into a tropical-wide SST dipole pattern with an enhanced trade wind and Walker circulation, similar as the observed changes during the satellite era. This mechanism reveals that the tropical ocean <span class="hlt">basins</span> are more tightly connected than previously thought, and the <span class="hlt">Atlantic</span> plays a key role in the tropical climate pattern formation and further the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1998JCli...11..551B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1998JCli...11..551B"><span>The Relationships between Tropical Pacific and <span class="hlt">Atlantic</span> SST and Northeast Brazil Monthly Precipitation.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bertacchi Uvo, Cintia; Repelli, Carlos A.; Zebiak, Stephen E.; Kushnir, Yochanan</p> <p>1998-04-01</p> <p>The monthly patterns of northeast Brazil (NEB) precipitation are analyzed in relation to sea surface temperature (SST) in the tropical Pacific and <span class="hlt">Atlantic</span> Oceans, using singular value decomposition. It is found that the relationships between precipitation and SST in both <span class="hlt">basins</span> vary considerably throughout the rainy season (February-May). In January, equatorial Pacific SST is weakly correlated with precipitation in small areas of southern NEB, but <span class="hlt">Atlantic</span> SST shows no significant correlation with regional precipitation. In February, Pacific SST is not well related to precipitation, but south equatorial <span class="hlt">Atlantic</span> SST is positively correlated with precipitation over the northern Nordeste, the latter most likely reflecting an anomalously early (or late) southward migration of the ITCZ precipitation zone. During March, equatorial Pacific SST is negatively correlated with Nordeste precipitation, but no consistent relationship between precipitation and <span class="hlt">Atlantic</span> SST is found. <span class="hlt">Atlantic</span> SST-precipitation correlations for April and May are the strongest found among all months or either ocean. Precipitation in the Nordeste is positively correlated with SST in the south tropical <span class="hlt">Atlantic</span> and negatively correlated with SST in the north tropical <span class="hlt">Atlantic</span>. These relationships are strong enough to determine the structure of the seasonal mean SST-precipitation correlations, even though the corresponding patterns for the earlier months of the season are quite different. Pacific SST-precipitation correlations for April and May are similar to those for March. Extreme wet (dry) years for the Nordeste occur when both Pacific and <span class="hlt">Atlantic</span> SST patterns for April and May occur simultaneously. A separate analysis reinforces previous findings in showing that SST in the tropical Pacific and the northern tropical <span class="hlt">Atlantic</span> are positively correlated and that tropical Pacific-south <span class="hlt">Atlantic</span> correlations are negligible.Time-lagged analyses show the potential for forecasting either seasonal mean</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140010711','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140010711"><span>Two Distinct Roles of <span class="hlt">Atlantic</span> SSTs in ENSO Variability: North Tropical <span class="hlt">Atlantic</span> SST and <span class="hlt">Atlantic</span> Nino</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ham, Yoo-Geun; Kug, Jong-Seong; Park, Jong-Yeon</p> <p>2013-01-01</p> <p>Two distinct roles of the <span class="hlt">Atlantic</span> sea surface temperatures (SSTs), namely, the North Tropical <span class="hlt">Atlantic</span> (NTA) SST and the <span class="hlt">Atlantic</span> Nino, on the El Nino-Southern Oscillation (ENSO) variability are investigated using the observational data from 1980 to 2010 and coupled model experiments. It appears that the NTA SST and the <span class="hlt">Atlantic</span> Nino can be used as two independent predictors for predicting the development of ENSO events in the following season. Furthermore, they are likely to be linked to different types of El Nino events. Specifically, the NTA SST cooling during February, March, and April contributes to the central Pacific warming at the subsequent winter season, while the negative <span class="hlt">Atlantic</span> Nino event during June, July, and August contributes to enhancing the eastern Pacific warming. The coupled model experiments support these results. With the aid of a lagged inverse relationship, the statistical forecast using two <span class="hlt">Atlantic</span> indices can successfully predict various ENSO indices.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70031367','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70031367"><span>Large fluctuations of dissolved oxygen in the Indian and Pacific oceans during Dansgaard-Oeschger oscillations caused by variations of North <span class="hlt">Atlantic</span> Deep Water subduction</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Schmittner, A.; Galbraith, E.D.; Hostetler, S.W.; Pedersen, Thomas F.; Zhang, R.</p> <p>2007-01-01</p> <p>Paleoclimate records from glacial Indian and Pacific oceans sediments document millennial-scale fluctuations of subsurface dissolved oxygen levels and denitrification coherent with North <span class="hlt">Atlantic</span> temperature oscillations. Yet the mechanism of this teleconnection between the remote ocean <span class="hlt">basins</span> remains elusive. Here we present model simulations of the oxygen and nitrogen cycles that explain how changes in deepwater subduction in the North <span class="hlt">Atlantic</span> can cause large and synchronous variations of oxygen minimum zones, throughout the Northern Hemisphere of the Indian and Pacific oceans, consistent with the paleoclimate records. Cold periods in the North <span class="hlt">Atlantic</span> are associated with reduced nutrient delivery to the upper Indo-Pacific oceans, thereby decreasing productivity. Reduced export production diminishes subsurface respiration of organic matter leading to higher oxygen concentrations and less denitrification. This effect of reduced oxygen consumption dominates at low latitudes. At high latitudes in the Southern Ocean and North Pacific, increased mixed layer depths and steepening of isopycnals improve ocean ventilation and oxygen supply to the subsurface. Atmospheric teleconnections through changes in wind-driven ocean circulation modify this <span class="hlt">basin</span>-scale pattern regionally. These results suggest that changes in the <span class="hlt">Atlantic</span> Ocean circulation, similar to those projected by climate models to possibly occur in the centuries to come because of anthropogenic climate warming, can have large effects on marine ecosystems and biogeochemical cycles even in remote areas. Copyright 2007 by the American Geophysical Union.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007PalOc..22.3207S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007PalOc..22.3207S"><span>Large fluctuations of dissolved oxygen in the Indian and Pacific oceans during Dansgaard-Oeschger oscillations caused by variations of North <span class="hlt">Atlantic</span> Deep Water subduction</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schmittner, Andreas; Galbraith, Eric D.; Hostetler, Steven W.; Pedersen, Thomas F.; Zhang, Rong</p> <p>2007-09-01</p> <p>Paleoclimate records from glacial Indian and Pacific oceans sediments document millennial-scale fluctuations of subsurface dissolved oxygen levels and denitrification coherent with North <span class="hlt">Atlantic</span> temperature oscillations. Yet the mechanism of this teleconnection between the remote ocean <span class="hlt">basins</span> remains elusive. Here we present model simulations of the oxygen and nitrogen cycles that explain how changes in deepwater subduction in the North <span class="hlt">Atlantic</span> can cause large and synchronous variations of oxygen minimum zones throughout the Northern Hemisphere of the Indian and Pacific oceans, consistent with the paleoclimate records. Cold periods in the North <span class="hlt">Atlantic</span> are associated with reduced nutrient delivery to the upper Indo-Pacific oceans, thereby decreasing productivity. Reduced export production diminishes subsurface respiration of organic matter leading to higher oxygen concentrations and less denitrification. This effect of reduced oxygen consumption dominates at low latitudes. At high latitudes in the Southern Ocean and North Pacific, increased mixed layer depths and steepening of isopycnals improve ocean ventilation and oxygen supply to the subsurface. Atmospheric teleconnections through changes in wind-driven ocean circulation modify this <span class="hlt">basin</span>-scale pattern regionally. These results suggest that changes in the <span class="hlt">Atlantic</span> Ocean circulation, similar to those projected by climate models to possibly occur in the centuries to come because of anthropogenic climate warming, can have large effects on marine ecosystems and biogeochemical cycles even in remote areas.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017DSRII.141..285P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017DSRII.141..285P"><span>Identifying Important <span class="hlt">Atlantic</span> Areas for the conservation of Balearic shearwaters: Spatial overlap with conservation areas</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pérez-Roda, Amparo; Delord, Karine; Boué, Amélie; Arcos, José Manuel; García, David; Micol, Thierry; Weimerskirch, Henri; Pinaud, David; Louzao, Maite</p> <p>2017-07-01</p> <p>Marine protected areas (MPAs) are considered one of the main tools in both fisheries and conservation management to protect threatened species and their habitats around the globe. However, MPAs are underrepresented in marine environments compared to terrestrial environments. Within this context, we studied the <span class="hlt">Atlantic</span> non-breeding distribution of the southern population of Balearic shearwaters (Puffinus mauretanicus) breeding in Eivissa during the 2011-2012 period based on global location sensing (GLS) devices. Our objectives were (1) to identify overall Important <span class="hlt">Atlantic</span> Areas (IAAs) from a southern population, (2) to describe spatio-temporal patterns of oceanographic habitat use, and (3) to assess whether existing conservation areas (Natura 2000 sites and marine Important Bird Areas (IBAs)) cover the main IAAs of Balearic shearwaters. Our results highlighted that the <span class="hlt">Atlantic</span> staging (from June to October in 2011) dynamic of the southern population was driven by individual segregation at both spatial and temporal scales. Individuals ranged in the North-East <span class="hlt">Atlantic</span> over four main IAAs (Bay of Biscay: BoB, Western Iberian shelf: WIS, Gulf of Cadiz: GoC, West of Morocco: WoM). While most individuals spent more time on the WIS or in the GoC, a small number of birds visited IAAs at the extremes of their <span class="hlt">Atlantic</span> distribution range (i.e., BoB and WoM). The chronology of the arrivals to the IAAs showed a latitudinal gradient with northern areas reached earlier during the <span class="hlt">Atlantic</span> staging. The IAAs coincided with the most productive areas (higher chlorophyll a values) in the <span class="hlt">NE</span> <span class="hlt">Atlantic</span> between July and October. The spatial overlap between IAAs and conservation areas was higher for Natura 2000 sites than marine IBAs (areas with and without legal protection, respectively). Concerning the use of these areas, a slightly higher proportion of estimated positions fell within marine IBAs compared to designated Natura 2000 sites, with Spanish and Portuguese conservation</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.9044P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.9044P"><span>Evolution of the eastern Austrian Molasse <span class="hlt">Basin</span>: The Lower Miocene (Burdigalian) as a key to the understanding of the Eastern Alps - Molasse <span class="hlt">Basin</span> system</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Palzer, Markus; Knierzinger, Wolfgang; Wagreich, Michael; Meszar, Maria E.; Gier, Susanne; Soliman, Ali; -Elena Kallanxhi, Mǎdǎlina</p> <p>2016-04-01</p> <p>The eastern Austrian Molasse <span class="hlt">Basin</span> is situated between the Bohemian Massif, the Waschberg-Zone and the Alps. There, sands of the Lower Miocene (Upper Ottnangian) Traisen Formation represent a clastic interval at the top of pelitic Schlier successions, which is correlated with the global sea level drop Bur3 (Burdigalian). North of the Danube River, the continuation of the Traisen-Formation is overlain by the Karpatian Laa-Formation. Drill cores from OMV-wells predominantly from the continuation of the Traisen Formation in deep parts in the <span class="hlt">NE</span> of the <span class="hlt">basin</span> show hundreds of meters of pelites with intersections of sands. Contrary to the exposed, mainly brackish TF, a turbiditic and predominantly fully marine deep-water environment is inferred from the cores. Profiles of carbonate content, XRD, XRF, whole rock chemistry, clay minerals, calcareous nannoplankton and dinoflagellate cysts of 7 wells were investigated representing a <span class="hlt">NE</span>-SW transect through the LAMB. Based on these data, a new stratigraphy for the Burdigalian distal parts of the LAMB can be defined and correlated with the proximal units. The Traisen Formation and its equivalents are characterized at their base by an increased clastic input in the south and by increasing mica content in the northern parts. The complete interval is characterized by the decreased carbonate content. The XRD data show strongly reduced calcite contents which goe hand in hand with the absence of nannoplankton. Whether the signal is related to a crisis in primary production or to carbonate dissolution remains unclear. The absence of dinoflagellate cysts and the chemical data (reduced B/Al* ratios indicate reduced salinity) are considered as an argument for an environmental crisis. However, the absence of resedimented Cretaceous to Paleocene nannofossils, which usually occur together with the autochthonous NN4-nannofossils, indicates carbonate dissolution. These results enable us to define a <span class="hlt">basinal</span> interval as equivalent to the</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_24 --> <div id="page_25" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="481"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.H43D1671W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.H43D1671W"><span>Climate controls on streamflow variability in the Missouri River <span class="hlt">Basin</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wise, E.; Woodhouse, C. A.; McCabe, G. J., Jr.; Pederson, G. T.; St-Jacques, J. M.</p> <p>2017-12-01</p> <p>The Missouri River's hydroclimatic variability presents a challenge for water managers, who must balance many competing demands on the system. Water resources in the Missouri River <span class="hlt">Basin</span> (MRB) have increasingly been challenged by the droughts and floods that have occurred over the past several decades and the potential future exacerbation of these extremes by climate change. Here, we use observed and modeled hydroclimatic data and estimated natural flow records to describe the climatic controls on streamflow in the upper and lower portions of the MRB, examine atmospheric and oceanic patterns associated with high- and low-flow years, and investigate trends in climate and streamflow over the instrumental period. Results indicate that the two main source regions for total outflow, in the uppermost and lowermost parts of the <span class="hlt">basin</span>, are under the influence of very different sets of climatic controls. Winter precipitation, impacted by changes in zonal versus meridional flow from the Pacific Ocean, as well as spring precipitation and temperature, play a key role in surface water supply variability in the upper <span class="hlt">basin</span>. Lower <span class="hlt">basin</span> flow is significantly correlated with precipitation in late spring and early summer, indicative of <span class="hlt">Atlantic</span>-influenced circulation variability affecting the flow of moisture from the Gulf of Mexico. The upper <span class="hlt">basin</span>, with decreasing snowpack and streamflow and warming spring temperatures, will be less likely to provide important flow supplements to the lower <span class="hlt">basin</span> in the future.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16.1508S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16.1508S"><span>Geomorphological context of the <span class="hlt">basins</span> of Northwestern Peninsular Malaysia</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sautter, Benjamin; Pubellier, Manuel; Menier, David</p> <p>2014-05-01</p> <p>Geomorphological context of the <span class="hlt">basins</span> of Northwestern Peninsular Malaysia Benjamin Sautter, Manuel Pubellier, David Menier Department of Petroleum Geosciences, Universiti Teknologi PETRONAS CNRS-UMR 8538, Ecole Normale Supérieure, 24, Rue Lhomond, 75231, Paris Cedex 05, France Petroleum <span class="hlt">basins</span> of Western Malaysia are poorly known and their formation is controlled by the Tertiary stress variations applied on Mesozoic basement structures. Among these are the Paleozoic-Mesozoic Bentong Raub, Inthanon, and Nan suture zones. By the end of Mesozoic times, the arrival of Indian plate was accompanied by strike slip deformation, accommodated by several Major Faults (Sagaing, Three Pagodas, Mae Ping, Red River, Ranong and Klong Marui Faults). Due to changes in the boundary forces, these areas of weakness (faults) were reactivated during the Tertiary, leading to the opening of <span class="hlt">basins</span> in most of Sundaland. Within this framework, while most of the Sundaland records stretching of the crust and opening of <span class="hlt">basins</span> (SCS, Malay, Penyu, Natuna, Mergui) during the Cenozoics, Peninsular Malaysia and the Strait of Malacca are considered to be in tectonic quiescence by most of the authors. We present the geomorphology of the Northwestern Malaysia Peninsula with emphasis on the deformations onshore from the Bentong Raub Suture Zone to the Bok Bak Fault, via the Kinta Valley, and offshore from the Port Klang Graben to the North Penang Graben. By analyzing Digital Elevation Model from ASTER and SRTM data, two main directions of fractures in the granitic plutons are highlighted: NW-SE to W-E sigmoidal faults and N-S to <span class="hlt">NE</span>-SW linear fractures which seem to cross-cut the others. In the field in the area of the Kinta Valley (Western Belt, NW Peninsular Malaysia), granitic bodies show intense fracturation reflecting several stages of deformation. The granites are generally syntectonic and do not cut fully across the Late Paleozoic platform limestone. Two sets of fractures (NW-SE and <span class="hlt">NE</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70046771','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70046771"><span>Catchments by Major River <span class="hlt">Basins</span> in the Conterminous United States: 30-Year Average Daily Minimum Temperature, 1971-2000</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Wieczorek, Michael; LaMotte, Andrew E.</p> <p>2010-01-01</p> <p>This tabular data set represents thecatchment-average for the 30-year (1971-2000) average daily minimum temperature in Celsius multiplied by 100 compiled for every MRB_E2RF1 catchment of selected Major River <span class="hlt">Basins</span> (MRBs, Crawford and others, 2006). The source data were the United States Average Monthly or Annual Minimum Temperature, 1971 - 2000 raster data set produced by the PRISM Group at Oregon State University. The MRB_E2RF1 catchments are based on a modified version of the Environmental Protection Agency's (USEPA) ERF1_2 and include enhancements to support national and regional-scale surface-water quality modeling (Nolan and others, 2002; Brakebill and others, 2011). Data were compiled for every MRB_E2RF1 catchment for the conterminous United States covering New England and Mid-<span class="hlt">Atlantic</span> (MRB1), South <span class="hlt">Atlantic</span>-Gulf and Tennessee (MRB2), the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy (MRB3), the Missouri (MRB4), the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf (MRB5), the Rio Grande, Colorado, and the Great <span class="hlt">basin</span> (MRB6), the Pacific Northwest (MRB7) river <span class="hlt">basins</span>, and California (MRB8).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/FR-2012-06-26/pdf/2012-15575.pdf','FEDREG'); return false;" href="https://www.gpo.gov/fdsys/pkg/FR-2012-06-26/pdf/2012-15575.pdf"><span>77 FR 38011 - <span class="hlt">Atlantic</span> Highly Migratory Species; <span class="hlt">Atlantic</span> Bluefin Tuna Fisheries</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collection.action?collectionCode=FR">Federal Register 2010, 2011, 2012, 2013, 2014</a></p> <p></p> <p>2012-06-26</p> <p>.... 110210132-1275-02] RIN 0648-XC055 <span class="hlt">Atlantic</span> Highly Migratory Species; <span class="hlt">Atlantic</span> Bluefin Tuna Fisheries AGENCY... northern area fishery for large medium and giant <span class="hlt">Atlantic</span> bluefin tuna (BFT) for the remainder of 2012... INFORMATION: Regulations implemented under the authority of the <span class="hlt">Atlantic</span> Tunas Convention Act (16 U.S.C. 971...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26089752','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26089752"><span>The <span class="hlt">Ne</span>Xus data format.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Könnecke, Mark; Akeroyd, Frederick A; Bernstein, Herbert J; Brewster, Aaron S; Campbell, Stuart I; Clausen, Björn; Cottrell, Stephen; Hoffmann, Jens Uwe; Jemian, Pete R; Männicke, David; Osborn, Raymond; Peterson, Peter F; Richter, Tobias; Suzuki, Jiro; Watts, Benjamin; Wintersberger, Eugen; Wuttke, Joachim</p> <p>2015-02-01</p> <p><span class="hlt">Ne</span>Xus is an effort by an international group of scientists to define a common data exchange and archival format for neutron, X-ray and muon experiments. <span class="hlt">Ne</span>Xus is built on top of the scientific data format HDF5 and adds domain-specific rules for organizing data within HDF5 files, in addition to a dictionary of well defined domain-specific field names. The <span class="hlt">Ne</span>Xus data format has two purposes. First, it defines a format that can serve as a container for all relevant data associated with a beamline. This is a very important use case. Second, it defines standards in the form of application definitions for the exchange of data between applications. <span class="hlt">Ne</span>Xus provides structures for raw experimental data as well as for processed data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/1391966-nexus-data-format','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/1391966-nexus-data-format"><span>The <span class="hlt">Ne</span>Xus data format</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Könnecke, Mark; Akeroyd, Frederick A.; Bernstein, Herbert J.</p> <p>2015-01-30</p> <p><span class="hlt">Ne</span>Xus is an effort by an international group of scientists to define a common data exchange and archival format for neutron, X-ray and muon experiments. <span class="hlt">Ne</span>Xus is built on top of the scientific data format HDF5 and adds domain-specific rules for organizing data within HDF5 files, in addition to a dictionary of well defined domain-specific field names. The <span class="hlt">Ne</span>Xus data format has two purposes. First, it defines a format that can serve as a container for all relevant data associated with a beamline. This is a very important use case. Second, it defines standards in the form of application definitionsmore » for the exchange of data between applications. <span class="hlt">Ne</span>Xus provides structures for raw experimental data as well as for processed data.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007MAP....97..255V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007MAP....97..255V"><span>Tornado outbreaks associated with landfalling hurricanes in the North <span class="hlt">Atlantic</span> <span class="hlt">Basin</span>: 1954 2004</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Verbout, S. M.; Schultz, D. M.; Leslie, L. M.; Brooks, H. E.; Karoly, D. J.; Elmore, K. L.</p> <p>2007-08-01</p> <p>Tornadoes are a notable potential hazard associated with landfalling hurricanes. The purpose of this paper is to discriminate hurricanes that produce numerous tornadoes (tornado outbreaks) from those that do not (nonoutbreaks). The data consists of all hurricane landfalls that affected the United States from the North <span class="hlt">Atlantic</span> <span class="hlt">basin</span> from 1954 to 2004 and the United States tornado record over the same period. Because of the more than twofold increase in the number of reported tornadoes over these 51 years, a simple least-squares linear regression (“the expected number of tornadoes”) was fit to the annual number of tornado reports to represent a baseline for comparison. The hurricanes were sorted into three categories. The first category, outbreak hurricanes, was determined by hurricanes associated with the number of tornado reports exceeding a threshold of 1.5% of the annual expected number of tornadoes and at least 8 F1 and greater tornadoes during the time of landfall (from outer rainbands reaching shore to dissipation of the system). Eighteen hurricane landfalls were classified as outbreak hurricanes. Second, 37 hurricanes having less than 0.5% of the annual expected number of tornadoes were classified as nonoutbreak landfalls. Finally, 28 hurricanes that were neither outbreak nor nonoutbreak hurricanes were classified as midclass hurricane landfalls. Stronger hurricanes are more likely to produce tornado outbreaks than weaker hurricanes. While 78% of outbreak hurricanes were category 2 or greater at landfall, only 32% of nonoutbreak hurricanes were category 2 or greater at landfall. Hurricanes that made landfall along the southern coast of the United States and recurved northeastward were more likely to produce tornadoes than those that made landfall along the east coast or those that made landfall along the southern coast but did not recurve. Recurvature was associated with a 500-hPa trough in the jet stream, which also contributed to increased deep</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ngmdb.usgs.gov/Prodesc/proddesc_77831.htm','USGSPUBS'); return false;" href="http://ngmdb.usgs.gov/Prodesc/proddesc_77831.htm"><span>Geologic map of the Vigo <span class="hlt">NE</span> quadrangle, Lincoln County, Nevada</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Scott, Robert B.; Harding, Anne E.</p> <p>2006-01-01</p> <p>This map of the Vigo <span class="hlt">NE</span> quadrangle, Lincoln County, Nevada records the distribution, stratigraphy, and structural relationships of Tertiary intracaldera lavas and tuffs in the southeastern part of the Kane Springs Wash caldera, extracaldera Tertiary and upper Paleozoic rocks, and late Cenozoic surficial deposits both within and outside the caldera. The alkaline to peralkaline Kane Springs Wash caldera is the youngest (14 Ma) of three chemically related metaluminous to peralkaline calderas (Boulder Canyon caldera, 15 Ma; Narrow Canyon caldera, 16 Ma) of the nested Kane Springs Wash caldera complex. The chemistry of this caldera complex became progressively more alkalic with time, in contrast to the older calc-alkalic calderas and caldera complexes to the north that migrated progressively southward in eastern Nevada. The increasingly peralkaline eruptions from the Kane Springs Wash caldera complex reached a climax that was simultaneous with the end of both rapid extension and magmatism in this part of the <span class="hlt">Basin</span> and Range. Using the assumption that degree of tilting is related to the degree of extension, the rate of extension increased until the abrupt halt at about 14 Ma. Silicic volcanism terminated at the Kane Springs Wash caldera followed only by local sporadic basaltic eruptions that ended by about 8 Ma. The northern boundary of an east-west-trending amagmatic corridor appears in the Vigo <span class="hlt">NE</span> quadrangle south of the Kane Springs Wash caldera.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17793234','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17793234"><span>Pollen and spores date origin of rift <span class="hlt">basins</span> from Texas to nova scotia as early late triassic.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Traverse, A</p> <p>1987-06-12</p> <p>Palynological studies of the nonmarine Newark Supergroup of eastern North America and of rift <span class="hlt">basins</span> in the northern Gulf of Mexico facilitate correlation with well-dated marine sections of Europe. New information emphasizes the chronological link between the Newark <span class="hlt">basins</span> and a Gulf of Mexico <span class="hlt">basin</span> and their common history in the rifting of North America from Pangea. Shales from the subsurface South Georgia <span class="hlt">Basin</span> are shown to be of late Karnian age (early Late Triassic). The known time of earliest sedimentation in the Culpeper <span class="hlt">Basin</span> is extended from Norian (late Late Triassic) to mid-Karnian, and the date of earliest sedimentation in the Richmond and Deep River <span class="hlt">basins</span> is moved to at least earliest Karnian, perhaps Ladinian. The subsurface Eagle Mills Formation in Texas and Arkansas has been dated palynologically as mid- to late Karnian. The oldest parts of the Newark Supergroup, and the Eagle Mills Formation, mostly began deposition in precursor rift <span class="hlt">basins</span> that formed in Ladinian to early Karnian time. In the southern Newark <span class="hlt">basins</span>, sedimentation apparently ceased in late Karnian but continued in the northern <span class="hlt">basins</span> well into the Jurassic, until genesis of the <span class="hlt">Atlantic</span> ended <span class="hlt">basin</span> sedimentation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.5293K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.5293K"><span>Analysing the teleconnection systems affecting the climate of the Carpathian <span class="hlt">Basin</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kristóf, Erzsébet; Bartholy, Judit; Pongrácz, Rita</p> <p>2017-04-01</p> <p>Nowadays, the increase of the global average near-surface air temperature is unequivocal. Atmospheric low-frequency variabilities have substantial impacts on climate variables such as air temperature and precipitation. Therefore, assessing their effects is essential to improve global and regional climate model simulations for the 21st century. The North <span class="hlt">Atlantic</span> Oscillation (NAO) is one of the best-known atmospheric teleconnection patterns affecting the Carpathian <span class="hlt">Basin</span> in Central Europe. Besides NAO, we aim to analyse other interannual-to-decadal teleconnection patterns, which might have significant impacts on the Carpathian <span class="hlt">Basin</span>, namely, the East <span class="hlt">Atlantic</span>/West Russia pattern, the Scandinavian pattern, the Mediterranean Oscillation, and the North-Sea Caspian Pattern. For this purpose primarily the European Centre for Medium-Range Weather Forecasts' (ECMWF) ERA-20C atmospheric reanalysis dataset and multivariate statistical methods are used. The indices of each teleconnection pattern and their correlations with temperature and precipitation will be calculated for the period of 1961-1990. On the basis of these data first the long range (i. e. seasonal and/or annual scale) forecast ability is evaluated. Then, we aim to calculate the same indices of the relevant teleconnection patterns for the historical and future simulations of Coupled Model Intercomparison Project Phase 5 (CMIP5) models and compare them against each other using statistical methods. Our ultimate goal is to examine all available CMIP5 models and evaluate their abilities to reproduce the selected teleconnection systems. Thus, climate predictions for the 21st century for the Carpathian <span class="hlt">Basin</span> may be improved using the best-performing models among all CMIP5 model simulations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009NIMPA.599...28A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009NIMPA.599...28A"><span>The MiniBoo<span class="hlt">NE</span> detector</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Aguilar-Arevalo, A. A.; Anderson, C. E.; Bartoszek, L. M.; Bazarko, A. O.; Brice, S. J.; Brown, B. C.; Bugel, L.; Cao, J.; Coney, L.; Conrad, J. M.; Cox, D. C.; Curioni, A.; Djurcic, Z.; Finley, D. A.; Fleming, B. T.; Ford, R.; Garcia, F. G.; Garvey, G. T.; Green, C.; Green, J. A.; Hart, T. L.; Hawker, E.; Imlay, R.; Johnson, R. A.; Karagiorgi, G.; Kasper, P.; Katori, T.; Kobilarcik, T.; Kourbanis, I.; Koutsoliotas, S.; Laird, E. M.; Linden, S. K.; Link, J. M.; Liu, Y.; Liu, Y.; Louis, W. C.; Mahn, K. B. M.; Marsh, W.; Martin, P. S.; McGregor, G.; Metcalf, W.; Meyer, H.-O.; Meyers, P. D.; Mills, F.; Mills, G. B.; Monroe, J.; Moore, C. D.; Nelson, R. H.; Nguyen, V. T.; Nienaber, P.; Nowak, J. A.; Ouedraogo, S.; Patterson, R. B.; Perevalov, D.; Polly, C. C.; Prebys, E.; Raaf, J. L.; Ray, H.; Roe, B. P.; Russell, A. D.; Sandberg, V.; Sands, W.; Schirato, R.; Schofield, G.; Schmitz, D.; Shaevitz, M. H.; Shoemaker, F. C.; Smith, D.; Soderberg, M.; Sorel, M.; Spentzouris, P.; Stancu, I.; Stefanski, R. J.; Sung, M.; Tanaka, H. A.; Tayloe, R.; Tzanov, M.; Van de Water, R.; Wascko, M. O.; White, D. H.; Wilking, M. J.; Yang, H. J.; Zeller, G. P.; Zimmerman, E. D.; MiniBooNE Collaboration</p> <p>2009-02-01</p> <p>The MiniBoo<span class="hlt">NE</span> neutrino detector was designed and built to look for ν→ν oscillations in the (sin 2θ,Δm) parameter space region where the LSND experiment reported a signal. The MiniBoo<span class="hlt">NE</span> experiment used a beam energy and baseline that were an order of magnitude larger than those of LSND so that the backgrounds and systematic errors would be completely different. This paper provides a detailed description of the design, function, and performance of the MiniBoo<span class="hlt">NE</span> detector.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PrOce.158..224B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PrOce.158..224B"><span>Diversity and distribution of hyperiid amphipods along a latitudinal transect in the <span class="hlt">Atlantic</span> Ocean</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Burridge, Alice K.; Tump, Marloes; Vonk, Ronald; Goetze, Erica; Peijnenburg, Katja T. C. A.</p> <p>2017-11-01</p> <p>As commensals and parasitoids of gelatinous plankton, hyperiid amphipods play unique and important ecological roles in pelagic food webs. Because the diversity and biogeography of this group in oceanic waters is poorly known, we examined diversity and distribution patterns of hyperiids along a <span class="hlt">basin</span>-scale meridional transect in the <span class="hlt">Atlantic</span> Ocean (<span class="hlt">Atlantic</span> Meridional Transect cruise 22). Hyperiids were collected from epipelagic and upper mesopelagic depths at 27 stations between 39°N and 45°S. A total of 70 species in 36 genera and 17 families were identified, the majority of which belonged to the epipelagic Physocephalata infraorder. We observed maximum species and genus richness in the equatorial upwelling region (up to 35 species, 27 genera per station; 7°N-8°S), which appeared largely driven by increased diversity in the superfamily Platysceloidea, as well as a significant and positive relationship between species richness and sea surface temperature. Cluster analyses of hyperiid species assemblages along the transect broadly supported a division into gyral, equatorial, transitional, and subantarctic assemblages, congruent with Longhurst's biogeochemical provinces. Steepest transitions in hyperiid species composition occurred at the southern subtropical convergence zone (34-38°S). The majority of zooplankton groups show maximal diversity in subtropical waters, and our observations of equatorial maxima in species and genus richness for hyperiids suggest that the mechanisms controlling diversity in this group are distinct from other zooplanktonic taxa. These patterns may be driven by the distribution and diversity of gelatinous hosts for hyperiids, which remain poorly characterized at ocean <span class="hlt">basin</span> scales. The data reported here provide new distributional records for epipelagic and upper mesopelagic hyperiids across six major oceanic provinces in the <span class="hlt">Atlantic</span> Ocean.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015Sci...350.1533R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015Sci...350.1533R"><span>Multidecadal increase in North <span class="hlt">Atlantic</span> coccolithophores and the potential role of rising CO2</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rivero-Calle, Sara; Gnanadesikan, Anand; Del Castillo, Carlos E.; Balch, William M.; Guikema, Seth D.</p> <p>2015-12-01</p> <p>As anthropogenic carbon dioxide (CO2) emissions acidify the oceans, calcifiers generally are expected to be negatively affected. However, using data from the Continuous Plankton Recorder, we show that coccolithophore occurrence in the North <span class="hlt">Atlantic</span> increased from ~2 to more than 20% from 1965 through 2010. We used random forest models to examine more than 20 possible environmental drivers of this change, finding that CO2 and the <span class="hlt">Atlantic</span> Multidecadal Oscillation were the best predictors, leading us to hypothesize that higher CO2 levels might be encouraging growth. A compilation of 41 independent laboratory studies supports our hypothesis. Our study shows a long-term <span class="hlt">basin</span>-scale increase in coccolithophores and suggests that increasing CO2 and temperature have accelerated the growth of a phytoplankton group that is important for carbon cycling.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25917285','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25917285"><span>Population structure and effective/census population size ratio in threatened three-spined stickleback populations from an isolated river <span class="hlt">basin</span> in northwest Spain.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Pérez-Figueroa, A; Fernández, C; Amaro, R; Hermida, M; San Miguel, E</p> <p>2015-08-01</p> <p>Variability at 20 microsatellite loci was examined to assess the population genetic structure, gene flow, and effective population size (<span class="hlt">N(e</span>)) in three populations of three-spined stickleback (Gasterosteus aculeatus) from the upper <span class="hlt">basin</span> of the Miño River in Galicia, NW Spain, where this species is threatened. The three populations showed similar levels of genetic diversity. There is a significant genetic differentiation between the three populations, but also significant gene flow. <span class="hlt">N(e</span>) estimates based on linkage disequilibrium yielded values of 355 for the Miño River population and 241 and 311 for the Rato and Guisande Rivers, respectively, although we expect that these are overestimates. <span class="hlt">N(e</span>) estimates based on temporal methods, considering gene flow or not, for the tributaries yielded values of 30-56 and 47-56 for the Rato and Guisande Rivers, respectively. Estimated census size (N(c)) for the Rato River was 880 individuals. This yielded a N(e)/N(c) estimate of 3-6 % for temporal estimation of <span class="hlt">N(e</span>), which is within the empirical range observed in freshwater fishes. We suggest that the three populations analyzed have a sufficient level of genetic diversity with some genetic structure. Additionally, the absence of physical barriers suggests that conservation efforts and monitoring should focus in the whole <span class="hlt">basin</span> as a unit.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20040082496','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20040082496"><span>Bio-Optical and Geochemical Properties of the South <span class="hlt">Atlantic</span> Subtropical Gyre</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Signorini, S. R.; Hooker, Stanford B.; McClain, Charles R.</p> <p>2003-01-01</p> <p>An investigation of the bio-optical properties of the South <span class="hlt">Atlantic</span> subtropical gyre (SASG) was conducted using data primarily from the UK <span class="hlt">Atlantic</span> Meridional Transect (AMT) program and SeaWiFS. The AMT cruises extend from the UK to the Falklands Islands (sailing on the RRS James Clark Ross) with the purpose of improving our knowledge of surface layer hydrography, biogeochemical processes, ecosystem dynamics and food webs across <span class="hlt">basin</span> scales in the <span class="hlt">Atlantic</span> Ocean. Two objectives of the AMT program relevant to this study are the characterization of biogeochemical provinces and the analysis of optical and pigment parameters in connection with remote sensing ocean color data. The primary focus of this NASA Technical Memorandum is on the variability of the vertical distribution of phytoplankton pigments and associated absorption properties across the SASG, and their relevance to remote sensing algorithms. Therefore, a subset of the AMT data within the SASG from all available cruises was used in the analyses. One of the challenges addressed here is the determination of the SASG geographic boundaries. One of the major problems is to reconcile the properties of biogeochemical provinces. We use water mass analysis, dynamics of ocean currents, and meridional gradients of bio-optical properties, to identify the SASG boundaries.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..1915511Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..1915511Z"><span>Holocene water mass history off <span class="hlt">NE</span> Greenland - A first high-resolution sediment record from the western Fram Strait</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zehnich, Marc; Palme, Tina; Spielhagen, Robert F.; Hass, H. Christian; Bauch, Henning A.</p> <p>2017-04-01</p> <p>While the Holocene history of the eastern Fram Strait seems well investigated, no high-resolution paleoenvironmental records were available from the western Fram Strait so far. A new sedimentary record, obtained during expedition PS93.1 (2015) of RV Polarstern on the outermost <span class="hlt">NE</span> Greenland shelf, allows for the first time to reconstruct Holocene changes in near-surface salinities, temperature, stratification and water masses (polar waters vs. <span class="hlt">Atlantic</span> Water), potentially related to variations of the freshwater and sea ice export from the Arctic Ocean. The 260 cm long sedimentary record from site PS93/025 (80.5°N, 8.5°W) was investigated for sediment composition, foraminifer contents, grain size variations (sortable silt) and the isotopic composition of planktic foraminifers. Radiocarbon datings reveal an age of 10.2 cal-ka for the core base and continuous sedimentation throughout most of the Holocene. The sediments are generally very fine-grained (<2% sand). The grain size record reveals a fining-upwards trend and sediments from <6.5 cal-ka consist of <0.5% coarse fraction. A comparison of foraminifer and coarse fraction abundances shows strong similarities. Apparently the contribution of coarse terrestrial material from iceberg transport was extremely low throughout the last 10.2 cal-ka. Foraminifer abundances (both planktic and benthic) are high in Early Holocene sediments until ca. 7 cal-ka and decrease rapidly thereafter. This is interpreted to reflect a relatively strong advection of <span class="hlt">Atlantic</span> Water to the NW Fram Strait, which correlates well with similar findings on the eastern side of the Arctic Gateway. Sortable silt grain sizes are high (27-32 µm) in the older part of the record and gradually decrease between 7 cal-ka and 4 cal-ka. After ca. 4 cal-ka, sortable silt shows values of 20-22 µm and little variation. Considering also the grain-size distribution curves, we propose a decline of bottom current velocities on the outer <span class="hlt">NE</span> Greenland shelf after 7</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1212697-nexus-data-format','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1212697-nexus-data-format"><span>The <span class="hlt">Ne</span>Xus data format</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Könnecke, Mark; Akeroyd, Frederick A.; Bernstein, Herbert J.; ...</p> <p>2015-01-30</p> <p><span class="hlt">Ne</span>Xus is an effort by an international group of scientists to define a common data exchange and archival format for neutron, X-ray and muon experiments. <span class="hlt">Ne</span>Xus is built on top of the scientific data format HDF5 and adds domain-specific rules for organizing data within HDF5 files, in addition to a dictionary of well defined domain-specific field names. The <span class="hlt">Ne</span>Xus data format has two purposes. First, it defines a format that can serve as a container for all relevant data associated with a beamline. This is a very important use case. Second, it defines standards in the form of application definitionsmore » for the exchange of data between applications. As a result, <span class="hlt">Ne</span>Xus provides structures for raw experimental data as well as for processed data.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26612836','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26612836"><span>Multidecadal increase in North <span class="hlt">Atlantic</span> coccolithophores and the potential role of rising CO₂.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Rivero-Calle, Sara; Gnanadesikan, Anand; Del Castillo, Carlos E; Balch, William M; Guikema, Seth D</p> <p>2015-12-18</p> <p>As anthropogenic carbon dioxide (CO2) emissions acidify the oceans, calcifiers generally are expected to be negatively affected. However, using data from the Continuous Plankton Recorder, we show that coccolithophore occurrence in the North <span class="hlt">Atlantic</span> increased from ~2 to more than 20% from 1965 through 2010. We used random forest models to examine more than 20 possible environmental drivers of this change, finding that CO2 and the <span class="hlt">Atlantic</span> Multidecadal Oscillation were the best predictors, leading us to hypothesize that higher CO2 levels might be encouraging growth. A compilation of 41 independent laboratory studies supports our hypothesis. Our study shows a long-term <span class="hlt">basin</span>-scale increase in coccolithophores and suggests that increasing CO2 and temperature have accelerated the growth of a phytoplankton group that is important for carbon cycling. Copyright © 2015, American Association for the Advancement of Science.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017QSRv..155..100L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017QSRv..155..100L"><span>Two millennia of Mesoamerican monsoon variability driven by Pacific and <span class="hlt">Atlantic</span> synergistic forcing</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lachniet, Matthew S.; Asmerom, Yemane; Polyak, Victor; Bernal, Juan Pablo</p> <p>2017-01-01</p> <p>The drivers of Mesoamerican monsoon variability over the last two millennia remain poorly known because of a lack of precisely-dated and climate-calibrated proxy records. Here, we present a new high resolution (∼2 yrs) and precisely-dated (± 4 yr) wet season hydroclimate reconstruction for the Mesoamerican sector of the North American Monsoon over the past 2250 years based on two aragonite stalagmites from southwestern Mexico which replicate oxygen isotope variations over the 950-1950 CE interval. The reconstruction is quantitatively calibrated to instrumental rainfall variations in the <span class="hlt">Basin</span> of Mexico. Comparisons to proxy indices of ocean-atmosphere circulation show a synergistic forcing by the North <span class="hlt">Atlantic</span> and El Niño/Southern Oscillations, whereby monsoon strengthening coincided with a La Niña-like mode and a negative North <span class="hlt">Atlantic</span> Oscillation, and vice versa for droughts. Our data suggest that weak monsoon intervals are associated with a strong North <span class="hlt">Atlantic</span> subtropical high pressure system and a weak Intertropical convergence zone in the eastern Pacific Ocean. Population expansions at three major highland Mexico civilization of Teotihuacan, Tula, and Aztec Tenochtitlan were all associated with drought to pluvial transitions, suggesting that urban population growth was favored by increasing freshwater availability in the semi-arid Mexican highlands, and that this hydroclimatic change was controlled by Pacific and <span class="hlt">Atlantic</span> Ocean forcing.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70024079','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70024079"><span>An index of biological integrity for northern Mid-<span class="hlt">Atlantic</span> Slope drainages</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Daniels, R.A.; Riva-Murray, K.; Halliwell, D.B.; Vana-Miller, D. L.; Bilger, Michael D.</p> <p>2002-01-01</p> <p>An index of biological integrity (IBI) was developed for streams in the Hudson, Delaware, and Susquehanna River drainages in the northeastern United States based on fish assemblage data from the Mohawk River drainage of New York. The original IBI, developed for streams in the U.S. Midwest, was modified to reflect the assemblage composition and structure present in Mid-<span class="hlt">Atlantic</span> Slope drainages. We replaced several of the Midwestern IBI metrics and criteria scores because fishes common to the Midwest are absent from or poorly represented in the Northeast and because stream fish assemblages in the Northeast are less rich than those in the Midwest. For all replacement metrics we followed the ecology-based rationale used in the development of each of the metrics of the Midwestern IBI so that the basic theoretical underpinnings of the IBI remained unchanged. The validity of this modified IBI is demonstrated by examining the quality of streams in the Hudson, Delaware, and lower Susquehanna River <span class="hlt">basins</span>. The relationships between the IBI and other indicators of environmental quality are examined using data on assemblages of fish and benthic macroinvertebrates and on chemical and physical stream characteristics obtained during 1993-2000 by the U.S. Geological Survey's National Water Quality Assessment Program in these three river <span class="hlt">basins</span>. A principal components analysis (PCA) of chemical and physical variables from 27 sites resulted in an environmental quality gradient as the primary PCA axis (eigenvalue, 0.41 ). Principal components analysis site scores were significantly correlated with such benthic macroinvertebrate metrics as the percentage of Ephemeroptera, Plecoptera, and Trichoptera taxa (Spearman R = -0.66, P < 0.001). Index of biological integrity scores for sites in these three river <span class="hlt">basins</span> were significantly correlated with this environmental quality gradient (Spearman R = -0.78, P = 0.0001). The northern Mid-<span class="hlt">Atlantic</span> Slope IBI appears to be sensitive to</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_25 --> <div class="footer-extlink text-muted" style="margin-bottom:1rem; text-align:center;">Some links on this page may take you to non-federal websites. 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