Sample records for tagus abyssal plain

  1. Seismic evidence of exhumed mantle rock basement at the Gorringe Bank and the adjacent Horseshoe and Tagus abyssal plains (SW Iberia)

    NASA Astrophysics Data System (ADS)

    Sallarès, Valentí; Martínez-Loriente, Sara; Prada, Manel; Gràcia, Eulàlia; Ranero, César; Gutscher, Marc-André; Bartolome, Rafael; Gailler, Audrey; Dañobeitia, Juan José; Zitellini, Nevio

    2013-03-01

    The Gorringe Bank is a gigantic seamount that separates the Horseshoe and Tagus abyssal plains offshore SW Iberia, in a zone that hosts the convergent boundary between the Africa and Eurasia plates. Although the region has been the focus of numerous investigations since the early 1970s, the lack of appropriate geophysical data makes the nature of the basement, and thus the origin of the structures, still debated. In this work, we present combined P-wave seismic velocity and gravity models along a transect that crosses the Gorringe Bank from the Tagus to the Horseshoe abyssal plains. The P-wave velocity structure of the basement is similar in the Tagus and Horseshoe plains. It shows a 2.5-3.0 km-thick top layer with a velocity gradient twice stronger than oceanic Layer 2 and an abrupt change to an underlying layer with a five-fold weaker gradient. Velocity and density is lower beneath the Gorringe Bank probably due to enhanced fracturing, that have led to rock disaggregation in the sediment-starved northern flank. In contrast to previous velocity models of this region, there is no evidence of a sharp crust-mantle boundary in any of the record sections. The modelling results indicate that the sediment overlays directly serpentinite rock, exhumed from the mantle with a degree of serpentinization decreasing from a maximum of 70-80% under the top of Gorringe Bank to less than 5% at a depth of ˜20 km. We propose that the three domains were originally part of a single serpentine rock band, of nature and possibly origin similar to the Iberia Abyssal Plain ocean-continent transition, which was probably generated during the earliest phase of the North Atlantic opening that followed continental crust breakup (Early Cretaceous). During the Miocene, the NW-SE trending Eurasia-Africa convergence resulted in thrusting of the southeastern segment of the exhumed serpentinite band over the northwestern one, forming the Gorringe Bank. The local deformation associated to plate

  2. The Laurentian Fan: Sohm Abyssal Plain

    USGS Publications Warehouse

    Piper, D.J.W.; Stow, D.A.V.; Normark, W.R.

    1984-01-01

    The 0.5- to 2-km thick Quaternary Laurentian Fan is built over Tertiary and Mesozoic sediments that rest on oceanic crust. Two 400-km long fan valleys, with asymmetric levees up to 700-m high, lead to an equally long, sandy, lobate basin plain (northern Sohm Abyssal Plain). The muddy distal Sohm Abyssal Plain is a further 400-km long. The sediment supplied to the fan is glacial in origin, and in part results from seismically triggered slumping on the upper continental slope. Sandy turbidity currents, such as the 1929 Grand Banks earthquake event, probably erode the fan-valley floors; but thick muddy turbidity currents build up the high levees. ?? 1984 Springer-Verlag New York Inc.

  3. Unexpectedly higher metazoan meiofauna abundances in the Kuril-Kamchatka Trench compared to the adjacent abyssal plains

    NASA Astrophysics Data System (ADS)

    Schmidt, Christina; Martínez Arbizu, Pedro

    2015-01-01

    We studied meiofauna standing stocks and community structure in the Kuril-Kamchatka Trench and its adjacent abyssal plains in the northwestern Pacific Ocean. In general, the Nematoda were dominant (93%) followed by the Copepoda (4%). Nematode abundances ranged from 87% to 96%; those of copepods from 2% to 7%. The most diverse deployment yielded 17 taxa: Acari, Amphipoda, Annelida, Bivalvia, Coelenterata, Copepoda, Cumacea, Gastrotricha, Isopoda, Kinorhyncha, Loricifera, Nematoda, Ostracoda, Priapulida, Tanaidacea, Tantulocarida, and Tardigrada. Nauplii were also present. Generally, the trench slope and the southernmost deployments had the highest abundances (850-1392 individuals/cm2). The results of non-metric multidimensional scaling indicated that these deployments were similar to each other in meiofauna community structure. The southernmost deployments were located in a zone of higher particulate organic carbon (POC) flux (g Corg m-2 yr-1), whereas the trench slope should have low POC flux due to depth attenuation. Also, POC and abundance were significantly correlated in the abyssal plains. This correlation may explain the higher abundances at the southernmost deployments. Lateral transport was also assumed to explain high meiofauna abundances on the trench slope. Abundances were generally higher than expected from model results. ANOSIM revealed significant differences between the trench slope and the northern abyssal plains, between the central abyssal plains and the trench slope, between the trench slope and the southern abyssal plains, between the central and the southern abyssal plains, and between the central and northern deployments. The northern and southern abyssal plains did not differ significantly. In addition, a U-test revealed highly significant differences between the trench-slope and abyssal deployments. The taxa inhabited mostly the upper 0-3 cm of the sediment layer (Nematoda 80-90%; Copepoda 88-100%). The trench-slope and abyssal did not differ

  4. Long-term change in the megabenthos of the Porcupine Abyssal Plain (NE Atlantic)

    NASA Astrophysics Data System (ADS)

    Billett, D. S. M.; Bett, B. J.; Rice, A. L.; Thurston, M. H.; Galéron, J.; Sibuet, M.; Wolff, G. A.

    A radical change in the abundance of invertebrate megafauna on the Porcupine Abyssal Plain is reported over a period of 10 years (1989-1999). Actiniarians, annelids, pycnogonids, tunicates, ophiuroids and holothurians increased significantly in abundance. However, there was no significant change in wet weight biomass. Two holothurian species, Amperima rosea and Ellipinion molle, increased in abundance by more than two orders of magnitude. Samples from the Porcupine Abyssal Plain over a longer period (1977-1999) show that prior to 1996 these holothurian species were always a minor component of the megafauna. From 1996 to 1999 A. rosea was abundant over a wide area of the Porcupine Abyssal Plain indicating that the phenomenon was not a localised event. Several dominant holothurian species show a distinct trend in decreasing body size over the study period. The changes in megafauna abundance may be related to environmental forcing (food supply) rather than to localised stochastic population variations. Inter-annual variability and long-term trends in organic matter supply to the seabed may be responsible for the observed changes in abundance, species dominance and size distributions.

  5. Ocean-Bottom Topography: The Divide between the Sohm and Hatteras Abyssal Plains.

    PubMed

    Pratt, R M

    1965-06-18

    A compilation of precision echo soundings has delineated the complex topography between the Sohm and Hatteras abyssal plains off the Atlantic coast of the United States. At present the divide between the two plains is a broad, flat area about 4950 meters deep; however, the configuration of channels and depressions suggests spillage of turbidity currents from the Sohm Plain into the Hatteras Plain and a shifting of the divide toward the northeast. Hudson Canyon terminates in the divide area and has probably fed sediment into both plains.

  6. GLORIA side-scan imagery of Aleutian basin, Bering Sea slope and Abyssal plain

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

    Carlson, P.R.; Cooper, A.K.; Gardner, J.V.

    1987-05-01

    During July-September 1986, about 700,000 km/sup 2/ of continental slope and abyssal plain of the Aleutian basin, Bering Sea, were insonified with GLORIA (Geological Long Range Inclined Asdic) side-scane sonar. A sonar mosaic displays prominent geomorphic features including the massive submarine canyons of the Beringian and the northern Aleutian Ridge slopes and shows well-defined sediment patterns including large deep-sea channels and fan systems on the Aleutian basin abyssal plain. Dominant erosional and sediment transport processes on both the Beringian and the Aleutian Ridge slopes include varieties of mass movement that range from small debris flows and slides to massive slidesmore » and slumps of blocks measuring kilometers in dimension. Sediment-flow patterns that appear to be formed by sheet flow rather than channelized flow extend basinward from the numerous canyons and gullies that incise the slopes of the Beringian margin and of Bowers Ridge and some places along the Aleutian Ridge. These Beringian and Bowers canyon sediment sources, however, appear to have contributed less modern sediment to the Aleutian basin than the large, well-defined channel systems that emanate from Bering, Umnak, and Amchitka submarine canyons and extend for several hundred kilometers across the abyssal plain. This GLORIA imagery emphasizes the important contribution of the Aleutian Ridge to modern sedimentation in the deep Bering Sea.« less

  7. Evidence from Ocean Drilling Program Leg 149 mafic igneous rocks for oceanic crust in the Iberia Abyssal Plain ocean-continent transition zone

    NASA Astrophysics Data System (ADS)

    Seifert, Karl E.; Chang, Cheng-Wen; Brunotte, Dale A.

    1997-04-01

    Leg 149 of the Ocean Drilling Program explored the ocean-continent transition (OCT) on the Iberia Abyssal Plain and its role in the opening of the Atlantic Ocean approximately 130 Ma. Mafic igneous rocks recovered from Holes 899B and 900A have Mid-Ocean Ridge Basalt (MORB) trace element and isotopic characteristics indicating that a spreading center was active during the opening of the Iberia Abyssal Plain OCT. The Hole 899B weathered basalt and diabase clasts have transitional to enriched MORB rare earth element characteristics, and the Hole 900A metamorphosed gabbros have MORB initial epsilon Nd values between +6 and +11. During the opening event the Iberia Abyssal Plain OCT is envisioned to have resembled the central and northern parts of the present Red Sea with localized spreading centers and magma chambers producing localized patches of MORB mafic rocks. The lack of a normal ocean floor magnetic anomaly pattern in the Iberia Abyssal Plain means that a continuous spreading center similar to that observed in the present southern Red Sea was not formed before spreading ceased in the Iberia Abyssal Plain OCT and jumped to the present Mid-Atlantic Ridge.

  8. Sediment dispersal patterns within the Nares Abyssal Plain: observations from GLORIA Sonographs

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

    Shephard, L.E.; Tucholke, B.E.; Fry, V.A.

    1985-01-01

    Features evident on GLORIA sonographs from the Nares Abyssal Plain suggest a sediment dispersal pattern for turbidity currents that varies temporally and spatially, resulting in randomly distributed turbidite deposits in the distal abyssal plain east of 64/sup 0/W. Regional variations in backscatter intensities across the abyssal plain are related to the frequency and thickness of near-surface silt beds, basement highs disrupting the seafloor, and subtle changes in surface and sub-surface bedforms related to low-relief turbidite flow paths, biologic activity, and possibly erosion. High backscatter intensities, prevalent west of 64/sup 0/W, are generally associated with those areas containing thicker silt bedsmore » and very regular subbottom reflectors on 3.5 kHz profiles. Low backscatter intensities, prevalent east of 64/sup 0/W, are associated with those areas containing thin silt beds or stringers with a much higher percentage of pelagic clay. Seafloor lineaments occur throughout the survey area but decrease in abundance east of 64/sup 0/W. These features have no apparent relief when crossed by surface-towed seismic reflection profiles. In some instances the lineaments may correspond to low-relief turbidite flow paths that contain varying textural compositions resulting in increased backscatter. These features would be indicative of sediment transport directions. Other possible origins for the lineaments, that often appear trackline parallel, include near-surface morphology that is preferentially detected and aligned by GLORIA, or possibly the lineaments result from complex subbottom interference patterns that would not be readily apparent in areas with a more irregular seafloor.« less

  9. Abyssal hills: Influence of topography on benthic foraminiferal assemblages

    NASA Astrophysics Data System (ADS)

    Stefanoudis, Paris V.; Bett, Brian J.; Gooday, Andrew J.

    2016-11-01

    Abyssal plains, often thought of as vast flat areas, encompass a variety of terrains including abyssal hills, features that constitute the single largest landscape type on Earth. The potential influence on deep-sea benthic faunas of mesoscale habitat complexity arising from the presence of abyssal hills is still poorly understood. To address this issue we focus on benthic foraminifera (testate protists) in the >150-μm fraction of Megacorer samples (0-1 cm layer) collected at five different sites in the area of the Porcupine Abyssal Plain Sustained Observatory (NE Atlantic, 4850 m water depth). Three sites are located on the tops of small abyssal hills (200-500 m elevation) and two on the adjacent abyssal plain. We examined benthic foraminiferal assemblage characteristics (standing stock, diversity, composition) in relation to seafloor topography (hills vs. plain). Density and rarefied diversity were not significantly different between the hills and the plain. Nevertheless, hills do support a higher species density (i.e. species per unit area), a distinct fauna, and act to increase the regional species pool. Topographically enhanced bottom-water flows that influence food availability and sediment type are suggested as the most likely mechanisms responsible for these differences. Our findings highlight the potential importance of mesoscale heterogeneity introduced by relatively modest topography in regulating abyssal foraminiferal diversity. Given the predominance of abyssal hill terrain in the global ocean, we suggest the need to include faunal data from abyssal hills in assessments of abyssal ecology.

  10. Lower Cretaceous smarl turbidites of the Argo Abyssal Plain, Indian Ocean

    USGS Publications Warehouse

    Dumoulin, Julie A.; Stewart, Sondra K.; Kennett, Diana; Mazzullo, Elsa K.

    1992-01-01

    Sediments recovered during Ocean Drilling Program (ODP) Leg 123 from the Argo Abyssal Plain (AAP) consist largely of turbidites derived from the adjacent Australian continental margin. The oldest abundant turbidites are Valanginian-Aptian in age and have a mixed (smarl) composition; they contain subequal amounts of calcareous and siliceous biogenic components, as well as clay and lesser quartz. Most are thin-bedded, fine sand to mud-sized, and best described by Stow and Piper's model (1984) for fine-grained biogenic turbidites. Thicker (to 3 m), coarser-grained (medium-to-coarse sand-sized) turbidites fit Bouma's model (1962) for sandy turbidites; these generally are base-cut-out (BCDE, BDE) sequences, with B-division parallel lamination as the dominant structure. Parallel laminae most commonly concentrate quartz and/or calcispheres vs. lithic clasts or clay, but distinctive millimeter to centimeter-thick, radiolarian-rich laminae occur in both fine and coarse-grained Valanginian-Hauterivian turbidites.AAP turbidites were derived from relatively deep parts of the continental margin (outer shelf, slope, or rise) that lay below the photic zone, but above the calcite compensation depth (CCD). Biogenic components are largely pelagic (calcispheres, foraminifers, radiolarians, nannofossils); lesser benthic foraminifers are characteristic of deep-water (abyssal to bathyal) environments. Abundant nonbiogenic components are mostly clay and clay clasts; smectite is the dominant clay species, and indicates a volcanogenic provenance, most likely the Triassic-Jurassic volcanic suite exposed along the northern Exmouth Plateau.Lower Cretaceous smarl turbidites were generated during eustatic lowstands and may have reached the abyssal plain via Swan Canyon, a submarine canyon thought to have formed during the Late Jurassic. In contrast to younger AAP turbidites, however, Lower Cretaceous turbidites are relatively fine-grained and do not contain notably older reworked fossils. Early

  11. Morphogenesis of the SW Balearic continental slope and adjacent abyssal plain, Western Mediterranean Sea

    NASA Astrophysics Data System (ADS)

    Camerlenghi, Angelo; Accettella, Daniela; Costa, Sergio; Lastras, Galderic; Acosta, Juan; Canals, Miquel; Wardell, Nigel

    2009-06-01

    We present the seafloor morphology and shallow seismic structure of the continental slope south-east of the Balearic promontory and of the adjacent Algero-Balearic abyssal plain from multibeam and chirp sonar data. The main purpose of this research was to identify the sediment pathways from the Balearic promontory to the Algero-Balearic deep basin from the Early Pliocene to the Present. The morphology of the southern Balearic margin is controlled by a SW-NE structural trend, whose main expressions are the Emile Baudot Escarpment transform fault, and a newly discovered WSW-ENE trend that affects the SW end of the escarpment and the abyssal plain. We relate the two structural trends to right-lateral simple shear as a consequence of the Miocene westward migration of the Gibraltar Arc. Newly discovered steep and narrow volcanic ridges were probably enabled to grow by local transtension along the transform margin. Abyssal plain knolls and seahills relate to the subsurface deformation of early stage halokinetic structures such as salt rollers, salt anticlines, and salt pillows. The limited thickness of the overburden and the limited amount of deformation in the deep basin prevent the formation of more mature halokinetic structures such as diapirs, salt walls, bulbs, and salt extrusions. The uppermost sediment cover is affected by a dense pattern of sub-vertical small throw normal faults resulting from extensional stress induced in the overburden by subsurface salt deformation structures. Shallow gas seismic character and the possible presence of an active polygonal fault system suggest upward fluid migration and fluid and sediment expulsion at the seafloor through a probable mud volcano and other piercement structures. One large debris flow deposit, named Formentera Debris Flow, has been identified on the lower slope and rise of the south Formentera margin. Based on current observations, we hypothesize that the landslide originating the Formentera Debris Flow occurred in

  12. Boundary current-controlled turbidite deposition: A sedimentation model for the Southern Nares Abyssal Plain, Western North Atlantic

    NASA Astrophysics Data System (ADS)

    Kuijpers, A.; Duin, E. J. Th.

    1986-03-01

    Examination of 38 sediment cores, bottom photographs, 7,000 km of 3.5 kHz reflection profiles and other seismic data from the southern part of the Nares Abyssal Plain suggests that complex sedimentary patterns and high sedimentation rates can be largely attributed to effects of a deep boundary current flowing eastward along the north flank of the Greater Antilles Outer Ridge. It is concluded that the areal dispersal pattern of turbidites on the plain results mainly from Quaternary climatically-induced fluctuations of the boundary current intensity.

  13. High-resolution sub-bottom seismic and sediment core records from the Chukchi Abyssal Plain reveal Quaternary glaciation impacts on the western Arctic Ocean

    NASA Astrophysics Data System (ADS)

    Joe, Y. J.; Seokhoon, Y.; Nam, S. I.; Polyak, L.; Niessen, F.

    2017-12-01

    For regional context of the Quaternary history of Arctic marine glaciations, such as glacial events in northern North America and on the Siberian and Chukchi margins, we used CHIRP sub-bottom profiles (SBP) along with sediment cores, including a 14-m long piston core ARA06-04JPC taken from the Chukchi abyssal plain during the RV Araon expedition in 2015. Based on core correlation with earlier developed Arctic Ocean stratigraphies using distribution of various sedimentary proxies, core 04JPC is estimated to extend to at least Marine Isotope Stage 13 (>0.5 Ma). The stratigraphy developed for SBP lines from the Chukchi abyssal plain to surrounding slopes can be divided into four major seismostratigraphic units (SSU 1-4). SBP records from the abyssal plain show well preserved stratification, whereas on the surrounding slopes this pattern is disrupted by lens-shaped, acoustically transparent sedimentary bodies interpreted as glaciogenic debris flow deposits. Based on the integration of sediment physical property and SBP data, we conclude that these debris flows were generated during several ice-sheet grounding events on the Chukchi and East Siberian margins, including adjacent ridges and plateaus, during the middle to late Quaternary.

  14. Abyssal seafloor waste isolation: the concept

    NASA Astrophysics Data System (ADS)

    Valent, Philip J.; Young, David K.; Sawyer, William B.; Wright, Thomas D.

    1998-05-01

    The Naval Research Laboratory (NRL), with industry and university participation, conducted an assessment of the concept of isolating certain wastes (i.e., sewage sludge, fly ash from municipal incinerators, and contaminated dredged material) on the oceans' abyssal seafloor. In this assessment the advantages, disadvantages, and economic and environmental viability of potential engineering methods for achieving abyssal waste isolation were identified and compared. This paper presents background to the Abyssal Plains Waste Isolation (APWI) Project, describes the characteristics of the waste streams and quantities potentially available for disposal via the abyssal isolation concept, summarizes regulations affecting use of the abyssal seafloor for disposal of wastes, and introduces the technical and scientific premises underlying implementation of the concept.

  15. Character, paleoenvironment, rate of accumulation, and evidence for seismic triggering of Holocene turbidites, Canada Abyssal Plain, Arctic Ocean

    USGS Publications Warehouse

    Grantz, A.; Phillips, R.L.; Mullen, M.W.; Starratt, S.W.; Jones, Glenn A.; Naidu, A.S.; Finney, B.P.

    1996-01-01

    Four box cores and one piston core show that Holocene sedimentation on the southern Canada Abyssal Plain for the last 8010??120 yr has consisted of a continuing rain of pelagic organic and ice-rafted elastic sediment with a net accumulation rate during the late Holocene of ???10 mm/1000 yr, and episodically emplaced turbidites 1-5 m thick deposited at intervals of 830 to 3450 yr (average 2000 yr). The average net accumulation rate of the mixed sequence of turbidites and thin pelagite interbeds in the cores is about 1.2 m/1000 yr. Physiography suggests that the turbidites originated on the Mackenzie Delta or its clinoform, and ??13C values of -27 to - 25??? in the turbidites are compatible with a provenance on a delta. Extant displaced neritic and lower slope to basin plain calcareous benthic foraminifers coexist in the turbidite units. Their joint occurence indicates that the turbidites originated on the modern continental shelf and entrained sediment from the slope and rise enroute to their final resting place on the Canada Abyssal Plain. The presence of Middle Pleistocene diatoms in the turbidites suggests, in addition, that the turbidites may have originated in shallow submarine slides beneath the upper slope or outer shelf. Small but consistent differences in organic carbon content and ??13C values between the turbidite units suggest that they did not share an identical provenance, which is at least compatible with an origin in slope failures. The primary provenance of the ice-rafted component of the pelagic beds was the glaciated terrane of northwestern Canada; and the provenance of the turbidite units was Pleistocene and Holocene sedimentary deposits on the outer continental shelf and upper slope of the Mackenzie Delta. Largely local derivation of the sediment of the Canada Abyssal Plain indicates that sediment accumulation rates in the Arctic Ocean are valid only for regions with similar depositional sources and processes, and that these rates cannot be

  16. New insights into the abyssal sponge fauna of the Kurile-Kamchatka plain and Trench region (Northwest Pacific)

    NASA Astrophysics Data System (ADS)

    Downey, Rachel V.; Janussen, Dorte

    2015-01-01

    -enclosed seas of Japan and Okhotsk. The importance of the dominant sub-Polar Gyre currents, the vast area of abyssal plain and similar levels of productivity, are likely to be driving the strong faunal connectivity in the North Pacific. The importance of utilising several forms of sampling equipment has been illustrated in this study, with half of all specimens caught with non-AGT (Agassiz trawl) equipment.

  17. Heat flow in the western abyssal plain of the Gulf of Mexico: Implications for thermal evolution of the old oceanic lithosphere

    NASA Astrophysics Data System (ADS)

    Nagihara, S.; Sclater, J. G.; Phillips, J. D.; Behrens, E. W.; Lewis, T.; Lawver, L. A.; Nakamura, Y.; Garcia-Abdeslem, J.; Maxwell, A. E.

    1996-02-01

    The seafloor depth of an oceanic basin reflects the average temperature of the lithosphere. Thus the western abyssal plain of the Gulf of Mexico, which has tectonically subsided much (>1 km) deeper than other basins of comparable ages (late Jurassic), should be underlain by an anomalously cold lithosphere. In order to examine this hypothesis, we made suites of high-accuracy heat flow measurements at 10 sites along a line connecting Deep Sea Drilling Project (DSDP) sites 90 and 91 in the Sigsbee abyssal plain. The new heat flow sites were initially surveyed by 3.5-kHz echo sounding, 4-channel seismic reflection, seismic refraction with eight ocean bottom seismometers, and nine piston cores. We occupied a total of 48 heat flow stations along the seismic survey line (3 to 6 at each site), including 28 where we measured in situ thermal conductivities over the practical depth interval (4 m) of the new multioutrigger bow heat flow probe. We determined the heat flow associated with the lithosphere by correcting the values measured at the seafloor (41 to 45 mW/m2) for (1) the thermal effect of the sedimentation and (2) the additional heat from the radioactive elements within the sediments. The sedimentation history, required for the first, was reconstructed at each heat flow site based on ages and thicknesses of the major seismic stratigraphical sequences, age data from the DSDP cores, 3.5-kHz subbottom reflectors, and correlation of turbidite units found in the piston cores. Radiogenic heat production was measured for 55 sediment samples from four DSDP holes in the gulf, whose age ranged from present to Early Cretaceous (0.83 μW/m3 on the average). This provided the correction for the second. The effects of these two secondary factors approximately cancel one another. The lithospheric heat flow under the abyssal plain thus estimated ranges from 40 to 47 mW/m2. These heat flow values are among the lowest in the Mesozoic ocean basins where highly reliable data (45 to 55 m

  18. Relationship between 'live' and dead benthic foraminiferal assemblages in the abyssal NE Atlantic

    NASA Astrophysics Data System (ADS)

    Stefanoudis, Paris V.; Bett, Brian J.; Gooday, Andrew J.

    2017-03-01

    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; NE Atlantic, 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).

  19. Geothermal influences on the abyssal ocean

    NASA Astrophysics Data System (ADS)

    Emile-Geay, J.; Madec, G.

    2017-12-01

    Long considered a negligible contribution to ocean dynamics, geothermal heat flow (GHF) is now increasingly recognized as an important contributor to the large scale ocean's deep structure and circulation. This presentation will review the history of theories regarding geothermal influences on the abyssal ocean. Though the contribution to the thermal structure was recognized early on, its potential in driving a circulation [Worthington, 1968] was largely ignored on the grounds that it could not materially affect potential vorticity. Huang [JPO, 1999] proposed that GHF may provide 30-50% of the energy available for deep mixing, a calculation that later proved too optimistic [Wunsch & Ferrari ARFM 2004]. Model simulations suggested that a uniform GHF of 50 mW/m2 could drive an abyssal of a few Sverdrups (1 Sv = 106 m3.s-1) [Adcroft et al, GRL 2001], but it was not until Emile-Geay & Madec [OS, 2009] (EM09) that GHF began to be taken seriously [Mashayek et al, GRL 2013; Voldoire et al. Clim. Dyn. 2013; Dufresnes et al., Clim. Dyn. 2013]. Using analytical and numerical approaches, the study made 3 main points: GHF brings as much energy to the deep ocean as intense diapycnal mixing (1 cm2/s). GHF consumes the densest water masses, inducing a deep circulation of 5 Sv even without mixing. This circulation varies in inverse proportion to abyssal stratification. The spatial structure of GHF, highest at mid-ocean ridges and lowest in abyssal plains, matters far less than the fact that it bathes vast fractions of the ocean floor in a relatively low, constant flux. EM09 concluded that GHF "is an important actor of abyssal dynamics, and should no longer be neglected in oceanographic studies". Recent work has confirmed that geothermal heat flow is of comparable importance to ocean circulation as bottom-intensified mixing induced by internal wave breaking [De Lavergne et al, JPO 2016a,b]. Thus, including GHF in ocean general circulation models improves abyssal structure and

  20. Triticella minini - a new ctenostome bryozoan from the abyssal plain adjacent to the Kuril-Kamchatka Trench

    NASA Astrophysics Data System (ADS)

    Grischenko, Andrei V.; Chernyshev, Alexei V.

    2015-01-01

    A new species of ctenostome bryozoan, Triticella minini sp. nov., is described from the abyssal plain adjacent to the Kuril-Kamchatka Trench, based on material collected by the Russian-German deep-sea expedition KuramBio 2012. Colonies of T. minini sp. nov. were found attached to the oral spines of irregular sea urchin Echinosigra (Echinogutta) amphoraMironov, 1974 by means of rhizoid fibers that penetrated the substratum through circular borings. The specimens were examined by light microscopy, scanning electron microscopy, and confocal laser scanning microscopy with phalloidin and nuclear labeling. The description of T. minini sp. nov. combines a general taxonomic description with a description of the anatomy of the muscular system. The new species differs from congeners in lacking a stolon. It has an intertentacular organ. T. minini sp. nov. is the eleventh species described in the genus TriticellaDalyell, 1848, and the first record for this genus from the northwestern Pacific. The new species is the fifth ctenostome bryozoan known to occur in 5001-5500 m depth interval worldwide, and the deepest record reported for Triticella.

  1. Structural Iron (II) of Basaltic Glass as an Energy Source for Zetaproteobacteria in an Abyssal Plain Environment, Off the Mid Atlantic Ridge

    PubMed Central

    Henri, Pauline A.; Rommevaux-Jestin, Céline; Lesongeur, Françoise; Mumford, Adam; Emerson, David; Godfroy, Anne; Ménez, Bénédicte

    2016-01-01

    To explore the capability of basaltic glass to support the growth of chemosynthetic microorganisms, complementary in situ and in vitro colonization experiments were performed. Microbial colonizers containing synthetic tholeitic basaltic glasses, either enriched in reduced or oxidized iron, were deployed off-axis from the Mid Atlantic Ridge on surface sediments of the abyssal plain (35°N; 29°W). In situ microbial colonization was assessed by sequencing of the 16S rRNA gene and basaltic glass alteration was characterized using Scanning Electron Microscopy, micro-X-ray Absorption Near Edge Structure at the Fe-K-edge and Raman microspectroscopy. The colonized surface of the reduced basaltic glass was covered by a rind of alteration made of iron-oxides trapped in a palagonite-like structure with thicknesses up to 150 μm. The relative abundance of the associated microbial community was dominated (39% of all reads) by a single operational taxonomic unit (OTU) that shared 92% identity with the iron-oxidizer Mariprofundus ferrooxydans PV-1. Conversely, the oxidized basaltic glass showed the absence of iron-oxides enriched surface deposits and correspondingly there was a lack of known iron-oxidizing bacteria in the inventoried diversity. In vitro, a similar reduced basaltic glass was incubated in artificial seawater with a pure culture of the iron-oxidizing M. ferrooxydans DIS-1 for 2 weeks, without any additional nutrients or minerals. Confocal Laser Scanning Microscopy revealed that the glass surface was covered by twisted stalks characteristic of this iron-oxidizing Zetaproteobacteria. This result supported findings of the in situ experiments indicating that the Fe(II) present in the basalt was the energy source for the growth of representatives of Zetaproteobacteria in both the abyssal plain and the in vitro experiment. In accordance, the surface alteration rind observed on the reduced basaltic glass incubated in situ could at least partly result from their activity

  2. Reconstruction of organochlorine compound inputs in the Tagus Prodelta.

    PubMed

    Mil-Homens, Mário; Vicente, Maria; Grimalt, Joan O; Micaelo, Cristina; Abrantes, Fátima

    2016-01-01

    Twenty century time-resolved variability of riverine deposits of polychlorobiphenyls (PCBs), DDTs, hexachlorocyclohexanes (HCHs) and hexachlorobenzene (HCB) was studied in three (210)Pb dated sediment cores collected in a depositional shelf area adjacent to the Tagus estuary (the Tagus Prodelta). The geographic and temporal distribution patterns were consistent with discharge of these organochlorine compounds (OCs) in the area associated with the Tagus mouth. Their concentrations were not correlated with the sedimentary total organic carbon. The PCB down-core profiles were dominated by CB138 and CB153 (hexa-CBs) congeners followed by CB180 (hepta-CBs). Principal Component Analysis of the congener distributions of these compounds did not define temporal down-core trends. The ratios of DDT metabolites (p,p'-DDE/p,p'-DDT) were consistent with recent DDT inputs into the environment and/or earlier applications and long-term residence in soils/sediments until these were eroded and remobilized. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Landscape-scale spatial heterogeneity in phytodetrital cover and megafauna biomass in the abyss links to modest topographic variation

    PubMed Central

    Morris, Kirsty J.; Bett, Brian J.; Durden, Jennifer M.; Benoist, Noelie M. A.; Huvenne, Veerle A. I.; Jones, Daniel O. B.; Robert, Katleen; Ichino, Matteo C.; Wolff, George A.; Ruhl, Henry A.

    2016-01-01

    Sinking particulate organic matter (POM, phytodetritus) is the principal limiting resource for deep-sea life. However, little is known about spatial variation in POM supply to the abyssal seafloor, which is frequently assumed to be homogenous. In reality, the abyss has a highly complex landscape with millions of hills and mountains. Here, we show a significant increase in seabed POM % cover (by ~1.05 times), and a large significant increase in megafauna biomass (by ~2.5 times), on abyssal hill terrain in comparison to the surrounding plain. These differences are substantially greater than predicted by current models linking water depth to POM supply or benthic biomass. Our observed variations in POM % cover (phytodetritus), megafauna biomass, sediment total organic carbon and total nitrogen, sedimentology, and benthic boundary layer turbidity, all appear to be consistent with topographically enhanced current speeds driving these enhancements. The effects are detectable with bathymetric elevations of only 10 s of metres above the surrounding plain. These results imply considerable unquantified heterogeneity in global ecology. PMID:27681937

  4. The role of tectonic inheritance in the morphostructural evolution of the Galicia continental margin and adjacent abyssal plains from digital bathymetric model (DBM) analysis (NW Spain)

    NASA Astrophysics Data System (ADS)

    Maestro, A.; Jané, G.; Llave, E.; López-Martínez, J.; Bohoyo, F.; Druet, M.

    2018-06-01

    The identification of recent major tectonic structures in the Galicia continental margin and adjacent abyssal plains was carried out by means of a quantitative analysis of the linear structures having bathymetric expression on the seabed. It was possible to identify about 5800 lineaments throughout the entire study area, of approximately 271,500 km2. Most lineaments are located in the Charcot and Coruña highs, in the western sector of the Galicia Bank, in the area of the Marginal Platforms and in the northern sector of the margin. Analysis of the lineament orientations shows a predominant NE-SW direction and three relative maximum directions: NW-SE, E-W and N-S. The total length of the lineaments identified is over 44,000 km, with a mode around 5000 m and an average length of about 7800 m. In light of different tectonic studies undertaken in the northwestern margin of the Iberian Peninsula, we establish that the lineaments obtained from analysis of the digital bathymetric model of the Galicia continental margin and adjacent abyssal plains would correspond to fracture systems. In general, the orientation of lineaments corresponds to main faults, tectonic structures following the directions of ancient faults that resulted from late stages of the Variscan orogeny and Mesozoic extension phases related to Triassic rifting and Upper Jurassic to Early Cretaceous opening of the North Atlantic Ocean. The N-S convergence between Eurasian and African plates since Palaeogene times until the Miocene, and NW-SE convergence from Neogene to present, reactivated the Variscan and Mesozoic fault systems and related physiography.

  5. Late Quaternary paleoenvironmental changes revealed by multi-proxy records from the Chukchi Abyssal Plain, western Arctic Ocean

    NASA Astrophysics Data System (ADS)

    Wang, Rujian; Xiao, Wenshen; März, Christian; Li, Qianyu

    2013-09-01

    Late Quaternary paleoenvironmental changes in the western Arctic Ocean are revealed by multi-proxy records of core 03M03 from the Chukchi Abyssal Plain (CAP). Proxy parameters include lithology, grain size fractions, and mineralogy and petrology of ice-rafted detritus (IRD), element contents, biogenic components, δ18O, δ13C and Mg/Ca of planktonic foraminifera Neogloboquadrina pachyderma (sin.) (Nps). Seven IRD (> 250 μm) peaks are interpreted as marking detrital input by rafting sea ice or icebergs during MIS 3 interstadials and early MIS 1. High MnO, CaO and MgO contents and high Ca/Al and Mg/Al ratios during MIS 3 and MIS 1 correspond to increases in ice-rafted detrital carbonates and the synchronous declines in siliciclastic elements (e.g., Al2O3, Fe2O3). Therefore, these warmer periods were characterized by a high detrital carbonate input entrained in icebergs from the Canadian Arctic Archipelago coeval with an increased input of Mn through rivers and/or coastal erosion. Relatively stable contents of siliciclastic elements and their ratios in the grayish sediment units are interpreted from turbid surface water plumes or nepheloid flows delivered by meltwater and/or brine rejection from ice-sheet margins at the Arctic Ocean periphery. Relatively stable clay- and silt-sized fractions were attributed mainly to sea ice entrainment over glacial-interglacial cycles. High foraminiferal abundances in the brown units during MIS 3 and 1 are related to enhanced calcareous plankton productivity under more open water conditions and/or the incremental input of Atlantic water masses. Relatively high TOC and opal contents in the grayish units of MIS 3 appear to have accumulated by lateral transport of organic matter from the Chukchi shelf to the deep abyssal plain. Lower contents of biogenic material in the brown units probably result from increased dilution by rapid IRD deposition, and from early diagenetic degradation. Depletions in Nps-δ18O and -δ13C concurrent with

  6. Ciliate diversity and distribution patterns in the sediments of a seamount and adjacent abyssal plains in the tropical Western Pacific Ocean.

    PubMed

    Zhao, Feng; Filker, Sabine; Stoeck, Thorsten; Xu, Kuidong

    2017-09-12

    Benthic ciliates and the environmental factors shaping their distribution are far from being completely understood. Likewise, deep-sea systems are amongst the least understood ecosystems on Earth. In this study, using high-throughput DNA sequencing, we investigated the diversity and community composition of benthic ciliates in different sediment layers of a seamount and an adjacent abyssal plain in the tropical Western Pacific Ocean with water depths ranging between 813 m and 4566 m. Statistical analyses were used to assess shifts in ciliate communities across vertical sediment gradients and water depth. Nine out of 12 ciliate classes were detected in the different sediment samples, with Litostomatea accounting for the most diverse group, followed by Plagiopylea and Oligohymenophorea. The novelty of ciliate genetic diversity was extremely high, with a mean similarity of 93.25% to previously described sequences. On a sediment depth gradient, ciliate community structure was more similar within the upper sediment layers (0-1 and 9-10 cm) compared to the lower sediment layers (19-20 and 29-30 cm) at each site. Some unknown ciliate taxa which were absent from the surface sediments were found in deeper sediments layers. On a water depth gradient, the proportion of unique OTUs was between 42.2% and 54.3%, and that of OTUs shared by all sites around 14%. However, alpha diversity of the different ciliate communities was relatively stable in the surface layers along the water depth gradient, and about 78% of the ciliate OTUs retrieved from the surface layer of the shallowest site were shared with the surface layers of sites deeper than 3800 m. Correlation analyses did not reveal any significant effects of measured environmental factors on ciliate community composition and structure. We revealed an obvious variation in ciliate community along a sediment depth gradient in the seamount and the adjacent abyssal plain and showed that water depth is a less important factor

  7. Direct observation of episodic growth in an abyssal xenophyophore (Protista)

    NASA Astrophysics Data System (ADS)

    Gooday, A. J.; Bett, B. J.; Pratt, D. N.

    1993-11-01

    Three specimens of the xenophyophore Reticulammina labyrinthica were photographed on the Madeira Abyssal Plain (31°6.1'N, 21°10.9'W; 4944 m) using the Bathysnap time-lapse camera system. During the 8 month observation period, the specimens underwent an estimated 3-10 fold increase in volume. Growth occurred episodically in several distinct phases, each lasting 2-3 days, during which sediment was collected and incorporated into the test. These phases were separated by fairly regular periods of about 2 months when the organisms showed little obvious activity. The growth phases were approximately synchronous between specimens. However, it is not clear whether the periodicity and apparent synchronization of these events resulted from an external (environmental) cue or whether growth is internally controlled and the synchronization arose by chance. These unique observations, which represent the first direct measurement of growth in any abyssal organism living outside a hydrothermal vent field, suggest that xenophyophores combine test growth with deposit feeding. The tests appear to grow more quickly, and to be more active, dynamic structures, than previously believed.

  8. Bathymetry (Part I), sedimentary regimes (Part II), and abyssal waste-disposal potential near the conterminous United States

    NASA Astrophysics Data System (ADS)

    Bowles, Frederick A.; Vogt, Peter R.; Jung, Woo-Yeol

    1998-05-01

    Placing waste on the seafloor, with the intention that it remain in place and isolated from mankind, requires a knowledge of the environmental factors that may be applicable to a specific seafloor area. DBDB5 (Digital Bathymetric Database gridded at 5' latitude by 5' longitude cell dimension) is used here for regional assessments of seafloor depth, slope, and relief at five surrogate abyssal waste sites; two each in the western Atlantic and eastern Pacific, and one in the Gulf of Mexico. Only Pacific-1 exhibits a `high' slope (2°) by DBDB5 standards, whereas the remaining sites are located on almost level seafloor. Detailed examination of the sites using multibeam-based contour sheets show the area around Atlantic-1 to be a featureless plain. Atlantic-2 and both Pacific sites are surrounded by abyssal hill topography, with local slopes ranging from greater than 6° at all sites to above 15° at Pacific-2. Neither Pacific site features a seafloor as `flat' as at Atlantic-1 or at the Gulf of Mexico site. Locating waste sites on sedimented slopes could have serious consequences due to catastrophic slope failure and downslope displacement of waste by mass sediment-transport processes. Neither slumping nor sliding are perceived as critical processes affecting the surrogate sites because of their locations on negligibly sloping seafloors. However, debris flows and turbidity currents are capable of transporting large volumes of sediment for long distances over low gradients and, in the case of turbidity currents, at great speed. Dispersal of loose waste material by these processes is virtually assured, but less likely if the waste is bagged. The turbidity current problem is alleviated (but not eliminated) by locating waste sites on distal portions of abyssal plains. Both Pacific sites are surrounded by abyssal hills and, in the case of Pacific-2, far beyond the reach of land-derived turbidity currents. Thin sediment cover and low rates of sedimentation have also resulted

  9. Option contracts for allocating water in inter-basin transfers: the case of the Tagus-Segura Transfer in Spain

    NASA Astrophysics Data System (ADS)

    Rey, Dolores; Garrido, Alberto; Calatraba, Javier

    2014-05-01

    Users in the Mediterranean region face significant water supply risks. Water markets mechanisms can provide flexibility to water systems run in tight situations. The largest water infrastructure in the Iberian Peninsula connects the Segura and Tagus Basins. Stakeholders and politicians in the Tagus Basin have asked that water transfers between the two basins be eventually phased out. The need to increase the statutory minimum environmental flow in the middle Tagus and to meet new urban demands is going to result in a redefinition of the Transfer's management rules, leading to a reduction in the transferable volumes. To minimise the consequences of such restrictions to irrigators in the Segura Basin who depend on the transferred volumes, we propose the establishment of water option contracts between both basins that represents an institutional innovation with respect to previous inter-basin spot market experiences. Based on the draft of the new Tagus Basin Plan, we propose both a modification of the Transfer's management rule and an innovative inter-basin option contract. The main goal of the paper is to define this contract and evaluate it with respect to non-market scenarios. We also assess the resulting impact on environmental flows in the Tagus River and water availability for users in the Segura Basin, together with the economic impacts of such contract on both basins. Our results show that the proposed option contract would reduce the impact of a change in the transfer's management rule, and reduce the supply risks of the recipient area. Keywords: environmental flow, inter-basin transfer, option contracts, Tagus-Segura, water markets, water supply reliability.

  10. Fatty acid compositions and trophic relationships of shelled molluscs from the Kuril-Kamchatka Trench and the adjacent abyssal plain

    NASA Astrophysics Data System (ADS)

    Kharlamenko, Vladimir I.; Würzberg, Laura; Peters, Janna; Borisovets, Evgeny E.

    2015-01-01

    Fatty acid (FA) compositions of 12 species of shelled molluscs (gastropods, bivalves, and scaphopods) from the Kuril-Kamchatka Trench and the adjacent abyssal plain were studied. According to the results of multivariate statistical analysis, molluscs were divided into three groups. Group I consisted of three scaphopod species, the bivalve Nucula profundorum and the gastropod Solariella delicata. FA compositions of this group were characterized by high levels of 20:4(n-6). We suggest that the FA pattern found in scaphopods with high values of 20:4(n-6) is most likely typical for that of benthic organisms feeding preferentially on foraminiferans. Group II included the bivalves Neilonella politissima, Bentharca asperula, and Rhinoclama filatovae. Bivalves from the second group had elevated concentrations of 22:6(n-3), and the ratio of 20:4(n-6) to 20:5(n-3) was lower than 1. Bivalves from the second group had elevated concentrations of 22:6(n-3). We propose that high concentrations of this FA can be used as a specific marker for a carnivorous feeding mode of deep-sea benthic invertebrates. The bivalve Bathyspinula calcarella as well as the scaphopod Polyschides sakuraii could not unambiguously be assigned to one group. Within the similarity analysis they rather clustered together with the foraminiferans feeders (group I), but forming an own subgroup. In the PCA on the other hand, P. sakuraii showed a position close to the other bivalves, while B. calcarella had an intermediate position between all three groups. Group III consisted of the gastropods Tacita holoserica and Paracteocina sp., which contained high concentrations of 20:5(n-3) and 22:5(n-3). Both are known to exhibit a carnivorous/scavenging feeding strategy. The very low content of DHA in both species is on first sight not consistent with the suggested carnivorous feeding behavior. A characteristic feature of Paracteocina sp. and T. holoserica was a high level of 22:5(n-3), and HUFA ratios indicate that DHA

  11. Influence of main forcing affecting the Tagus turbid plume under high river discharges using MODIS imagery

    PubMed Central

    Gómez-Gesteira, M.; Mendes, R.; deCastro, M.; Vaz, N.; Dias, J. M.

    2017-01-01

    The role of river discharge, wind and tide on the extension and variability of the Tagus River plume was analyzed from 2003 to 2015. This study was performed combining daily images obtained from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor located onboard the Aqua and Terra satellites. Composites were generated by averaging pixels with the same forcing conditions. River discharge shows a strong relation with the extension of the Tagus plume. The plume grows with the increasing river discharge and express a two day lag caused by the long residence time of water within the estuary. The Tagus turbid plume was found to be smaller under northerly and easterly winds, than under southerly and westerly winds. It is suggested that upwelling favoring winds provoke the offshore movement of the plume material with a rapidly decrease in turbidity values whereas downwelling favoring winds retain plume material in the north coast close to the Tagus mouth. Eastern cross-shore (oceanward) winds spread the plume seaward and to the north following the coast geometry, whereas western cross-shore (landward) winds keep the plume material in both alongshore directions occupying a large part of the area enclosed by the bay. Low tides produce larger and more turbid plumes than high tides. In terms of fortnightly periodicity, the maximum plume extension corresponding to the highest turbidity is observed during and after spring tides. Minimum plume extension associated with the lowest turbidity occurs during and after neap tides. PMID:29073209

  12. Influence of main forcing affecting the Tagus turbid plume under high river discharges using MODIS imagery.

    PubMed

    Fernández-Nóvoa, D; Gómez-Gesteira, M; Mendes, R; deCastro, M; Vaz, N; Dias, J M

    2017-01-01

    The role of river discharge, wind and tide on the extension and variability of the Tagus River plume was analyzed from 2003 to 2015. This study was performed combining daily images obtained from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor located onboard the Aqua and Terra satellites. Composites were generated by averaging pixels with the same forcing conditions. River discharge shows a strong relation with the extension of the Tagus plume. The plume grows with the increasing river discharge and express a two day lag caused by the long residence time of water within the estuary. The Tagus turbid plume was found to be smaller under northerly and easterly winds, than under southerly and westerly winds. It is suggested that upwelling favoring winds provoke the offshore movement of the plume material with a rapidly decrease in turbidity values whereas downwelling favoring winds retain plume material in the north coast close to the Tagus mouth. Eastern cross-shore (oceanward) winds spread the plume seaward and to the north following the coast geometry, whereas western cross-shore (landward) winds keep the plume material in both alongshore directions occupying a large part of the area enclosed by the bay. Low tides produce larger and more turbid plumes than high tides. In terms of fortnightly periodicity, the maximum plume extension corresponding to the highest turbidity is observed during and after spring tides. Minimum plume extension associated with the lowest turbidity occurs during and after neap tides.

  13. Long-term change in benthopelagic fish abundance in the abyssal northeast Pacific Ocean.

    PubMed

    Bailey, D M; Ruhl, H A; Smith, K L

    2006-03-01

    Food web structure, particularly the relative importance of bottom-up and top-down control of animal abundances, is poorly known for the Earth's largest habitats: the abyssal plains. A unique 15-yr time series of climate, productivity, particulate flux, and abundance of primary consumers (primarily echinoderms) and secondary consumers (fish) was examined to elucidate the response of trophic levels to temporal variation in one another. Towed camera sled deployments in the abyssal northeast Pacific (4100 m water depth) showed that annual mean numbers of the dominant fish genus (Coryphaenoides spp.) more than doubled over the period 1989-2004. Coryphaenoides spp. abundance was significantly correlated with total abundance of mobile epibenthic megafauna (echinoderms), with changes in fish abundance lagging behind changes in the echinoderms. Direct correlations between surface climate and fish abundances, and particulate organic carbon (POC) flux and fish abundances, were insignificant, which may be related to the varied response of the potential prey taxa to climate and POC flux. This study provides a rare opportunity to study the long-term dynamics of an unexploited marine fish population and suggests a dominant role for bottom-up control in this system.

  14. A numerical study of local variations in tidal regime of Tagus estuary, Portugal.

    PubMed

    Dias, João Miguel; Valentim, Juliana Marques; Sousa, Magda Catarina

    2013-01-01

    Tidal dynamics of shallow estuaries and lagoons is a complex matter that has attracted the attention of a large number of researchers over the last few decades. The main purpose of the present work is to study the intricate tidal dynamics of the Tagus estuary, which states as the largest estuary of the Iberian Peninsula and one of the most important wetlands in Portugal and Europe. Tagus has large areas of low depth and a remarkable geomorphology, both determining the complex propagation of tidal waves along the estuary of unknown manner. A non-linear two-dimensional vertically integrated hydrodynamic model was considered to be adequate to simulate its hydrodynamics and an application developed from the SIMSYS2D model was applied to study the tidal propagation along the estuary. The implementation and calibration of this model revealed its accuracy to predict tidal properties along the entire system. Several model runs enabled the analysis of the local variations in tidal dynamics, through the interpretation of amplitude and phase patterns of the main tidal constituents, tidal asymmetry, tidal ellipses, form factor and tidal dissipation. Results show that Tagus estuary tidal dynamics is extremely dependent on an estuarine resonance mode for the semi-diurnal constituents that induce important tidal characteristics. Besides, the estuarine coastline features and topography determines the changes in tidal propagation along the estuary, which therefore result essentially from a balance between convergence/divergence and friction and advection effects, besides the resonance effects.

  15. A Numerical Study of Local Variations in Tidal Regime of Tagus Estuary, Portugal

    PubMed Central

    Dias, João Miguel; Valentim, Juliana Marques; Sousa, Magda Catarina

    2013-01-01

    Tidal dynamics of shallow estuaries and lagoons is a complex matter that has attracted the attention of a large number of researchers over the last few decades. The main purpose of the present work is to study the intricate tidal dynamics of the Tagus estuary, which states as the largest estuary of the Iberian Peninsula and one of the most important wetlands in Portugal and Europe. Tagus has large areas of low depth and a remarkable geomorphology, both determining the complex propagation of tidal waves along the estuary of unknown manner. A non-linear two-dimensional vertically integrated hydrodynamic model was considered to be adequate to simulate its hydrodynamics and an application developed from the SIMSYS2D model was applied to study the tidal propagation along the estuary. The implementation and calibration of this model revealed its accuracy to predict tidal properties along the entire system. Several model runs enabled the analysis of the local variations in tidal dynamics, through the interpretation of amplitude and phase patterns of the main tidal constituents, tidal asymmetry, tidal ellipses, form factor and tidal dissipation. Results show that Tagus estuary tidal dynamics is extremely dependent on an estuarine resonance mode for the semi-diurnal constituents that induce important tidal characteristics. Besides, the estuarine coastline features and topography determines the changes in tidal propagation along the estuary, which therefore result essentially from a balance between convergence/divergence and friction and advection effects, besides the resonance effects. PMID:24312474

  16. Internal tide generation by abyssal hills using analytical theory

    NASA Astrophysics Data System (ADS)

    Melet, Angélique; Nikurashin, Maxim; Muller, Caroline; Falahat, S.; Nycander, Jonas; Timko, Patrick G.; Arbic, Brian K.; Goff, John A.

    2013-11-01

    Internal tide driven mixing plays a key role in sustaining the deep ocean stratification and meridional overturning circulation. Internal tides can be generated by topographic horizontal scales ranging from hundreds of meters to tens of kilometers. State of the art topographic products barely resolve scales smaller than ˜10 km in the deep ocean. On these scales abyssal hills dominate ocean floor roughness. The impact of abyssal hill roughness on internal-tide generation is evaluated in this study. The conversion of M2 barotropic to baroclinic tidal energy is calculated based on linear wave theory both in real and spectral space using the Shuttle Radar Topography Mission SRTM30_PLUS bathymetric product at 1/120° resolution with and without the addition of synthetic abyssal hill roughness. Internal tide generation by abyssal hills integrates to 0.1 TW globally or 0.03 TW when the energy flux is empirically corrected for supercritical slope (i.e., ˜10% of the energy flux due to larger topographic scales resolved in standard products in both cases). The abyssal hill driven energy conversion is dominated by mid-ocean ridges, where abyssal hill roughness is large. Focusing on two regions located over the Mid-Atlantic Ridge and the East Pacific Rise, it is shown that regionally linear theory predicts an increase of the energy flux due to abyssal hills of up to 100% or 60% when an empirical correction for supercritical slopes is attempted. Therefore, abyssal hills, unresolved in state of the art topographic products, can have a strong impact on internal tide generation, especially over mid-ocean ridges.

  17. Species diversity in the cryptic abyssal holothurian Psychropotes longicauda (Echinodermata)

    NASA Astrophysics Data System (ADS)

    Gubili, Chrysoula; Ross, Elizabeth; Billett, David S. M.; Yool, Andrew; Tsairidis, Charalampos; Ruhl, Henry A.; Rogacheva, Antonina; Masson, Doug; Tyler, Paul A.; Hauton, Chris

    2017-03-01

    Despite the plethora of studies on swallow-water invertebrates, almost nothing is known about the evolution and population structure of deep-sea species at the global scale. The aim of this study was to assess phylogeographic patterns of a common and cosmopolitan, predominantly abyssal sea cucumber, Psychropotes longicauda, based on samples from the Atlantic, Southern, Indian and Pacific oceans. Sequences of the mitochondrial COI and 16S genes were analysed for 128 specimens of P. longicauda. In addition, temporal genetic variation was investigated at one site, the Porcupine Abyssal Plain, NE Atlantic Ocean over a period of 34 years. Two distinct lineages within the global distribution were identified. The sister clades probably could be classified as separate species based on the observed genetic divergence (>5.0%) and phylogenetic reconstruction with indications of a Southern Hemisphere origin. Moreover, significant population differentiation was detected between the North Atlantic and localities in both the Pacific and Indian oceans. No bathymetric structuring was detected among lineages. Temporal genetic shifts were detected in a time series of samples from 1977 to 2011. Our data confirm the previously suspected cryptic species diversity throughout the wide distributional range previously attributed to the single species P. longicauda. The presence of sympatric species in the North Pacific and Indian Oceans has been underestimated by previous morphological analyses. The differentiation at the population level detected in the main lineages among the four oceans could suggest restricted gene flow despite wide-scale dispersal potential of the species.

  18. Evidences of Paleoearthquakes in Palaeolithic settlements within fluvial sequences of the Tagus Basin (Madrid, Central Spain).

    NASA Astrophysics Data System (ADS)

    Silva, Pablo G.; Rodríguez Pascua, M. A.; Pérez López, R.; Giner Robles, J. L.; Roquero, E.; Tapias, F.; López Recio, M.; Rus, I.; Morin, J.

    2010-05-01

    Multiple evidences of soft-sediment to brittle deformation within the Pleistocene fluvial terraces of the Tagus, Jarama, Tajuña and Manzanares river valleys have been described since the middle 20th Century. Cryoturbation, hydroplastic deformations due to underlying karstic collapses or halokinesis on the substratum of neogene gypsums, and seismic shaking have been proposed to interpret these structures. These deformations are typically concentrated in the +18-20 m terrace levels, and closely linked to well-known Palaeolithic sites, in some cases overlaying and/or affecting true prehistoric settlements (i.e. Arganda, Arriaga and Tafesa sites) within the Jarama and Manzanares valleys. The affected settlements typically display acheulian lithic industry linked to the scavenging of large Pleistocene mammals (i.e. Elephas antiquus). Commonly, deformational structures are concentrated in relatively thin horizons (10-50 cm thick) bracketed by undeformed fluvial sands and gravels. The soft-sediment deformations usually consist on medium to fine sized sands injected and protruded in overlaying flood-plain clayey silts, showing a wide variety of convolutes, injections, sand-dikes, dish and pillar structures, mud volcanoes, faults and folds, some times it is possible to undertake their 3D geometrical analysis due to the exceptional conservation of the structures (Tafesa). Recent geo-archaeological prospecting on the for the Palaeolithic Site of Arriaga (South Madrid City) conducted during the year 2009, let to find out an exceptional horizon of deformation of about 1.20 m thick. It consisted on highly disturbed and pervasively liquefacted sands, which hardly can be attributed to no-seismic processes. The acheulian lithic industry of the Madrid Region have been classically attributed the Late Middle Pleistocene (< 350 kyr BP), but recent OSL dating indicate that the basal horizons of the +18-20 m fluvial terraces hold ages younger than c.a. 120-100 kyr BP in this zone. All

  19. Geomorphological and sedimentary processes of the glacially influenced northwestern Iberian continental margin and abyssal plains

    NASA Astrophysics Data System (ADS)

    Llave, Estefanía; Jané, Gloria; Maestro, Adolfo; López-Martínez, Jerónimo; Hernández-Molina, F. Javier; Mink, Sandra

    2018-07-01

    The offshore region of northwestern Iberia offers an opportunity to study the impacts of along-slope processes on the morphology of a glacially influenced continental margin, which has traditionally been conceptually characterised by predominant down-slope sedimentary processes. High-resolution multibeam bathymetry, acoustic backscatter and ultrahigh-resolution seismic reflection profile data are integrated and analysed to describe the present-day and recent geomorphological features and to interpret their associated sedimentary processes. Seventeen large-scale seafloor morphologies and sixteen individual echo types, interpreted as structural features (escarpments, marginal platforms and related fluid escape structures) and depositional and erosional bedforms developed either by the influence of bottom currents (moats, abraded surfaces, sediment waves, contourite drifts and ridges) or by gravitational features (gullies, canyons, slides, channel-levee complexes and submarine fans), are identified for the first time in the study area (spanning 90,000 km2 and water depths of 300 m to 5 km). Different types of slope failures and turbidity currents are mainly observed on the upper and lower slopes and along submarine canyons and deep-sea channels. The middle slope morphologies are mostly determined by the actions of bottom currents (North Atlantic Central Water, Mediterranean Outflow Water, Labrador Sea Water and North Atlantic Deep Water), which thereby define the margin morphologies and favour the reworking and deposition of sediments. The abyssal plains (Biscay and Iberian) are characterised by pelagic deposits and channel-lobe systems (the Cantabrian and Charcot), although several contourite features are also observed at the foot of the slope due to the influence of the deepest water masses (i.e., the North Atlantic Deep Water and Lower Deep Water). This work shows that the study area is the result of Mesozoic to present-day tectonics (e.g. the marginal platforms

  20. Abyssal fauna of the UK-1 polymetallic nodule exploration area, Clarion-Clipperton Zone, central Pacific Ocean: Cnidaria.

    PubMed

    Dahlgren, Thomas G; Wiklund, Helena; Rabone, Muriel; Amon, Diva J; Ikebe, Chiho; Watling, Les; Smith, Craig R; Glover, Adrian G

    2016-01-01

    We present data from a DNA taxonomy register of the abyssal Cnidaria collected as part of the Abyssal Baseline (ABYSSLINE) environmental survey cruise 'AB01' to the UK Seabed Resources Ltd (UKSRL) polymetallic-nodule exploration area 'UK-1' in the eastern Clarion-Clipperton Zone (CCZ), central Pacific Ocean abyssal plain. This is the second paper in a series to provide regional taxonomic data for a region that is undergoing intense deep-sea mineral exploration for high-grade polymetallic nodules. Data were collected from the UK-1 exploration area following the methods described in Glover et al. (2015b). Morphological and genetic data are presented for 10 species and 18 records identified by a combination of morphological and genetic data, including molecular phylogenetic analyses. These included 2 primnoid octocorals, 2 isidid octocorals, 1 anemone, 4 hydroids (including 2 pelagic siphonophores accidentally caught) and a scyphozoan jellyfish (in the benthic stage of the life cycle). Two taxa matched previously published genetic sequences (pelagic siphonophores), two taxa matched published morphological descriptions (abyssal primnoids described from the same locality in 2015) and the remaining 6 taxa are potentially new species, for which we make the raw data, imagery and vouchers available for future taxonomic study. We have used a precautionary approach in taxon assignments to avoid over-estimating species ranges. The Clarion-Clipperton Zone is a region undergoing intense exploration for potential deep-sea mineral extraction. We present these data to facilitate future taxonomic and environmental impact study by making both data and voucher materials available through curated and accessible biological collections. For some of the specimens we also provide image data collected at the seabed by ROV, wich may facilitate more accurate taxon designation in coming ROV or AUV surveys.

  1. Phytopigments as biomarkers of selectivity in abyssal holothurians; interspecific differences in response to a changing food supply

    NASA Astrophysics Data System (ADS)

    FitzGeorge-Balfour, Tania; Billett, David S. M.; Wolff, George A.; Thompson, Anu; Tyler, Paul A.

    2010-08-01

    Holothurians dominate the abyssal megabenthos. They are key consumers and bioturbators of surficial sediment. Compounds essential for holothurian reproduction, such as carotenoids, are in short supply in the deep ocean. Holothurians cannot synthesise carotenoids de novo; the compounds are supplied with the flux of phytodetritus. Therefore, the supply of these compounds may play an important role in regulating processes on the seafloor. This study examines the link between the diet of abyssal holothurians and their ovarian carotenoid biochemistry. Phytodetritus, surficial sediment, holothurian gut content and ovaries were sampled in June 2004 and in July 2005 at the Porcupine Abyssal Plain (PAP), NE Atlantic. Gut content chlorophyll a concentration showed that Amperima rosea, Peniagone diaphana and Oneirophanta mutabilis fed selectively on fresh organic matter, although when this was scarce, O. mutabilis was outcompeted and fed on more refractory material. All three species display consistent ovarian carotenoid profiles and have relatively high carotenoid concentrations in their ovaries. Psychropotes longicauda, Paroriza prouhoi, Pseudostichopus aemulatus, P. villosus and Molpadia blakei fed less selectively and exhibited low ovarian carotenoid concentrations with inconsistent profiles. The results suggest that abyssal holothurian ovarian biochemistry is a complex function of OM supply, holothurian feeding guild and reproductive adaptation. Changes in upper ocean biogeochemistry, altering the composition of organic matter reaching the deep-sea floor, may favour certain holothurian species, as suggested by the interspecific differences in holothurian ovarian biochemistry. This may lead to large community changes as seen at the PAP, which can alter the reworking rates of sediment, probably affecting carbon burial. The study also demonstrated that using the presence of biomarkers in gut contents to infer feeding selectivity should be used with caution. Only biomarkers

  2. Abyssal fauna of the UK-1 polymetallic nodule exploration area, Clarion-Clipperton Zone, central Pacific Ocean: Cnidaria

    PubMed Central

    Wiklund, Helena; Rabone, Muriel; Amon, Diva J; Ikebe, Chiho; Watling, Les; Smith, Craig R; Glover, Adrian G

    2016-01-01

    Abstract Background We present data from a DNA taxonomy register of the abyssal Cnidaria collected as part of the Abyssal Baseline (ABYSSLINE) environmental survey cruise ‘AB01’ to the UK Seabed Resources Ltd (UKSRL) polymetallic-nodule exploration area ‘UK-1’ in the eastern Clarion-Clipperton Zone (CCZ), central Pacific Ocean abyssal plain. This is the second paper in a series to provide regional taxonomic data for a region that is undergoing intense deep-sea mineral exploration for high-grade polymetallic nodules. Data were collected from the UK-1 exploration area following the methods described in Glover et al. (2015b). New information Morphological and genetic data are presented for 10 species and 18 records identified by a combination of morphological and genetic data, including molecular phylogenetic analyses. These included 2 primnoid octocorals, 2 isidid octocorals, 1 anemone, 4 hydroids (including 2 pelagic siphonophores accidentally caught) and a scyphozoan jellyfish (in the benthic stage of the life cycle). Two taxa matched previously published genetic sequences (pelagic siphonophores), two taxa matched published morphological descriptions (abyssal primnoids described from the same locality in 2015) and the remaining 6 taxa are potentially new species, for which we make the raw data, imagery and vouchers available for future taxonomic study. We have used a precautionary approach in taxon assignments to avoid over-estimating species ranges. The Clarion-Clipperton Zone is a region undergoing intense exploration for potential deep-sea mineral extraction. We present these data to facilitate future taxonomic and environmental impact study by making both data and voucher materials available through curated and accessible biological collections. For some of the specimens we also provide image data collected at the seabed by ROV, wich may facilitate more accurate taxon designation in coming ROV or AUV surveys. PMID:27660533

  3. Northwest African Continental Margin: History of sediment accumulation, landslide deposits, and hiatuses as revealed by drilling the Madeira Abyssal Plain

    NASA Astrophysics Data System (ADS)

    Weaver, P. P. E.

    2003-03-01

    ODP drill sites in the Madeira Abyssal Plain reveal sequences of organic-rich turbidites derived from the northwest African margin, in which each turbidite has a volume of tens to hundreds of cubic kilometers. The frequency of turbidite emplacement has been combined with core and seismic data to show the volume of redeposited sediment. The basin began to fill about 22 Ma with numerous small turbidites, up to 100 per million years, each with volumes of a few cubic kilometers. The total volume of turbidites deposited increased between 16 and 11 Ma, as did their individual volumes, and then declined to 7 Ma. At 7 Ma, there was a dramatic increase in the amount of turbidite input to 768 km3/Myr and a rise in the average volume of each unit to 59 km3. These high values have been maintained to the present day. The variations in the amount of redeposited sediment most likely reflect the rates of sedimentation on the northwest African margin since high sedimentation leads to oversteepening of the slopes and eventual mass wasting. The dramatic changes at about 7 Ma may be due to a large increase in upwelling off northwest Africa caused by circulation changes associated with increased glaciation of the poles. Up to 20% of sediment may be remobilized by landslides, with each event leaving a hiatus. Each of these hiatuses extends over an average area of ˜4800 km2 and represents removal of sediment layers several tens of meters thick and of several hundred thousand years duration.

  4. Global variations in abyssal peridotite compositions

    NASA Astrophysics Data System (ADS)

    Warren, Jessica M.

    2016-04-01

    Abyssal peridotites are ultramafic rocks collected from mid-ocean ridges that are the residues of adiabatic decompression melting. Their compositions provide information on the degree of melting and melt-rock interaction involved in the formation of oceanic lithosphere, as well as providing constraints on pre-existing mantle heterogeneities. This review presents a compilation of abyssal peridotite geochemical data (modes, mineral major elements, and clinopyroxene trace elements) for > 1200 samples from 53 localities on 6 major ridge systems. On the basis of composition and petrography, peridotites are classified into one of five lithological groups: (1) residual peridotite, (2) dunite, (3) gabbro-veined and/or plagioclase-bearing peridotite, (4) pyroxenite-veined peridotite, and (5) other types of melt-added peridotite. Almost a third of abyssal peridotites are veined, indicating that the oceanic lithospheric mantle is more fertile, on average, than estimates based on residual peridotites alone imply. All veins appear to have formed recently during melt transport beneath the ridge, though some pyroxenites may be derived from melting of recycled oceanic crust. A limited number of samples are available at intermediate and fast spreading rates, with samples from the East Pacific Rise indicating high degrees of melting. At slow and ultra-slow spreading rates, residual abyssal peridotites define a large (0-15% modal clinopyroxene and spinel Cr# = 0.1-0.6) compositional range. These variations do not match the prediction for how degree of melting should vary as a function of spreading rate. Instead, the compositional ranges of residual peridotites are derived from a combination of melting, melt-rock interaction and pre-existing compositional variability, where melt-rock interaction is used here as a general term to refer to the wide range of processes that can occur during melt transport in the mantle. Globally, 10% of abyssal peridotites are refractory (0% clinopyroxene

  5. Sedimentology of the Argo and Gascoyne abyssal plains, NW Australia: Report on Ocean Drilling Program Leg 123 (Sept. 1–Nov. 1, 1988)

    USGS Publications Warehouse

    Thurow, Jürgen

    1988-01-01

    Ocean Drilling Program Leg 123 drilled two sites in the Indian Ocean in order to study the rifting and early spreading of one of the world’s oldest ocean basins.Site 765 was drilled in 5714 meters of water on the Argo Abyssal Plain northwest of Australia. The sedimentary succession records the opening of an ocean basin, from the first sediments deposited atop young oceanic crust, to the present day. The oldest sediments are microlaminated brown silty claystones, locally rich in calcareous bioclasts. Most of the sequence is dominated by turbidites (primarily calcareous) which probably originated within canyons cut into the margin of the drowned platform of the North West Shelf of Australia.Site 766 is located in 3998 meters of water, at the base of the steep western margin of the Exmouth Plateau. The oldest sediments penetrated are glauconitic, volcaniclastic, and bioclastic sandstones and siltstones, which are interbedded with inclined basaltic sills. These sediments were deposited by a prograding submarine fan system which shed shallow marine sediments westward or northwestward off of the western rim of the Exmouth Plateau. Sandstones are succeeded by silty claystones, recording gradual abandonment or redirection of the fan system. An overlying sequence of pelagic and hemipelagic clayey and zeolitic calcareous oozes and chalks is succeeded by featureless and homogeneous pelagic nannofossil oozes.

  6. Comparative feeding ecology of abyssal and hadal fishes through stomach content and amino acid isotope analysis

    NASA Astrophysics Data System (ADS)

    Gerringer, M. E.; Popp, B. N.; Linley, T. D.; Jamieson, A. J.; Drazen, J. C.

    2017-03-01

    The snailfishes, family Liparidae (Scorpaeniformes), have found notable success in the hadal zone from 6000-8200 m, comprising the dominant ichthyofauna in at least five trenches worldwide. Little is known about the biology of these deepest-living fishes, nor the factors that drive their success at hadal depths. Using recent collections from the Mariana Trench, Kermadec Trench, and neighboring abyssal plains, this study investigates the potential role of trophic ecology in structuring fish communities at the abyssal-hadal boundary. Stomach contents were analyzed from two species of hadal snailfishes, Notoliparis kermadecensis and a newly-discovered species from the Mariana Trench. Amphipods comprised the majority (Kermadec: 95.2%, Mariana: 97.4% index of relative importance) of stomach contents in both species. Decapod crustaceans, polychaetes (N. kermadecensis only), and remains of carrion (squid and fish) were minor dietary components. Diet analyses of abyssal species (families Macrouridae, Ophidiidae, Zoarcidae) collected from near the trenches and the literature are compared to those of the hadal liparids. Stomachs from abyssal fishes also contained amphipods, however macrourids had a higher trophic plasticity with a greater diversity of prey items, including larger proportions of carrion and fish remains; supporting previous findings. Suction-feeding predatory fishes like hadal liparids may find an advantage to descending into the trench - where amphipods are abundant. More generalist feeders and scavengers relying on carrion, such as macrourids, might not benefit from this nutritional advantage at hadal depths. Compound specific isotope analysis of amino acids was used to estimate trophic level of these species (5.3±0.2 Coryphaenoides armatus, 5.2±0.2 C. yaquinae, 4.6±0.2 Spectrunculus grandis, 4.2±0.2 N. kermadecensis, 4.4±0.2 Mariana snailfish). Source amino acid δ15N values were especially high in hadal liparids (8.0±0.3‰ Kermadec, 6.7±0.2

  7. Is long-term change in the abyssal Northeast Atlantic driven by qualitative changes in export flux? Evidence from selective feeding in deep-sea holothurians

    NASA Astrophysics Data System (ADS)

    Wigham, in deep-sea holothurians [review article] B. D.; Hudson, I. R.; Billett, D. S. M.; Wolff, G. A.

    2003-12-01

    The Porcupine Abyssal Plain (NE Atlantic) time-series has shown large, wide-scale, changes in the composition of the benthic community at 4800 m depth (48°50‧N, 16°30‧W). The abundance of holothurians has increased significantly since 1996 and one species in particular, Amperimarosea, has increased in abundance by three orders of magnitude. Environmental forcing in the form of phytodetrital food supply to the benthos is believed to be driving these changes. Chlorophyll and carotenoid pigments were determined from the gut sediments of seven species of abyssal holothurian, sampled from the Porcupine Abyssal Plain during Autumn 2000 and Spring 2002. These two samples fell either side of the main phytoplankton bloom in the NE Atlantic, providing an opportunity for seasonal comparisons. Significant inter-species differences in pigment profiles were observed among the seven species. Seasonal differences were noted among four species sampled in both time periods. All seven species were collected from the same geographical area and depth. As algal pigments cannot be synthesised by the holothurians, they provide good biomarkers for the composition of the phytodetritus. Differences in pigments from gut sediment profiles are indicative of selective feeding among the holothurians. A.rosea had a gut profile dominated by the pigments zeaxanthin, chlorophyll a/echineone and β-carotene; these pigments were all present in significantly smaller quantities in the other species. The high quantities of these pigments are indicative of a diet rich in cyanobacteria. The gut sediments of A. rosea also lacked many chloropigments characteristic of other phytoplankton groups, which were observed in the guts of other holothurian species. Ovarian tissue for the five species taken in the pre-spring bloom 2002 sample were examined. All species showed similar carotenoid profiles, dominated by zeaxanthin, echinenone and β-carotene, all of which are important compounds for reproductive

  8. Can the source–sink hypothesis explain macrofaunal abundance patterns in the abyss? A modelling test

    PubMed Central

    Hardy, Sarah M.; Smith, Craig R.; Thurnherr, Andreas M.

    2015-01-01

    Low food availability is a major structuring force in deep-sea benthic communities, sustaining only very low densities of organisms in parts of the abyss. These low population densities may result in an Allee effect, whereby local reproductive success is inhibited, and populations are maintained by larval dispersal from bathyal slopes. This slope–abyss source–sink (SASS) hypothesis suggests that the abyssal seafloor constitutes a vast sink habitat with macrofaunal populations sustained only by an influx of larval ‘refugees' from source areas on continental slopes, where higher productivity sustains greater population densities. Abyssal macrofaunal population densities would thus be directly related to larval inputs from bathyal source populations. We evaluate three predictions derived from the SASS hypothesis: (i) slope-derived larvae can be passively transported to central abyssal regions within a single larval period, (ii) projected larval export from slopes to the abyss reproduces global patterns of macrofaunal abundance and (iii) macrofaunal abundance decreases with distance from the continental slope. We find that abyssal macrofaunal populations are unlikely to be sustained solely through influx of larvae from slope sources. Rather, local reproduction probably sustains macrofaunal populations in relatively high-productivity abyssal areas, which must also be considered as potential larval source areas for more food-poor abyssal regions. PMID:25948686

  9. Depositional history, nannofossil biostratigraphy, and correlation of Argo Abyssal Plain Sites 765 and 261

    USGS Publications Warehouse

    Dumoulin, Julie A.; Bown, Paul R.; Stewart, Sondra K.; Kennett, Diana; Mazzullo, Elsa K.

    1992-01-01

    Sediments from the Argo Abyssal Plain (AAP), northwest of Australia, are the oldest known from the Indian Ocean and were recovered from ODP Site 765 and DSDP Site 261. New biostratigraphic and sedimentologic data from these sites, as well as reinterpretations of earlier findings, indicate that basal sediments at both localities are of Late Jurassic age and delineate a history of starved sedimentation punctuated by periodic influx of calcareous pelagic turbidites.Biostratigraphy and correlation of Upper Jurassic-Lower Cretaceous sediments is based largely on calcareous nannofossils. Both sites yielded variably preserved nannofossil successions ranging from Tithonian to Hauterivian at Site 765 and Kimmeridgian to Hauterivian at Site 261. The nannofloras are comparable to those present in the European and Atlantic Boreal and Tethyan areas, but display important differences that reflect biogeographic differentiation. The Argo region is thought to have occupied a position at the southern limit of the Tethyan nannofloral realm, thus yielding both Tethyan and Austral biogeographic features.Sedimentary successions at the two sites are grossly similar, and differences largely reflect Site 765 's greater proximity to the continental margin. Jurassic sediments were deposited at rates of about 2 m/m.y. near the carbonate compensation depth (CCD) and contain winnowed concentrations of inoceramid prisms and nannofossils, redeposited layers rich in calcispheres and calcisphere debris, manganese nodules, and volcanic detritus. Lower Cretaceous and all younger sediments accumulated below the CCD at rates that were highest (about 20 m/m.y.) during mid-Cretaceous and Neogene time. Background sediment in this interval is noncalcareous claystone; turbidites dominate the sequence and are thicker and coarser grained at Site 765.AAP turbidites consist mostly of calcareous and siliceous biogenic components and volcanogenic smectite clay; they were derived from relatively deep parts of the

  10. Abyssal Upwelling in Mid-Ocean Ridge Fracture Zones

    NASA Astrophysics Data System (ADS)

    Clément, Louis; Thurnherr, Andreas M.

    2018-03-01

    Turbulence in the abyssal ocean plays a fundamental role in the climate system by sustaining the deepest branch of the overturning circulation. Over the western flank of the Mid-Atlantic Ridge in the South Atlantic, previously observed bottom-intensified and tidally modulated mixing of abyssal waters appears to imply a counterintuitive densification of deep and bottom waters. Here we show that inside fracture zones, however, turbulence is elevated away from the seafloor because of intensified downward propagating near-inertial wave energy, which decays below a subinertial shear maximum. Ray-tracing simulations predict a decay of wave energy subsequent to wave-mean flow interactions. The hypothesized wave-mean flow interactions drive a deep flow toward lighter densities of up to 0.6 Sv over the mid-ocean ridge flank in the Brazil Basin, and the same process may also cause upwelling of abyssal waters in other ocean basins with mid-ocean ridges with fracture zones.

  11. Sources and distribution of yttrium and rare earth elements in surface sediments from Tagus estuary, Portugal.

    PubMed

    Brito, Pedro; Prego, Ricardo; Mil-Homens, Mário; Caçador, Isabel; Caetano, Miguel

    2018-04-15

    The distribution and sources of yttrium and rare-earth elements (YREE) in surface sediments were studied on 78 samples collected in the Tagus estuary (SW Portugal, SW Europe). Yttrium and total REE contents ranged from 2.4 to 32mg·kg -1 and 18 to 210mg·kg -1 , respectively, and exhibited significant correlations with sediment grain-size, Al, Fe, Mg and Mn, suggesting a preferential association to fine-grained material (e.g. aluminosilicates but also Al hydroxides and Fe oxyhydroxides). The PAAS (Post-Archean Australian Shale) normalized patterns display three distinct YREE fractionation pattern groups along the Tagus estuary: a first group, characterized by medium to coarse-grained material, a depleted and almost flat PAAS-normalized pattern, with a positive anomaly of Eu, representing one of the lithogenic components; a second group, characterized mainly by fine-grained sediment, with higher shale-normalized ratios and an enrichment of LREE relative to HREE, associated with waste water treatment plant (WWTP) outfalls, located in the northern margin; and, a third group, of fine-grained material, marked by a significant enrichment of Y, a depletion of Ce and an enrichment of HREE over LREE, located near an inactive chemical-industrial complex (e.g. pyrite roast plant, chemical and phosphorous fertilizer industries), in the southern margin. The data allow the quantification of the YREE contents and its spatial distribution in the surface sediments of the Tagus estuary, identifying the main potential sources and confirming the use of rare earth elements as tracers of anthropogenic activities in highly hydrodynamic estuaries. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Biogeochemical evidence of vigorous mixing in the abyssal ocean

    NASA Astrophysics Data System (ADS)

    Lampitt, Richard S.; Popova, Ekaterina E.; Tyrrell, Toby

    2003-05-01

    The metabolic activities of biological communities living at the abyssal seabed create a strong source of nutrients and a sink for oxygen. If the published estimates of vertical mixing based on instantaneous microstructure measurements are correct, near to the abyssal seabed away from rough topographic features there should be enhanced concentrations of nitrate and phosphate and depletion of oxygen. Recent data on the vertical concentration profiles of inorganic nutrients and oxygen over the bottom 1000 m of the water column (World Ocean Circulation Experiment - WOCE) provide no such evidence. It is concluded that the effective vertical mixing rates are much more vigorous than previously indicated and may even be higher than estimates of average basin scale rates based on temperature and salinity distributions. We propose that the enhanced mixing associated with rough topography influences the entire volume of the abyssal ocean on short time scales (e.g., one month - one year).

  13. Abyssal BEnthic Laboratory (ABEL): a novel approach for long-term investigation at abyssal depths

    NASA Astrophysics Data System (ADS)

    Berta, M.; Gasparoni, F.; Capobianco, M.

    1995-03-01

    This study assesses the feasibility of a configuration for a benthic underwater system, called ABEL (Abyssal BEnthic Laboratory), capable of operating both under controlled and autonomous modes for periods of several months to over one year at abyssal depths up to 6000 m. A network of stations, capable of different configurations, has been identified as satisfying the widest range of scientific expectations, and at the same time to address the technological challenge to increase the feasibility of scientific investigations, even when the need is not yet well specified. The overall system consists of a central Benthic Investigation Laboratory, devoted to the execution of the most complex scientific activities, with fixed Satellite Stations acting as nodes of a measuring network and a Mobile Station extending ABEL capabilities with the possibility to carry out surveys over the investigation area and interventions on the fixed stations. ABEL architecture also includes a dedicated deployment and recovery module, as well as sea-surface and land-based facilities. Such an installation constitutes the sea-floor equivalent of a meteorological or geophysical laboratory. Attention has been paid to selecting investigation tools supporting the ABEL system to carry out its mission with high operativity and minimal risk and environmental impact. This demands technologies to enable presence and operation at abyssal depths for the required period of time. Presence can be guaranteed by proper choice of power supply and communication systems. Operations require visual and manipulative capabilities, as well as deployment and retrieval capabilities. Advanced control system architectures must be considered, along with knowledge based approaches, to comply with the requirements for autonomous control. The results of this investigation demonstrate the feasibility of the ABEL concept and the pre-dimensioning of its main components.

  14. Vesicomyinae (Bivalvia: Vesicomyidae) of the Kuril-Kamchatka Trench and adjacent abyssal regions

    NASA Astrophysics Data System (ADS)

    Krylova, Elena M.; Kamenev, Gennady M.; Vladychenskaya, Irina P.; Petrov, Nikolai B.

    2015-01-01

    Representatives of the subfamily Vesicomyinae (Bivalvia, Vesicomyidae) are tiny deep-sea molluscs distributed worldwide and reaching huge abundances of hundreds and thousands of specimens in trawl catches. During the German-Russian deep-sea expedition KuramBio (R/V Sonne, 2012) for the first time two vesicomyin species were collected from the abyssal plain adjacent to the Kuril-Kamchatka Trench from the depths of 4861-5787 m, Vesicomya pacifica (Smith, 1885) and "Vesicomya" filatovae sp.n. Two species of vesicomyins, V. sergeeviFilatova, 1971 and V. profundiFilatova, 1971, which were previously reported from the hadal of the Kuril-Kamchatka Trench, were not collected at the abyssal depth despite of the close geographical proximity of the sampling area to their distribution ranges. Altogether nine species of vesicomyins are recorded now from the West and Indo-West Pacific; data on distribution and morpho-anatomical characters of these species are provided. Taxonomic description of V. pacifica is revised including information on its soft part anatomy, new localities and COI sequences. For the first time for a vesicomyin bivalve molecular data is given for a species with an explicit morphological description and unambiguous taxonomic affiliation. Molecular analysis of 160 published COI sequences of vesicomyids and newly obtained molecular data on V. pacifica showed that V. pacifica and two undescribed vesicomyin species forming a monophyletic clade which exhibits sister relationships with the Pliocardiinae, the group of chemosymbiotic vesicomyids. "Vesicomya" filatovae sp.n. is provisionally assigned to the genus Vesicomya (s.l.) until additional morphological and molecular data are obtained. It differs from Vesicomya s.s. by a broader hinge margin with more radiating teeth and the presence of only one pair of demibranchs.

  15. The Ocean's Abyssal Mass Flux Sustained Primarily By the Wind: Vector Correlation of Time Series in Upper and Abyssal Layers

    NASA Astrophysics Data System (ADS)

    Hancock, L. O.

    2003-12-01

    As Wunsch has recently noted (2002), use of the term "thermohaline circulation" is muddled. The term is used with at least seven inconsistent meanings, among them abyssal circulation, the circulation driven by density and pressure differences in the deep ocean, the global conveyor, and at least four others. The use of a single term for all these concepts can create an impression that an understanding exists whereby in various combinations the seven meanings have been demonstrated to mean the same thing. But that is not the case. A particularly important consequence of the muddle is the way in which abyssal circulation is sometimes taken to be driven mostly or entirely by temperature and density differences, and equivalent to the global conveyor. But in fact the distinction between abyssal and upper-layer circulation has not been measured. To find out whether available data justifies a distinction between the upper-layer and abyssal circulations, this study surveyed velocity time series obtained by deep current meter moorings. Altogether, 114 moorings were identified, drawn from about three dozen experiments worldwide over the period 1973-1996, each of which deployed current meters in both the upper (200abyssal (z>3750) layers. For each pair of current meters, the Kundu and Crosby measures of vector correlation were estimated, as well as coherences for periods from 10 to 60 days. In the North Atlantic, for example, Kundu vector correlation (50-day window): 0.48 +/- .03 Crosby vector correlation (absolute value, 50 day window): 0.46 +/- .07 Coherence at 60 days: .36 +/- .07 - at 30 days: 0.40 +/- .06 - at 10 days: 0.22 +/- .05 Most figures for the South Atlantic, Pacific and Southern Oceans are similar. Those obtained in the Indian Ocean or near the Equator are somewhat different. The statistics obtained here are consistent with the work of Wunsch (1997), and tend to confirm Wunsch's result that current velocities at depth are linked with those in the

  16. Aerobic Mercury-resistant bacteria alter Mercury speciation and retention in the Tagus Estuary (Portugal).

    PubMed

    Figueiredo, Neusa L; Canário, João; O'Driscoll, Nelson J; Duarte, Aida; Carvalho, Cristina

    2016-02-01

    Aerobic mercury-resistant bacteria were isolated from the sediments of two highly mercury-polluted areas of the Tagus Estuary (Barreiro and Cala do Norte) and one natural reserve area (Alcochete) in order to test their capacity to transform mercury. Bacterial species were identified using 16S rRNA amplification and sequencing techniques and the results indicate the prevalence of Bacillus sp. Resistance patterns to mercurial compounds were established by the determination of minimal inhibitory concentrations. Representative Hg-resistant bacteria were further tested for transformation pathways (reduction, volatilization and methylation) in cultures containing mercury chloride. Bacterial Hg-methylation was carried out by Vibrio fluvialis, Bacillus megaterium and Serratia marcescens that transformed 2-8% of total mercury into methylmercury in 48h. In addition, most of the HgR bacterial isolates showed Hg(2+)-reduction andHg(0)-volatilization resulting 6-50% mercury loss from the culture media. In summary, the results obtained under controlled laboratory conditions indicate that aerobic Hg-resistant bacteria from the Tagus Estuary significantly affect both the methylation and reduction of mercury and may have a dual face by providing a pathway for pollution dispersion while forming methylmercury, which is highly toxic for living organisms. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. Benthic hydroids (Cnidaria, Hydrozoa) from bathyal and abyssal depths of the Northeast Atlantic held in the modern Discovery Collections.

    PubMed

    Cantero, Álvaro L Peña; Horton, Tammy

    2017-11-10

    The deep-sea benthic hydroid fauna remains poorly known, in part because of less frequent sampling than the shelf fauna, in part owing to the immense study area, and partly also because available samples have been little studied by experts. In order to correct this, deep-sea benthic hydroid material from the modern Discovery Collections has been studied. Samples come from localities in the North-East Atlantic including the Porcupine Seabight, Porcupine Abyssal Plain, Rockall Trough, Rockall Bank, and the Mid-Atlantic Ridge. Sixteen species belonging to 12 families and 16 genera were found. Leptothecata are clearly dominant, being represented by 14 species; the remaining species belong to Anthoathecata. Lafoeidae and Tiarannidae are the most diverse families with three species each; the remaining families being represented by a single species. The low species diversity is remarkable at the generic level, with each genus being represented by a single species. Hydroid occurrence is low: twelve species were found in ≤ 9% of stations; Amphinema biscayana has the highest occurrence (27% of stations). Fifteen species were recorded in the Porcupine Seabight, two in the Rockall Trough, one at Rockall Bank, one on the Porcupine Abyssal Plain, and two at the Mid-Atlantic Ridge. The known bathymetric range for a third of the species is extended; the increase is particularly noteworthy in Amphinema biscayana, Acryptolaria crassicaulis, Clytia gigantea and Schizotricha profunda. Two distinct bathymetric groups are recognized: strictly deep-sea inhabitants and eurybathic species. Most species are globally distributed, some are widely distributed in the Atlantic, and others are limited to the North Atlantic or the Northeast Atlantic.

  18. Seismic ground motion scenarios in Lower Tagus Valley Basin

    NASA Astrophysics Data System (ADS)

    Borges, José; Torres, Ricardo; Furtado, José; Silva, Hugo; Caldeira, Bento; Pinto, Carlos; Bezzeghoud, Mourad; Carvalho, João

    2013-04-01

    Throughout its history the Lower Tagus Valley (LTV) has been struck by several earthquakes which produced important material damage and loss of lives: The 1st of November 1755 Lisbon earthquake and the 1969 earthquake (Mw=7.3), located in the SW Iberia Margin and the 1344, 1531 and 1909 (M= 6 to 7) with epicenter located inside the LTV basin. Since this region is the most highly populated region in Portugal, it is expected that an earthquake of similar magnitude of those that have occurred in the past will cause an enormous destruction and casualties. This fact makes LTV a high priority area for earthquake research in Portugal. In order to overcome the problems related to the absence of geological outcrops, low slip-rates (<0,4 mm/year) and the processes of sedimentation and erosion, we use in this work seismic reflection profiles, potential field data, soundings, wells and geological cartography to obtain a map of the main seismogenic structures and to characterize their seismic potential [1]. Moreover, a 3D structural model has been developed for de LTV based on Seismic reflection, Seismic Noise and potential field data [2,3]. In order to improve assessment of the seismic hazard in the LTV basin, we simulate long-period (0-1 Hz) ground motion time histories for a suite of scenarios earthquakes (Mw =5.5 to 7) within the basin, using fault geometries and the 3D seismic velocity structure based on the previous mentioned works. References [1] Pinto, Carlos C. (2011). Identification of Seismogenic Structures in the Lower Tagus Basin. Master Thesis, Universidade de Évora, 128 pp. [2] Torres, R.J.G., (2012). Modelo de velocidade da Bacia do Vale do Tejo: uma abordagem baseada no estudo do ruído sísmico ambiental, Master Thesis, Universidade de Évora, 83pp. [3] Furtado, J.A (2010). Confirmação do modelo da estrutura 3D do Vale Inverior do Tejo a partir de dados de ruído sísmico ambiente, Master Thesis, Universidade de Évora, 136pp.

  19. Abyssal ocean overturning shaped by seafloor distribution.

    PubMed

    de Lavergne, C; Madec, G; Roquet, F; Holmes, R M; McDougall, T J

    2017-11-08

    The abyssal ocean is broadly characterized by northward flow of the densest waters and southward flow of less-dense waters above them. Understanding what controls the strength and structure of these interhemispheric flows-referred to as the abyssal overturning circulation-is key to quantifying the ocean's ability to store carbon and heat on timescales exceeding a century. Here we show that, north of 32° S, the depth distribution of the seafloor compels dense southern-origin waters to flow northward below a depth of about 4 kilometres and to return southward predominantly at depths greater than 2.5 kilometres. Unless ventilated from the north, the overlying mid-depths (1 to 2.5 kilometres deep) host comparatively weak mean meridional flow. Backed by analysis of historical radiocarbon measurements, the findings imply that the geometry of the Pacific, Indian and Atlantic basins places a major external constraint on the overturning structure.

  20. Abyssal ocean overturning shaped by seafloor distribution

    NASA Astrophysics Data System (ADS)

    de Lavergne, C.; Madec, G.; Roquet, F.; Holmes, R. M.; McDougall, T. J.

    2017-11-01

    The abyssal ocean is broadly characterized by northward flow of the densest waters and southward flow of less-dense waters above them. Understanding what controls the strength and structure of these interhemispheric flows—referred to as the abyssal overturning circulation—is key to quantifying the ocean’s ability to store carbon and heat on timescales exceeding a century. Here we show that, north of 32° S, the depth distribution of the seafloor compels dense southern-origin waters to flow northward below a depth of about 4 kilometres and to return southward predominantly at depths greater than 2.5 kilometres. Unless ventilated from the north, the overlying mid-depths (1 to 2.5 kilometres deep) host comparatively weak mean meridional flow. Backed by analysis of historical radiocarbon measurements, the findings imply that the geometry of the Pacific, Indian and Atlantic basins places a major external constraint on the overturning structure.

  1. Teaching the abyss: living the art-science of nursing.

    PubMed

    Ramey, Sandra L; Bunkers, Sandra Schmidt

    2006-10-01

    This column addresses how nurse educators can provide the teaching-learning experiences for novice nurses to develop the leadership competence to effectively practice nursing in an extremely demanding healthcare environment. The authors delve into Mitchell and Bunkers' use of the metaphor of an abyss to explore the lived experience of risking being with others in extremely intense interpersonal situations. Using reflection, students' journal narratives affirm connections made among past experiences and the new knowledge gleaned from exploring and naming the phenomenon of the abyss. Several teaching-learning strategies are offered as ways for addressing the leadership issues related to dealing with intense relational experiences in nursing practice, including exploring nurse theorist Rosemarie Rizzo Parse's essentials of leadership.

  2. Caesium-137 and strontium-90 temporal series in the Tagus River: experimental results and a modelling study.

    PubMed

    Miró, Conrado; Baeza, Antonio; Madruga, María J; Periañez, Raul

    2012-11-01

    The objective of this work consisted of analysing the spatial and temporal evolution of two radionuclide concentrations in the Tagus River. Time-series analysis techniques and numerical modelling have been used in this study. (137)Cs and (90)Sr concentrations have been measured from 1994 to 1999 at several sampling points in Spain and Portugal. These radionuclides have been introduced into the river by the liquid releases from several nuclear power plants in Spain, as well as from global fallout. Time-series analysis techniques have allowed the determination of radionuclide transit times along the river, and have also pointed out the existence of temporal cycles of radionuclide concentrations at some sampling points, which are attributed to water management in the reservoirs placed along the Tagus River. A stochastic dispersion model, in which transport with water, radioactive decay and water-sediment interactions are solved through Monte Carlo methods, has been developed. Model results are, in general, in reasonable agreement with measurements. The model has finally been applied to the calculation of mean ages of radioactive content in water and sediments in each reservoir. This kind of model can be a very useful tool to support the decision-making process after an eventual emergency situation. Copyright © 2012 Elsevier Ltd. All rights reserved.

  3. Nitrate probability mapping in the northern aquifer alluvial system of the river Tagus (Portugal) using Disjunctive Kriging.

    PubMed

    Mendes, Maria Paula; Ribeiro, Luís

    2010-02-01

    The Water Framework Directive and its daughter directives recognize the urgent need to adopt specific measures against the contamination of water by individual pollutants or a group of pollutants that present a significant risk to the quality of water. Probability maps showing that the nitrate concentrations exceed a legal threshold value in any location of the aquifer are used to assess risk of groundwater quality degradation from intensive agricultural activity in aquifers. In this paper we use Disjunctive Kriging to map the probability that the Nitrates Directive limit (91/676/EEC) is exceeded for the Nitrate Vulnerable Zone of the River Tagus alluvium aquifer. The Tagus alluvial aquifer system belongs to one of the most productive hydrogeological unit of continental Portugal and it is used to irrigate crops. Several groundwater monitoring campaigns were carried out from 2004 to 2006 according to the summer crops cycle. The study reveals more areas on the west bank with higher probabilities of contamination by nitrates (nitrate concentration values above 50mg/L) than on the east bank. The analysis of synthetic temporal probability map shows the areas where there is an increase of nitrates concentration during the summers. Copyright 2009 Elsevier B.V. All rights reserved.

  4. Glacial magnetite dissolution in abyssal NW Pacific sediments - evidence for carbon trapping?

    NASA Astrophysics Data System (ADS)

    Korff, Lucia; von Dobeneck, Tilo; Frederichs, Thomas; Kasten, Sabine; Kuhn, Gerhard; Gersonde, Rainer; Diekmann, Bernhard

    2016-04-01

    The abyssal North Pacific Ocean's large volume, depth, and terminal position on the deep oceanic conveyor make it a candidate site for deep carbon trapping as postulated by climate theory to explain the massive glacial drawdown of atmospheric CO2. As the major basins of the North Pacific have depths of 5500-6500m, far below the modern and glacial Calcite Compensation Depths (CCD), these abyssal sediments are carbonate-free and therefore not suitable for carbonate-based paleoceanographic proxy reconstructions. Instead, paleo-, rock and environmental magnetic methods are generally well applicable to hololytic abyssal muds and clays. In 2009, the international paleoceanographic research cruise SO 202 INOPEX ('Innovative North Pacific Experiment') of the German RV SONNE collected two ocean-spanning EW sediment core transects of the North Pacific and Bering Sea recovering a total of 50 piston and gravity cores from 45 sites. Out of seven here considered abyssal Northwest Pacific piston cores collected at water depths of 5100 to 5700m with mostly coherent shipboard susceptibility logs, the 20.23m long SO202-39-3, retrieved from 5102 m water depth east of northern Shatsky Rise (38°00.70'N, 164°26.78'E), was rated as the stratigraphically most promising record of the entire core transect and selected for detailed paleo- and environmental magnetic, geochemical and sedimentological investigations. This core was dated by correlating its RPI and Ba/Ti records to well-dated reference records and obviously provides a continuous sequence of the past 940 kyrs. The most striking orck magnetic features are coherent magnetite-depleted zones corresponding to glacial periods. In the interglacial sections, detrital, volcanic and even submicron bacterial magnetite fractions are excellently preserved. These alternating magnetite preservation states seem to reflect dramatic oxygenation changes in the deep North Pacific Ocean and hint at large-scale benthic glacial carbon trapping

  5. Temperatures and cooling rates recorded in REE in coexisting pyroxenes in ophiolitic and abyssal peridotites

    NASA Astrophysics Data System (ADS)

    Dygert, Nick; Liang, Yan

    2015-06-01

    Mantle peridotites from ophiolites are commonly interpreted as having mid-ocean ridge (MOR) or supra-subduction zone (SSZ) affinity. Recently, an REE-in-two-pyroxene thermometer was developed (Liang et al., 2013) that has higher closure temperatures (designated as TREE) than major element based two-pyroxene thermometers for mafic and ultramafic rocks that experienced cooling. The REE-in-two-pyroxene thermometer has the potential to extract meaningful cooling rates from ophiolitic peridotites and thus shed new light on the thermal history of the different tectonic regimes. We calculated TREE for available literature data from abyssal peridotites, subcontinental (SC) peridotites, and ophiolites around the world (Alps, Coast Range, Corsica, New Caledonia, Oman, Othris, Puerto Rico, Russia, and Turkey), and augmented the data with new measurements for peridotites from the Trinity and Josephine ophiolites and the Mariana trench. TREE are compared to major element based thermometers, including the two-pyroxene thermometer of Brey and Köhler (1990) (TBKN). Samples with SC affinity have TREE and TBKN in good agreement. Samples with MOR and SSZ affinity have near-solidus TREE but TBKN hundreds of degrees lower. Closure temperatures for REE and Fe-Mg in pyroxenes were calculated to compare cooling rates among abyssal peridotites, MOR ophiolites, and SSZ ophiolites. Abyssal peridotites appear to cool more rapidly than peridotites from most ophiolites. On average, SSZ ophiolites have lower closure temperatures than abyssal peridotites and many ophiolites with MOR affinity. We propose that these lower temperatures can be attributed to the residence time in the cooling oceanic lithosphere prior to obduction. MOR ophiolites define a continuum spanning cooling rates from SSZ ophiolites to abyssal peridotites. Consistent high closure temperatures for abyssal peridotites and the Oman and Corsica ophiolites suggests hydrothermal circulation and/or rapid cooling events (e.g., normal

  6. Orogenic, Ophiolitic, and Abyssal Peridotites

    NASA Astrophysics Data System (ADS)

    Bodinier, J.-L.; Godard, M.

    2003-12-01

    "Tectonically emplaced" mantle rocks include subcontinental, suboceanic, and subarc mantle rocks that were tectonically exhumed from the upper mantle and occur:(i) as dispersed ultramafic bodies, a few meters to kilometers in size, in suture zones and mountain belts (i.e., the "alpine," or "orogenic" peridotite massifs - De Roever (1957), Thayer (1960), Den Tex (1969));(ii) as the lower ultramafic section of large (tens of kilometers) ophiolite or island arc complexes, obducted on continental margins (e.g., the Oman Ophiolite and the Kohistan Arc Complex - Coleman (1971), Boudier and Coleman (1981), Burg et al. (1998));(iii) exhumed above the sea level in ocean basins (e.g., Zabargad Island in the Red Sea, St. Paul's islets in the Atlantic and Macquarie Island in the southwestern Pacific - Tilley (1947), Melson et al. (1967), Varne and Rubenach (1972), Bonatti et al. (1981)).The "abyssal peridotites" are samples from the oceanic mantle that were dredged on the ocean floor, or recovered from drill cores (e.g., Bonatti et al., 1974; Prinz et al., 1976; Hamlyn and Bonatti, 1980).Altogether, tectonically emplaced and abyssal mantle rocks provide insights into upper mantle compositions and processes that are complementary to the information conveyed by mantle xenoliths (See Chapter 2.05). They provide coverage to vast regions of the Earth's upper mantle that are sparsely sampled by mantle xenoliths, particularly in the ocean basins and beneath passive continental margins, back-arc basins, and oceanic island arcs.Compared with mantle xenoliths, a disadvantage of some tectonically emplaced mantle rocks for representing mantle compositions is that their original geodynamic setting is not exactly known and their significance is sometimes a subject of speculation. For instance, the provenance of orogenic lherzolite massifs (subcontinental lithosphere versus upwelling asthenosphere) is still debated (Menzies and Dupuy, 1991, and references herein), as is the original setting

  7. Orphan strontium-87 in abyssal peridotites: daddy was a granite.

    PubMed

    Snow, J E; Hart, S R; Dick, H J

    1993-12-17

    The (87)Sr/(86)Sr ratios in some bulk abyssal and alpine peridotites are too high to be binary mixtures of depleted mantle and seawater components. The apparent excess, or "orphan," (87)Sr appears to be separated from its radioactive parent. Such observations were widely held to be analytical artifacts. Study of several occurrences of orphan (87)Sr shows that the orphan component in abyssal peridotite is located in the alteration products of olivine and enstatite in the peridotite. The orphan (87)Sr is most likely introduced by infiltration of low-temperature (<200 degrees C) seawater bearing suspended detrital particulates. These particulates include grains of detrital clay that are partly derived from continental (that is, granitic) sources and thus are highly radiogenic. Orphan (87)Sr and other radiogenic isotopes may provide a tracer for low-temperature seawater penetrating into the oceanic crust.

  8. Orphan Strontium-87 in Abyssal Peridotites: Daddy Was a Granite

    NASA Astrophysics Data System (ADS)

    Snow, Jonathan E.; Hart, Stanley R.; Dick, Henry J. B.

    1993-12-01

    The 87Sr/86Sr ratios in some bulk abyssal and alpine peridotites are too high to be binary mixtures of depleted mantle and seawater components. The apparent excess, or "orphan," 87Sr appears to be separated from its radioactive parent. Such observations were widely held to be analytical artifacts. Study of several occurrences of orphan 87Sr shows that the orphan component in abyssal peridotite is located in the alteration products of olivine and enstatite in the peridotite. The orphan 87Sr is most likely introduced by infiltration of low-temperature (<200^circC) seawater bearing suspended detrital particulates. These particulates include grains of detrital clay that are partly derived from continental (that is, granitic) sources and thus are highly radiogenic. Orphan 87Sr and other radiogenic isotopes may provide a tracer for low-temperature seawater penetrating into the oceanic crust.

  9. Source-To-Sink Perspectives On The Mississippi River System, Miocene To Present, Mountain To Abyss

    NASA Astrophysics Data System (ADS)

    Bentley, S. J.; Blum, M. D.

    2013-12-01

    . The objective of this study is to present a synthesis of the Mississippi River source-to-sink system, from montane source to abyssal sink, to elucidate specific geomorphic components and boundaries in the system, controls on mass transfer, and resultant geomorphic and statigraphic development. The Mississippi River source-to-sink system constitutes one of the largest sources, conduits, and depocenters of sediment on Earth, extending from elevations of 3.7 km in the Rocky Mountains to the Gulf of Mexico abyssal plain. Despite being one of the most intensely studied fluvial-marine systems in the world, comprehensive understanding and management of the system's resources remain a challenge. The system is valuable in many ways: it provides navigation and water to the heart of North America, and sustains extensive marine fisheries. The river has built a delta that is home to millions of people and yet is subsiding rapidly. Ancestral Mississippi fluvial-marine deposits continue to yield high-value petroleum resources to exploration. To address the range of temporal and spatial scales over which the system has developed and continues to evolve, we will focus on three geological time spans that display contrasting geologic forcing and response: Miocene, Pleistocene, and late Holocene. The present configuration of source, conduit, and sink were established during the Miocene epoch, when tectonics (via the uplifting southern Rockies, and later the rejuvenated Appalachians) and climate (wet in the east and dry in the west) provided abundant water and sediment to prograde the shelf margin and initiate deep-sea fan growth. Pleistocene continental glaciation, eustasy, and catastrophic drainage events further sculpted the alluvial valley, and extended the shelf margin, and fan. Studies of Modern processes and Holocene delta development have provided keys to both the delta's past and future evolution, in terms of cyclic autogenic lobe-switching, mass-transport events, storm

  10. Heavy metal distribution and partitioning in the vicinity of the discharge areas of Lisbon drainage basins (Tagus Estuary, Portugal)

    NASA Astrophysics Data System (ADS)

    Duarte, Bernardo; Silva, Gilda; Costa, José Lino; Medeiros, João Paulo; Azeda, Carla; Sá, Erica; Metelo, Inês; Costa, Maria José; Caçador, Isabel

    2014-10-01

    Worldwide estuarine ecosystems are by their privileged geographic location, anthropogenically impacted systems. Heavy metal contamination in estuarine waters and sediments are well known to be one of the most important outcomes driven from human activities. The partitioning of these elements has been widely focused, due to its importance not only on the estuarine biogeochemistry but also on its bioavailability to the trophic webs. As observed in other estuaries, in the Tagus basin, no increase in the partition coefficients with the increasing suspended particulate matter concentrations was observed, mostly due to a permanent dilution process of the suspended matter, rich in heavy metals and less contaminated and resuspended bottom sediments. Another important outcome of this study was the common origin of all the analysed heavy metals, probably due to the large industrialization process that the margins of the Tagus estuary suffered in the past, although no relationship was found with the presence of the different discharge areas. In fact, metal partitioning seems to be mostly influenced by the chemical species in which the pollutant is delivered to the system and on water chemistry, with a higher emphasis on the metal cycling essentially between the particulate and dissolved phase. This partitioning system acquires a relevant importance while evaluating the impacts of marine construction and the associated dredging operations, and consequent changes in the estuarine water chemistry.

  11. Channel changes in the Jarama and Tagus rivers (central Spain) over the past 500 years

    NASA Astrophysics Data System (ADS)

    Uribelarrea, D.; Pérez-González, A.; Benito, G.

    2003-10-01

    Long-term channel changes of the Tagus and the Jarama Rivers in central Spain were studied in relation to variations in hydroclimatic factors, such as rainfall and flooding, and also with respect to human activities undertaken in their valleys. Data were taken from historical (1580-1823) and topographical (1877-1988) maps, as well as aerial photographs (1945-1999). The available hydroclimatic data consists of a series of monthly rainfall totals (1859-1994) and mean river flow values recorded at gauging stations (1911-1985). In addition, a historical flood record (1550-1947) was produced from documentary sources. Some of the data was incorporated into a geographical information system (GIS) to quantify the changes in the course of the rivers. The results show there have been two distinct periods: before and after human intervention in the river system, which took place around 1950. During the earlier period (1550-1950), a correlation exists between climate, frequency and magnitude of flooding and changes in fluvial geomorphology. Between 1860 and 1892 an increase in flood frequency and magnitude occurred, which produced half of the cut-offs recorded in the study area between 1823 and 1877. The meanders length ( L), width ( W) and radius of curvature (RC) of the Tagus River have decreased since 1750. However, those of the Jarama reached their maximum values during flood periods. Both rivers have different geomorphological responses during flood events, which can explain these different trends. Floods in the Jarama not only led to the cut-offs, but also enlarged the channel size ( L, W and RC). In the second period (1956—present), flow regulation via dams and gravel mining modified the system completely and impeded the natural development of these rivers.

  12. Chronology of fluvial terrace sequences for large Atlantic rivers in the Iberian Peninsula (Upper Tagus and Duero drainage basins, Central Spain)

    NASA Astrophysics Data System (ADS)

    Silva, Pablo G.; Roquero, Elvira; López-Recio, Mario; Huerta, Pedro; Martínez-Graña, Antonio M.

    2017-06-01

    This work analyses the chronology of fluvial terrace sequences of the two most important fluvial basins from central Spain draining to the Atlantic Ocean (Upper Tagus and Duero drainage basins). Both basins 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.

  13. 186Os-187Os and highly siderophile element abundance systematics of the mantle revealed by abyssal peridotites and Os-rich alloys

    NASA Astrophysics Data System (ADS)

    Day, James M. D.; Walker, Richard J.; Warren, Jessica M.

    2017-03-01

    Abyssal peridotites are oceanic mantle fragments that were recently processed through ridges and represent residues of both modern and ancient melting. To constrain the nature and timing of melt depletion processes, and the composition of the mantle, we report high-precision Os isotope data for abyssal peridotites from three ocean basins, as well as for Os-rich alloys, primarily from Mesozoic ophiolites. These data are complemented by whole-rock highly siderophile element (HSE: Os, Ir, Ru, Pt, Pd, Re), trace- and major-element abundances for the abyssal peridotites, which are from the Southwest Indian (SWIR), Central Indian (CIR), Mid-Atlantic (MAR) and Gakkel Ridges. The results reveal a limited role for melt refertilization or secondary alteration processes in modifying abyssal peridotite HSE compositions. The abyssal peridotites examined have experienced variable melt depletion (2% to >16%), which occurred >0.5 Ga ago for some samples. Abyssal peridotites typically exhibit low Pd/Ir and, combined with high-degrees of estimated total melt extraction, imply that they were relatively refractory residues prior to incorporation into their present ridge setting. Recent partial melting processes and mid-ocean ridge basalt (MORB) generation therefore played a limited role in the chemical evolution of their precursor mantle domains. The results confirm that many abyssal peridotites are not simple residues of recent MORB source melting, having a more complex and long-lived depletion history. Peridotites from the Gakkel Ridge, SWIR, CIR and MAR indicate that the depleted MORB mantle has 186Os/188Os of 0.1198356 ± 21 (2SD). The Phanerozoic Os-rich alloys yield an average 186Os/188Os within uncertainty of abyssal peridotites (0.1198361 ± 20). Melt depletion trends defined between Os isotopes and melt extraction indices (e.g., Al2O3) allow an estimate of the primitive mantle (PM) composition, using only abyssal peridotites. This yields 187Os/188Os (0.1292 ± 25), and 186Os

  14. Edwardsia sojabio sp. n. (Cnidaria: Anthozoa: Actiniaria: Edwardsiidae), a new abyssal sea anemone from the Sea ofJapan

    NASA Astrophysics Data System (ADS)

    Sanamyan, Nadya; Sanamyan, Karen

    2013-02-01

    The paper describes new deep-water edwardsiid sea anemone Edwardsia sojabio sp. n. which is very common on soft muddy bottoms at lower bathyal and upper abyssal depths in the Sea of Japan. It was recorded in high quantity in depths between 2545 and 3550 m and is the second abyssal species of the genus Edwardsia.

  15. Composition of abyssal macrofauna along the Vema Fracture Zone and the hadal Puerto Rico Trench, northern tropical Atlantic

    NASA Astrophysics Data System (ADS)

    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.

    2018-02-01

    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-Atlantic Ridge serves as a barrier limiting benthic taxon distribution in the abyssal basins on both sides of the ridge or whether the fracture zone permits the migration of species between the western and eastern abyssal Atlantic basins. The Puerto Rico Trench, much deeper than the surrounding abyssal West Atlantic, was sampled to determine whether the biodiversity of its hadal macrofauna differs from that of the abyssal Atlantic. 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

  16. Testing deep-sea biodiversity paradigms on abyssal nematode genera and Acantholaimus species

    NASA Astrophysics Data System (ADS)

    Lins, Lidia; da Silva, Maria Cristina; Neres, Patrícia; Esteves, André Morgado; Vanreusel, Ann

    2018-02-01

    Biodiversity patterns in the deep sea have been extensively studied in the last decades. In this study, we investigated whether reputable concepts in deep-sea ecology also explain diversity and distribution patterns of nematode genera and species in the abyss. Among them, three paradigms were tackled: (1) the deep sea is a highly diverse environment at a local scale, while on a regional and even larger geographical scale, species and genus turnover is limited; (2) the biodiversity of deep-sea nematode communities changes with the nature and amount of organic matter input from the surface; and (3) patch-mosaic dynamics of the deep-sea environment drive local diversity. To test these hypotheses, diversity and density of nematode assemblages and of species of the genus Acantholaimus were studied along two abyssal E-W transects. These two transects were situated in the Southern Ocean ( 50°S) and the North Atlantic ( 10°N). Four different hierarchical scales were used to compare biodiversity: at the scale of cores, between stations from the same region, and between regions. Results revealed that the deep sea harbours a high diversity at a local scale (alpha diversity), but that turnover can be shaped by different environmental drivers. Therefore, these results question the second part of the paradigm about limited species turnover in the deep sea. Higher surface primary productivity was correlated with greater nematode densities, whereas diversity responses to the augmentation of surface productivity showed no trend. Areas subjected to a constant and low food input revealed similar nematode communities to other oligotrophic abyssal areas, while stations under high productivity were characterized by different dominant genera and Acantholaimus species, and by a generally low local diversity. Our results corroborate the species-energy hypothesis, where productivity can set a limit to the richness of an ecosystem. Finally, we observed no correlation between sediment

  17. The Tagus River delta (off Lisbon, Portugal) as a repository of landslides. Implications on trigger mechanisms, tsunami hazard and neotectonics

    NASA Astrophysics Data System (ADS)

    Terrinha, Pedro; Duarte, Henrique; Noiva, João; Ribeiro, Carlos; Brito, Pedro; Baptista, Maria Ana; Miranda, Miguel; Omira, Rachid; Magalhães, Vitor; Roque, Cristina

    2015-04-01

    The seismic stratigraphy of the Tagus estuary ebb-tidal delta of Lisbon (Portugal) is investigated with the purpose of searching for evidences of possible sedimentary or erosive features associated with landslides or mass wasting deposits (MTD) events. A special attention was given to events that could have been triggered by large earthquakes that are known to have struck the West of Portugal and Spain in historical and pre-historical times. These earthquakes destroyed Lisbon at least twice in the last 500 years, being the 1755 Lisbon earthquake of estimated magnitude >8.5. To investigate these geological features the seismic reflection dataset used in this work consists of Chirp (Lisboa98 dataset), Sparker single channel (PACEMAKER 2011 dataset) and multichannel seismic (MCS) data (TAGUSDELTA 2013 dataset). Cross-lines of MCS data were acquired crossing the core sampling sites done in previous works. Calibration of the seismic lines width the core data led to infer that the Tagus ebb delta started its formation around 17ky BP and it consists of two main stratigraphic units, the younger of which initiated its formation at approximately 13ky BP. The lower deltaic unit contains several MTDs and/or landslides that could not be mapped with the present dataset. In the upper unit we report the existence of a landslide with 10km of length, 4.5km of width and 20m of maximum thickness that accounted for the collapse of half of the Tagus river delta front. The internal structure of the landslide varies laterally. The main different aspects are, as follows, i) the landslide can be dismembered along slope due to stretching parallel associated to differential movement along slope, ii) it can show internal discontinuities that represent mechanical detachments that separate imbricate wedges and iii) distal deposited bodies completely detached from the main landslide body. The age of the landslide is discussed; an estimated age of >8ky BP is proposed by stratigraphic correlation

  18. Microbial diversity and stratification of South Pacific abyssal marine sediments.

    PubMed

    Durbin, Alan M; Teske, Andreas

    2011-12-01

    Abyssal marine sediments cover a large proportion of the ocean floor, but linkages between their microbial community structure and redox stratification have remained poorly constrained. This study compares the downcore gradients in microbial community composition to porewater oxygen and nitrate concentration profiles in an abyssal marine sediment column in the South Pacific Ocean. Archaeal 16S rRNA clone libraries showed a stratified archaeal community that changed from Marine Group I Archaea in the aerobic and nitrate-reducing upper sediment column towards deeply branching, uncultured crenarchaeotal and euryarchaeotal lineages in nitrate-depleted, anaerobic sediment horizons. Bacterial 16S rRNA clone libraries revealed a similar shift on the phylum and subphylum level within the bacteria, from a complex community of Alpha-, Gamma- and Deltaproteobacteria, Actinobacteria and Gemmatimonadetes in oxic surface sediments towards uncultured Chloroflexi and Planctomycetes in the anaerobic sediment column. The distinct stratification of largely uncultured bacterial and archaeal groups within the oxic and nitrate-reducing marine sediment column provides initial constraints for their microbial habitat preferences. © 2011 Society for Applied Microbiology and Blackwell Publishing Ltd.

  19. Does deep ocean mixing drive upwelling or downwelling of abyssal waters?

    NASA Astrophysics Data System (ADS)

    Ferrari, R. M.; McDougall, T. J.; Mashayek, A.; Nikurashin, M.; Campin, J. M.

    2016-02-01

    It is generally understood that small-scale mixing, such as is caused by breaking internal waves, drives upwelling of the densest ocean waters that sink to the ocean bottom at high latitudes. However the observational evidence that the turbulent fluxes generated by small-scale mixing in the stratified ocean interior are more vigorous close to the ocean bottom than above implies that small-scale mixing converts light waters into denser ones, thus driving a net sinking of abyssal water. Using a combination of numerical models and observations, it will be shown that abyssal waters return to the surface along weakly stratified boundary layers, where the small-scale mixing of density decays to zero. The net ocean meridional overturning circulation is thus the small residual of a large sinking of waters, driven by small-scale mixing in the stratified interior, and a comparably large upwelling, driven by the reduced small-scale mixing along the ocean boundaries.

  20. Phytoplankton community indicators of changes associated with dredging in the Tagus estuary (Portugal).

    PubMed

    Cabrita, Maria Teresa

    2014-08-01

    This work reports changes in suspended particulate matter, turbidity, dissolved Cr, Ni, Cu, Cd, Hg and Pb concentrations, and phytoplankton biomass and composition during a 5-month period dredging operation, in a trace element contaminated area of the Tagus estuary (Portugal). Phytoplankton biomass, diatom:other groups ratio, benthic:pelagic diatom ratio, Margalef's, Simpson's diversity, Shannon-Wiever's, and Warwick and Clarke's taxonomic diversity and distinctness indices, and individual taxa were investigated as indicators of dredging induced changes. Significant rise in sediment resuspension and trace element mobilisation caused by dredging influenced the community structure but not the overall biomass. Benthic diatom displacement into the water column maintained species diversity, and therefore, none of the indices highlighted community changes. Contrastingly, diatom:other groups ratio and benthic:pelagic diatom ratio were reliable indicators for the assessment of dredging induced changes. A shift in composition towards species less susceptible to trace elements was observed, disclosing some individual taxa as potential indicators. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Influence of Melting and Hydrothermal Alteration on Lead in Abyssal Peridotites

    NASA Astrophysics Data System (ADS)

    Warren, J. M.; D'Errico, M. E.; Godard, M.; Coble, M. A.; Horan, M.

    2017-12-01

    The lead isotopic system is a key tracer of mantle convection, yet the abundance and mineralogical hosts of Pb in the upper mantle are poorly constrained. To address this, we analyzed the concentration of Pb in minerals and bulk rock powders of abyssal peridotites. These samples represent the oceanic upper mantle following melt extraction. They can be used to explore the mantle Pb budget, assuming that the amount of Pb lost during mantle melting and gained during seafloor alteration can be determined. We performed in situ analysis of the three main silicate phases (olivine, orthopyroxene, and clinopyroxene), which yield Pb concentrations of 2-30 ppb. Olivine is the main mineralogical host of Pb, unlike other trace elements, which are predominantly hosted in clinopyroxene. Sulfide contains an average of 3 ppm Pb, but these high concentrations are offset by low modal abundances (<0.01%), making this mineral a minor source of peridotite Pb. Whole rock Pb concentrations of abyssal peridotites measured by thermal ionization mass spectrometry range from 3 to 38 ppb. These values are close to the reconstructed whole rock values of 2 to 14 ppb, calculated from the mineral concentrations of Pb multiplied by their modes. In contrast, the average value among literature data for whole rock abyssal peridotites is >100 ppb [1, 2], measured by inductively-coupled plasma mass spectrometry. The higher values among literature data may reflect a combination of lower analytical sensitivity and effects of alteration. Samples in this study include an unaltered peridotite from the Gakkel Ridge, which shows the closest agreement between reconstructed and measured whole rock values. We estimate that our peridotites have undergone 5 to 9% melting [3], based on non-modal fractional melt modeling of rare earth element abundances. Assuming 18 to 23 ppb Pb in the depleted source mantle [4, 5], expected concentrations in abyssal peridotites after melting are <1 ppb. However, as suggested by [5

  2. The effects of depth, distance, and the Mid-Atlantic Ridge on genetic differentiation of abyssal and hadal isopods (Macrostylidae)

    NASA Astrophysics Data System (ADS)

    Riehl, Torben; Lins, Lidia; Brandt, Angelika

    2018-02-01

    The largest habitat on Earth, the abyssal oceans below 3500 m depth, is commonly assumed to represent a continuous environment due to homogeneity of environmental factors and the lack of physical barriers. Yet, the presence of bathymetric features, such as Mid-Ocean Ridges, and hadal trenches provide a discontinuation. During the Vema-TRANSIT expedition in 2014/2015 to the tropical North Atlantic, a transatlantic transect was studied following the full extent of the Vema Fracture Zone in an east-west direction and including the Puerto Rico Trench (PRT). The aim of this study was to test whether large bathymetric features represent barriers to dispersal and may lead to differentiation and eventually speciation. In this study, these potential barriers included the Mid-Atlantic Ridge (MAR) and the transition ( 3000 m) from the hadal PRT to the adjacent abyss. Genetic differentiation and differences in community structure (species composition) from east and west of the MAR, as well as abyssal and hadal depth zones were tested for using the poor dispersers Macrostylidae (Crustacea, Isopoda) as a model Distribution patterns showed that certain macrostylid species have ranges extending more than 2000 km, in some cases across oceanic ridges and trench-abyss transitions. Contrastingly, there was a clear signal for geographic population structure coinciding with the east-west division of the Atlantic by the MAR as well as with the abyss-hadal zonation. These results support the hypotheses that depth gradients as well as oceanic ridges reduce dispersal even though barriers may not be absolute. Additionally, positive correlation between genetic- and geographic distances showed that the vast size of the deep sea itself is a factor responsible for creating diversity.

  3. Mooring Measurements of the Abyssal Circulations in the Western Pacific Ocean

    NASA Astrophysics Data System (ADS)

    Wang, J.; Wang, F.

    2016-12-01

    A scientific observing network in the western tropical Pacific has initially been established by the Institute of Oceanology, Chinese Academy of Sciences (IOCAS). Using fifteen moorings that gives unprecedented measurements in the intermediate and abyssal layers, we present multi-timescale variations of the deep ocean circulations prior to and during 2015 El Niño event. The deep ocean velocities increase equatorward with high standard deviation and nearly zero mean. The deep ocean currents mainly flow in meridional direction in the central Philippine Basin, and are dominated by a series of alternating westward and eastward zonal jets in the Caroline Basin. The currents in the deep channel connecting the East and West Mariana Basins mainly flow southeastward. Seasonal variation is only present in the deep jets in the Caroline Basin, associating with vertical propagating annual Rossby wave. The high-frequency flow bands are dominated by diurnal, and semi-diurnal tidal currents, and near-inertial currents. The rough topography has a strong influence on the abyssal circulations, including the intensifications in velocity and internal tidal energy, and the formation of upwelling flow.

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

    Finley, P.D.; Krason, J.; Dominic, K.

    Multichannel and selected single-channel seismic lines of the continental margin sediments of the Colombia basin display compelling evidence for large accumulations of natural gas hydrate. Seismic bottom simulating reflectors (BSRs), interpreted to mark the base of the hydrate stability zone, are pronounced and very widespread along the entire Panama-Colombia lower continental slope. BSRs have also been identified at two locations on the abyssal plain. Water depths for these suspected hydrate occurrences range from 900 to 4000 m. Although no gas hydrate samples have been recovered from this area, biogenic methane is abundant in Pliocene turbidites underlying the abyssal plain. Moremore » deeply buried rocks beneath the abyssal plain are thermally mature. Thermogenic gas from these rocks may migrate upward along structural pathways into the hydrate stability zone and form hydrate. Impermeable hydrate layers may form caps over large accumulations of free gas, accounting for the very well-defined BSRs in the area. The abyssal plain and the deformed continental margin hold the highest potential for major economic accumulations of gas hydrate in the basin. The extensive continuity of BSRs, relatively shallow water depths, and promixity to onshore production facilities render the marginal deformed belt sediments the most favorable target for future economic development of the gas hydrate resource within the Colombia basin. The widespread evidence of gas hydrates in the Colombia basin suggests a high potential for conventional hydrocarbon deposits offshore of Panama and Colombia.« less

  5. Controls on melting at spreading ridges from correlated abyssal peridotite - mid-ocean ridge basalt compositions

    NASA Astrophysics Data System (ADS)

    Regelous, Marcel; Weinzierl, Christoph G.; Haase, Karsten M.

    2016-09-01

    Variations in the volume and major element composition of basalt erupted along the global mid-ocean ridge system have been attributed to differences in mantle potential temperature, mantle composition, or plate spreading rate and lithosphere thickness. Abyssal peridotites, the residues of mantle melting beneath mid-ocean ridges, provide additional information on the melting process, which could be used to test these hypotheses. We compiled a global database of abyssal peridotite compositions averaged over the same ridge segments defined by Gale et al. (2013). In addition, we calculated the distance of each ridge segment to the nearest hotspots. We show that Cr# in spinel in abyssal peridotites is negatively correlated with Na90 in basalts from the same ridge segments on a global scale. Ridge segments that erupt basalts apparently produced by larger degrees of mantle melting are thus underlain by peridotites from which large amounts of melt have been extracted. We find that near-ridge hotspots have a more widespread influence on mid-ocean ridge basalt (MORB) composition and ridge depth than previously thought. However, when these hotspot-influenced ridge segments are excluded, the remaining segments show clear relationships between MORB composition, peridotite composition, and ridge depth with spreading rate. Very slow-spreading ridges (<20 mm/yr) are deeper, erupt basalts with higher Na90, Al90, K90/Ti90, and lower Fe90, Ca90/Al90, and expose peridotites with lower Cr# than intermediate and fast-spreading ridges. We show that away from hotspots, the spreading-rate dependence of the maximum degree of mantle melting inferred from Cr# in peridotites (FM) and the bulk degree of melting inferred from Na90 in basalts (FB) from the same ridge segments is unlikely to be due to variations in mantle composition. Nor can the effects of dynamic mantle upwelling or incomplete melt extraction at low spreading rates satisfactorily explain the observed compositions of abyssal

  6. Threatened by mining, polymetallic nodules are required to preserve abyssal epifauna

    PubMed Central

    Vanreusel, Ann; Hilario, Ana; Ribeiro, Pedro A.; Menot, Lenaick; Arbizu, Pedro Martínez

    2016-01-01

    Polymetallic nodule mining at abyssal depths in the Clarion Clipperton Fracture Zone (Eastern Central Pacific) will impact one of the most remote and least known environments on Earth. Since vast areas are being targeted by concession holders for future mining, large-scale effects of these activities are expected. Hence, insight into the fauna associated with nodules is crucial to support effective environmental management. In this study video surveys were used to compare the epifauna from sites with contrasting nodule coverage in four license areas. Results showed that epifaunal densities are more than two times higher at dense nodule coverage (>25 versus ≤10 individuals per 100 m2), and that taxa such as alcyonacean and antipatharian corals are virtually absent from nodule-free areas. Furthermore, surveys conducted along tracks from trawling or experimental mining simulations up to 37 years old, suggest that the removal of epifauna is almost complete and that its full recovery is slow. By highlighting the importance of nodules for the epifaunal biodiversity of this abyssal area, we urge for cautious consideration of the criteria for determining future preservation zones. PMID:27245847

  7. Threatened by mining, polymetallic nodules are required to preserve abyssal epifauna.

    PubMed

    Vanreusel, Ann; Hilario, Ana; Ribeiro, Pedro A; Menot, Lenaick; Arbizu, Pedro Martínez

    2016-06-01

    Polymetallic nodule mining at abyssal depths in the Clarion Clipperton Fracture Zone (Eastern Central Pacific) will impact one of the most remote and least known environments on Earth. Since vast areas are being targeted by concession holders for future mining, large-scale effects of these activities are expected. Hence, insight into the fauna associated with nodules is crucial to support effective environmental management. In this study video surveys were used to compare the epifauna from sites with contrasting nodule coverage in four license areas. Results showed that epifaunal densities are more than two times higher at dense nodule coverage (>25 versus ≤10 individuals per 100 m(2)), and that taxa such as alcyonacean and antipatharian corals are virtually absent from nodule-free areas. Furthermore, surveys conducted along tracks from trawling or experimental mining simulations up to 37 years old, suggest that the removal of epifauna is almost complete and that its full recovery is slow. By highlighting the importance of nodules for the epifaunal biodiversity of this abyssal area, we urge for cautious consideration of the criteria for determining future preservation zones.

  8. Demographic indicators of change in a deposit-feeding abyssal holothurian community (Station M, 4000 m)

    NASA Astrophysics Data System (ADS)

    Huffard, Christine L.; Kuhnz, Linda A.; Lemon, Larissa; Sherman, Alana D.; Smith, Kenneth L.

    2016-03-01

    Holothurians are among the most abundant benthic megafauna at abyssal depths, and important consumers and bioturbators of organic carbon on the sea floor. Significant fluctuations in abyssal holothurian density are often attributed to species-specific responses to variable particulate organic carbon flux (food supply) stemming from surface ocean events. We report changes in densities of 19 holothurian species at the abyssal monitoring site Station M in the northeast Pacific, recorded during 11 remotely operated vehicle surveys between Dec 2006 and Oct 2014. Body size demographics are presented for Abyssocucumis abyssorum, Synallactidae sp. 1, Paelopatides confundens, Elpidia sp. A, Peniagone gracilis, Peniagone papillata, Peniagone vitrea, Peniagone sp. A, Peniagone sp. 1, and Scotoplanes globosa. Densities were lower and species evenness was higher from 2006-2009 compared to 2011-2014. Food supply of freshly-settled phytodetritus was exceptionally high during this latter period. Based on relationships between median body length and density, numerous immigration and juvenile recruitment events of multiple species appeared to take place between 2011 and 2014. These patterns were dominated by elpidiids (Holothuroidea: Elasipodida: Elpidiidae), which consistently increased in density during a period of high food availability, while other groups showed inconsistent responses. We considered minimum body length to be a proxy for size at juvenile recruitment. Patterns in density clustered by this measure, which was a stronger predictor of maximum density than median and mean body length.

  9. Highly siderophile element systematics of abyssal peridotites from intermediate and fast spreading ridges

    NASA Astrophysics Data System (ADS)

    Brown, D. B.; Day, J. M.; Waters, C. L.

    2016-12-01

    Abyssal peridotites are residues of both modern and ancient partial melt extraction at oceanic ridges and can be used to examine melting processes and mantle heterogeneity. The highly siderophile elements (HSE: Os, Ir, Ru, Pt, Pd, Re, and the 187Re-187Os system embedded within them), are useful for investigating these issues, as they are generally strongly compatible. To date, limited data on HSE and Os isotopes has been obtained on abyssal peridotites from fast spreading centers. Here, we report new HSE abundance and 187Os/188Os data for Pacific Antarctic Ridge (PAR) and East Pacific Rise (EPR) abyssal peridotites. Samples from the PAR were dredged from two separate localities along the Udintsev Fracture Zone, and EPR samples were taken from Hess Deep. The PAR full spreading rate ranges from 54-83mm/year [1,2] and is 75 mm/year [2] at the Udintsev Fracture Zone. These spreading rates characterize the PAR as an intermediate spreading ridge, whereas the fast spreading EPR has a full rate ranging from 128-157 mm/year [3]. The 187Os/188Os ratios for whole-rocks from the PAR range from 0.114 to 0.134, with Re depletion ages (TRD) varying from 1 Ga to present. Despite the large variation in 187Os/188Os, HSE patterns are primitive mantle-like [4], with Ru/Ir ratios ranging from 1.5-2.1. Depletions in Re and Pd are present, as is expected in partial melt residues, and the samples have undergone 4-15% partial melting based on the rare earth elements (REE). The EPR exhibits higher levels of melt depletion ranging from 18-24%. New results show Hess Deep samples have 187Os/188Os ratios of 0.123 and 0.125 for whole-rocks. These findings indicate that PAR and EPR Os isotopic data overlap with the global record of abyssal peridotites from slower ridges and that Os isotopic heterogeneities are preserved across a wide range of spreading rates and degrees of melt extraction. [1] Géli, L., et al. (1997), Science, 278, 1281-1284; [2] Castillo, P.R., et al. (1998) EPSL, 154

  10. The absence of sharks from abyssal regions of the world's oceans

    PubMed Central

    Priede, Imants G; Froese, Rainer; Bailey, David M; Bergstad, Odd Aksel; Collins, Martin A; Dyb, Jan Erik; Henriques, Camila; Jones, Emma G; King, Nicola

    2006-01-01

    The oceanic abyss (depths greater than 3000 m), one of the largest environments on the planet, is characterized by absence of solar light, high pressures and remoteness from surface food supply necessitating special molecular, physiological, behavioural and ecological adaptations of organisms that live there. Sampling by trawl, baited hooks and cameras we show that the Chondrichthyes (sharks, rays and chimaeras) are absent from, or very rare in this region. Analysis of a global data set shows a trend of rapid disappearance of chondrichthyan species with depth when compared with bony fishes. Sharks, apparently well adapted to life at high pressures are conspicuous on slopes down to 2000 m including scavenging at food falls such as dead whales. We propose that they are excluded from the abyss by high-energy demand, including an oil-rich liver for buoyancy, which cannot be sustained in extreme oligotrophic conditions. Sharks are apparently confined to ca 30% of the total ocean and distribution of many species is fragmented around sea mounts, ocean ridges and ocean margins. All populations are therefore within reach of human fisheries, and there is no hidden reserve of chondrichthyan biomass or biodiversity in the deep sea. Sharks may be more vulnerable to over-exploitation than previously thought. PMID:16777734

  11. The absence of sharks from abyssal regions of the world's oceans.

    PubMed

    Priede, Imants G; Froese, Rainer; Bailey, David M; Bergstad, Odd Aksel; Collins, Martin A; Dyb, Jan Erik; Henriques, Camila; Jones, Emma G; King, Nicola

    2006-06-07

    The oceanic abyss (depths greater than 3000 m), one of the largest environments on the planet, is characterized by absence of solar light, high pressures and remoteness from surface food supply necessitating special molecular, physiological, behavioural and ecological adaptations of organisms that live there. Sampling by trawl, baited hooks and cameras we show that the Chondrichthyes (sharks, rays and chimaeras) are absent from, or very rare in this region. Analysis of a global data set shows a trend of rapid disappearance of chondrichthyan species with depth when compared with bony fishes. Sharks, apparently well adapted to life at high pressures are conspicuous on slopes down to 2000 m including scavenging at food falls such as dead whales. We propose that they are excluded from the abyss by high-energy demand, including an oil-rich liver for buoyancy, which cannot be sustained in extreme oligotrophic conditions. Sharks are apparently confined to ca 30% of the total ocean and distribution of many species is fragmented around sea mounts, ocean ridges and ocean margins. All populations are therefore within reach of human fisheries, and there is no hidden reserve of chondrichthyan biomass or biodiversity in the deep sea. Sharks may be more vulnerable to over-exploitation than previously thought.

  12. Diversity of macrofaunal Mollusca of the abyssal Vema Fracture Zone and hadal Puerto Rico Trench, Tropical North Atlantic

    NASA Astrophysics Data System (ADS)

    Linse, Katrin; Schwabe, Enrico

    2018-02-01

    While biodiversity patterns of Atlantic deep-sea bivalves and gastropods have served as model taxa for setting global latitudinal and bathymetric hypotheses, less is known on abyssal, amphi-Atlantic molluscan assemblage compositions. The Vema-TRANSIT expedition sampled 17 stations in the Vema Fracture Zone (VFZ) and the Puerto Rico Trench (PRT) by epibenthic sledge. These samples comprised a total of 1333 specimens and 64 morphospecies of the classes Caudofoveata (7 species), Solenogastres (7 spp.), Bivalvia (22 spp.), Gastropoda (24 spp.), and Scaphopoda (4 spp.) while Cephalopoda, Monoplacophora and Polyplacophora were absent. The majority of species was rare with 21 uniques (32.8% of all species) and 10 duplicates (15.6% of all species) and of these 15 (48% of rare/23.4% of all species) morphospecies were singletons and 8 (25.8% of rare/12.5% of all species) morphospecies were doubletons. Overall bivalves (686 specimens) were most abundant, followed by scaphopods (314 spec.), while solenogastres (180 spec.), caudofoveates (86 spec.) and gastropods (67 spec.) were less abundant. The abyssal macro-molluscan species composition did not vary significantly between the eastern and western Atlantic sides of the VFZ while abundances standardized to 1000 m2 trawled area were higher on the eastern side. The abyssal PRT stations resembled the VFZ ones in species composition and abundances, in the latter the eastern VFZ. The hadal PRT differed in species composition from the abyssal VFZ and PRT and abundances were similarly low like the western VFZ. The Mid-Atlantic Ridge appeared not to be a barrier for the dispersal of the mostly lecitotrophic or plankotrophic larval stages of the reported molluscan species in this study.

  13. Reproductive patterns of the abyssal asteroid Styracaster elongatus from the N.E. Atlantic Ocean

    NASA Astrophysics Data System (ADS)

    Benítez-Villalobos, Francisco; Díaz-Martínez, Julia P.

    2010-01-01

    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 (N.E. Atlantic). 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.

  14. Engineering concepts for the placement of wastes on the abyssal seafloor

    NASA Astrophysics Data System (ADS)

    Valent, Philip J.; Palowitch, Andrew W.; Young, David K.

    1998-05-01

    The Naval Research Laboratory (NRL), with industry and academic participation, has completed a study of the concept of isolating industrial wastes (i.e., sewage sludge, fly ash from municipal incinerators, and dredged material) on the abyssal seafloor. This paper presents results of the technical and economic assessment of this waste management concept. The results of the environmental impacts portion of the study are presented in a companion paper. The technical assessment began with identification of 128 patents addressing waste disposal in the ocean. From these 128 patents, five methods for transporting wastes through the water column and emplacing wastes within an easily monitored area on the abyssal seafloor were synthesized for technical assessment. In one method waste is lowered to the seafloor in a bucket of 190 m 3. In a second method waste is pumped down to the seafloor in pipes, 1.37 m in diameter and 6100 m in length. In a third method waste is free-fallen from the ocean surface in 380-m 3 geosynthetic fabric containers (GFCs). In the fourth and fifth methods, waste is carried to near the seafloor in GFCs transported in (a) a 20,000 metric ton displacement (loaded), unpowered, unmanned submersible glider, or (b) a 2085 metric ton displacement (loaded) disk-shaped transporter traversing to and from the seafloor much like an untethered elevator. In the last two methods the transporter releases the GFCs to free-fall the last few hundred meters to the seafloor. Two reliability analyses, a Fault Tree Analysis (FTA), and a Failure Modes, Effects, and Criticality Analysis (FMECA), showed that the free-fall GFC method posed the least overall relative risk, provided that fabric container and transporter designs eliminate the potential for tearing of the containers on release from the surface transporter. Of the five methods, the three GFC methods were shown to offer cost-effective waste management options when compared with present-day waste management

  15. Geophysical study of the Ota-VF Xira-Lisbon-Sesimbra fault zone and the lower Tagus Cenozoic basin

    NASA Astrophysics Data System (ADS)

    Carvalho, João; Rabeh, Taha; Bielik, Miroslav; Szalaiová, Eva; Torres, Luís; Silva, Marisa; Carrilho, Fernando; Matias, Luís; Miranda, Jorge Miguel

    2011-09-01

    This paper focuses on the interpretation of seismic reflection, gravimetric, topographic, deep seismic refraction and seismicity data to study the recently proposed Ota-Vila Franca de Xira-Lisbon-Sesimbra (OVLS) fault zone and the lower Tagus Cenozoic basin (LTCB). The studied structure is located in the lower Tagus valley (LTV), an area with over 2 million inhabitants that has experienced historical earthquakes which caused significant damage and economical losses (1344, 1531 and 1909 earthquakes) and whose tectonic sources are thought to be local but mostly remain unknown. This study, which is intended as a contribution to improve the seismic hazard of the area and the neotectonics of the region, shows that the above-proposed fault zone is probably a large crustal thrust fault that constitutes the western limit of the LTCB. Gravimetric, deep refraction and seismic reflection data suggest that the LTCB is a foreland basin, as suggested previously by some authors, and that the OVLS northern and central sectors act as the major thrusts. The southern sector fault has been dominated by strike-slip kinematics due to a different orientation to the stress field. Indeed, geological outcrop and seismic reflection data interpretation suggests that, based on fault geometry and type of deformation at depth, the structure is composed of three major segments. These data suggest that these segments have different kinematics in agreement with their orientation to the regional stress field. The OVLS apparently controls the distribution of the seismicity in the area. Geological and geophysical information previously gathered also points that the central segment is active into the Quaternary. The segment lengths vary between 20 and 45 km. Since faults usually rupture only by segments, maximum expectable earthquake magnitudes and other parameters have been calculated for the three sectors of the OVLS fault zone using empirical relationships between earthquake statistics and

  16. Hydrothermal Mineral Deposits From a Young (0.1Ma) Abyssal Hill on the Flank of the Fast-Spreading East Pacific Rise

    NASA Astrophysics Data System (ADS)

    Benjamin, S. B.; Haymon, R. M.

    2004-12-01

    It has been estimated from heat flow measurements that at least 40% of the total hydrothermal heat lost from oceanic lithosphere is removed from 0.1-5 Ma abyssal hill terrain on mid-ocean ridge flanks. Despite the large magnitude of estimated hydrothermal heat loss from young abyssal hills, little is known about characteristics of hydrothermal vents and mineral deposits in this setting. This study describes the first abyssal hill hydrothermal samples to be collected on the flank of a fast-spreading ridge. The mineral deposits were discovered at "Tevnia Site" on the axis-facing fault scarp of an abyssal hill, located on ˜0.1 Ma lithosphere ˜5 km east of the East Pacific Rise (EPR) axis at 10\\deg 20'N. Observations of Galatheid crabs, "dandelion" siphonophores, and colonies of dead, yet still intact, Tevnia worm tubes at this site during Alvin dives in 1994 suggests relatively recent hydrothermal activity. The deposits are friable hydrothermal precipitates incorporating volcanic clasts brecciated at both the micro and macro scales. The petrographic sequence of brecciation, alteration, and cementation exhibited by the samples suggests that they formed from many pulses of hydrothermal venting interspersed with, and perhaps triggered by, repeated tectonic events as the abyssal hill was uplifted and moved off-axis (see also Haymon et al., this session). Observed minerals include x-ray amorphous opaline silica and Fe-oxide phases, crystalline Mn-oxides (birnessite and todorokite), an irregularly stratified mixed layer nontronite-celadonite, and residual calcite in sediment-derived microfossils incorporated into the breccia matrix. This mineral assemblage suggests that the deposits precipitated from moderately low-temperature (<140\\deg C) fluids, enriched in K, Fe, Si, and Mn, with a near-neutral pH. The presence of tubeworm casings at the site is evidence that the hydrothermal fluids carried H2S, however no metal sulfide phases were identified in the samples. Although

  17. Seafloor Age-Stacking Reveals No Evidence for Milankovitch Cycle Influence on Abyssal Hills at Intermediate, Fast and Super-Fast Spreading Rates

    NASA Astrophysics Data System (ADS)

    Goff, J.; Zahirovic, S.; Müller, D.

    2017-12-01

    Recently published spectral analyses of seafloor bathymetry concluded that abyssal hills, highly linear ridges that are formed along seafloor spreading centers, exhibit periodicities that correspond to Milankovitch cycles - variations in Earth's orbit that affect climate on periods of 23, 41 and 100 thousand years. These studies argue that this correspondence could be explained by modulation of volcanic output at the mid-ocean ridge due to lithostatic pressure variations associated with rising and falling sea level. If true, then the implications are substantial: mapping the topography of the seafloor with sonar could be used as a way to investigate past climate change. This "Milankovitch cycle" hypothesis predicts that the rise and fall of abyssal hills will be correlated to crustal age, which can be tested by stacking, or averaging, bathymetry as a function of age; stacking will enhance any age-dependent signal while suppressing random components, such as fault-generated topography. We apply age-stacking to data flanking the Southeast Indian Ridge ( 3.6 cm/yr half rate), northern East Pacific Rise ( 5.4 cm/yr half rate) and southern East Pacific Rise ( 7.8 cm/yr half rate), where multibeam bathymetric coverage is extensive on the ridge flanks. At the greatest precision possible given magnetic anomaly data coverage, we have revised digital crustal age models in these regions with updated axis and magnetic anomaly traces. We also utilize known 2nd-order spatial statistical properties of abyssal hills to predict the variability of the age-stack under the null hypothesis that abyssal hills are entirely random with respect to crustal age; the age-stacked profile is significantly different from zero only if it exceeds this expected variability by a large margin. Our results indicate, however, that the null hypothesis satisfactorily explains the age-stacking results in all three regions of study, thus providing no support for the Milankovitch cycle hypothesis. The

  18. Abyssal Sequestration of Nuclear Waste in Earth's Crust

    NASA Astrophysics Data System (ADS)

    Germanovich, L. N.; Garagash, D.; Murdoch, L. C.; Robinowitz, M.

    2013-12-01

    This work outlines a new method for disposing of hazardous (e.g., nuclear) waste. The technique is called Abyssal Sequestration, and it involves placing the waste at extreme depths in Earth's crust where it could achieve the geologically-long period of isolation. Abyssal Sequestration involves storing the waste in hydraulic fractures driven by gravity, a process we term gravity fracturing. In short, we suggest creating a dense fluid (slurry) containing waste, introducing the fluid into a fracture, and extending the fracture downward until it becomes long enough to propagate independently. The fracture will continue to propagate downward to great depth, permanently isolating the waste. Storing solid wastes by mixing them with fluids and injecting them into hydraulic fractures is a well-known technology. The essence of our idea differs from conventional hydraulic fracturing techniques only slightly in that it uses fracturing fluid heavier than the surrounding rock. This difference is fundamental, however, because it allows hydraulic fractures to propagate downward and carry wastes by gravity instead of or in addition to being injected by pumping. An example of similar gravity-driven fractures with positive buoyancy is given by magmatic dikes that may serve as an analog of Abyssal Sequestration occurring in nature. Mechanics of fracture propagation in conditions of positive (diking) and negative (heavy waste slurry) buoyancy is similar and considered in this work for both cases. Analog experiments in gelatin show that fracture breadth (horizontal dimension) remains nearly stationary when fracturing process in the fracture 'head' (where breadth is 'created') is dominated by solid toughness, as opposed to the viscous fluid dissipation dominant in the fracture tail. We model propagation of the resulting 'buoyant' or 'sinking' finger-like fracture of stationary breadth with slowly varying opening along the crack length. The elastic response of the crack to fluid loading

  19. Calcareous sponges from abyssal and bathyal depths in the Weddell Sea, Antarctica

    NASA Astrophysics Data System (ADS)

    Rapp, Hans Tore; Janussen, Dorte; Tendal, Ole S.

    2011-03-01

    Calcareous sponges have traditionally been regarded as shallow-water organisms, a persistent myth created by Hentschel (1925), partly supported by the problematic question of calcareous skeletal secretion under high partial CO 2-pressure below the CCD in the abyss. Up to now, only few species world-wide of the sponge class Calcarea have been described from depths below 2000 m. By far, the largest number of records of Antarctic Calcarea is known from shelf areas between 50 and 400 m depth. They have only been sporadically recorded on the lower shelf and the upper slope from depths between 570 and 850 m. From abyssal depths in the Antarctic there are no previous records of calcareous sponges. It was therefore a big surprise when the first true deep-sea Calcarea from the Antarctic were collected at depths between 1120 and 4400 m during the ANDEEP I, II and III expeditions ( Janussen et al., 2006). To date, five calcareous sponge species have been found, including three species new to science. The three new species belong to the genera Ascaltis, Clathrina and Leucetta. Although calcareous sponges are rare in the Antarctic deep sea, they seem to constitute a constant component of the fauna. Antarctic Calcarea shows all the characteristics of need for revision and further collection and investigation. Still, many new species are likely to be discovered in the Antarctic deep-sea.

  20. Continuing and New Measurements at the Abyssal ALOHA Cabled Observatory

    NASA Astrophysics Data System (ADS)

    Howe, B. M.; Potemra, J. T.; Butler, R.; Santiago-Mandujano, F.; Lukas, R.; Duennebier, F. K.; Karl, D. M.; Aucan, J.

    2016-02-01

    The ALOHA Cabled Observatory (ACO) is a general purpose "node" providing power, communications and timing connectivity for science use at Station ALOHA 100 km north of Oahu. Included are a suite of basic sensors making core measurements, some local and some sensing the water column. At 4728 m deep, it is the deepest scientific outpost on the planet with power and Internet. Importantly, Station ALOHA is the field site of the NSF-funded Hawaii Ocean Time-series (HOT) program that has investigated temporal dynamics in biology, physics, and chemistry since 1988, at a site that is representative of roughly 70% of the world ocean, sampling the ocean from top to bottom to monitor and study changes on scales of months to decades. The co-located Woods Hole mooring (WHOTS) provides meteorological and upper ocean physical data. The CMORE (Center for Microbial Oceanography Research and Education) and SCOPE (Simons Collaboration on Ocean Processes and Ecology) programs address their respective science topics at ALOHA. Together these programs provide a truly unique means for observing the ocean across all disciplines and regimes (deep sea, near surface, etc.). ACO has been operating in the abyss since June 2011, collecting temperature, salinity, velocity, acoustic, and video data (see for instance the abstract by Lukas et al., Spatial Analysis of Abyssal Temperature Variations Observed from the ALOHA Cabled Observatory and WHOTS Moorings). Using the University of Hawaii remotely operated vehicle ROV Lu`ukai, a basic sensor package was recently installed equipped with a Paroscientific nano-resolution pressure sensor, a WetLabs fluorometer/turbidity sensor, and a Seabird CTDO2 instrument. These data will be presented and described.

  1. Bait attending fishes of the abyssal zone and hadal boundary: Community structure, functional groups and species distribution in the Kermadec, New Hebrides and Mariana trenches

    NASA Astrophysics Data System (ADS)

    Linley, T. D.; Stewart, A. L.; McMillan, P. J.; Clark, M. R.; Gerringer, M. E.; Drazen, J. C.; Fujii, T.; Jamieson, A. J.

    2017-03-01

    Baited landers were deployed at 83 stations at four locations in the west Pacific Ocean from bathyal to hadal depths: The Kermadec Trench, the New Hebrides Trench, the adjoining South Fiji Basin and the Mariana Trench. Forty-seven putative fish species were observed. Distinct fish faunal groups were identified based on maximum numbers and percentage of observations. Both analyses broadly agreed on the community structure: A bathyal group at <3000 m in the New Hebrides and Kermadec trenches, an abyssal group (3039 - 4692 m) in the Kermadec Trench, an abyssal-hadal transition zone (AHTZ) group (Kermadec: 4707-6068 m, Mariana: 4506-6198 m, New Hebrides: 2578-6898 m, South Fiji Basin: 4074-4101 m), and a hadal group of endemic snailfish in the Kermadec and Mariana trenches (6750-7669 m and 6831-8143 m respectively). The abyssal and hadal groups were absent from the New Hebrides Trench. Depth was the single factor that best explained the biological variation between samples (16%), the addition of temperature and average surface primary production for the previous year increased this to 36% of variation. The absence of the abyssal group from the New Hebrides Trench and South Fiji Basin was due to the absence of macrourids (Coryphaenoides spp.), which defined the group. The macrourids may be energetically limited in these areas. In their absence the species of the AHTZ group appear released of competition with the macrourids and are found far shallower at these sites. The fish groups had distinct feeding strategies while attending the bait: The bathyal and abyssal groups were almost exclusively necrophagous, the AHTZ group comprised predatory and generalist feeders, while the hadal snailfishes were exclusively predators. With increasing depth, predation was found to increase while scavenging decreased. The data suggest scavenging fish fauna do not extend deeper than the hadal boundary.

  2. Abyssal intimacies and temporalities of care: How (not) to care about deformed leaf bugs in the aftermath of Chernobyl.

    PubMed

    Schrader, Astrid

    2015-10-01

    Prompted by a classroom discussion on knowledge politics in the aftermath of the Chernobyl disaster, this article offers a reading of Hugh Raffles' Insectopedia entry on Chernobyl. In that entry, Raffles describes how Swiss science-artist and environmental activist Cornelia Hesse-Honegger collects, studies, and paints morphologically deformed leaf bugs that she finds in the proximity of nuclear power plants. In exploring how to begin to care about beings, such as leaf bugs, this article proposes a notion of care that combines an intimate knowledge practice with an ethical relationship to more-than-human others. Jacques Derrida's notion of 'abyssal intimacy' is central to such a combination. Hesse-Honegger's research practices enact and her paintings depict an 'abyssal intimacy' that deconstructs the oppositions between concerns about human suffering and compassion for seemingly irrelevant insects and between knowledge politics and ethics. At the heart of such a careful knowledge production is a fundamental passivity, based on a shared vulnerability. An abyssal intimacy is not something we ought to recognize; rather, it issues from particular practices of care that do not identify their subjects of care in advance. Caring or becoming affected thus entails the dissociation of affection not only from the humanist subject, but also from movements in time: from direct helping action and from the assumption that advocacy necessarily means speaking for an other, usually assumed to be inferior.

  3. Identification of potential sites for deep-ocean waste isolation with a geographic site-selection model

    NASA Astrophysics Data System (ADS)

    Fleischer, Peter; Bowles, Frederick A.; Richardson, Michael D.

    1998-05-01

    Identification of optimal sites for the isolation of waste on the abyssal seafloor was performed with two approaches: by the traditional method of map overlays of relevant attributes, and by a specially developed, automated Site-Selection Model (SSM). Five initial, Surrogate Sites, identified with the map-overlay approach, were then compared with the more rigorously produced scores from the SSM. The SSM, a process for optimization of site locations, accepts subjective, expert-based judgments and transforms them into a quantitative, reproducible, and documented product. The SSM is adaptable to any siting scenario. Forty-one factors relevant to the isolation scenario, including 21 weightable factors having a total of 123 scorable categories, have been entered into the SSM. Factors are grouped under project definition, unique environments, anthropogenic, geologic, biologic, weather, oceanographic and distance criteria. The factor scores are linked to a georeferenced database array of all factors, corresponding to 1°×1° latitude-longitude squares. The SSM includes a total of 2241 one-degree squares within 1000 n.m. of the U.S. coasts, including the western North Atlantic, the Gulf of Mexico, and the eastern North Pacific. Under a carefully weighted and scored scenario of isolation, the most favorable sites identified with the SSM are on the Hatteras and Nares Abyssal Plains in the Atlantic. High-scoring sites are also located in the Pacific abyssal hills province between the Murray and Molokai Fracture Zones. Acceptable 1° squares in the Gulf of Mexico are few and of lower quality, with the optimum location on the northern Sigsbee Abyssal Plain. Two of the five Surrogate Site locations, on the Hatteras and Sigsbee Abyssal Plains, correspond to the best SSM sites in each ocean area. Two Pacific and a second Atlantic Surrogate Site are located in low-scoring regions or excluded by the SSM. Site-selection results from the SSM, although robust, are an initial attempt

  4. Metabolic rates are significantly lower in abyssal Holothuroidea than in shallow-water Holothuroidea

    PubMed Central

    van Oevelen, Dick

    2018-01-01

    Recent analyses of metabolic rates in fishes, echinoderms, crustaceans and cephalopods have concluded that bathymetric declines in temperature- and mass-normalized metabolic rate do not result from resource-limitation (e.g. oxygen or food/chemical energy), decreasing temperature or increasing hydrostatic pressure. Instead, based on contrasting bathymetric patterns reported in the metabolic rates of visual and non-visual taxa, declining metabolic rate with depth is proposed to result from relaxation of selection for high locomotory capacity in visual predators as light diminishes. Here, we present metabolic rates of Holothuroidea, a non-visual benthic and benthopelagic echinoderm class, determined in situ at abyssal depths (greater than 4000 m depth). Mean temperature- and mass-normalized metabolic rate did not differ significantly between shallow-water (less than 200 m depth) and bathyal (200–4000 m depth) holothurians, but was significantly lower in abyssal (greater than 4000 m depth) holothurians than in shallow-water holothurians. These results support the dominance of the visual interactions hypothesis at bathyal depths, but indicate that ecological or evolutionary pressures other than biotic visual interactions contribute to bathymetric variation in holothurian metabolic rates. Multiple nonlinear regression assuming power or exponential models indicates that in situ hydrostatic pressure and/or food/chemical energy availability are responsible for variation in holothurian metabolic rates. Consequently, these results have implications for modelling deep-sea energetics and processes. PMID:29892403

  5. Submarine landslides in Arctic sedimentation: Canada Basin

    USGS Publications Warehouse

    Mosher, David C.; Shimeld, John; Hutchinson, Deborah R.; Lebedova-Ivanova, N; Chapman, C.

    2016-01-01

    Canada Basin of the Arctic Ocean is the least studied ocean basin in the World. Marine seismic field programs were conducted over the past 6 years using Canadian and American icebreakers. These expeditions acquired more than 14,000 line-km of multibeam bathymetric and multi-channel seismic reflection data over abyssal plain, continental rise and slope regions of Canada Basin; areas where little or no seismic reflection data existed previously. Canada Basin is a turbidite-filled basin with flat-lying reflections correlateable over 100s of km. For the upper half of the sedimentary succession, evidence of sedimentary processes other than turbidity current deposition is rare. The Canadian Archipelago and Beaufort Sea margins host stacked mass transport deposits from which many of these turbidites appear to derive. The stratigraphic succession of the MacKenzie River fan is dominated by mass transport deposits; one such complex is in excess of 132,000 km2 in area and underlies much of the southern abyssal plain. The modern seafloor is also scarred with escarpments and mass failure deposits; evidence that submarine landsliding is an ongoing process. In its latest phase of development, Canada Basin is geomorphologically confined with stable oceanographic structure, resulting in restricted depositional/reworking processes. The sedimentary record, therefore, underscores the significance of mass-transport processes in providing sediments to oceanic abyssal plains as few other basins are able to do.

  6. Analysis of the performance of contractualization primary health care indicators in the period 2009-2015 in Lisbon and Tagus Valley.

    PubMed

    Monteiro, Baltazar Ricardo; Candoso, Fátima; Reis, Magda; Bastos, Sónia

    2017-03-01

    Reforms started in 1996 intended that Regional Health Administrations (ARS) should play a relevant role in the process of transforming an integrated model towards a contractual health care model. The essential tool of this transformation would be the Contractualization Agency, established in each ARS. Its role in the new contractualization culture was to negotiate prospective budgets with health care institutions, which included Primary Health Care (PHC). This paper is a longitudinal analysis of the development of a set of nine PHC contractualization indicators in three Health Center Clusters (ACeS) of the Regional Health Administration of Lisbon and Tagus Valley (ARSLVT). We have noticed that the setting of goals, in terms of external contractualization and its monitoring and follow-up are decisive and help health professionals to define trajectories and performance goals. We also recognize the need to revise baseline indicators by developing them into outcome indicators.

  7. The long-term evolution of the Congo deep-sea fan: A basin-wide view of the interaction between a giant submarine fan and a mature passive margin (ZaiAngo project)

    NASA Astrophysics Data System (ADS)

    Anka, Zahie; Séranne, Michel; Lopez, Michel; Scheck-Wenderoth, Magdalena; Savoye, Bruno

    2009-05-01

    We have integrated the relatively unknown distal domains of the Lower Congo basin, where the main depocenters of the Congo submarine fan are located, with the better-constrained successions on the shelf and upper slope, through the analysis of thousands of km of 2D seismic reflection profiles off-shore the Congo-Angola passive margin. The basin architecture is depicted by two ca. 800-km-long regional cross sections through the northern (Congo) and southern (Angola) margin. A large unit deposited basinward of the Aptian salt limit is likely to be the abyssal-plain equivalent of the upper-Cretaceous carbonate shelf that characterized the first post-rift deposits in West-equatorial African margins. A latest-Turonian shelf-deepening event is recorded in the abyssal plain as a long period (Coniacian-Eocene) of condensed sedimentation and basin starvation. The onset of the giant Tertiary Congo deep-sea fan in early Oligocene following this event reactivates the abyssal plain as the main depocenter of the basin. The time-space partitioning of sedimentation within the deep-sea fan results from the interplay among increasing sediment supply, margin uplift, rise of the Angola salt ridge, and canyon incision throughout the Neogene. Oligocene-early Miocene turbidite sedimentation occurs mainly in NW-SE grabens and ponded inter-diapir basins on the southern margin (Angola). Seaward tilting of the margin and downslope salt withdrawal activates the up-building of the Angola escarpment, which leads to a northward (Congo) shift of the transfer zones during late Miocene. Around the Miocene-Pliocene boundary, the incision of the Congo submarine canyon confines the turbidite flows and drives a general basinward progradation of the submarine fan into the abyssal plain The slope deposition is dominated by fine-grained hemipelagic deposits ever since. Results from this work contribute to better understand the signature in the ultra-deep deposits of processes acting on the continental

  8. Vema-TRANSIT - An interdisciplinary study on the bathymetry of the Vema-Fracture Zone and Puerto Rico Trench as well as abyssal Atlantic biodiversity

    NASA Astrophysics Data System (ADS)

    Riehl, Torben; Kaiser, Stefanie; Brandt, Angelika

    2018-02-01

    The seafloor below 3500 m remains largely unexplored. The paucity of knowledge of abyssal and hadal environments encompasses a wide spectrum of geological and biological patterns and processes as well as their interactions. Historically most marine research has been conducted in the North Atlantic. However, the high proportion of undescribed taxa frequently discovered at greater depth there underline the need to fill in these knowledge gaps. The Vema-TRANSIT campaign in northern winter 2014-2015 surveyed and sampled along almost the entire extent of one of the major offsets of the Mid-Atlantic Ridge (MAR), the Vema Fracture Zone (VFZ), as well as the deepest trench in the Atlantic, the Puerto Rico Trench (PRT). The discoveries that were made include new data on deep-sea habitats showing geologically complex features across all crust ages from 110 Ma until present. Moreover, some new species and genera of the abyssal and hadal benthos were described herein. Not only the taxa themselves, but also their distributions and genetic structure were elucidated. In this context, significant differences in abundances, community composition, and species distribution were detected that were affected by the MAR as well as by the depth transition between hadal PRT and the adjacent abyss. Despite significant differences between eastern and western communities, the MAR does not represent an absolute barrier. Instead, the VFZ, and especially the VTF may serve as a connecting feature between east and west and this may be exemplary for fracture zones across the whole Atlantic. Nevertheless, the MAR as well as the 3000-m-depth gradient between abyss and hadal appear to restrict gene flow for poor dispersers and thus contribute to speciation processes in the deep sea.

  9. Transport of branched tetraether lipids from the Tagus River basin to the coastal ocean of the Portuguese margin: Consequences for the interpretation of the MBT'/CBT paleothermometer

    NASA Astrophysics Data System (ADS)

    Zell, Claudia; Kim, Jung-Hyun; Balinsha, Maria; Dorhout, Denise; Santos Fernandez, Cten; Baas, Marianne; Sinninghe Damsté, Jaap S.

    2014-05-01

    Branched glycerol dialkyl glycerol tetraethers (brGDGTs), which are transported from soil to marine sediment by rivers, have been used to reconstruct the mean annual air temperature(MAAT) and soil pH of the drainage basin using the methylation index of branched tetraethers(MBT, recently refined as MBT') and cyclization index of branched tetraethers (CBT) from coastal marine sediment records. In this study we are tracing the brGDGTs from source to sink in the Tagus River basin, the longest river system on the Iberian Peninsula, by determining their concentration and distribution in soils, river suspended particulate matter (SPM), riverbank sediments, marine SPM, and marine surface sediments. The concentrations of brGDGTs in river SPM were substantially higher and their distributions were different compared to those of the drainage basin soils. This indicates that brGDGTs are mainly produced in the river itself. In the marine environment, the brGDGT concentrations rapidly decreased with increasing distance from the Tagus estuary. At the same time, the brGDGT distributions in marine sediments also changed,indicating that marine in-situ production also takes place. These results show that there are various problems that complicate the use of the MBT'/CBT for paleoreconstructions using coastal marine sediments in the vicinity of a river. However, if the majority of brGDGTs are produced in the river, it might be possible to reconstruct the environmental (temperature and pH) conditions of the river water using appropriate aquatic calibrations, provided that marine core locations are chosen in such a way that the brGDGTs in their sediments are predominantly derived from riverine in-situ production.

  10. Transport of branched tetraether lipids from the Tagus River basin to the coastal ocean of the Portuguese margin: consequences for the interpretation of the MBT'/CBT paleothermometer

    NASA Astrophysics Data System (ADS)

    Zell, C.; Kim, J.-H.; Balsinha, M.; Dorhout, D.; Fernandes, C.; Baas, M.; Sinninghe Damsté, J. S.

    2014-03-01

    Branched glycerol dialkyl glycerol tetraethers (brGDGTs), which are transported from soil to marine sediment by rivers, have been used to reconstruct the mean annual air temperature (MAAT) and soil pH of the drainage basin using the methylation index of branched tetraethers (MBT, recently refined as MBT') and cyclization index of branched tetraethers (CBT) from coastal marine sediment records. In this study we are tracing the brGDGTs from source to sink in the Tagus River basin, the longest river system on the Iberian Peninsula, by determining their concentration and distribution in soils, river suspended particulate matter (SPM), riverbank sediments, marine SPM, and marine surface sediments. The concentrations of brGDGTs in river SPM were substantially higher and their distributions were different compared to those of the drainage basin soils. This indicates that brGDGTs are mainly produced in the river itself. In the marine environment, the brGDGT concentrations rapidly decreased with increasing distance from the Tagus estuary. At the same time, the brGDGT distributions in marine sediments also changed, indicating that marine in-situ production also takes place. These results show that there are various problems that complicate the use of the MBT'/CBT for paleoreconstructions using coastal marine sediments in the vicinity of a river. However, if the majority of brGDGTs are produced in the river, it might be possible to reconstruct the environmental (temperature and pH) conditions of the river water using appropriate aquatic calibrations, provided that marine core locations are chosen in such a way that the brGDGTs in their sediments are predominantly derived from riverine in-situ production.

  11. Transport of branched tetraether lipids from the Tagus River basin to the coastal ocean of the Portuguese margin: consequences for the interpretation of the MBT'/CBT paleothermometer

    NASA Astrophysics Data System (ADS)

    Zell, C.; Kim, J.-H.; Balsinha, M.; Dorhout, D.; Fernandes, C.; Baas, M.; Sinninghe Damsté, J. S.

    2014-10-01

    Branched glycerol dialkyl glycerol tetraethers (brGDGTs), which are thought to be transported from soil to marine sediment by rivers, have been used to reconstruct the mean annual air temperature (MAAT) and soil pH of the drainage basin using the methylation index of branched tetraethers (MBT, recently refined as MBT') and cyclization index of branched tetraethers (CBT) from coastal marine sediment records. In this study, we trace the brGDGTs from source to sink in the Tagus River basin, the longest river system on the Iberian Peninsula, by determining their concentration and distribution in soils, river suspended particulate matter (SPM), riverbank sediments, marine SPM, and marine surface sediments. The concentrations of brGDGTs in river SPM were substantially higher and their distributions were different compared to those of the drainage basin soils. This indicates that brGDGTs are mainly produced in the river itself. In the marine environment, the brGDGT concentrations rapidly decreased with increasing distance from the Tagus estuary. At the same time, the brGDGT distributions in marine sediments also changed, indicating that marine in situ production also takes place. These results show that there are various problems that complicate the use of the MBT'/CBT for paleoreconstructions using coastal marine sediments in the vicinity of a river. However, if the majority of brGDGTs are produced in the river, it might be possible to reconstruct the environmental (temperature and pH) conditions of the river water using appropriate aquatic calibrations, provided that marine core locations are chosen in such a way that the brGDGTs in their sediments are predominantly derived from riverine in situ production.

  12. Implications of spinel compositions for the petrotectonic history of abyssal peridotite from Southwest Indian Ridge (SWIR)

    NASA Astrophysics Data System (ADS)

    Chen, T.; Jin, Z.; Wang, Y.; Tao, C.

    2012-12-01

    Abyssal peridotites generate at mid-ocean ridges. Lherzolite and harzburgite are the main rock types of peridotites in the uppermost mantle. The lherzolite subtype, less depleted and less common in ophiolites, characterizes mantle diapirs and slow-spreading ridges. Along the Earth's mid-ocean ridges, abyssal peridotites undergo hydration reactions to become serpentinite minerals, especially in slow to ultraslow spreading mid-ocean ridges. Spinel is common in small quantities in peridotites, and its compositions have often been used as petrogenetic indicators [1]. The Southwest Indian Ridge (SWIR) is one of the two ultraslow spreading ridges in the world. The studied serpentinized peridotite sample was collected by the 21st Voyage of the Chinese oceanic research ship Dayang Yihao (aka Ocean No. 1) from a hydrothermal field (63.5°E, 28.0°S, and 3660 m deep) in SWIR. The studied spinels in serpentinized lherzolite have four zones with different compositions: relic, unaltered core is magmatic Al-spinels; micro- to nano- sized ferrichromite zoned particles; narrow and discontinuous magnetite rim; and chlorite aureoles. The values Cr# of the primary Al-spinels indicate the range of melting for abyssal peridotites from SWIR extends from ~4% to ~7% [2]. The alteration rims of ferrichromite have a chemical composition characterized by Fe enrichment and Cr# increase indicating chromite altered under greenschist-amphibolite facies. Magnetites formed in syn- and post- serpentinization. Chlorite (clinochlore) formed at the boundary and crack of spinel indicating it had undergone with low-temperature MgO- and SiO2-rich hydrothermal fluids [3]. It suggests that serpentinized lherzolite from SWIR had undergone poly-stage hydration reactions with a wide range of temperature. Acknowledgments: EMPA experiment was carried out by Xihao Zhu and Shu Zheng in The Second Institute of Oceanography and China University of Geosciences, respectively. The work was supported by NSFC

  13. Tracking the Mediterranean Abyss

    NASA Astrophysics Data System (ADS)

    Aracri, S.; Schroeder, K.; Chiggiato, J.; Bryden, H. L.; McDonagh, E.; Josey, S. A.; Hello, Y.; Borghini, M.

    2016-02-01

    The Mediterranean Sea is well known to be a miniature ocean with small enough timescales to allow the observation of main oceanographic events, e.g. deep water formation and overturning circulation, in a human life time. This renders the Mediterranean Sea the perfect observatory to study and forecast the behaviour of the world ocean. Considering the coherence between NAO (North Atlantic Oscillation), AMO (Atlantic Multidecadal Oscillation) and Mediterranean oscillation and bearing in mind that the Mediterranean outflow at Gibraltar constitutes a constant source of intermediate, warm and saline water, it has been suggested that "the system composed of the North Atlantic, the Mediterranean Sea/Gibraltar Strait and the Arctic Sea/Fram Strait might work as a unique oceanographic entity, with the physical processes within the straits determining the exchange of the fresh and salty waters between the marginal seas and the open ocean".In the light of the present knowledge the Mediterranean might, then, be considered as a key oceanographic observatory site. The deep sea is still challenging to monitor, especially given the latest years lack of fundings and ships availability. Therefore optimizing the existing methods and instrumentation has become a priority. This work is focused on the North-Western Mediterranean basin, where deep water formation events often occur in the Gulf of Lion as well as deep convection in the neighbour Ligurian Sea. A different application of submarine robots - Mermaids- designed to observe underwater seismic waves aiming to improve ocean tomography is presented. In order to improve our knowledge of the North-Western Mediterranean abyssal circulation we track Mermaids extracting their velocity, correcting it and comparing it with the historically estimated values and with the geostrophic velocity extracted from a 40 years long hydrographic datasets.

  14. Morphological and ontogenetic stratification of abyssal and hadal Eurythenes gryllus sensu lato (Amphipoda: Lysianassoidea) from the Peru-Chile Trench

    NASA Astrophysics Data System (ADS)

    Eustace, Ryan M.; Ritchie, Heather; Kilgallen, Niamh M.; Piertney, Stuart B.; Jamieson, Alan J.

    2016-03-01

    The globally ubiquitous lysianassoid amphipod, Eurythenes gryllus, has been shown to consist of multiple genetically distinct cryptic taxa, with depth considered a major driver of speciation and morphological divergence. Here we examine morphological variation of E. gryllus sensu lato through a continuous depth distribution that spans from abyssal (3000-6000 m) into hadal depths (>6000 m) in the Peru-Chile Trench (SE Pacific Ocean). Three distinct morphospecies were identified: one was confirmed as being E. magellanicus (4602-5329 m) based on DNA sequence and morphological similarity. The other two morphologically distinct species were named based upon depth of occurrence; Abyssal (4602-6173 m) and Hadal (6173-8074 m). The three Eurythenes morphospecies showed vertical ontogenetic stratification across their bathymetric range, where juveniles were found shallower in their depth range and mature females deeper. Potential ecological and evolutionary drivers that explain the observed patterns of intra and inter-specific structure, such as hydrostatic pressure and topographical isolation, are discussed.

  15. An abyssal mobilome: viruses, plasmids and vesicles from deep-sea hydrothermal vents.

    PubMed

    Lossouarn, Julien; Dupont, Samuel; Gorlas, Aurore; Mercier, Coraline; Bienvenu, Nadege; Marguet, Evelyne; Forterre, Patrick; Geslin, Claire

    2015-12-01

    Mobile genetic elements (MGEs) such as viruses, plasmids, vesicles, gene transfer agents (GTAs), transposons and transpovirions, which collectively represent the mobilome, interact with cellular organisms from all three domains of life, including those thriving in the most extreme environments. While efforts have been made to better understand deep-sea vent microbial ecology, our knowledge of the mobilome associated with prokaryotes inhabiting deep-sea hydrothermal vents remains limited. Here we focus on the abyssal mobilome by reviewing accumulating data on viruses, plasmids and vesicles associated with thermophilic and hyperthermophilic Bacteria and Archaea present in deep-sea hydrothermal vents. Copyright © 2015 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  16. Life history of abyssal and hadal fishes from otolith growth zones and oxygen isotopic compositions

    NASA Astrophysics Data System (ADS)

    Gerringer, M. E.; Andrews, A. H.; Huss, G. R.; Nagashima, K.; Popp, B. N.; Linley, T. D.; Gallo, N. D.; Clark, M. R.; Jamieson, A. J.; Drazen, J. C.

    2018-02-01

    Hadal trenches are isolated habitats that cover the greatest ocean depths (6,500-11,000 m) and are believed to host high levels of endemism across multiple taxa. A group of apparent hadal endemics is within the snailfishes (Liparidae), found in at least five geographically separated trenches. Little is known about their biology, let alone the reasons for their success at hadal depths around the world. This study investigated the life history of hadal liparids using sagittal otoliths of two species from the Kermadec (Notoliparis kermadecensis) and Mariana (Pseudoliparis swirei) trenches in comparison to successful abyssal macrourids found at the abyssal-hadal transition zone. Otoliths for each species revealed alternating opaque and translucent growth zones that could be quantified in medial sections. Assuming these annuli represent annual growth, ages were estimated for the two hadal liparid species to be from five to 16 years old. These estimates were compared to the shallower-living snailfish Careproctus melanurus, which were older than described in previous studies, expanding the potential maximum age for the liparid family to near 25 years. Age estimates for abyssal macrourids ranged from eight to 29 years for Coryphaenoides armatus and six to 16 years for C. yaquinae. In addition, 18O/16O ratios (δ18O) were measured across the otolith using secondary ion mass spectrometry (SIMS) to investigate the thermal history of the three liparids, and two macrourids. Changes in δ18O values were observed across the otoliths of C. melanurus, C. armatus, and both hadal liparids, the latter of which may represent a change of >5 °C in habitat temperature through ontogeny. The results would indicate there is a pelagic larval stage for the hadal liparids that rises to a depth above 1000 m, followed by a return to the hadal environment as these liparids grow. This result was unexpected for the hadal liparids given their isolated environment and large eggs, and the biological

  17. Sandstone detrital modes in the Makran accretionary wedge, southwest Pakistan: implications for tectonic setting and long-distance turbidite transportation

    NASA Astrophysics Data System (ADS)

    Critelli, Salvatore; De Rosa, Rosanna; Platt, John Paul

    1990-10-01

    Detrital modes of Early Miocene to Early Pliocene sandstones from the Makran accretionary wedge in southwest Pakistan show a mainly quartzolithic composition with an evolution from the transitional recycled to quartzose recycled. The lithic types, however, indicate two distinct petrofacies. Accreted abyssal plain turbidites have Qp 11Lvm 27Lsm 62 and Lm 39Lv 27Ls 34, showing a predominant supply from sedimentary and metasedimentary source terranes whereas slope and shelf facies sediments deposited on the accretionary wedge have Qp 7Lvm 47Lsm 47 and Lm 22Lv 48Ls 30 due to an increase of volcanic detritus. The detrital modes of the abyssal plain sediments suggest a recycled orogenic source, probably the Himalayan collision zone. The facies and longitudinal dispersal pattern suggest deposition in an Oligo-Miocene analogue of the present Indus fan. The sediment must have been transported across strike, parallel to the transform structure linking the Makran wedge to the Himalayas (Chaman-Ornach Nal fault system), and fed into the fan at the western end of the subduction zone. The detrital modes also show an increase in volcanic detritus with time (Lv/L = 0.27 for the Early Miocene abyssal plain sediments to 0.47 for the slope sequences). This may have been derived from Late Mesozoic volcanic terrains in northern Baluchistan or the Ladakh Himalayas, or more probably from the Early to middle Miocene andesitic volcanic centre in the northern Makran.

  18. Does the Mid-Atlantic Ridge affect the distribution of abyssal benthic crustaceans across the Atlantic Ocean?

    NASA Astrophysics Data System (ADS)

    Bober, Simon; Brix, Saskia; Riehl, Torben; Schwentner, Martin; Brandt, Angelika

    2018-02-01

    A trans-Atlantic 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-Atlantic Ridge (MAR) isolates the abyssal fauna of the western and eastern abyssal basins. 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.

  19. Abyssal Upwelling and Downwelling and the role of boundary layers

    NASA Astrophysics Data System (ADS)

    McDougall, T. J.; Ferrari, R. M.

    2016-02-01

    The bottom-intensified mixing activity arising from the interaction of internal tides with bottom topography implies that the dianeutral advection in the ocean interior is downwards, rather than upwards as is required by continuity. The upwelling of Bottom Water through density surfaces in the deep ocean is however possible because of the sloping nature of the sea floor. A budget study of the abyss (deeper than 2000m) will be described that shows that while the upwelling of Bottom Water might be 25 Sv, this is achieved by very strong upwelling in the bottom turbulent boundary layer (of thickness 50m) of 100 Sv and strong downwelling in the ocean interior of 75 Sv. This downwelling occurs within 10 degrees of longitude of the continental boundaries. This near-boundary confined strong upwelling and downwelling clearly has implications for the Stommel-Arons circulation.

  20. Influence of the sediment on lead speciation in the Tagus estuary.

    PubMed

    Mota, A M; Cruz, P; Vilhena, C; Gonçalves, M L S

    2005-04-01

    The aim of this work is to study the influence of the Tagus estuarine sediment on lead speciation in the overlying natural water. The water sample in the presence of the sediment was contaminated three times with Pb(II) in a laboratory experiment. In different periods of time, at 1-7 days after each contamination, small volumes of water were titrated with lead. The titration was followed by anodic stripping voltammetry in differential pulse mode. Before and after contamination systematic analysis of the voltammetric parameters (peak current, peak potential and peak width) were carried out to get a clear picture of Pb(II) complexation in the soluble fraction in contact with the sediment. Two main types of organic ligands, macromolecular ligands and small compounds, were detected before contamination. Both of them form labile complexes (degree of lability within the timescale of some milliseconds). The small compounds, with a diffusion coefficient similar to that of the free metal ion, present a homogeneous behaviour in terms of Pb complexation. On the other hand macromolecular ligands, with a diffusion coefficient of 1.2 x 10(-6) cm2s(-1), can be described by two different binding groups, which might be of phenolic and carboxylic type as presented by humic matter. The sediment eliminated lead contamination (10(-6) moldm(-3) was the maximum concentration added) from 12 dm3 of water (surface of 8 dm2) within 2 days. It was also found that the sediment released organic ligands responsible for both labile and inert Pb complexes "seen" by voltammetry. The release of organic ligands that decreases the bioavailability of Pb(II) was clearly detected 1 week after contamination. Therefore, the sediment acts as a buffer for lead through two mechanisms against lead contamination: removing lead ions from the solution and releasing organic ligands to the water column. In a short period of time the sediment responds as a self-cleaning system for Pb(II) contamination in the

  1. Seismic evidence for Messinian salt deformation and fluid circulation on the South Balearic margin (Western Mediterranean)

    NASA Astrophysics Data System (ADS)

    Wardell, Nigel; Camerlenghi, Angelo; Urgeles, Roger; Geletti, Riccardo; Tinivella, Umberta; Giustiniani, Michela; Accettella, Daniela

    2014-05-01

    The south Balearic margin is characterized by an abrupt tectonically-controlled transition between a steep continental slope (Emile Baudot escarpment) and the Algero-Balearic abyssal plain, in which Messinain salt-induced deformation affects the seafloor morphology. Multichannel seismic profiles, multibeam bathymetry, and shallow seismic data demonstrate that the extent of salt deformation does not coincide with the bathymetric plain-slope transition. Instead, deformation occurs south of linear structure in the abyssal plain located some tens of kilometres from the base of the slope. The quality of the multi-channel seismic record in the deep water deformed area is severely decreased by the three dimensional character of the salt structures. However, the abyssal plain near the base of the slope reveals details on the Messinian sequence, its structure, post-Messinan deformation, and relation with subsurface fluids. The analysis of part of the EUROFLEETS SALTFLU multichannel seismic data set has included detailed RMS velocity analysis, post-stack and pre-stack time migration. An anomalously thick (up to 800 ms twt) acoustically laminated unit comprising the Messinian Upper Unit (UU) is present near the base of the slope and is characterized by syn-sedimentary gentle symmetric folding. The crests of such folds are affected by small-offset, layer-bound fractures and faults propagating from the upper part to the UU to the Plio-Quaternary sequence. Amplitude anomalies, polarity inversion and at times acoustic blanking reveal the presence of fluids (presumably gas) within the Messinian sequence. A clear seismic evidence for the Mobile Unit (MU, or salt layer) is missing in this area. Seismic evidence for the MU exists south of the linear structural boundary, where salt induced deformation has created vertical displacements of several hundreds of metres, diapiric growth, and at least two salt/mud piercement structures at the seafloor. In the highly deformed area, the UU

  2. Can neap-spring tidal cycles modulate biogeochemical fluxes in the abyssal near-seafloor water column?

    NASA Astrophysics Data System (ADS)

    Turnewitsch, Robert; Dale, Andrew; Lahajnar, Niko; Lampitt, Richard S.; Sakamoto, Kei

    2017-05-01

    Before particulate matter that settles as 'primary flux' from the interior ocean is deposited into deep-sea sediments it has to traverse the benthic boundary layer (BBL) that is likely to cover almost all parts of the seafloor in the deep seas. Fluid dynamics in the BBL differ vastly from fluid dynamics in the overlying water column and, consequently, have the potential to lead to quantitative and compositional changes between primary and depositional fluxes. Despite this potential and the likely global relevance very little is known about mechanistic and quantitative aspects of the controlling processes. Here, results are presented for a sediment-trap time-series study that was conducted on the Porcupine Abyssal Plain in the abyssal Northeast Atlantic, with traps deployed at 2, 40 and 569 m above bottom (mab). The two bottommost traps were situated within the BBL-affected part of the water column. The time series captured 3 neap and 4 spring tides and the arrival of fresh settling material originating from a surface-ocean bloom. In the trap-collected material, total particulate matter (TPM), particulate inorganic carbon (PIC), biogenic silica (BSi), particulate organic carbon (POC), particulate nitrogen (PN), total hydrolysable amino acids (AA), hexosamines (HA) and lithogenic material (LM) were determined. The biogeochemical results are presented within the context of time series of measured currents (at 15 mab) and turbidity (at 1 mab). The main outcome is evidence for an effect of neap/spring tidal oscillations on particulate-matter dynamics in BBL-affected waters in the deep sea. Based on the frequency-decomposed current measurements and numerical modelling of BBL fluid dynamics, it is concluded that the neap/spring tidal oscillations of particulate-matter dynamics are less likely due to temporally varying total free-stream current speeds and more likely due to temporally and vertically varying turbulence intensities that result from the temporally varying

  3. The Plains of Venus

    NASA Astrophysics Data System (ADS)

    Sharpton, V. L.

    2013-12-01

    Volcanic plains units of various types comprise at least 80% of the surface of Venus. Though devoid of topographic splendor and, therefore often overlooked, these plains units house a spectacular array of volcanic, tectonic, and impact features. Here I propose that the plains hold the keys to understanding the resurfacing history of Venus and resolving the global stratigraphy debate. The quasi-random distribution of impact craters and the small number that have been conspicuously modified from the outside by plains-forming volcanism have led some to propose that Venus was catastrophically resurfaced around 725×375 Ma with little volcanism since. Challenges, however, hinge on interpretations of certain morphological characteristics of impact craters: For instance, Venusian impact craters exhibit either radar dark (smooth) floor deposits or bright, blocky floors. Bright floor craters (BFC) are typically 100-400 m deeper than dark floor craters (DFC). Furthermore, all 58 impact craters with ephemeral bright ejecta rays and/or distal parabolic ejecta patterns have bright floor deposits. This suggests that BFCs are younger, on average, than DFCs. These observations suggest that DFCs could be partially filled with lava during plains emplacement and, therefore, are not strictly younger than the plains units as widely held. Because the DFC group comprises ~80% of the total crater population on Venus the recalculated emplacement age of the plains would be ~145 Ma if DFCs are indeed volcanically modified during plains formation. Improved image and topographic data are required to measure stratigraphic and morphometric relationships and resolve this issue. Plains units are also home to an abundant and diverse set of volcanic features including steep-sided domes, shield fields, isolated volcanoes, collapse features and lava channels, some of which extend for 1000s of kilometers. The inferred viscosity range of plains-forming lavas, therefore, is immense, ranging from the

  4. Abyssal near-bottom dispersal stages of benthic invertebrates in the Clarion-Clipperton polymetallic nodule province

    NASA Astrophysics Data System (ADS)

    Kersten, Oliver; Smith, Craig R.; Vetter, Eric W.

    2017-09-01

    Growing interest in polymetallic nodule mining has intensified the need to characterize the abundance, community structure and vertical flux of meroplankton in the Clarion-Clipperton Zone (CCZ) to facilitate the estimation of larval supply and potential connectivity of benthic populations. These ecological parameters are essential to predict recolonization processes following the expected large-scale, high intensity disturbances associated with nodule extraction. Here, we present the first description of the composition, abundance, temporal variability, and mesoscale distribution of dispersing stages of the benthos in two study areas in the eastern CCZ. Samples from free-vehicle plankton pumps showed little variation in meroplankton diversity and abundance over scales of 30-100 km for time scales of days to weeks. However, sediment-trap samples revealed high temporal variability in vertical flux over weeks to months. Larval abundances and fluxes measured in the abyssal CCZ are 1-2 orders of magnitude lower than observed at deep-sea ridge and hydrothermal-vent habitats. We found significantly higher downward larval fluxes at 11 m above the bottom (mab) than at 146 mab, indicating accumulation or retention of meroplankton within the Benthic Boundary Layer (BBL). The high abundance of meroplankton in the BBL emphasizes its importance to dispersing stages and suggests that the creation of large sediment plumes in the BBL during nodule mining could compromise the dispersal and recruitment abilities of the abyssal benthos, potentially slowing rates and altering patterns of benthic community recovery following mining disturbance.

  5. Charon's Smooth Plains

    NASA Astrophysics Data System (ADS)

    Beyer, R. A.; Spencer, J. R.; Nimmo, F.; Beddingfield, C.; Grundy, W. M.; McKinnon, W. B.; Moore, J.; Robbins, S.; Runyon, K.; Schenk, P.; Singer, K.; Weaver, H.; Young, L. A.; Ennico, K.; Olkin, C.; Stern, S. A.; New Horizons Science Team

    2018-06-01

    We hypothesize that Charon's smooth plains result from its global extension that caused crustal blocks to founder. Then, a viscous cryoflow composed of ammonia-rich mantle material rose up, enveloped the sinking blocks, and produced the plains.

  6. 3D lithospheric mapping of the Iberian Peninsula and surrounding Atlantic and Mediterranean margins from 3D joint inversion of potential field and elevation data.

    NASA Astrophysics Data System (ADS)

    Torne, Montserrat; Zeyen, Hermann; Jimenez-Munt, Ivone; Fernandez, Manel; Vergés, Jaume

    2017-04-01

    We investigate the lithospheric density structure of the Iberian Peninsula and the surrounding Atlantic and Mediterranean margins from a 3D joint inversion of free-air, geoid and elevation data, based on a Bayesian approach. In addition, the crustal structure has been further constrained by incorporating about 750 Moho values from DSS investigations and RF analysis covering the entire region. Our preliminary results shows a significant lithospheric deformation along the plate boundaries, the Bay of Biscay-Pyrenees to the North and the Azores-Gibraltar to the south, where the CMB and LAB are located at depths more than 45 and 150 km, respectively. Noteworthy is the arcuate lithospheric thickening located at the westernmost end of the Gibraltar Arc system showing the presence of the NW-to-Westward retreated Gibraltar Arc slab that has given rise to the formation of the Betics-Rif Alpine belt system and the back arc Alboran basin. To the west, the stable-slightly deformed Iberian massif shows a quasi-flat CMB and LAB topography (30 to 32 km and about 110 km, respectively). The crust and mantle lithosphere thin towards the Mediterranean and Atlantic margins, with the exception of its northern margin where lithospheric thickening extends offshore to the Gulf of Biscay. In the western Mediterranean the SE-Neogene slab retreat has resulted in a significant thinning of the crust and mantle lithosphere. Thin lithosphere is also observed in the Tagus-Horseshoe abyssal plain region where the LAB shallows to less than 90 km. This work has been funded by the Spanish projects MITE (CGL2014-59516-P) and WEME-CSIC project 201330E11.

  7. Observations on Cretaceous abyssal hills in the northeast Pacific

    USGS Publications Warehouse

    Eittreim, S.L.; Piper, D.Z.; Chezar, H.; Jones, D.R.; Kaneps, A.

    1984-01-01

    An abyssal hills area of 50 ?? 60 km in the northeast Pacific was studied using bottom transponder navigation, closely spaced survey lines, and long-traverse oblique photography. The block-faulted north-south hills are bounded by scarps, commonly with 40?? slopes. On these steep scarps sedimentation is inhibited and pillow basalts often crop out. An ash layer of high acoustic reflectivity at about 7 m subbottom depth blankets the area. This ash occurs in multiple beds altered to phillipsite and is highly consolidated. A 24 m.y. age for the ash is based on ichthyolith dates from samples in the overlying sediments. Acoustically transparent Neogene sediments above the ash are thickest in trough bottoms and are absent or thin on steep slopes. These Neogene sediments are composed of pale-brown pelagic clays of illite, quartz, smectite, chlorite and kaolinite. Dark-brown pelagic clays, rich in smectite and amorphous iron oxides, underlie the Neogene surficial sediments. Manganese nodules cover the bottom in varying percentages. The nodules are most abundant near basement outcrops and where the subbottom ash layer is absent. ?? 1984.

  8. Effects of the Sea-Bed on Acoustic Propagation.

    DTIC Science & Technology

    1983-11-15

    from the plane-wave reflection curves presented in Fig. 7, which have been computed from a numerical model developed by Hastrup [8]. Since good...La Spezia, Italy, SACLANT ASW Research Centre, 1983. 8. HASTRUP , O.F. Digital analysis of acoustic reflectivity in the Tyrrhenian abyssal plain. J

  9. Subsurface dolomite formation during post-depositional flow of sulphate-bearing fluids from underlying salt giants: Early Pliocene example at DSDP Leg 42A, Site 374, Ionian Abyssal Plain

    NASA Astrophysics Data System (ADS)

    McKenzie, Judith A.; Evans, Nick; Hodell, David; Aloisi, Giovanni; Vasconcelos, Crisogono

    2017-04-01

    Deciphering exact mechanisms for the formation of massive dolomite deposits has long been an enigma in sedimentary geology. The recognition that microbes can play a role in the dolomite precipitation process has added a new dimension to the study of the origin of dolomite formations in both shallow and deep-water environments. This scientific advance has evolved, particularly, through the investigation of dolomite-containing, organic-rich hemipelagic sediments cored on various continental margins during DSDP and ODP drilling campaigns, as well as intensive evaluations of modern hypersaline dolomite-precipitating environments with complementary culture experiments conducted in the laboratory. For example, the association of an active subsurface microbial community in contact with underlying brines of unknown origin leading to in situ dolomite precipitation has been observed in a Quaternary sequence of hemi-pelagic, organic carbon-rich sediments drilled on the Peru Margin, ODP Leg 201, Site 1229 (1). Specifically, it can be concluded that the long-term activity of subsurface microbes can be maintained by post-depositional flow of sulfate-bearing fluids from underlying large-scale evaporite deposits, or salt giants, promoting in situ dolomite precipitation. Another example of dolomite precipitation directly associated with the underlying Messinian salt giant was found at DSDP Leg 42A, Site 374 in the Ionian Abyssal Plain. Deep-sea drilling recovered a lowermost Pliocene sequence of diagenetically altered sediment (Unit II) separating the overlying Pliocene open-marine deposits (Unit I) and the underlying end Messinian dolomitic mudstone with gypsum layers (Unit III). The lower portion of this altered interval contained in Core 11, Section 2 (378.0 - 381.5 mbsf) comprises a dolomicrite with an unusual crystal morphology (2). The original interstitial water geochemical profiles indicate that a saline brine is diffusing upwards from below and into the dolomicrite

  10. Resilience of benthic deep-sea fauna to mining activities.

    PubMed

    Gollner, Sabine; Kaiser, Stefanie; Menzel, Lena; Jones, Daniel O B; Brown, Alastair; Mestre, Nelia C; van Oevelen, Dick; Menot, Lenaick; Colaço, Ana; Canals, Miquel; Cuvelier, Daphne; Durden, Jennifer M; Gebruk, Andrey; Egho, Great A; Haeckel, Matthias; Marcon, Yann; Mevenkamp, Lisa; Morato, Telmo; Pham, Christopher K; Purser, Autun; Sanchez-Vidal, Anna; Vanreusel, Ann; Vink, Annemiek; Martinez Arbizu, Pedro

    2017-08-01

    With increasing demand for mineral resources, extraction of polymetallic sulphides at hydrothermal vents, cobalt-rich ferromanganese crusts at seamounts, and polymetallic nodules on abyssal plains may be imminent. Here, we shortly introduce ecosystem characteristics of mining areas, report on recent mining developments, and identify potential stress and disturbances created by mining. We analyze species' potential resistance to future mining and perform meta-analyses on population density and diversity recovery after disturbances most similar to mining: volcanic eruptions at vents, fisheries on seamounts, and experiments that mimic nodule mining on abyssal plains. We report wide variation in recovery rates among taxa, size, and mobility of fauna. While densities and diversities of some taxa can recover to or even exceed pre-disturbance levels, community composition remains affected after decades. The loss of hard substrata or alteration of substrata composition may cause substantial community shifts that persist over geological timescales at mined sites. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Branimycins B and C, Antibiotics Produced by the Abyssal Actinobacterium Pseudonocardia carboxydivorans M-227.

    PubMed

    Braña, Alfredo F; Sarmiento-Vizcaíno, Aida; Pérez-Victoria, Ignacio; Otero, Luis; Fernández, Jonathan; Palacios, Juan José; Martín, Jesús; de la Cruz, Mercedes; Díaz, Caridad; Vicente, Francisca; Reyes, Fernando; García, Luis A; Blanco, Gloria

    2017-02-24

    Two new antibiotics, branimycins B (2) and C (3), were produced by fermentation of the abyssal actinobacterium Pseudonocardia carboxydivorans M-227, isolated from deep seawater of the Avilés submarine Canyon. Their structures were elucidated by HRMS and NMR analyses. These compounds exhibit antibacterial activities against a panel of Gram-positive bacteria, including Corynebacterium urealyticum, Clostridium perfringens, and Micrococcus luteus, and against the Gram-negative bacterium Neisseria meningitidis. Additionally, branimycin B displayed moderate antibacterial activity against other Gram-negative bacteria such as Bacteroides fragilis, Haemophilus influenzae, and Escherichia coli, and branimycin C against the Gram-positive Enterococcus faecalis and methicillin-sensitive and methicillin-resistant Staphylococcus aureus.

  12. Sedimentary depositional environments in the Gulf of Alaska from GLORIA Imagery

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

    Carlson, P.R.; Bruns, T.R.; Stevenson, A.J.

    1990-05-01

    GLORIA side-scan images provide new insight to the morphology and sedimentology of the Gulf of Alaska and show that tectonism strongly influences downslope and abyssal plain sediment transport. Along the Fairweather-Queen Charlotte transform margin south of Cross Sound short, chute-like canyons cross the slope to submarine-fan channels. At least one canyon is offset by strike-slip motion along the fault Fan channels coalesce to form two deep-sea turbidite channels (Mukluk and Horizon) that extend 1,000 km southward to the Tufts Abyssal Plain. From Cross Sound to Pamplona Spur, dendritic gulley systems and short chutes cross the slope into tributary channels thatmore » merge into major channels. Tributary channels from Cross Sound to Alsek Valley form the Chirikov channel system which bends westward and ends in turbidite fans south of the Kodiak-Bowie Seamount chain. A probable ancestral Chirikov channel carried sediment westward to the Aleutian Trench, Channels from Alsek Valley to Pamplona Spur coalesce 280 km seaward of the slope to form the Surveyor Channel which meanders across the abyssal plain 500 km to the Aleutian trench. Between Pamplona Spur and Middleton Island, dendritic slope canyons reach the eastern end of the Aleutian Trench sediment moves southwestward along the trench. Southwest of Middleton Island, discontinuous trench-parallel subduction ridges change slope drainage from a dendritic to trellised pattern as sediment is forced to flow around the ridges to the Aleutian Trench. At least two small fans have been constructed on the trench floor. Southwest of Kodiak Island, subduction ridges create mid-slope basins that trap modern sediment.« less

  13. Metabolic enzyme activities of abyssal and hadal fishes: pressure effects and a re-evaluation of depth-related changes

    NASA Astrophysics Data System (ADS)

    Gerringer, M. E.; Drazen, J. C.; Yancey, P. H.

    2017-07-01

    Metabolic enzyme activities of muscle tissue have been useful and widely-applied indicators of whole animal metabolic capacity, particularly in inaccessible systems such as the deep sea. Previous studies have been conducted at atmospheric pressure, regardless of organism habitat depth. However, maximum reaction rates of some of these enzymes are pressure dependent, complicating the use of metabolic enzyme activities as proxies of metabolic rates. Here, we show pressure-related rate changes in lactate and malate dehydrogenase (LDH, MDH) and pyruvate kinase (PK) in six fish species (2 hadal, 2 abyssal, 2 shallow). LDH maximal reaction rates decreased with pressure for the two shallow species, but, in contrast to previous findings, it increased for the four deep species, suggesting evolutionary changes in LDH reaction volumes. MDH maximal reaction rates increased with pressure in all species (up to 51±10% at 60 MPa), including the tide pool snailfish, Liparis florae (activity increase at 60 MPa 44±9%), suggesting an inherent negative volume change of the reaction. PK was inhibited by pressure in all species tested, including the hadal liparids (up to 34±3% at 60 MPa), suggesting a positive volume change during the reaction. The addition of 400 mM TMAO counteracted this inhibition at both 0.5 and 2.0 mM ADP concentrations for the hadal liparid, Notoliparis kermadecensis. We revisit depth-related trends in metabolic enzyme activities according to these pressure-related rate changes and new data from seven abyssal and hadal species from the Kermadec and Mariana trenches. Results show that, with abyssal and hadal species, pressure-related rate changes are another variable to be considered in the use of enzyme activities as proxies for metabolic rate, in addition to factors such as temperature and body mass. Intraspecific increases in tricarboxylic acid cycle enzymes with depth of capture, independent of body mass, in two hadal snailfishes suggest improved nutritional

  14. On evaluating health centers groups in Lisbon and Tagus Valley: efficiency, equity and quality

    PubMed Central

    2013-01-01

    Background Bearing in mind the increasing health expenses and their weight in the Portuguese gross domestic product, it is of the utmost importance to evaluate the performance of Primary Health Care providers taking into account both efficiency, quality and equity. This paper aims to contribute to a better understanding of the performance of Primary Health Care by measuring it in a Portuguese region (Lisbon and Tagus Valley) and identifying best practices. It also intends to evaluate the quality and equity provided. Methods For the purpose of measuring the efficiency of the health care centers (ACES) the non-parametric full frontier technique of data envelopment analysis (DEA) was adopted. The recent partial frontier method of order-m was also used to estimate the influence of exogenous variables on the efficiency of the ACES. The horizontal equity was investigated by applying the non-parametric Kruskal-Wallis test with multiple comparisons. Moreover, the quality of service was analyzed by using the ratio between the complaints and the total activity of the ACES. Results On the whole, a significant level of inefficiency was observed, although there was a general improvement in efficiency between 2009 and 2010. It was found that nursing was the service with the lowest scores. Concerning the horizontal equity, the analysis showed that there is no evidence of relevant disparities between the different subregions(NUTS III). Concerning the exogenous variables, the purchasing power, the percentage of patients aged 65 years old or older and the population size affect the efficiency negatively. Conclusions This research shows that better usage of the available resources and the creation of a learning network and dissemination of best practices will contribute to improvements in the efficiency of the ACES while maintaining or even improving quality and equity. It was also proved that the market structure does matter when efficiency measurement is addressed. PMID:24359014

  15. An Investigation of Acoustic Interaction with the Ocean Bottom from Experimental Time Series Generated by Explosive Sources.

    DTIC Science & Technology

    1983-12-01

    near the turbidity channels. Furthermore, Hastrup concludes, after an analysis of time series data taken from the Tyrrhenian abyssal plain, that the top...Bottom-Interacting Ocean Acoustics edited by W. A. Kuperman and F. B. Jensen (Plenum Press, N York, 1980). 84 24. 0. F. Hastrup , "Digital Analysis of

  16. The abyssal and deep circulation of the Northeast Pacific Basin

    NASA Astrophysics Data System (ADS)

    Hautala, Susan L.

    2018-01-01

    Three-dimensional abyssal and deep circulation of the region to the east and north of the Emperor Seamount Chain/Hawaiian Ridge is determined from a compilation of CTD and Argo float data, using a new overdetermined inverse technique for the geostrophic reference velocity and diapycnal/lateral mixing coefficients. The Northeast Pacific Basin is primarily sourced from its northern boundary, at a rate of 3.5 Sv across 47°N below 3000 m. Bottom water in the western subarctic gyre recirculates cyclonically between the Emperor Seamount Chain and 155°W. Bottom water east of 155°W takes a more direct path southward along the flank of a broad topographic slope. In the deep water, a ridge of potential vorticity lying along the Mendocino Fracture Zone separates circulation systems north and south of ∼40°N. The region has very weak diapycnal and lateral mixing, and an aspect ratio for the overturning circulation that is correspondingly flat, with bottom water parcels rising less than 1 km during their long transit from the Aleutian Trench to the latitude of Hawaii.

  17. Investigating the effects of abyssal peridotite alteration on Si, Mg and Zn isotopes

    NASA Astrophysics Data System (ADS)

    Savage, P. S.; Wimpenny, J.; Harvey, J.; Yin, Q.; Moynier, F.

    2013-12-01

    Around 1/3 of Earth's divergent ridge system is now classified as "slow" spreading [1], exposing ultramafic rocks (abyssal peridotites) at the seafloor. Such material is often highly altered by serpentinisation and steatisation (talc formation). It is crucial to understand such processes in order to access the original composition of the mantle, and to quantify any impact on ocean composition. Here we examine the effect of both serpentinisation and steatisation on Si, Mg and Zn isotopes. Hydrothermal alteration and seafloor weathering are both sources of oceanic Si [2] and weathering of abyssal peridotites is a source of oceanic Mg [3]; hence isotopic fractionation as a result of seafloor alteration could affect oceanic Si and Mg isotope composition. Zinc isotopes can provide complimentary information; the magnitude and direction of fractionation is highly dependent on complexing ligand [4] and can provide compositional information on the fluids driving metasomatism. For this study, two cores from the well-characterised abyssal peridotites recovered on ODP Leg 209 were examined [5]. Hole 1274a peridotites exhibit variable serpentinisation at ~200°C, whereas samples from Hole 1268a have been comprehensively serpentinised and then subsequently steatised to talc facies at ~350°C, by a low Mg/Si, low pH fluid. The Si, Mg and Zn isotope compositions of 1274a samples are extremely homogeneous, identical to that of pristine mantle rocks (BSE) i.e., serpentinisation at this locality was predominantly isochemical [5]. In contrast, samples from 1268a show greater isotopic variability. In all samples, Mg is enriched in the heavier isotopes relative to BSE, consistent with formation of isotopically heavy secondary phases [6]. For Si, serpentinised samples are slightly enriched in the lighter isotopes compared to BSE, again consistent with the behaviour of Si during formation of secondary phases [7]. Within the steatised samples, some exhibit enrichments in the lighter Si

  18. Mountains, Craters and Plains

    NASA Image and Video Library

    2016-03-17

    New Horizons views of the informally named Sputnik Planum on Pluto (top) and the informally named Vulcan Planum on Charon (bottom). Both scale bars measure 20 miles (32 kilometers) long; illumination is from the left in both instances. The Sputnik Planum view is centered at 11°N, 180°E, and covers the bright, icy, geologically cellular plains. Here, the cells are defined by a network of interconnected troughs that crisscross these nitrogen-ice plains. At right, in the upper image, the cellular plains yield to pitted plains of southern Sputnik Planum. This observation was obtained by the Ralph/Multispectral Visible Imaging Camera (MVIC) at a resolution of 1,050 feet (320 meters) per pixel. The Vulcan Planum view in the bottom panel is centered at 4°S, 4°E, and includes the "moated mountain" Clarke Mons just above the center of the image. As well as featuring impact craters and sinuous troughs, the water ice-rich plains display a range of surface textures, from smooth and grooved at left, to pitted and hummocky at right. This observation was obtained by the Long Range Reconnaissance Imager (LORRI) at a resolution of 525 feet (160 meters) per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA20535

  19. 7 CFR 650.25 - Flood-plain management.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 6 2010-01-01 2010-01-01 false Flood-plain management. 650.25 Section 650.25... Flood-plain management. Through proper planning, flood plains can be managed to reduce the threat to... encourages sound flood-plain management decisions by land users. (a) Policy—(1) General. NRCS provides...

  20. 7 CFR 650.25 - Flood-plain management.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 6 2011-01-01 2011-01-01 false Flood-plain management. 650.25 Section 650.25... Flood-plain management. Through proper planning, flood plains can be managed to reduce the threat to... encourages sound flood-plain management decisions by land users. (a) Policy—(1) General. NRCS provides...

  1. The response of abyssal organisms to low pH conditions during a series of CO2-release experiments simulating deep-sea carbon sequestration

    NASA Astrophysics Data System (ADS)

    Barry, J. P.; Buck, K. R.; Lovera, C.; Brewer, P. G.; Seibel, B. A.; Drazen, J. C.; Tamburri, M. N.; Whaling, P. J.; Kuhnz, L.; Pane, E. F.

    2013-08-01

    The effects of low-pH, high-pCO2 conditions on deep-sea organisms were examined during four deep-sea CO2 release experiments simulating deep-ocean C sequestration by the direct injection of CO2 into the deep sea. We examined the survival of common deep-sea, benthic organisms (microbes; macrofauna, dominated by Polychaeta, Nematoda, Crustacea, Mollusca; megafauna, Echinodermata, Mollusca, Pisces) exposed to low-pH waters emanating as a dissolution plume from pools of liquid carbon dioxide released on the seabed during four abyssal CO2-release experiments. Microbial abundance in deep-sea sediments was unchanged in one experiment, but increased under environmental hypercapnia during another, where the microbial assemblage may have benefited indirectly from the negative impact of low-pH conditions on other taxa. Lower abyssal metazoans exhibited low survival rates near CO2 pools. No urchins or holothurians survived during 30-42 days of exposure to episodic, but severe environmental hypercapnia during one experiment (E1; pH reduced by as much as ca. 1.4 units). These large pH reductions also caused 75% mortality for the deep-sea amphipod, Haploops lodo, near CO2 pools. Survival under smaller pH reductions (ΔpH<0.4 units) in other experiments (E2, E3, E5) was higher for all taxa, including echinoderms. Gastropods, cephalopods, and fish were more tolerant than most other taxa. The gastropod Retimohnia sp. and octopus Benthoctopus sp. survived exposure to pH reductions that episodically reached -0.3 pH units. Ninety percent of abyssal zoarcids (Pachycara bulbiceps) survived exposure to pH changes reaching ca. -0.3 pH units during 30-42 day-long experiments.

  2. Lipid, sterols and fatty acid composition of abyssal holothurians and ophiuroids from the North-East Pacific Ocean: food web implications.

    PubMed

    Drazen, Jeffrey C; Phleger, Charles F; Guest, Michaela A; Nichols, Peter D

    2008-09-01

    The lipid, fatty acid (FA), and sterol composition of two ophiuroids and four holothurians from the abyssal eastern North Pacific were analysed to assess their feeding habits and to ascertain their composition for use in a larger study to examine food web dynamics and trophic ecology. Holothurians were rich in phytosterols and algal derived FA such as docosahexaenoic acid and eicosapentaenoic suggesting tight trophic coupling to phytodetritus. Large proportions of stanols were found, probably a result of enteric bacteria but they may come from sterol metabolism in the holothurians themselves. Oneirophanta mutabilis was distinct with much higher levels of stanols and bacterially derived FA suggesting specific selection of bacteria rich detrital particles or the activity of enteric and integumental bacteria. The ophiuroids sterol and FA compositions differed greatly from the holothurians and reflected consumption of animal material in addition to phytodetritus. Large proportions of energy storage lipids suggested a sporadic food supply. Several unusual fatty acids were found in these abyssal echinoderms. Tetracosahexaenoic acid, 24:6omega3, in ophiuroids and 23:1 in holothurians may be good biomarkers for food web studies. We report the first occurrence of alphaOH 24:1 in holothurians with none detected in ophiuroids. Its function is presently unknown.

  3. Insights into the abundance and diversity of abyssal megafauna in a polymetallic-nodule region in the eastern Clarion-Clipperton Zone

    PubMed Central

    Amon, Diva J.; Ziegler, Amanda F.; Dahlgren, Thomas G.; Glover, Adrian G.; Goineau, Aurélie; Gooday, Andrew J.; Wiklund, Helena; Smith, Craig R.

    2016-01-01

    There is growing interest in mining polymetallic nodules in the abyssal Clarion-Clipperton Zone (CCZ) in the Pacific. Nonetheless, benthic communities in this region remain poorly known. The ABYSSLINE Project is conducting benthic biological baseline surveys for the UK Seabed Resources Ltd. exploration contract area (UK-1) in the CCZ. Using a Remotely Operated Vehicle, we surveyed megafauna at four sites within a 900 km2 stratum in the UK-1 contract area, and at a site ~250 km east of the UK-1 area, allowing us to make the first estimates of abundance and diversity. We distinguished 170 morphotypes within the UK-1 contract area but species-richness estimators suggest this could be as high as 229. Megafaunal abundance averaged 1.48 ind. m−2. Seven of 12 collected metazoan species were new to science, and four belonged to new genera. Approximately half of the morphotypes occurred only on polymetallic nodules. There were weak, but statistically significant, positive correlations between megafaunal and nodule abundance. Eastern-CCZ megafaunal diversity is high relative to two abyssal datasets from other regions, however comparisons with CCZ and DISCOL datasets are problematic given the lack of standardised methods and taxonomy. We postulate that CCZ megafaunal diversity is driven in part by habitat heterogeneity. PMID:27470484

  4. 49 CFR 229.64 - Plain bearings.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Plain bearings. 229.64 Section 229.64 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION....64 Plain bearings. A plain bearing box shall contain visible free oil and may not be cracked to the...

  5. Into the deep: A coarse-grained carbonate turbidite thalweg generated by gigantic submarine chutes

    NASA Astrophysics Data System (ADS)

    Mulder, Thierry; Gillet, Hervé; Reijmer, John; Droxler, André; cavailhes, Thibault; Hanquiez, Vincent; Fauquembergue, Kelly; Bujan, Stéphane; Blanck, David; bashah, Sara; Guiastrennec, Léa; Fabregas, Natacha; Recouvreur, Audrey; Seibert, Chloé

    2017-04-01

    New high-resolution multibeam mapping, in the Southeastern Bahamas, images in exquisite details the southern part of Exuma Sound, and its unchartered transition area to the deep abyssal plain of the Western North Atlantic bounded by the Bahama Escarpment (BE) between San Salvador Island and Samana Cay, referred here to the San Salvador abyssal plain. The transition area is locally referred to as Crooked Island Passage, loosely delineated by Crooked, Long, and Conception Islands, Rum and Samana Cays. Surprisingly in such a pure carbonate landscape, the newly established map reveals the detailed and complex morphology of a giant valley formed by numerous gravity flows originated in Exuma Sound itself, in addition to many secondary slope gullies and smaller tributaries draining the surrounding upper slopes. The valley referred here as the Exuma canyon system starts with a perched valley with low sinuosity, characterized by several flow restrictions and knickpoints initiated by the presence of drowned isolated platforms and merging tributaries. The valley abruptly transforms itself into a deep incised canyon, rivaling the depth of the Colorado Grand Canyon, through two major knickpoints with outsized chutes exceeding several hundred of meters in height, a total of 1600-1800 m. The sudden transformation of the wide valley into a deep narrow canyon, occurring when the flows incised deep into an underlying lower Cretaceous drowned carbonate platform, generates a huge hydraulic jump and creates an enormous plunge pool and related deposits with mechanisms comparable to the ones operating along giant subaerial waterfalls. The high kinetic flow energy, constrained by this narrow and deeply incised canyon, formed, when it is released at its mouth in the abyssal plain, a wide deep-sea channel with well-developed levees and fan, made of coarse-grained carbonate defined layers separated by fine carbonate sediments mixed with fine siliciclastics transported along the BE by the

  6. The Plains are Not Plain

    NASA Image and Video Library

    2016-06-01

    This image from NASA Mars Reconnaissance Orbiter spacecraft covers some of the plains south of Capri Chasma in eastern Valles Marineris. Where the aeolian (wind-blown) sedimentary cover has been stripped away, we see diverse colors indicative of of a variety of altered minerals formed in Mars' wetter past. http://photojournal.jpl.nasa.gov/catalog/PIA20730

  7. 3 CFR 8392 - Proclamation 8392 of June 12, 2009. National Oceans Month, 2009

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... and affect our lives in a variety of ways. This month we celebrate the wonder of the oceans, and we... supporting life. From the abyssal plains of the Pacific to the shallow coral reefs and seagrass beds of the Florida Keys, oceans support an incredible diversity of marine life and ecosystems. The base of the...

  8. Genetic variation in Great Plains Juniperus

    Treesearch

    David F. Van Haverbeke; Rudy M. King

    1990-01-01

    Fifth-year analyses of Great Plains Juniperus seed sources indicate eastern redcedar should be collected in east-central Nebraska for use throughout the Great Plains; Rocky Mountain juniper seed should be collected from northwest Nebraska, or central Montana, for planting southward through the Great Plains into west-central Kansas west of the 100th meridian.

  9. The Plains City Story

    ERIC Educational Resources Information Center

    van Olphen, Marcela; Rios, Francisco; Berube, William; Dexter, Robin; McCarthy, Robert

    2006-01-01

    This case study portrays a contemporary phenomenon that affects many U.S. school districts. Specifically, the authors address the challenges that the superintendent of the Plains City school district faced as a result of a change in the demographic distribution of his district. The gradual development of the pig farming industry in Plains City…

  10. Great plains, Chapter 11

    Treesearch

    C.M. Clark

    2011-01-01

    The North American Great Plains are the largest contiguous ecoregion in North America, covering 3.5 million square km2, or 16 percent of the continental area (CEC 1997). In the United States, the Great Plains ecoregion encompasses a roughly triangular region (Figure 2.2), bordered on the west by the Rocky Mountains and the southwestern deserts in...

  11. Reproduction among protobranch bivalves of the family Nuculidae from sublittoral, bathyal, and abyssal depths off the New England coast of North America

    NASA Astrophysics Data System (ADS)

    Scheltema, Rudolf S.; Williams, Isabelle P.

    2009-09-01

    Protobranch bivalve species of the family Nuculidae pass through either a planktonic lecithotrophic larval stage or a direct non-planktonic development. Oogenesis of the three sublittoral species examined is synchronous. Deposition of egg masses by Nucula delphinodonta and spawning by Nucula annulata and Nucula proxima occur only during summer months. Among the four bathyal and abyssal species, Ennucula similis, Ennucula granulosa, Deminucula atacellana, and Brevinucula verrilli, oogenesis is asynchronous and there is no discernable pattern of periodicity of spawning. Absence of periodicity in reproduction in these deep-sea species is confirmed by examination of individuals from dredge samples taken at different times of the year. The median apparent fecundity among both sublittoral and deep-sea species is directly related to size (i.e. shell length) and age. Among the Nuculidae the median apparent fecundity is greater among sublittoral than bathyal and abyssal species. The geographic distribution of a species depends on its capacity to disperse. The dispersal of the planktonic lecithotrophic larvae of the sublittoral species N. annulata and N. proxima is limited to the continental shelf of the northwestern Atlantic by inshore bottom circulation and because these very small planktonic larvae (<2.5 mm) lack the capacity to move vertically upward through the water column into the offshore currents. On the other hand, the bathyal and abyssal species having lecithotrophic larvae have a very wide amphi-Atlantic distribution extending from 60°N to 40°S latitude along the North and South American coasts and from 55°N to ca. 19°S from off Europe southwards to the coast of West Africa as a consequence of dispersal by planktonic lecithotrophic larvae along the seafloor. The amphi-Atlantic dispersal must occur stepwise between deep-sea populations (e.g., off Greenland). Such a geographic distribution indicates a widespread dispersal and is supported by the genetic

  12. Novel benthic foraminifera are abundant and diverse in an area of the abyssal equatorial Pacific licensed for polymetallic nodule exploration

    NASA Astrophysics Data System (ADS)

    Goineau, Aurélie; Gooday, Andrew J.

    2017-04-01

    The benthic biota of the Clarion-Clipperton Zone (CCZ, abyssal eastern equatorial Pacific) is the focus of a major research effort linked to possible future mining of polymetallic nodules. Within the framework of ABYSSLINE, a biological baseline study conducted on behalf of Seabed Resources Development Ltd. in the UK-1 exploration contract area (eastern CCZ, ~4,080 m water depth), we analysed foraminifera (testate protists), including ‘live’ (Rose Bengal stained) and dead tests, in 5 cores (0-1 cm layer, >150-μm fraction) recovered during separate megacorer deployments inside a 30 by 30 km seafloor area. In both categories (live and dead) we distinguished between complete and fragmented specimens. The outstanding feature of these assemblages is the overwhelming predominance of monothalamids, a group often ignored in foraminiferal studies. These single-chambered foraminifera, which include agglutinated tubes, spheres and komokiaceans, represented 79% of 3,607 complete tests, 98% of 1,798 fragments and 76% of the 416 morphospecies (live and dead combined) in our samples. Only 3.1% of monothalamid species and 9.8% of all species in the UK-1 assemblages are scientifically described and many are rare (29% singletons). Our results emphasise how little is known about foraminifera in abyssal areas that may experience major impacts from future mining activities.

  13. Tectonic and Sedimentation Interactions in the East Caribbean Subduction Zone: AN Overview from the Orinoco Delta to the Barbados Accretionary Prism

    NASA Astrophysics Data System (ADS)

    Deville, E.

    2011-12-01

    Recent marine geophysical acquisitions and piston-coring allow to better understand the close interactions between the sand-rich Orinoco turbidite system and the compressional structures of the Barbados prism. Because of the morphologic and tectonic control in the east-Caribbean active margin, the Orinoco turbiditic pattern system does not exhibit a classic fan geometry. The sea-floor geometry between the slope of the front of the Barbados prism and the slope of the South-American margin induces the convergence of the turbidite channels toward the abyssal plain, at the front of the accretionary prism. Also, whereas in most passive margins the turbidite systems are organized upstream to downstream as canyon, then channel-levee, then lobes, here, due to the tectonic control, the sedimentary system is organized as channel-levee, then canyons, then channelized lobes. At the edge of the Orinoco platform, the system has multiple sources with several distributaries and downward the channel courses are complex with frequent convergences or divergences that are emphasized by the effects of the undulating seafloor tectonic morphologies associated with active thrust tectonics and mud volcanism. On top of the accretionary prism, turbidite sediments are filling transported piggy-back basins whose timing of sedimentation vs. deformation is complex. Erosion processes are almost absent on the highly subsiding Orinoco platform and in the upper part of the turbidite system. Erosion processes develop mostly between 2000 and 4000 m of water depth, above the compressional structures of the Barbados prism (canyons up to 3 km wide and 300 m deep). In the abyssal plain, turbiditic channels develop on very long distance (> 1000 km) joining the mid-Atlantic channel (sourced mostly by the Amazon), filling several elongated basins corresponding to transform faults (notably the Barracuda Basin), and finally sourcing the Puerto-Rico trench, the deepest morphologic depression of this region

  14. From the epipelagic zone to the abyss: Trophic structure at two seamounts in the subtropical and tropical Eastern Atlantic - Part I zooplankton and micronekton

    NASA Astrophysics Data System (ADS)

    Denda, Anneke; Stefanowitsch, Benjamin; Christiansen, Bernd

    2017-12-01

    Specific mechanisms, driving trophic interactions within the pelagic community may be highly variable in different seamount systems. This study investigated the trophic structure of zooplankton and micronekton above and around Ampère and Senghor, two shallow seamounts in the subtropical and tropical Eastern Atlantic, and over the adjacent abyssal plains. For the identification of food sources and trophic positions stable isotope ratios (δ13C and δ15N) were used. δ13C ranged from -24.7‰ to -15.0‰ and δ15N covered a total range of 0.9-15.9‰. Based on epipelagic particulate organic matter, zooplankton and micronekton usually occupied the 1st-3rd trophic level, including herbivorous, omnivorous and carnivorous taxa. δ13C and δ15N values were generally lower in zooplankton and micronekton of the subtropical waters as compared to the tropical region, due to the differing nutrient availability and phytoplankton communities. Correlations between δ13C and δ15N values of particulate organic matter, zooplankton, micronekton and benthopelagic fishes suggest a linear food chain based on a single energy source from primary production for Ampère Seamount, but no evidence was found for an autochthonus seamount production as compared to the open ocean reference site. Between Senghor Seamount and the open ocean δ13C signatures indicate that hydrodynamic effects at seamounts may modify the energy supply at times, but evidence for a seamount effect on the trophic structure of the pelagic communities was weak, which supports the assumption that seamount communities rely to a large extent on advected food sources.

  15. Origin of lunar light plains

    NASA Technical Reports Server (NTRS)

    Chao, E. C. T.; Hodges, C. A.; Boyce, J. M.; Soderblom, L. A.

    1975-01-01

    In order to determine the origin of Cayley-type lunar light plains, their physical properties, distribution, and relative ages are examined from Apollo orbital and Lunar Orbiter photographs. The distribution and apparent age of the plains deposits and data on highly feldspathic breccias indicate that these superficial materials are neither locally derived nor part of the Imbrium ejecta. The existence of a planar facies of continuous ejecta at Orientale and in the ejecta blankets of small craters is demonstrated. The data and interpretation presented support the hypothesis that the surface and near-surface materials of some light plains, including those at the Apollo 16 site, are at least partly composed of ejecta from the Orientale basin and that the materials of many rugged areas, such as the Descartes highlands, are overlain by similar material. The possibility that some Cayley-type plains may have a different origin is not excluded.

  16. 44 CFR 10.14 - Flood plains and wetlands.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 44 Emergency Management and Assistance 1 2010-10-01 2010-10-01 false Flood plains and wetlands. 10... Flood plains and wetlands. For any action taken by FEMA in a flood plain or wetland, the provisions of... Executive Order 11988, Flood Plain Management, and Executive Order 11990, Protection of Wetlands (44 CFR...

  17. River flood plains: Some observations on their formation

    USGS Publications Warehouse

    Wolman, M. Gordon; Leopold, Luna Bergere

    1957-01-01

    On many small rivers and most great rivers, the flood plain consists of channel and overbank deposits. The proportion of the latter is generally very small.Frequency studies indicate that the flood plains of many streams of different sizes flowing in diverse physiographic and climatic regions are subject to flooding about once a year.The uniform frequency of flooding of the flood-plain surface and the small amount of deposition observed in great floods (average 0.07 foot) support the conclusion that overbank deposition contributes only a minor part of the material constituting the flood plain. The relatively high velocities (1 to 4 fps) which can occur in overbank flows and the reduction in sediment concentration which often accompanies large floods may also help account for this. Although lateral migration of channels is important in controlling the elevation of the flood plain, rates of migration are extremely variable and alone cannot account for the uniform relation the flood-plain surface bears to the channel.Detailed studies of flood plains in Maryland and in North Carolina indicate that it is difficult to differentiate between channel and overbank deposits in a stratigraphic section alone.Because deposition on the flood plain does not continue indefinitely, the flood-plain surface can only be transformed into a terrace surface by some tectonic or climatic change which alters the regimen of the river and causes it to entrench itself below its established bed and associated flood plain. A terrace, then, is distinguished from a flood plain by the frequency with which each is overflowed.

  18. 12 CFR 611.1217 - Plain language requirements.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 12 Banks and Banking 6 2011-01-01 2011-01-01 false Plain language requirements. 611.1217 Section 611.1217 Banks and Banking FARM CREDIT ADMINISTRATION FARM CREDIT SYSTEM ORGANIZATION Termination of System Institution Status § 611.1217 Plain language requirements. (a) Plain language presentation. All...

  19. 12 CFR 611.1217 - Plain language requirements.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 12 Banks and Banking 6 2010-01-01 2010-01-01 false Plain language requirements. 611.1217 Section 611.1217 Banks and Banking FARM CREDIT ADMINISTRATION FARM CREDIT SYSTEM ORGANIZATION Termination of System Institution Status § 611.1217 Plain language requirements. (a) Plain language presentation. All...

  20. Origin of salt giants in abyssal serpentinite systems

    NASA Astrophysics Data System (ADS)

    Scribano, Vittorio; Carbone, Serafina; Manuella, Fabio C.; Hovland, Martin; Rueslåtten, Håkon; Johnsen, Hans-K.

    2017-10-01

    Worldwide marine salt deposits ranging over the entire geological record are generally considered climate-related evaporites, derived from the precipitation of salts (mainly chlorides and sulfates) from saturated solutions driven by solar evaporation of seawater. This explanation may be realistic for a salt thickness ≤100 m, being therefore inadequate for thicker (>1 km) deposits. Moreover, sub-seafloor salt deposits in deep marine basins are difficult to reconcile with a surface evaporation model. Marine geology reports on abyssal serpentinite systems provide an alternative explanation for some salt deposits. Seawater-driven serpentinization consumes water and increases the salinity of the associated aqueous brines. Brines can be trapped in fractures and cavities in serpentinites and the surrounding `country' rocks. Successive thermal dehydration of buried serpentinites can mobilize and accumulate the brines, forming highly saline hydrothermal solutions. These can migrate upwards and erupt onto the seafloor as saline geysers, which may form salt-saturated water pools, as are currently observed in numerous deeps in the Red Sea and elsewhere. The drainage of deep-seated saline brines to seafloor may be a long-lasting, effective process, mainly occurring in areas characterized by strong tectonic stresses and/or igneous intrusions. Alternatively, brines could be slowly expelled from fractured serpentinites by buoyancy gradients and, hence, separated salts/brines could intrude vertically into surrounding rocks, forming salt diapirs. Serpentinization is an ubiquitous, exothermic, long-lasting process which can modify large volumes of oceanic lithosphere over geological times. Therefore, buried salt deposits in many areas of the world can be reasonably related to serpentinites.

  1. 27 CFR 9.207 - Outer Coastal Plain.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Outer Coastal Plain. (a) Name. The name of the viticultural area described in this section is “Outer...,000 scale. (c) Boundary. The Outer Coastal Plain viticultural area includes all of Cumberland, Cape... Counties in the State of New Jersey. The boundary of the Outer Coastal Plain viticultural area is as...

  2. Depopulation of the Northern Plains Natives.

    PubMed

    Decker, J F

    1991-01-01

    Nine major epidemics of acute infectious diseases swept the Northern Plains of the Western Interior of Canada between 1774 and 1839. The Blackfeet, Plains Cree and Assiniboin, Atsina and Saulteaux who exploited the Plains were differentially exposed to these epidemics of smallpox, measles, whooping cough and influenza. Mortality estimates from these epidemics were used in assessing the degree to which a series of epidemics contributed to depopulation of the Plains Natives. A criteria was established to determine an epidemic from a depopulation epidemic, which involved among other factors, the determination of age-selective mortality. The analysis concludes that despite the fact several Native groups exploited, and in some cases co-resided in a similar ecological area, they suffered differential mortality and depopulation rates.

  3. Evaluation of abyssal meiobenthos in the eastern central Pacific (Clarion-Clipperton fracture zone)

    NASA Astrophysics Data System (ADS)

    Renaud-Mornant, Jeanne; Gourbault, Nicole

    Meiobenthos were sampled from 17 stations in the abyssal deep-sea system of the central Pacific centered around 14°N, 130°W at depths 4960-5154m, during the Nixo 47 R/V Jean Charcot cruise. Meiofaunal density range from 45-89 ind. 10cm 2. Predominant taxa are nematodes (84-100%) and copepods (0-10%). Rotifera, Polychaeta, and Acarina also occur. Nematodes are uniformly distributed spatially with 45 species or so; Monhysteridae is the dominant taxon, and Syringolaimus sp. (Ironidae) co-occurs faithfully. Low biomass (0.4-70.6μg 10cm 2) are attributed to supposed dwarfism of metazoan meiofauna and very high proportion (60-80%) of juveniles and pre-adult forms. The majority of protozoans and metazoans are detritus- or deposit-feeders; in addition symbiotic associations, coprophagy and gardening activities are frequent. In such an oligotrophic environment, low food supply may limit meiofaunal abundance, biomass and maturation, and to a lesser extent species richness.

  4. Abyssal fauna of the UK-1 polymetallic nodule exploration area, Clarion-Clipperton Zone, central Pacific Ocean: Mollusca

    PubMed Central

    Wiklund, Helena; Taylor, John D.; Dahlgren, Thomas G.; Todt, Christiane; Ikebe, Chiho; Rabone, Muriel; Glover, Adrian G.

    2017-01-01

    Abstract We present the first DNA taxonomy publication on abyssal Mollusca from the Clarion-Clipperton Zone (CCZ), central Pacific ocean, using material collected as part of the Abyssal Baseline (ABYSSLINE) environmental survey cruise ‘AB01’ to the UK Seabed Resources Ltd (UKSRL) polymetallic-nodule exploration area ‘UK-1’ in the eastern CCZ. This is the third paper in a series to provide regional taxonomic data for a region that is undergoing intense deep-sea mineral exploration for high-grade polymetallic nodules. Taxonomic data are presented for 21 species from 42 records identified by a combination of morphological and genetic data, including molecular phylogenetic analyses. These included 3 heterodont bivalves, 5 protobranch bivalves, 4 pteriomorph bivalves, 1 caudofoveate, 1 monoplacophoran, 1 polyplacophoran, 4 scaphopods and 2 solenogastres. Gastropoda were recovered but will be the subject of a future study. Seven taxa matched published morphological descriptions for species with deep Pacific type localities, and our sequences provide the first genetic data for these taxa. One taxon morphologically matched a known cosmopolitan species but with a type locality in a different ocean basin and was assigned the open nomenclature ‘cf’ as a precautionary approach in taxon assignments to avoid over-estimating species ranges. One taxon is here described as a new species, Ledella knudseni sp. n. For the remaining 12 taxa, we have determined them to be potentially new species, for which we make the raw data, imagery and vouchers available for future taxonomic study. The Clarion-Clipperton Zone is a region undergoing intense exploration for potential deep-sea mineral extraction. We present these data to facilitate future taxonomic and environmental impact study by making both data and voucher materials available through curated and accessible biological collections. PMID:29118626

  5. Environmental and bathymetric influences on abyssal bait-attending communities of the Clarion Clipperton Zone

    NASA Astrophysics Data System (ADS)

    Leitner, Astrid B.; Neuheimer, Anna B.; Donlon, Erica; Smith, Craig R.; Drazen, Jeffrey C.

    2017-07-01

    The Clarion-Clipperton Zone (CCZ) is one of the richest manganese nodule provinces in the world and has recently become a focus area for manganese nodule mining interests. However, this vast area remains poorly studied and highly undersampled. In this study, the abyssal bait-attending fauna is documented for the first time using a series of baited camera deployments in various locations across the CCZ. A bait-attending community intermediate between those typical of the California margin and Hawaii was found in the larger CCZ area, generally dominated by rattail fishes, dendrobranchiate shrimp, and zoarcid and ophidiid fishes. Additionally, the western and eastern ends of the CCZ had different communities, with the western region characterized by decreased dominance of rattails and small shrimps and increased dominance of ophidiids (especially Bassozetus sp. and Barathrites iris) and large shrimps. This trend may be related to increasing distance from the continental margin. We also test the hypothesis that bait-attending communities change across the CCZ in response to key environmental predictors, especially topography and nodule cover. Our analyses showed that higher nodule cover and elevated topography, as quantified using the benthic positioning index (BPI), increase bait-attending community diversity. Elevated topography generally had higher relative abundances, but taxa also showed differing responses to the BPI metric and bottom temperature, causing significant community compositional change over varying topography and temperatures. Larger individuals of the dominant scavenger in the CCZ, Coryphaenoides spp., were correlated with areas of higher nodule cover and with abyssal hills, suggesting these areas may be preferred habitat. Our results suggest that nodule cover is important to all levels of the benthic ecosystem and that nodule mining could have negative impacts on even the top-level predators and scavengers in the CCZ. Additionally, there is

  6. Chenier plain development: feedbacks between waves, mud and sand

    NASA Astrophysics Data System (ADS)

    Nardin, W.; Fagherazzi, S.

    2015-12-01

    Cheniers are sandy ridges parallel to the coast established by high energy waves. Here we discuss Chenier plains ontogeny through dimensional analysis and numerical results from the morphodynamic model Delft3D-SWAN. Our results show that wave energy and shelf slope play an important role in the formation of Chenier plains. In our numerical experiments waves affect Chenier plain development in three ways: by winnowing sediment from the mudflat, by eroding mud and accumulating sand over the beach during extreme wave events. We further show that different sediment characteristics and wave climates can lead to three alternative coastal landscapes: strand plains, mudflats, or the more complex Chenier plains. Low inner-shelf slopes are the most favorable for strand plain and Chenier plain formation, while high slopes decrease the likelihood of mudflat development and preservation.

  7. Diversity and Biogeography of Bathyal and Abyssal Seafloor Bacteria

    PubMed Central

    Bienhold, Christina; Zinger, Lucie; Boetius, Antje; Ramette, Alban

    2016-01-01

    The deep ocean floor covers more than 60% of the Earth’s surface, and hosts diverse bacterial communities with important functions in carbon and nutrient cycles. The identification of key bacterial members remains a challenge and their patterns of distribution in seafloor sediment yet remain poorly described. Previous studies were either regionally restricted or included few deep-sea sediments, and did not specifically test biogeographic patterns across the vast oligotrophic bathyal and abyssal seafloor. Here we define the composition of this deep seafloor microbiome by describing those bacterial operational taxonomic units (OTU) that are specifically associated with deep-sea surface sediments at water depths ranging from 1000–5300 m. We show that the microbiome of the surface seafloor is distinct from the subsurface seafloor. The cosmopolitan bacterial OTU were affiliated with the clades JTB255 (class Gammaproteobacteria, order Xanthomonadales) and OM1 (Actinobacteria, order Acidimicrobiales), comprising 21% and 7% of their respective clades, and about 1% of all sequences in the study. Overall, few sequence-abundant bacterial types were globally dispersed and displayed positive range-abundance relationships. Most bacterial populations were rare and exhibited a high degree of endemism, explaining the substantial differences in community composition observed over large spatial scales. Despite the relative physicochemical uniformity of deep-sea sediments, we identified indicators of productivity regimes, especially sediment organic matter content, as factors significantly associated with changes in bacterial community structure across the globe. PMID:26814838

  8. Geochemical impacts of waste disposal on the abyssal seafloor

    NASA Astrophysics Data System (ADS)

    Jahnke, Richard A.

    1998-05-01

    The response of pore water oxygen, nitrate, sulfate, sulfide, ammonium and methane and particulate organic carbon distributions to the input of 8.5 million m 3 (3.8×10 12 g) of organic-rich waste materials is simulated. The deposit is assumed to be conical with a maximum thickness of approximately 20 m. Remineralization reactions within the deposit rapidly deplete any initially available pore water oxidants such as oxygen, nitrate and sulfate, and are subsequently dominated by fermentation reactions. Diffusion downward of reduced metabolites, sulfide, ammonium and methane, depletes the available oxidants in the pore waters below the waste pile, increasing the thickness of the anoxic layer. While the impacted region is limited to essentially the deposition site, recovery of the pore waters is estimated to be >10 4 years. The overall computational results are corroborated by the pore water distributions observed at turbidite boundaries. Numerous uncertainties in the parameterizations limit the overall accuracy of the calculations presented. The most significant of these are: (1) A quantitatively accurate assessment of the remineralization rate of the deposited organic matter including its rate of inoculation by abyssal microorganisms; (2) a detailed assessment of potential non-diffusive pore water transport processes including advection due to compaction and buoyancy-driven flows and enhanced exchange due to macrobenthic irrigation activities and (3) an assessment of the potential alteration of pore space and methane reactivity due to gas hydrate formation.

  9. Great Plains Drought in Simulations of Twentieth Century

    NASA Astrophysics Data System (ADS)

    McCrary, R. R.; Randall, D. A.

    2008-12-01

    The Great Plains region of the United States was influenced by a number of multi-year droughts during the twentieth century. Most notable were the "Dust Bowl" drought of the 1930s and the 1950s Great Plains drought. In this study we evaluate the ability of three of the Coupled Global Climate Models (CGCMs) used in the Fourth Assessment Report (AR4) of the IPCC to simulate Great Plains drought with the same frequency and intensity as was observed during the twentieth century. The models chosen for this study are: GFDL CM 2.0, NCAR CCSM3, and UKMO HadCM3. We find that the models accurately capture the climatology of the hydrologic cycle of the Great Plains, but that they tend to overestimate the variability in Great Plains precipitation. We also find that in each model simulation at least one long-term drought occurs over the Great Plains region during their representations 20th Century Climate. The multi-year droughts produced by the models exhibit similar magnitudes and spatial scales as was observed during the twentieth century. This study also investigates the relative roles that external forcing from the tropical Pacific and local feedbacks between the land surface and the atmosphere have in the initiation and perpetuation of Great Plains drought in each model. We find that cool, La Nina-like conditions in the tropical pacific are often associated with long-term drought conditions over the Great Plains in GFDL CM 2.0 and UKMO HadCM3, but there appears to be no systematic relationship between tropical Pacific SST variability and Great Plains drought in CCSM3. It is possible the strong coupling between the land surface and the atmosphere in the NCAR model causes precipitation anomalies to lock into phase over the Great Plains thereby perpetuating drought conditions. Results from this study are intended to help assess whether or not these climate models are credible for use in the assessment of future drought over the Great Plains region of the United States.

  10. Expansive Northern Volcanic Plains

    NASA Image and Video Library

    2015-04-16

    Mercury northern region is dominated by expansive smooth plains, created by huge amounts of volcanic material flooding across Mercury surface in the past, as seen by NASA MESSENGER spacecraft. The volcanic lava flows buried craters, leaving only traces of their rims visible. Such craters are called ghost craters, and there are many visible in this image, including a large one near the center. Wrinkle ridges cross this scene and small troughs are visible regionally within ghost craters, formed as a result of the lava cooling. The northern plains are often described as smooth since their surface has fewer impact craters and thus has been less battered by such events. This indicates that these volcanic plains are younger than Mercury's rougher surfaces. Instrument: Mercury Dual Imaging System (MDIS) Center Latitude: 60.31° N Center Longitude: 36.87° E Scale: The large ghost crater at the center of the image is approximately 103 kilometers (64 miles) in diameter http://photojournal.jpl.nasa.gov/catalog/PIA19415

  11. Subsidence driving forces in large Delta Plain

    NASA Astrophysics Data System (ADS)

    Grall, C.; Steckler, M. S.

    2017-12-01

    Recent studies show large variability in subsidence rates among large delta plains that directly impact coastal management of these highly vulnerable environments. Observations show both significant spatial variation in subsidence across each delta, as well as large differences in magnitude between different deltas. This variability raises the question of what are the driving forces that control subsidence in large delta plains that this study aims to address. Subsidence and sediment compaction is studied in 4 end-member large Delta Plains: the Ganges-Brahmaputra, the Mekong, the Mississippi and the Nile. Those large delta plains drastically contrast in subsidence rates (from values to several mm/yr to several cm/yr), in the nature of the sediment (notably in clay and organic matter content), and in the volume of sediment supplied by the large rivers that feed those coastal environments. The volume of sediment deposited in each delta plain during the Holocene is estimated and the compaction of the underlying sedimentary column is computed by using a backstripping approach. Sediment compaction behaviors are defined accordingly to the observed clay, silt and organic contents, and the rate of subsidence associated with compaction is determined. Results suggest that about 2/3 of observed Holocene subsidence may be associated with the mechanical and chemical compaction of the underlying sedimentary column due to the load of sediment deposited. The compaction appears to be significantly higher in delta plains characterized by a high sediment input and a high organic matter and clay content. Thus, the observed subsidence rates in the (muddy) Mekong delta appear to be one order of magnitude higher than other delta plains. In contrast, subsidence rates are modest in the Ganges-Brahmaputra, the Mississippi and the Nile delta plains, except away from the major rivers where deposits are muddier.

  12. Flood information for flood-plain planning

    USGS Publications Warehouse

    Bue, Conrad D.

    1967-01-01

    Floods are natural and normal phenomena. They are catastrophic simply because man occupies the flood plain, the highwater channel of a river. Man occupies flood plains because it is convenient and profitable to do so, but he must purchase his occupancy at a price-either sustain flood damage, or provide flood-control facilities. Although large sums of money have been, and are being, spent for flood control, flood damage continues to mount. However, neither complete flood control nor abandonment of the flood plain is practicable. Flood plains are a valuable resource and will continue to be occupied, but the nature and degree of occupancy should be compatible with the risk involved and with the degree of protection that is practicable to provide. It is primarily to meet the needs for defining the risk that the flood-inundation maps of the U.S. Geological Survey are prepared.

  13. High Plains Regional Ground-water Study web site

    USGS Publications Warehouse

    Qi, Sharon L.

    2000-01-01

    Now available on the Internet is a web site for the U.S. Geological Survey's (USGS) National Water-Quality Assessment (NAWQA) Program-High Plains Regional Ground-Water Study. The purpose of the web site is to provide public access to a wide variety of information on the USGS investigation of the ground-water resources within the High Plains aquifer system. Typical pages on the web site include the following: descriptions of the High Plains NAWQA, the National NAWQA Program, the study-area setting, current and past activities, significant findings, chemical and ancillary data (which can be downloaded), listing and access to publications, links to other sites about the High Plains area, and links to other web sites studying High Plains ground-water resources. The High Plains aquifer is a regional aquifer system that underlies 174,000 square miles in parts of eight States (Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming). Because the study area is so large, the Internet is an ideal way to provide project data and information on a near real-time basis. The web site will be a collection of living documents where project data and information are updated as it becomes available throughout the life of the project. If you have an interest in the High Plains area, you can check this site periodically to learn how the High Plains NAWQA activities are progressing over time and access new data and publications as they become available.

  14. Rapid changes and long-term cycles in the benthic megafaunal community observed over 24 years in the abyssal northeast Pacific

    NASA Astrophysics Data System (ADS)

    Kuhnz, Linda A.; Ruhl, Henry A.; Huffard, Christine L.; Smith, Kenneth L.

    2014-05-01

    The abyssal seafloor community in the NE Pacific (Station M, ∼4000 m depth) was studied between 2006 and 2012 using remotely operated vehicles (ROVs) as part of a continuing 24-year time-series study. New patterns continue to emerge showing that the deep-sea can be dynamic on short time scales, rather than static over long periods. In just over 2 years the community shifted from a sessile, suspension-feeding, sponge-dominated community to a mobile, detritus-feeding, sea cucumber-dominated assemblage. In 2006 megafaunal diversity (Simpson’s Diversity Index, SDI) was high, yet the community was depauperate in terms of density compared to later periods. Over an 18-month period beginning in spring 2011, the densities of mobile organisms increased by nearly an order of magnitude while diversity decreased below 2006 levels. In late 2012 four sea cucumbers (two Peniagone spp., Elpidia sp. A, and Scotoplanes globosa) were at the highest densities recorded since investigations began at Station M in 1989. For a group of 10 echinoderms investigated over the entire study period, we saw evidence of a long-term cycle spanning 2 decades. These changes can be tied to a variable food supply originating in shallow water. Large variations over decadal-scales indicate that remote abyssal communities are dynamic and likely subject to impacts from anthropogenic changes like ocean warming, acidification, and pollution manifested in the upper ocean. The degree of dynamism indicates that one-time or short-term investigations are not sufficient for assessing biological community structure in conservation or exploitation studies in the deep sea.

  15. Meiofauna communities along an abyssal depth gradient in the Drake Passage

    NASA Astrophysics Data System (ADS)

    Gutzmann, E.; Martínez Arbizu, P.; Rose, A.; Veit-Köhler, G.

    2004-07-01

    Meiofauna standing stocks and community structure are reported for the first time for abyssal soft-sediment samples in Antarctic waters. At seven stations within a depth range of 2274-5194 m a total of 128 sediment cores were retrieved with a multiple corer (MUC) on board of the R.V. Polarstern during the ANDEEP-1 cruise (ANT XIX/3). The metazoan meiofauna (defined by a lower size limit of 40 μm) was identified and counted, and one core per station was preserved for CPE, C/N, TOM and grain size analyses. Meiofauna densities are in the range of 2731 Ind./10 cm 2 at 2290 m depth and 75 Ind./10 cm 2 at 3597 m depth, with nematodes being the dominant group at all stations. Nematodes account for 84-94% followed by copepods with 2-8% of the total meiofauna. Other frequent taxa found at each station are kinorhynchs, loriciferans, tantulocarids, ostracods and tardigrades. There is a general tendency of decreasing abundances of metazoan meiofauna with increasing depth, but not all higher level taxa displayed this pattern. In addition, a tendency of decreasing higher taxon density with increasing depth was observed. Standing stocks are higher than the average found at similar depths in other oceans.

  16. KM3NeT-ORCA: Oscillation Research with Cosmics in the Abyss

    NASA Astrophysics Data System (ADS)

    Coyle, Paschal; KM3NeT Collaboration

    2017-09-01

    KM3NeT, currently under construction in the abysses of the Mediterranean Sea, is a distributed research infrastructure that will host a km3-scale neutrino telescope (ARCA) for high-energy neutrino astronomy, and a megaton scale detector (ORCA) for neutrino oscillation studies of atmospheric neutrinos. ORCA is optimised for a measurement of the mass hierarchy, providing a sensitivity of 3σ after 3-4 years. It will also measure the atmospheric mixing parameters Δm2 atm and θ23 with a precision comparable to the NOvA and T2K experiments using both the muon neutrino disappearance and tau neutrino appearance channels. It will provide a measurement of the tau neutrino appearance rate with better than 10% precision, a crucial ingredient for tests of unitarity. It will probe the octant of the mixing angle θ23 via matter resonance effects on neutrinos and antineutrinos crossing the core and mantle, which are largely independent on the CP phase. The observation of neutrino oscillations over a wide range of baselines and energies will provide broad sensitivity to new physics such as non-standard neutrino interactions (NSI) and sterile neutrinos.

  17. Community change in the variable resource habitat of the abyssal northeast Pacific.

    PubMed

    Ruhl, Henry A

    2008-04-01

    Research capable of differentiating resource-related community-level change from random ecological drift in natural systems has been limited. Evidence for nonrandom, resource-driven change is presented here for an epibenthic megafauna community in the abyssal northeast Pacific Ocean from 1989 to 2004. The sinking particulate organic carbon food supply is linked not only to species-specific abundances, but also to species composition and equitability. Shifts in rank abundance distributions (RADs) and evenness, from more to less equitable, correlated to increased food supply during La Niña phases of the El Niño Southern Oscillation. The results suggest that each taxon exhibited a differential response to a sufficiently low dimension resource, which led to changes in community composition and equitability. Thus the shifts were not likely due to random ecological drift. Although the community can undergo population-level variations of one or more orders of magnitude, and the shape of the RADs was variable, the organization retained a significant consistency, providing evidence of limits for such changes. The growing evidence for limited resource-driven changes in RADs and evenness further emphasizes the potential importance of temporally variable disequilibria in understanding why communities have certain basic attributes.

  18. The geomorphology of the Mississippi River chenier plain

    USGS Publications Warehouse

    Penland, S.; Suter, J.R.

    1989-01-01

    The chenier plain of the Mississippi River is a shore-parallel zone of alternating transgressive clastic ridges separated by progradational mudflats. The term chenier is derived from the cajun term chene for oak, the tree species that colonizes the crests of the higher ridges. The Mississippi River chenier plain stretches 200 km from Sabine Pass, Texas, to Southwest Point, Louisiana and ranges between 20 and 30 km wide, with elevations of 2-6 m. The timing and the process of formation could be re-evaluated in the light of new chronostratigraphic findings in the Mississippi River delta plain. The stratigraphic relationship between the Teche and Lafourche delta complexes and Ship Shoal offshore indicates that these delta complexes belong to different delta plains that developed at different sealevels. It appears that the Teche delta complex is associated with the late Holocene delta plain which developed 7000 to 3000 yrs B.P. when sealevel stood 5-6 m lower than present. A regional transgression occurred between approximately 3000 BP and 2500 yrs B.P., leading to the transgressive submergence of the late Holocene delta plain, producing the regional Teche shoreline. The timing of this transgression conforms to the age of the most landward ridge in the chenier plain, the Little Chenier-Little Pecan Island trend, which dates at about 2500 yrs B.P. This ridge trend was originally interpreted as representing the Teche delta complex switching event with the landward Holocene/Pleistocene contact representing the high stand shoreline. The implication of this new interpretation is that the Little Chenier-Little Pecan Island trend represents the high stand shoreline, a continuation of the Teche shoreline separating the late Holocene and Recent delta plains, and that the Holocene/Pleistocene contact represents the leading edge of the marshes transgressing onto the Prairie Terrace. Significant mudflat progradation seems to require a westerly position of the Mississippi River

  19. The geologic story of the Great Plains

    USGS Publications Warehouse

    Trimble, Donald E.

    1980-01-01

    For more than half a century after Lewis and Clark crossed the country in 1805-6, the Great Plains was the testing ground of frontier America here America grew to maturity (fig. 1). In 1805-7, explorer Zebulon Pike crossed the southcentral Great Plains, following the Arkansas River from near Great Bend, Kans., to the Rocky Mountains. In later years, Santa Fe traders, lured by the wealth of New Mexican trade, followed Pike's path as far as Bents Fort, Colo., where they turned southwestward away from the river route. Those pioneers who later crossed the plains on the Oregon Trail reached the Platte River near the place that would become Kearney, Nebr., by a nearly direct route from Independence, Mo., and followed the Platte across the central part of the Great Plains.

  20. Cetacean Community Ecology in the Waters of Sri Lanka and the Bay of Bengal

    DTIC Science & Technology

    2014-09-30

    dolphins, “blackfish” (pilot, melon-headed, and false killer whales ), sperm whales , beaked whales , pygmy and dwarf sperm whales , and several baleen... whale species occur over the continental slope and abyssal plain of the oceanic Bay (Leatherwood et al. 1984, Ballance and Pittman 1998, de Boer et...al. 2002). Among all the cetaceans, the presence of baleen whales in this low-latitude habitat, including blue, humpback, fin, minke, and Bryde’s

  1. Cetacean Community Ecology in the Waters of Sri Lanka and the Bay of Bengal

    DTIC Science & Technology

    2013-09-30

    variety of oceanic dolphins, “blackfish” (pilot, melon-headed, and false killer whales ), sperm whales , beaked whales , pygmy and dwarf sperm whales , and...several baleen whale species occur over the continental slope and abyssal plain of the oceanic Bay (Leatherwood et al. 1984, Ballance and Pittman 1998...de Boer et al. 2002). Among all the cetaceans, the presence of baleen whales in this low-latitude habitat, including blue, humpback, fin, minke

  2. Suspended particulate loads and transports in the nepheloid layer of the abyssal Atlantic Ocean

    USGS Publications Warehouse

    Biscaye, P.E.; Eittreim, S.L.

    1977-01-01

    Vertical profiles of light scattering from over 1000 L-DGO nephelometer stations in the Atlantic Ocean have been used to calculate mass concentrations of suspended particles based on a calibration from the western North American Basin. 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 Atlantic. 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

  3. Geochemical signature of provenance, tectonics and chemical weathering in the Quaternary flood plain sediments of the Hindon River, Gangetic plain, India

    NASA Astrophysics Data System (ADS)

    Mondal, M. E. A.; Wani, H.; Mondal, Bulbul

    2012-09-01

    The Ganga basin in the Himalayan foreland is a part of the world's largest area of modern alluvial sedimentation. Flood plain sediments of the Hindon River of the Gangetic plain have been analyzed for sediment texture, major and trace elements including rare earth elements (REEs). The results have been used to characterize the source rock composition and to understand the intensity of chemical weathering, tectonics and their interplay in the Hindon flood plain. The sediments of the Hindon flood plain dominantly consist of sand sized particles with little silt and clay. The geochemistry of the Hindon sediments has been compared to the Siwalik mudstone of the Siwalik Group (Siwaliks). The Siwalik sedimentary rocks like sandstones, mudstones and conglomerates are the known source rocks for the Hindon flood plain sediments. Mudstone geochemistry has been considered best to represent the source rock characteristics. The UCC (Upper Continental Crust) normalized major and trace elements of the Hindon flood plain sediments are very similar to the Siwalik mudstone except for Th and Cr. Furthermore, the average chondrite normalized REE pattern of the Hindon flood plain sediments is similar to the Siwalik mudstone. Textural immaturity, K/Rb ratios and the average CIA (Chemical Index of Alteration) and PIA (Plagioclase Index of Alteration) values of the Hindon flood plain sediments indicate that the sediments have not been affected by chemical weathering. Our study suggests that the active tectonics of the Himalayas and monsoon climate enhances only physical erosion of the source rocks (Siwaliks) rather than the chemical alteration. These factors help the Hindon sediments to retain their parental and tectonic signature even after recycling.

  4. Deep ocean communities impacted by changing climate over 24 y in the abyssal northeast Pacific Ocean.

    PubMed

    Smith, Kenneth L; Ruhl, Henry A; Kahru, Mati; Huffard, Christine L; Sherman, Alana D

    2013-12-03

    The deep ocean, covering a vast expanse of the globe, relies almost exclusively on a food supply originating from primary production in surface waters. With well-documented warming of oceanic surface waters and conflicting reports of increasing and decreasing primary production trends, questions persist about how such changes impact deep ocean communities. A 24-y time-series study of sinking particulate organic carbon (food) supply and its utilization by the benthic community was conducted in the abyssal northeast Pacific (~4,000-m depth). Here we show that previous findings of food deficits are now punctuated by large episodic surpluses of particulate organic carbon reaching the sea floor, which meet utilization. Changing surface ocean conditions are translated to the deep ocean, where decadal peaks in supply, remineralization, and sequestration of organic carbon have broad implications for global carbon budget projections.

  5. Deep ocean communities impacted by changing climate over 24 y in the abyssal northeast Pacific Ocean

    PubMed Central

    Smith, Kenneth L.; Ruhl, Henry A.; Kahru, Mati; Huffard, Christine L.; Sherman, Alana D.

    2013-01-01

    The deep ocean, covering a vast expanse of the globe, relies almost exclusively on a food supply originating from primary production in surface waters. With well-documented warming of oceanic surface waters and conflicting reports of increasing and decreasing primary production trends, questions persist about how such changes impact deep ocean communities. A 24-y time-series study of sinking particulate organic carbon (food) supply and its utilization by the benthic community was conducted in the abyssal northeast Pacific (∼4,000-m depth). Here we show that previous findings of food deficits are now punctuated by large episodic surpluses of particulate organic carbon reaching the sea floor, which meet utilization. Changing surface ocean conditions are translated to the deep ocean, where decadal peaks in supply, remineralization, and sequestration of organic carbon have broad implications for global carbon budget projections. PMID:24218565

  6. 'Endurance' Goal Across the Plains

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This mosaic image from the Mars Exploration Rover Opportunity's panoramic camera provides an overview of the rover's drive direction toward 'Endurance Crater,' which is in the upper right corner of image.

    The plains appear to be uniform in character from the rovers current position all the way to Endurance Crater. Granules of various sizes blanket the plains. Spherical granules fancifully called blueberries are present some intact and some broken. Larger granules pave the surface, while smaller grains, including broken blueberries, form small dunes. Randomly distributed 1-centimeter (0.4 inch) sized pebbles (as seen just left of center in the foreground of the image) make up a third type of feature on the plains. The pebbles' composition remains to be determined. Scientists plan to examine these in the coming sols.

    Examination of this part of Mars by NASA's Mars Global Surveyor orbiter revealed the presence of hematite, which led NASA to choose Meridiani Planum as Opportunity's landing site. The rover science conducted on the plains of Meridiani Planum serves to integrate what the rovers are seeing on the ground with what orbital data have shown.

    Opportunity will make stop at a small crater called 'Fram' (seen in the upper left, with relatively large rocks nearby) before heading to the rim of Endurance Crater.

  7. Geologic history of the Cerberus Plains, Mars

    NASA Astrophysics Data System (ADS)

    Lanagan, Peter Denham

    This work examines the relative chronology of geologic units within the Cerberus Plains of Mars with an emphasis on lava flows emplaced after the last Marte Valles fluvial episode. High resolution images show the bulk of the Cerberus Plains is covered by platy-ridged and inflated lavas, which are interpreted as insulated sheet flows. Eastern Cerberus Plains lavas originate at Cerberus Fossae fissures and shields. Some flows extend for >2000 km through Marte Valles into Amazonis Planitia. Athabasca Valles are both incised into pristine lavas and embayed by pristine lavas, indicating that Athabascan fluvial events were contemporaneous with volcanic eruptions. Deposits of the Medusae Fossae Formation lie both over and under lavas, suggesting the deposition of the Medusae Fossae Formation was contemporaneous with volcanism. Statistics of small craters indicate lavas in the Western Cerberus Plains may be less than a million years old, but the model isochrons may be unreliable if the small crater population is dominated by secondary craters. Images showing no large craters with diameters >500 m superimposed on Western Cerberus Plains lavas indicate the same surface is younger than 49 Ma. High resolution Mars Orbiter Camera (MOC) images have revealed the existence of small cones in the Cerberus Plains, Marte Valles, and Amazonis Planitia. These cones are similar in both morphology and planar dimensions to the larger Icelandic rootless cones, which form due to explosive interactions between surficial lavas and near-surface groundwater. If martian cones form in the same manner as terrestrial rootless cones, then equatorial ground-ice or ground water must have been present near the surface in geologically recent times. Evidence for a shallow lake in the Western Cerberus Plains during the Late Amazonian is also presented. High-resolution images show features interpreted as flood-eroded scarps and fluvial spillways exiting the lake. Based on present-day topography, a lake

  8. 49 CFR 230.102 - Tender plain bearing journal boxes.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Tender plain bearing journal boxes. 230.102... Locomotives and Tenders Running Gear § 230.102 Tender plain bearing journal boxes. Plain bearing journal boxes... expected to damage the bearing; or have a detrimental effect on the lubrication of the journal and bearing...

  9. 49 CFR 230.102 - Tender plain bearing journal boxes.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Tender plain bearing journal boxes. 230.102... Locomotives and Tenders Running Gear § 230.102 Tender plain bearing journal boxes. Plain bearing journal boxes... expected to damage the bearing; or have a detrimental effect on the lubrication of the journal and bearing...

  10. Planetary stations and Abyssal Benthic Laboratories: An overview of parallel approaches for long-term investigation in extreme environments

    NASA Technical Reports Server (NTRS)

    Dipippo, S.; Prendin, W.; Gasparoni, F.

    1994-01-01

    In spite of the apparent great differences between deep ocean and space environment, significant similarities can be recognized when considering the possible solutions and technologies enabling the development of remote automatic stations supporting the execution of scientific activities. In this sense it is believed that mutual benefits shall be derived from the exchange of experiences and results between people and organizations involved in research and engineering activities for hostile environments, such as space, deep sea, and polar areas. A significant example of possible technology transfer and common systematic approach is given, which describes in some detail how the solutions and the enabling technologies identified for an Abyssal Benthic Laboratory can be applied for the case of a lunar or planetary station.

  11. Geologic map of the northern plains of Mars

    USGS Publications Warehouse

    Tanaka, Kenneth L.; Skinner, James A.; Hare, Trent M.

    2005-01-01

    The northern plains of Mars cover nearly a third of the planet and constitute the planet's broadest region of lowlands. Apparently formed early in Mars' history, the northern lowlands served as a repository both for sediments shed from the adjacent ancient highlands and for volcanic flows and deposits from sources within and near the lowlands. Geomorphic evidence for extensive tectonic deformation and reworking of surface materials through release of volatiles occurs throughout the northern plains. In the polar region, Planum Boreum contains evidence for the accumulation of ice and dust, and surrounding dune fields suggest widespread aeolian transport and erosion. The most recent regional- and global-scale maps describing the geology of the northern plains are largely based on Viking Orbiter image data (Dial, 1984; Witbeck and Underwood, 1984; Scott and Tanaka, 1986; Greeley and Guest, 1987; Tanaka and Scott, 1987; Tanaka and others, 1992a; Rotto and Tanaka, 1995; Crumpler and others, 2001; McGill, 2002). These maps reveal highland, plains, volcanic, and polar units based on morphologic character, albedo, and relative ages using local stratigraphic relations and crater counts. This geologic map of the northern plains is the first published map that covers a significant part of Mars using topography and image data from both the Mars Global Surveyor and Mars Odyssey missions. The new data provide a fresh perspective on the geology of the region that reveals many previously unrecognizable units, features, and temporal relations. In addition, we adapted and instituted terrestrial mapping methods and stratigraphic conventions that we think result in a clearer and more objective map. We focus on mapping with the intent of reconstructing the history of geologic activity within the northern plains, including deposition, volcanism, erosion, tectonism, impact cratering, and other processes with the aid of comprehensive crater-density determinations. Mapped areas include all

  12. Chemical weathering outputs from the flood plain of the Ganga

    NASA Astrophysics Data System (ADS)

    Bickle, Michael J.; Chapman, Hazel J.; Tipper, Edward; Galy, Albert; De La Rocha, Christina L.; Ahmad, Talat

    2018-03-01

    Transport of sediment across riverine flood plains contributes a significant but poorly constrained fraction of the total chemical weathering fluxes from rapidly eroding mountain belts which has important implications for chemical fluxes to the oceans and the impact of orogens on long term climate. We report water and bedload chemical analyses from the Ganges flood-plain, a major transit reservoir of sediment from the Himalayan orogen. Our data comprise six major southern tributaries to the Ganga, 31 additional analyses of major rivers from the Himalayan front in Nepal, 79 samples of the Ganga collected close to the mouth below the Farakka barrage every two weeks over three years and 67 water and 8 bedload samples from tributaries confined to the Ganga flood plain. The flood plain tributaries are characterised by a shallow δ18O - δD array, compared to the meteoric water line, with a low δDexcess from evaporative loss from the flood plain which is mirrored in the higher δDexcess of the mountain rivers in Nepal. The stable-isotope data confirms that the waters in the flood plain tributaries are dominantly derived from flood plain rainfall and not by redistribution of waters from the mountains. The flood plain tributaries are chemically distinct from the major Himalayan rivers. They can be divided into two groups. Tributaries from a small area around the Kosi river have 87Sr/86Sr ratios >0.75 and molar Na/Ca ratios as high as 6. Tributaries from the rest of the flood plain have 87Sr/86Sr ratios ≤0.74 and most have Na/Ca ratios <1. One sample of the Gomti river and seven small adjacent tributaries have elevated Na concentrations likely caused by dissolution of Na carbonate salts. The compositions of the carbonate and silicate components of the sediments were determined from sequential leaches of floodplain bedloads and these were used to partition the dissolved cation load between silicate and carbonate sources. The 87Sr/86Sr and Sr/Ca ratios of the carbonate

  13. Chenier plain genesis explained by feedbacks between waves, mud, and sand

    NASA Astrophysics Data System (ADS)

    Nardin, William; Fagherazzi, Sergio

    2017-04-01

    Cheniers are sandy ridges parallel to the coast established by high energy waves. Here we discuss ontogeny of chenier plains through dimensional analysis and numerical results from the morphodynamic model Delft3D-SWAN. Our results show that wave energy and inner-shelf slope play an important role in the formation of chenier plains. In our numerical experiments, waves affect chenier plain development in three ways: by winnowing coarse sediment from the mudflat, by eroding mud and accumulating sand over the beach during extreme wave events. We further show that different sediment characteristics and wave climates can lead to three alternative coastal landscapes: strand plains, mudflats, or the more complex chenier plains. Low inner-shelf slopes are the most favorable for strand plain and chenier plain formation, while high slopes decrease the likelihood of mudflat development and preservation.

  14. Plain Language to Communicate Physical Activity Information: A Website Content Analysis.

    PubMed

    Paige, Samantha R; Black, David R; Mattson, Marifran; Coster, Daniel C; Stellefson, Michael

    2018-04-01

    Plain language techniques are health literacy universal precautions intended to enhance health care system navigation and health outcomes. Physical activity (PA) is a popular topic on the Internet, yet it is unknown if information is communicated in plain language. This study examined how plain language techniques are included in PA websites, and if the use of plain language techniques varies according to search procedures (keyword, search engine) and website host source (government, commercial, educational/organizational). Three keywords ("physical activity," "fitness," and "exercise") were independently entered into three search engines (Google, Bing, and Yahoo) to locate a nonprobability sample of websites ( N = 61). Fourteen plain language techniques were coded within each website to examine content formatting, clarity and conciseness, and multimedia use. Approximately half ( M = 6.59; SD = 1.68) of the plain language techniques were included in each website. Keyword physical activity resulted in websites with fewer clear and concise plain language techniques ( p < .05), whereas fitness resulted in websites with more clear and concise techniques ( p < .01). Plain language techniques did not vary by search engine or the website host source. Accessing PA information that is easy to understand and behaviorally oriented may remain a challenge for users. Transdisciplinary collaborations are needed to optimize plain language techniques while communicating online PA information.

  15. Mountain-Plains Curriculum.

    ERIC Educational Resources Information Center

    Mountain-Plains Education and Economic Development Program, Inc., Glasgow AFB, MT.

    The document lists the Mountain-Plains curriculum by job title (where applicable), including support courses. The curriculum areas covered are mathematics skills, communication skills, office education, lodging services, food services, marketing and distribution, welding support, automotive, small engines, career guidance, World of Work, health…

  16. Ground-water conditions in the Plaine de Moustiques, Haiti

    USGS Publications Warehouse

    Taylor, George C.; Lemoine, Rémy C.

    1949-01-01

    The Plaine des Moustiques lies on the north coast of Haiti about 12 kilometers west-southwest of Port-de-Paix. During January 1949 the writers made a brief geologic study to determine the availability of ground water in the plain for irrigation. At present irrigation is practiced by diversions from the Rivière des Moustiques. However, the dry-season flow of this stream is generally inadequate for irrigation or is sufficient to cover only a small part of the Irrigable area of the plain. According to Lieurance1 there is a total of about 1,120 hectares of irrigable land in the plain.

  17. Sphaerodoropsis kitazatoi, a new species and the first record of Sphaerodoridae (Annelida: Phyllodocida) in SW Atlantic abyssal sediments around a whale carcass

    NASA Astrophysics Data System (ADS)

    Shimabukuro, Maurício; Rizzo, Alexandra E.; Alfaro-Lucas, Joan M.; Fujiwara, Yoshihiro; Sumida, Paulo Y. G.

    2017-12-01

    A new polychaete species, Sphaerodoropsis kitazatoi (Annelida: Phyllodocida: Sphaerodoridae), is described from the abyssal Southwest Atlantic Ocean at the base of São Paulo Ridge (4204 m depth). This species was found in sediments impacted by a whale carcass. The new species has four longitudinal rows of macrotubercles and one transversal row per chaetiger and shares several characters with S. anae Aguado and Rouse, 2006 that is also associated with chemosynthetic environments. They can be clearly distinguished from S. anae and other Sphaerodoropsis species by the arrangement and the number of prostomial, body and parapodial papillae.

  18. Smooth plains on Mercury. A comparison with Vesta.

    NASA Astrophysics Data System (ADS)

    Zambon, F.; Capaccioni, F.; Carli, C.; De Sanctis, M. C.; Filacchione, G.; Giacomini, L.

    Mercury, the closest planet to the Sun, has been visited by the MESSENGER spacecraft \\citet{solomon2007}. After 3 years of orbit around Mercury a global coverage of the surface has been done revealing that ∼27% of Mercury's surface is covered by smooth plains \\citet{denevi2013}. Large part of Mercury's smooth plain (SP) seems to have volcanic origin. Different composition has been observed, most of the SP have a magnesian alkali-basalt-like composition, while some of them have been interpreted as ultramafic. A further 2% of smooth plains have been identified as Odin-type plains and represent the knobby and hummocky plains surrounding the Caloris basin \\citet{denevi2013}. Application of classification methods \\citet{adams2006} applied to color image data of the MESSENGER wide angle camera (MDIS-WAC) \\citet{MDIS} and a spectral analysis of the spec- trometer data (MASCS-VIRS) \\citet{MASCS} are useful to highlight the differences in composition of the smooth planes. A compa rison between Mercury's SP and those of other solar system bodies, such as Vesta \\citet{desanctis2012}, reveals useful to obtain information on the origin and the evolution of this bodies.

  19. From technical jargon to plain English for application.

    PubMed Central

    Lindsley, O R

    1991-01-01

    These examples of translating technical jargon into plain English application words, acronyms, letter codes, and simple tests were necessary as we developed Precision Teaching. I hope our experience is useful to others facing the problems of applying technology in practical settings. At the least, our experience should give you an idea of the work and time involved in making your own translations. Above all, be patient. Accurate plain English translations do not come easily. They cannot be made at your desk. A search often takes years to produce one new accurate plain English translation. Rapid publication pressures, journal editorial policies, and investments in materials, books, and computer programs all combine to hamper these translations. It's possible that you will find some of our plain English equivalents useful in your own applied behavior analysis applications. PMID:1752836

  20. Study on ecological regulation of coastal plain sluice

    NASA Astrophysics Data System (ADS)

    Yu, Wengong; Geng, Bing; Yu, Huanfei; Yu, Hongbo

    2018-02-01

    Coastal plains are densely populated and economically developed, therefore their importance is self-evident. However, there are some problems related with water in coastal plains, such as low flood control capacity and severe water pollution. Due to complicated river network hydrodynamic force, changeable flow direction and uncertain flood concentration and propagation mechanism, it is rather difficult to use sluice scheduling to realize flood control and tackle water pollution. On the base of the measured hydrological data during once-in-a-century Fitow typhoon in 2013 in Yuyao city, by typical analysis, theoretical analysis and process simulation, some key technologies were researched systematically including plain river network sluice ecological scheduling, “one tide” flood control and drainage scheduling and ecological running water scheduling. In the end, single factor health diagnostic evaluation, unit hydrograph of plain water level and evening tide scheduling were put forward.

  1. Ground water in the Cul-de-Sac Plain, Haiti

    USGS Publications Warehouse

    Taylor, George C.; Lemoine, Rémy C.

    1949-01-01

    The Cul-de-Sac Plain is perhaps the most important agricultural area in Haiti because of its nearness and accessibility to Port-au-Prince, the nation's capital, metropolis, and principal seaport. Most of the agricultural produce consumed in Port-au-Prince as well as a considerable part of that exported from Haiti is grown in the plain.Because of variable and poorly distributed rainfall, high temperature, and high evaporation, semiarid climatic conditions prevail in the plain. Irrigation is, therefore, necessary for successful farming. There are no regulatory or storage facilities on the streams that enter the plain, but the mean and low-water stream flow and the discharge of springs are almost entirely appropriated for irrigation. Ground water has been utilized for irrigation to an increasing extent by the Haitian American Sugar Company, which has put down about 100 wells in the plain since 1919.Outside the existing irrigated areas of the plain are large tracts of potentially irrigable land that are uncultivated and agriculturally unproductive for lack of water. The object of the present study was to determine the possibilities of bringing these lands into cultivation by irrigation from wells. This study was part of a larger program of the Food Supply Division, Institute of Inter-American Affairs, to increase the production of food in Haiti.From September through November 1948 the senior author, a member of the U. S. Geological Survey, spent three months in the field in an investigation of the geology and ground-water resources of the Cul-de-Sac Plain. He was ably assisted by Mr. Rémy C. Lemoine, Haitian engineer-geologist, employed by the Food Supply Division. The field work included principally the geologic mapping of' the plain and the adjacent mountain borders, a ground-water inventory of existing wells and springs, and a general evaluation of significant geologic and hydrologic features.

  2. Plain packaging of cigarettes: do we have sufficient evidence?

    PubMed Central

    Smith, Collin N; Kraemer, John D; Johnson, Andrea C; Mays, Darren

    2015-01-01

    Tobacco industry marketing is a primary factor influencing cigarette smoking behavior and the cigarette pack has become an important marketing vehicle for tobacco companies. Standardized “plain” cigarette packaging is advocated as a public health policy to prevent and reduce morbidity and mortality caused by smoking by reducing youth smoking initiation and promoting cessation among smokers. Plain packaging was implemented in Australia in December 2012, and several other countries are considering doing so, but each faces foreseeable legal resistance from opponents to such measures. Tobacco companies have challenged these public health policies, citing international trade agreements and intellectual property laws. Decision-making in these court cases will hinge in part on whether the evidence indicates the public health benefits of plain packaging outweigh any potential harm to tobacco manufacturers’ interests. We reviewed the available evidence in support of plain packaging, finding evidence from observational, experimental, and population-based studies. Results indicate that plain packaging can reduce positive perceptions of smoking and dissuade tobacco use. Governments deciding to implement plain cigarette packaging measures can rely on this evidence to help make a strong case that plain packaging plays an important role in the context of comprehensive smoking prevention efforts. PMID:25897269

  3. Tobacco plain packaging: Evidence based policy or public health advocacy?

    PubMed

    McKeganey, Neil; Russell, Christopher

    2015-06-01

    In December 2012, Australia became the first country to require all tobacco products be sold solely in standardised or 'plain' packaging, bereft of the manufacturers' trademarked branding and colours, although retaining large graphic and text health warnings. Following the publication of Sir Cyril Chantler's review of the evidence on the effects of plain tobacco packaging, the Ministers of the United Kingdom Parliament voted in March 2015 to implement similar legislation. Support for plain packaging derives from the belief that tobacco products sold in plain packs have reduced appeal and so are more likely to deter young people and non-smokers from starting tobacco use, and more likely to motivate smokers to quit and stay quit. This article considers why support for the plain packaging policy has grown among tobacco control researchers, public health advocates and government ministers, and reviews Australian survey data that speak to the possible introductory effect of plain packaging on smoking prevalence within Australia. The article concludes by emphasising the need for more detailed research to be undertaken before judging the capacity of the plain packaging policy to deliver the multitude of positive effects that have been claimed by its most ardent supporters. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Geomorphology of the Eastern North American Continental Margin: the role of deep sea sedimentation processes

    NASA Astrophysics Data System (ADS)

    Mosher, D. C.; Campbell, C.; Piper, D.; Chaytor, J. D.; Gardner, J. V.; Rebesco, M.

    2016-12-01

    Deep-sea sedimentation processes impart a fundamental control on the morphology of the western North Atlantic continental margin from Blake Spur to Hudson Strait. This fact is illustrated by the variable patterns of cross-margin gradients that are based on extensive new multibeam echo-sounder data in concert with subbottom profiler and seismic reflection data. Most of the continental margin has a steep (>3o) upper slope down to 1500 to 2500 m and then a gradual middle and lower slope with a general concave upward shape There is a constant interplay of deep sea sedimentation processes, but the general morphology is dictated by the dominant one. Erosion by off-shelf sediment transport in turbidity currents creating channels, gullies and canyons creates the steep upper slope. These gullies and canyons amalgamate to form singular channels that are conduits to the abyssal plain. This process results in a general seaward flattening of gradients, producing an exponentially decaying slope profile. Comparatively, sediment mass failure produces steeper upper slopes due to head scarp development and a wedging architecture to the lower slope as deposits thin in the downslope direction. This process results in either a two-segment slope, and/or a significant downslope gradient change where MTDs pinch out. Large sediment bodies deposited by contour-following currents are developed all along the margin. Blake Ridge, Sackville Spur, and Hamilton Spur are large detached drifts on disparate parts of the margin. Along their crests, they form a linear profile from the shelf to abyssal plain. Deeper portions of the US continental margin are dominated by the Chesapeake Drift and Hatteras Outer Ridge; both plastered elongate mounded drifts. Farther north, particularly on the Grand Banks margin, are plastered and separated drifts. These drifts tend to form bathymetric steps in profile, where they onlap the margin. Stacked drifts create several steps. Turbidites of the abyssal plain onlap

  5. Seafloor mapping of the southeast Iberian margin (from Cabo de Palos to Cabo de Gata)

    NASA Astrophysics Data System (ADS)

    Lastras, Galderic; Leon, César; Elvira, Elena; Pascual, Laura; Muñoz, Araceli; de Cárdenas, Enrique; Acosta, Juan; Canals, Miquel

    2014-05-01

    We present the multibeam bathymetry and derived maps of the southeast Iberian margin from Cabo de Palos to Cabo de Gata, 37º35'N to 35º45'N and 2º10'W to 0º20'E, from the coastline down to the Algero-Balearic abyssal plain at depths exceeding 2600 m. The edition of of the maps is carried out within the Complementary Action VALORPLAT ("Scientific valorisation of multibeam bathymetry data from the Spanish continental shelf and slope"), funded by the Spanish Ministry of Economy and Competitivity. The multibeam bathymetry data of the slope and abyssal plain were obtained during different surveys in 2004, 2006 and 2007 on board R/V Vizconde de Eza with a Simrad EM300 multibeam echo-sounder as part of the CAPESME Project, a collaboration between the Spanish Institute of Oceanography (IEO) and General Secretariat of Fisheries (SGP), primarily aiming at creating maps of the fishing grounds of the Mediterranean continental margins of Spain. Multibeam bathymetry data from the continental shelf were obtained within the ESPACE project, also in a cooperative frame between IEO and SGP. The map series is constituted by a general map at 1:400,000 scale and 14 detailed maps at 1:75,000 scale, which include inset maps on slope gradients and seafloor nature (rock or sediment type), the later obtained with rock dredges and Shipeck sediment dredges. Both the detailed maps and the general map are available in paper print, and the whole collection is also distributed in an edited USB. The geological features displayed in the different maps include the continental shelf, with abundant geomorphic features indicative of past sea-level changes, the continental slope carved by the Palos, Tiñoso, Cartagena Este, Cartagena Oeste, Águilas, Almanzora, Alias, Garrucha and Gata submarine canyons, the Mazarrón, Palomares and Al-Mansour escarpments, the Abubácer, Maimonides and Yusuf ridges, the Águilas and Al-Mansour seamounts, and the Algero-Balearic abyssal plain where prominent

  6. Perceptions of branded and plain cigarette packaging among Mexican youth.

    PubMed

    Mutti, Seema; Hammond, David; Reid, Jessica L; White, Christine M; Thrasher, James F

    2017-08-01

    Plain cigarette packaging, which seeks to remove all brand imagery and standardize the shape and size of cigarette packs, represents a novel policy measure to reduce the appeal of cigarettes. Plain packaging has been studied primarily in high-income countries like Australia and the UK. It is unknown whether the effects of plain packaging may differ in low-and-middle income countries with a shorter history of tobacco regulation, such as Mexico. An experimental study was conducted in Mexico City to examine perceptions of branded and plain cigarette packaging among smoking and non-smoking Mexican adolescents (n = 359). Respondents were randomly assigned to a branded or plain pack condition and rated 12 cigarette packages for appeal, taste, harm to health and smoker-image traits. As a behavioral measure of appeal, respondents were offered (although not given) four cigarette packs (either branded or plain) and asked to select one to keep. The findings indicated that branded packs were perceived to be more appealing (β = 3.40, p < 0.001) and to contain better tasting cigarettes (β = 3.53, p < 0.001), but were not perceived as less harmful than plain packs. Participants rated people who smoke the branded packs as having relatively more positive smoker-image traits overall (β = 2.10, p < 0.001), with particularly strong differences found among non-smokers for the traits 'glamorous', 'stylish', 'popular' and 'sophisticated' (p < 0.001). No statistically significant difference was found for the proportion of youth that accepted when offered branded compared with plain packs. These results suggest that plain packaging may reduce brand appeal among Mexican youth, consistent with findings in high-income countries. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  7. The evolution of the New Jersey Pine Plains.

    PubMed

    Ledig, F Thomas; Hom, John L; Smouse, Peter E

    2013-04-01

    Fire in the New Jersey Pine Plains has selectively maintained a dwarf growth form of pitch pine (Pinus rigida), which is distinct from the surrounding tall forest of the Pine Barrens and has several other inherited adaptations that enable it to survive in an environment dominated by fire. Pitch pine progeny from two Pine Plains sites, the West and East Pine Plains, were grown in common garden environments with progeny from two Pine Barrens stands, Batsto and Great Egg Harbor River. The tests were replicated in five locations: in New Jersey, Connecticut, two sites in Massachusetts, and Korea. One of the tests was monitored for up to 36 yr. Progeny of Pine Plains origin were, in general, shorter, more crooked, precocious, bore more cones, had a higher frequency of serotinous cones, and had a higher frequency of stem cones than did Pine Barrens progeny, wherever they were grown. The Pine Plains is an ecotype that has evolved in response to disturbance. The several characters that distinguish it from the surrounding tall forest of the Pine Barrens are inherited. The dwarf stature and crooked form not only enable the ecotype to persist in an environment of frequent fires but also increase its flammability.

  8. Stratigraphy of the Martian northern plains

    NASA Technical Reports Server (NTRS)

    Tanaka, K. L.

    1993-01-01

    The northern plains of Mars are roughly defined as the large continuous region of lowlands that lies below Martian datum, plus higher areas within the region that were built up by volcanism, sedimentation, tectonism, and impacts. These northern lowlands span about 50 x 10(exp 6) km(sup 2) or 35 percent of the planet's surface. The age and origin of the lowlands continue to be debated by proponents of impact and tectonic explanations. Geologic mapping and topical studies indicate that volcanic, fluvial, and eolian deposition have played major roles in the infilling of this vast depression. Periglacial, glacial, fluvial, eolian, tectonic, and impact processes have locally modified the surface. Because of the northern plains' complex history of sedimentation and modification, much of their stratigraphy was obscured. Thus the stratigraphy developed is necessarily vague and provisional: it is based on various clues from within the lowlands as well as from highland areas within and bordering the plains. The results are summarized.

  9. Ground-water geology of the Gonaives Plain, Haiti

    USGS Publications Warehouse

    Taylor, George C.; Lemoine, Rémy C.

    1950-01-01

    The Gonaives Plain lies in northern Haiti at the head of the Gulf of Gonaives. Ground water in the plain is used widely for domestic and stock purposes but only to limited extent for irrigation. The future agricultural development of the plain will depend in large measure on the proper utilization of available ground-water supplies for irrigation. The rocks in the region of the Gonaives Plain belong to the upper (?) Cretaceous series of the Cretaceous system, the Nocene and Oligovene series of the Tertiary system, and the Pleistocene and Recent series of the Quarternary system. The structural depression occupied by the Gonaives Plain was formed in post-Miocene time by the dislocation of Oligocene and older rocks along normal faults and by the tilting of the adjacent crustal blocks. The lower parts of the depression contain a Pleistocene and Recent alluvial fill deposited by streams tributary to the plain. The upper (?) Cretaceous rocks include aniesite and basalt lava flows locally intercalated with some beds of tuff and agglomerate. These rocks are generally dense and impervious but locally small springs rise from fractures and bedding planes or from weathered zones. The Nocene rocks are hard, thin-bedded, cherty limestones with some beds of massive chalky limestone. Considerable ground water circulates through joints, bedding planes, and solution passages in these rocks giving rise to important springs such as Sources Madame Charles. These springs discharge at the rate of about 110 liters per second. The Oligocene rocks include limestone, shely limestone, limy sandstone, marl, and shale. The limestone beds contain solution passages and other openings and these may afford capacity for the circulation of ground water. However, no wells or springs in Oligocene rocks were observed during the present study. The alluvial fill of the plain is composed of interbedded lenses of clay, silt, sand, and gravel. These deposits contain a zone of saturation whose upper limit is

  10. Desert plains classification based on Geomorphometrical parameters (Case study: Aghda, Yazd)

    NASA Astrophysics Data System (ADS)

    Tazeh, mahdi; Kalantari, Saeideh

    2013-04-01

    This research focuses on plains. There are several tremendous methods and classification which presented for plain classification. One of The natural resource based classification which is mostly using in Iran, classified plains into three types, Erosional Pediment, Denudation Pediment Aggradational Piedmont. The qualitative and quantitative factors to differentiate them from each other are also used appropriately. In this study effective Geomorphometrical parameters in differentiate landforms were applied for plain. Geomorphometrical parameters are calculable and can be extracted using mathematical equations and the corresponding relations on digital elevation model. Geomorphometrical parameters used in this study included Percent of Slope, Plan Curvature, Profile Curvature, Minimum Curvature, the Maximum Curvature, Cross sectional Curvature, Longitudinal Curvature and Gaussian Curvature. The results indicated that the most important affecting Geomorphometrical parameters for plain and desert classifications includes: Percent of Slope, Minimum Curvature, Profile Curvature, and Longitudinal Curvature. Key Words: Plain, Geomorphometry, Classification, Biophysical, Yazd Khezarabad.

  11. Abyssal ostracods from the South and Equatorial Atlantic Ocean: Biological and paleoceanographic implications

    USGS Publications Warehouse

    Yasuhara, Moriaki; Cronin, T. M.; Martinez, Arbizu P.

    2008-01-01

    We report the distribution of ostracods from ???5000 m depth from the Southeast and Equatorial Atlantic Ocean recovered from the uppermost 10 cm of minimally disturbed sediments taken by multiple-corer during the R/V Meteor DIVA2 expedition M63.2. Five cores yielded the following major deep-sea genera: Krithe, Henryhowella, Poseidonamicus, Legitimocythere, Pseudobosquetina, and Pennyella. All genera are widely distributed in abyssal depths in the world's oceans and common in Cenozoic deep-sea sediments. The total number of ostracod specimens is higher and ostracod shell preservation is better near the sediment-water interface, especially at the 0-1 cm core depths. Core slices from ???5 to 10 cm were barren or yielded a few poorly preserved specimens. The DIVA2 cores show that deep-sea ostracod species inhabit corrosive bottom water near the carbonate compensation depth (CCD) even though their calcareous valves are rarely preserved as fossils in sediment cores due to postmortem dissolution. Their occurrence at great water depths may partially explain the well-known global distributions of major deep-sea taxa in the world's oceans, although further expeditions using minimal-disturbance sampling devices are needed to fill geographic gaps. ?? 2008 Elsevier Ltd. All rights reserved.

  12. Nemerteans of the Vema-TRANSIT expedition: First data on diversity with description of two new genera and species

    NASA Astrophysics Data System (ADS)

    Chernyshev, Alexei V.; Polyakova, Neonila E.

    2018-02-01

    Approximately 30 nemertean specimens were obtained from the samples collected with an epibenthic sledge during the Vema-TRANSIT expedition (2014-2015) to the Vema Fracture Zone. A preliminary molecular phylogenetic analysis of eight samples revealed four eumonostiliferan and three tubulanid species. Abyssonemertes kajiharai gen. et sp. nov. and Nemertovema hadalis gen. et sp. nov. are described based on morphological and DNA (16S, 18S, 28S, COI, and H3) data; the latter species is the deepest known nemertean to date. It was collected in the Puerto Rico Trench from a depth of 8336-8339 m. A preliminary molecular phylogenetic analysis based on the five genes indicates that three tubulanid species form a monophyletic group with the only previously known abyssal tubulanid (Tubulanidae gen. sp. IZ 45557) from the abyssal plain adjacent to the Kuril-Kamchatka Trench, but the four eumonostiliferan species belong to three different clades. Additionally, a roadmap on the most pressing questions and issues on abyssal and hadal nemerteans is provided. This is based on the processing of the nemertean material collected during the four deep-sea expeditions SoJaBio, KuramBio I, SokhoBio, and KuramBio II and shall provide a direction for future studies.

  13. Stratigraphic and hydrogeologic framework of the Alabama Coastal Plain

    USGS Publications Warehouse

    Davis, M.E.

    1988-01-01

    Tertiary and Cretaceous sand aquifers of the Southeastern United States Coastal Plain comprise a major multlstate aquifer system informally defined as the Southeastern Coastal Plain aquifer system, which is being studied as part of the U.S. Geological Survey's Regional Aquifer System Analysis (RASA) program. The major objectives of each RASA study are to identify, delineate, and map the distribution of permeable clastlc rock, to examine the pattern of ground-water flow within the regional aquifers, and to develop digital computer simulations to understand the flow system. The Coastal Plain aquifers in Alabama are being studied as a part of this system. This report describes the stratlgraphlc framework of the Cretaceous, Tertiary, and Quaternary Systems in Alabama to aid in delineating aquifers and confining units within the thick sequence of sediments that comprises the Southeastern Coastal Plain aquifer system in the State. Stratigraphlc units of Cretaceous and Tertiary age that make up most of the aquifer system in the Coastal Plain of Alabama consist of clastlc deposits of Early Cretaceous age; the Coker and Gordo Formations of the Tuscaloosa Group, Eutaw Formation, and Selma Group of Late Cretaceous age; and the Midway, Wilcox, and Clalborne Groups of Tertiary age. However, stratigraphlc units of late Eocene to Holocene age partially overlie and are hydraulically connected to clastic deposits in southern Alabama. These upper carbonate and clastlc stratlgraphic units also are part of the adjoining Florldan and Gulf Coastal Lowlands aquifer systems. The Coastal Plain aquifer system is underlain by pre-Cretaceous rocks consisting of low-permeabillty sedimentary rocks of Paleozolc, Triassic, and Jurassic age, and a complex of metamorphic and igneous rocks of Precambrian and Paleozolc age similar to those found near the surface in the Piedmont physiographic province. Twelve hydrogeologlc units in the Alabama Coastal Plain are defined--slx aquifers and six confining

  14. 49 CFR 215.107 - Defective plain bearing box: General.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD FREIGHT CAR SAFETY STANDARDS Freight Car Components... service a car, if the car has— (a) A plain bearing box that does not contain visible free oil; (b) A plain...

  15. 49 CFR 215.107 - Defective plain bearing box: General.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD FREIGHT CAR SAFETY STANDARDS Freight Car Components... service a car, if the car has— (a) A plain bearing box that does not contain visible free oil; (b) A plain...

  16. 49 CFR 215.107 - Defective plain bearing box: General.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD FREIGHT CAR SAFETY STANDARDS Freight Car Components... service a car, if the car has— (a) A plain bearing box that does not contain visible free oil; (b) A plain...

  17. 49 CFR 215.107 - Defective plain bearing box: General.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD FREIGHT CAR SAFETY STANDARDS Freight Car Components... service a car, if the car has— (a) A plain bearing box that does not contain visible free oil; (b) A plain...

  18. 49 CFR 215.107 - Defective plain bearing box: General.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD FREIGHT CAR SAFETY STANDARDS Freight Car Components... service a car, if the car has— (a) A plain bearing box that does not contain visible free oil; (b) A plain...

  19. Harmonizing human-hydrological system under climate change: A scenario-based approach for the case of the headwaters of the Tagus River

    NASA Astrophysics Data System (ADS)

    Lobanova, Anastasia; Liersch, Stefan; Tàbara, J. David; Koch, Hagen; Hattermann, Fred F.; Krysanova, Valentina

    2017-05-01

    Conventional water management strategies, that serve solely socio-economic demands and neglect changing natural conditions of the river basins, face significant challenges in governing complex human-hydrological systems, especially in the areas with constrained water availability. In this study we assess the possibility to harmonize the inter-sectoral water allocation scheme within a highly altered human-hydrological system under reduction in water availability, triggered by projected climate change applying scenario-based approach. The Tagus River Basin headwaters, with significant disproportion in the water resources allocation between the environmental and socio-economic targets were taken as a perfect example of such system out of balance. We propose three different water allocation strategies for this region, including two conventional schemes and one imposing shift to sustainable water management and environmental restoration of the river. We combine in one integrated modelling framework the eco-hydrological process-based Soil and Water Integrated Model (SWIM), coupled with the conceptual reservoir and water allocation modules driven by the latest bias-corrected climate projections for the region and investigate possible water allocation scenarios in the region under constrained water availability in the future. Our results show that the socio-economic demands have to be re-considered and lowered under any water allocation strategy, as the climate impacts may significantly reduce water availability in the future. Further, we show that a shift to sustainable water management strategy and river restoration is possible even under reduced water availability. Finally, our results suggest that the adaptation of complex human-hydrological systems to climate change and a shift to a more sustainable water management are likely to be parts of one joint strategy to cope with climate change impacts.

  20. Second chance for the plains bison

    USGS Publications Warehouse

    Freese, Curtis H.; Aune, K.; Boyd, D.; Derr, James N.; Forrest, Steven C.; Gates, C. Cormack; Gogan, Peter J.; Grassel, Shaun M.; Halbert, Natalie D.; Kunkel, Kyran; Redford, Kent

    2007-01-01

    Before European settlement the plains bison (Bison bison bison) numbered in the tens of millions across most of the temperate region of North America. Within the span of a few decades during the mid- to late-1800s its numbers were reduced by hunting and other factors to a few hundred. The plight of the plains bison led to one of the first major movements in North America to save an endangered species. A few individuals and the American Bison Society rescued the remaining animals. Attempts to hybridize cattle and bison when bison numbers were low resulted in extensive cattle gene introgression in bison. Today, though approximately 500,000 plains bison exist in North America, few are free of cattle gene introgression, 96% are subject to anthropogenic selection for commodity production, and only 4% are in herds managed primarily for conservation purposes. Small herd size, artificial selection, cattle-gene introgression, and other factors threaten the diversity and integrity of the bison genome. In addition, the bison is for all practical purposes ecologically extinct across its former range, with multiple consequences for grassland biodiversity. Urgent measures are needed to conserve the wild bison genome and to restore the ecological role of bison in grassland ecosystems. Socioeconomic trends in the Great Plains, combined with new information about bison conservation needs and new conservation initiatives by both the public and public sectors, have set the stage for significant progress in bison conservation over the next few years.

  1. Mantle melting and melt refertilization beneath the Southwest Indian Ridge: Mineral composition of abyssal peridotites

    NASA Astrophysics Data System (ADS)

    Chen, Ling; Zhu, Jihao; Chu, Fengyou; Dong, Yan-hui; Liu, Jiqiang; Li, Zhenggang; Zhu, Zhimin; Tang, Limei

    2017-04-01

    As one of the slowest spreading ridges of the global ocean ridge system, the Southwest Indian Ridge (SWIR) is characterized by discontinued magmatism. The 53°E segment between the Gallieni fracture zone (FZ) (52°20'E) and the Gazelle FZ (53°30'E) is a typical amagmatic segment (crustal thickness <2km) (Zhou and Dick, 2013) that opens a window to the mantle thus provides a chance to detect the mantle composition directly. We examine the mineral compositions of 17 peridotite samples from the 53°E amagmatic segment. The results show that the peridotites can be divided into two groups. The Group 1 peridotites are characterized by clinopyroxenes having LREE depleted patterns that is typical for the abyssal peridotite, thus are thought to be the residue of the mantle melting. The Group 2 peridotites show the lowest HREE content within the SWIR peridotites but are anomaly enriched in LREE, with flat or U-type REE patterns, thus cannot be the pure residue of mantle melting. Mineral compositions of the Group 2 peridotites are more depleted than that of peridotites sampled near the Bouvet hot spot (Johnson et al., 1990), implying that the depleted mantle beneath the 53°E segment may be the residue of ancient melting event. This hypothesis is supported by the the low Ol/Opx ratios, coarse grain sizes (>1cm) Opx, and Mg-rich mineral compositions akin to harzburgite xenoliths that sample old continental lithospheric mantle (Kelemen et al., 1998). Melt refertilization model shows that Group 2 peridotites were affected by an enriched low-degree partial melt from the garnet stability field. These results indicate that depleted mantle which experiences ancient melting event are more sensitive to melt refertilization, thus may reduce the melt flux, leading to extremely thin crust at 53°E segment. This research was granted by the National Basic Research Programme of China (973 programme) (grant No. 2013CB429705) and the Fundamental Research Funds of Second Institute of

  2. Plain ABDO X-rays: a waste of time?

    PubMed

    2002-03-01

    Plain abdominal radiographs are commonly requested for acute medical emergencies on patients with non-specific abdominal symptoms and signs. In this study, 131 plain abdominal radiographs performed on the day of admission were prospectively analysed by the research team. In only 16 cases (12 per cent) the reasons for requests conformed to the recommended guidelines by the Royal College of Radiologists. The reason for the request was stated in the case notes in only three cases. In 62 cases (47 per cent), there was no comment made on the film by the requesting clinician. There was a discrepancy in the interpretation of the radiograph between the clinician and the radiologist in 31 cases (24 per cent). The clinical management was influenced by plain abdominal radiographs in only nine cases (7 per cent). The researchers argue that most plain abdominal radiographs requested on acute medical emergencies are inappropriate. They suggest there is a need to ensure guidelines are followed to prevent unnecessary exposure of patients to radiation as well as preventing expenditure on irrelevant investigations.

  3. Estimated historical distribution of grassland communities of the Southern Great Plains

    USGS Publications Warehouse

    Reese, Gordon C.; Manier, Daniel J.; Carr, Natasha B.; Callan, Ramana; Leinwand, Ian I.F.; Assal, Timothy J.; Burris, Lucy; Ignizio, Drew A.

    2016-12-07

    The purpose of this project was to map the estimated distribution of grassland communities of the Southern Great Plains prior to Euro-American settlement. The Southern Great Plains Rapid Ecoregional Assessment (REA), under the direction of the Bureau of Land Management and the Great Plains Landscape Conservation Cooperative, includes four ecoregions: the High Plains, Central Great Plains, Southwestern Tablelands, and the Nebraska Sand Hills. The REA advisors and stakeholders determined that the mapping accuracy of available national land-cover maps was insufficient in many areas to adequately address management questions for the REA. Based on the recommendation of the REA stakeholders, we estimated the potential historical distribution of 10 grassland communities within the Southern Great Plains project area using data on soils, climate, and vegetation from the Natural Resources Conservation Service (NRCS) including the Soil Survey Geographic Database (SSURGO) and Ecological Site Information System (ESIS). The dominant grassland communities of the Southern Great Plains addressed as conservation elements for the REA area are shortgrass, mixed-grass, and sand prairies. We also mapped tall-grass, mid-grass, northwest mixed-grass, and cool season bunchgrass prairies, saline and foothill grasslands, and semi-desert grassland and steppe. Grassland communities were primarily defined using the annual productivity of dominant species in the ESIS data. The historical grassland community classification was linked to the SSURGO data using vegetation types associated with the predominant component of mapped soil units as defined in the ESIS data. We augmented NRCS data with Landscape Fire and Resource Management Planning Tools (LANDFIRE) Biophysical Settings classifications 1) where NRCS data were unavailable and 2) where fifth-level watersheds intersected the boundary of the High Plains ecoregion in Wyoming. Spatial data representing the estimated historical distribution of

  4. Late Holocene evolution of a coupled, mud-dominated delta plain-chenier plain system, coastal Louisiana, USA

    NASA Astrophysics Data System (ADS)

    Hijma, Marc P.; Shen, Zhixiong; Törnqvist, Torbjörn E.; Mauz, Barbara

    2017-11-01

    Major deltas and their adjacent coastal plains are commonly linked by means of coast-parallel fluxes of water, sediment, and nutrients. Observations of the evolution of these interlinked systems over centennial to millennial timescales are essential to understand the interaction between point sources of sediment discharge (i.e. deltaic distributaries) and adjacent coastal plains across large spatial (i.e. hundreds of kilometres) scales. This information is needed to constrain future generations of numerical models to predict coastal evolution in relation to climate change and other human activities. Here we examine the coastal plain (Chenier Plain, CP) adjacent to the Mississippi River delta, one of the world's largest deltas. We use a refined chronology based on 22 new optically stimulated luminescence and 22 new radiocarbon ages to test the hypothesis that cyclic Mississippi subdelta shifting has influenced the evolution of the adjacent CP. We show that over the past 3 kyr, accumulation rates in the CP were generally 0-1 Mt yr-1. However, between 1.2 and 0.5 ka, when the Mississippi River shifted to a position more proximal to the CP, these rates increased to 2.9 ±1.1 Mt yr-1 or 0.5-1.5 % of the total sediment load of the Mississippi River. We conclude that CP evolution during the past 3 kyr was partly a direct consequence of shifting subdeltas, in addition to changing regional sediment sources and modest rates of relative sea-level (RSL) rise. The RSL history of the CP during this time period was constrained by new limiting data points from the base of overwash deposits associated with the cheniers. These findings have implications for Mississippi River sediment diversions that are currently being planned to restore portions of this vulnerable coast. Only if such diversions are located in the western portion of the Mississippi Delta plain could they potentially contribute to sustaining the CP shoreline. Our findings highlight the importance of a better

  5. Plains Traveler

    NASA Technical Reports Server (NTRS)

    2006-01-01

    10 April 2006 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a dust devil traveling across a plain west-southwest of Schiaparelli Crater, in far eastern Sinus Meridiani. The dust devil is casting a shadow toward the northeast, just south (below) of an egg-shaped crater.

    Location near: 6.4oS, 349.3oW Image width: 3 km (1.9 mi) Illumination from: lower left Season: Southern Summer

  6. Detailed Analysis of the Intra-Ejecta Dark Plains of Caloris Basin, Mercury

    NASA Technical Reports Server (NTRS)

    Buczkowski, Debra L.; Seelos, K. S.

    2010-01-01

    The Caloris basin on Mercury is floored by light-toned plains and surrounded by an annulus of dark-toned material interpreted to be ejecta blocks and smooth, dark, ridged plains. Strangely, preliminary crater counts indicate that these intra-ejecta dark plains are younger than the light-toned plains within the Caloris basin. This would imply a second, younger plains emplacement event, possibly involving lower albedo material volcanics, which resurfaced the original ejecta deposit. On the other hand, the dark plains may be pre-Caloris light plains covered by a thin layer of dark ejecta. Another alternative to the hypothesis of young, dark volcanism is the possibility that previous crater counts have not thoroughly distinguished between superposed craters (fresh) and partly-buried craters (old) and therefore have not accurately determined the ages of the Caloris units. This abstract outlines the tasks associated with a new mapping project of the Caloris basin, intended to improve our knowledge of the geology and geologic history of the basin, and thus facilitate an understanding of the thermal evolution of this region of Mercury.

  7. Plain packaging policy: Preventing industry innovations.

    PubMed

    Al-Hamdani, Mohammed

    2017-04-20

    The pack is a marketing tool for the tobacco industry - its shape, colour, fonts, descriptors and logos attract and mislead smokers. Health warnings on cigarette packs serve as a knowledge reminder for smokers to quit smoking. Plain packaging eliminates brand imagery elements from cigarette packs and has many benefits, including the reduction of intention to smoke and the denormalization of smoking behaviour. The tobacco industry has devised pack and product marketing innovations that thwart the effectiveness of health warnings. Plain packaging policy needs to address these innovations by restricting their use and preventing them from undermining health warnings.

  8. Young adult smokers' perceptions of plain packaging: a pilot naturalistic study.

    PubMed

    Moodie, Crawford; Mackintosh, Anne Marie; Hastings, Gerard; Ford, Allison

    2011-09-01

    To explore the impact, if any, that using plain (non-branded) cigarette packs in real-life settings has on young adult smokers. Naturalistic-type research was employed, where smokers used brown 'plain' packs for 2 weeks and their regular packs for 2 weeks, in real-life settings. Participants were recruited in Glasgow, Scotland. Of the 140 smokers aged 18-35 years who participated in the naturalistic study, 48 correctly completed and returned all questionnaires. Over the 4-week study period, participants completed a questionnaire twice a week assessing pack perceptions and feelings, feelings about smoking, salience of health warnings and smoking-related behaviours. A subsample of 18 participated in a post-study interview, which employed a semistructured topic guide to assess perceptions and experiences of using plain packs. Trends in the data show that in comparison with branded packaging, plain packaging increased negative perceptions and feelings about the pack and about smoking. Plain packaging also increased avoidant behaviour (hiding the pack, covering the pack), certain smoking cessation behaviours, such as smoking less around others and forgoing cigarettes, and thinking about quitting. Almost half (n=8) of those in the post-study interview, predominantly women (n=6), reported that the use of plain packs had either increased avoidant behaviour or reduced consumption. This pilot naturalistic study suggests that plain packaging could potentially help reduce tobacco consumption among some young adult smokers, and women in particular. Employing an innovative research methodology, the findings of this study are consistent with, and indeed support, past plain packaging research.

  9. Causes and Predictability of the 2012 Great Plains Drought

    NASA Technical Reports Server (NTRS)

    Hoerling, M.; Eischeid, J.; Kumar, A.; Leung, R.; Mariotti, A.; Mo, K.; Schubert, S.; Seager, R.

    2013-01-01

    Central Great Plains precipitation deficits during May-August 2012 were the most severe since at least 1895, eclipsing the Dust Bowl summers of 1934 and 1936. Drought developed suddenly in May, following near-normal precipitation during winter and early spring. Its proximate causes were a reduction in atmospheric moisture transport into the Great Plains from the Gulf of Mexico. Processes that generally provide air mass lift and condensation were mostly absent, including a lack of frontal cyclones in late spring followed by suppressed deep convection in summer owing to large-scale subsidence and atmospheric stabilization. Seasonal forecasts did not predict the summer 2012 central Great Plains drought development, which therefore arrived without early warning. Climate simulations and empirical analysis suggest that ocean surface temperatures together with changes in greenhouse gases did not induce a substantial reduction in summertime precipitation over the central Great Plains during 2012. Yet, diagnosis of the retrospective climate simulations also reveals a regime shift toward warmer and drier summertime Great Plains conditions during the recent decade, most probably due to natural decadal variability. As a consequence, the probability for severe summer Great Plains drought may have increased in the last decade compared to the 1980s and 1990s, and the so-called tail-risk for severe drought may have been heightened in summer 2012. Such an extreme drought event was nonetheless still found to be a rare occurrence within the spread of 2012 climate model simulations. Implications of this study's findings for U.S. seasonal drought forecasting are discussed.

  10. Oxygen Fugacity of Abyssal Peridotites Along the Gakkel Ridge

    NASA Astrophysics Data System (ADS)

    Said, M.; Birner, S.; Cottrell, E.

    2015-12-01

    The oxygen budget of the Earth's mantle is important in understanding how our planet evolves chemically over time. The Gakkel Ridge is the world's slowest spreading ridge [1], and exposes peridotites along its axis that record the activity of oxygen in the upper mantle. Our samples comprise relatively fertile lherzolites and harzburgites (Cr#=0.13-0.17, 3.1-8.3% modal cpx [2]) as well as refractory harzburgites (Cr#=0.43-0.55, 0.2-1.0% modal cpx [2]). Using spinel peridotite oxygen barometry [3], we calculated the oxygen fugacity (fO2) of a suite of 10 peridotites from the Gakkel Ridge in order to investigate how melt processes affect the oxygen budget of the Earth's interior. We show that the low-Cr# lherzolites and harzburgites range from -0.1 to +0.6 log units relative to the QFM buffer, consistent with the global abyssal peridotite array, whereas high-Cr# refractory harzburgites have low fO2 values, ranging from -0.7 to -2.7 log units below QFM, with the most refractory samples falling significantly lower than the global array. Because D'Errico et al. (submitted) interprets the refractory samples as recording ancient melt extraction, the low fO2 recorded by these samples may originate in the geologic past, perhaps even in a different tectonic setting. While LREE enrichment in the refractory harzburgites [2] provides evidence for refertilization by an infiltrating melt that could have recently imprinted reducing conditions, we see no corresponding increase in TiO2 content in the spinels, which weakens this hypothesis. Further research on additional refractory harzburgites is needed to constrain whether the reduced nature of these samples is telling us something about the effect of extreme melt extraction on fO2 at ridges, or whether these samples record a unique history that obscures processes operating at ridges today. [1] Coakley and Cochran, EPSL (1998), [2] D'Errico et al., submitted, [3] Bryndzia and Wood, American Journal of Science (1990)

  11. Young Craters on Smooth Plains

    NASA Image and Video Library

    2000-01-15

    This image, from NASA Mariner 10 spacecraft which launched in 1974, shows young craters superposed on smooth plains. Larger young craters have central peaks, flat floors, terraced walls, and radial ejecta deposits.

  12. Hyperbaric versus plain bupivacaine for spinal anesthesia for cesarean delivery.

    PubMed

    Heng Sia, Alex Tiong; Tan, Kok Hian; Sng, Ban Leong; Lim, Yvonne; Chan, Edwin S Y; Siddiqui, Fahad Javaid

    2015-01-01

    Bupivacaine is an amide local anesthetic used in hyperbaric and plain forms administered as spinal anesthesia for cesarean delivery. In this systematic review, we summarized the effectiveness and safety of hyperbaric versus plain bupivacaine in providing anesthesia for cesarean delivery. We considered the adequacy of anesthesia for completion of cesarean delivery and the need for interventions to treat complications. We searched the CENTRAL, MEDLINE, and EMBASE databases. We imposed no language restriction. We included all randomized controlled trials involving patients undergoing spinal anesthesia for elective cesarean delivery that compared the use of hyperbaric bupivacaine with plain bupivacaine. We included 6 studies with a total of 394 patients in this review. These studies have small sample size, few observed events, differences in methodology, and insufficient information pertaining to assessment of risk of bias. This prevented us from calculating pooled estimates. Results show that there is no compelling evidence in favor of the use of intrathecal plain or hyperbaric bupivacaine for spinal anesthesia for cesarean delivery. There is a lack of clear evidence regarding the superiority of hyperbaric compared with plain bupivacaine for spinal anesthesia for cesarean delivery. The need for conversion to general anesthesia because of failed spinal anesthesia is an important clinical outcome, but current data are insufficient to compare spinal anesthesia induced with hyperbaric compared with plain bupivacaine for this outcome. Further research is required.

  13. Analysis of High Plains Resource Risk and Economic Impacts

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

    Tidwell, Vincent C.; Vargas, Vanessa N; Jones, Shannon M

    2016-04-01

    The importance of the High Plains Aquifer is broadly recognized as is its vulnerability to continued overuse. T his study e xplore s how continued depletions of the High Plains Aquifer might impact both critical infrastructure and the economy at the local, r egional , and national scale. This analysis is conducted at the county level over a broad geographic region within the states of Kansas and Nebraska. In total , 140 counties that overlie the High Plains Aquifer in these two states are analyzed. The analysis utilizes future climate projections to estimate crop production. Current water use and managementmore » practices are projected into the future to explore their related impact on the High Plains Aquifer , barring any changes in water management practices, regulat ion, or policy. Finally, the impact of declining water levels and even exhaustion of groundwater resources are projected for specific sectors of the economy as well as particular elements of the region's critical infrastructure.« less

  14. Water-level changes in the High Plains aquifer; predevelopment to 1991

    USGS Publications Warehouse

    McGrath, T.J.; Dugan, J.T.

    1993-01-01

    Regional variability in water-level change in the High Plains aquifer underlying parts of Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming results from large regional differences in climate, soils, land use, and ground-water withdrawals for irrigation. From the beginning of significant development of the High Plains aquifer for irrigation to 1980, substantial water-level declines have occurred in several areas. The estimated average area-weighted water-level decline from predevelopment to 1980 for the High Plains was 9.9 feet, an average annual decline of about 0.25 foot. These declines exceeded 100 feet in some parts of the Central and Southern High Plains. Declines were much smaller and less extensive in the Northern High Plains as a result of later irrigation development. Since 1980, water levels in those areas of large declines in the Central and Southern High Plains have continued to decline, but at a much slower annual rate. The estimated average area-weighted water-level decline from 1980 to 1991 for the entire High Plains was 1.41 feet, an average annual decline of about 0.13 foot. The relatively small decline since 1980, in relation to the declines prior to 1980, is associated with a decrease in ground-water application for irrigated agriculture and greater than normal precipitation. Water-conserving practices and technology, in addition to reductions in irrigated acreages, contributed to the decrease in ground-water withdrawals for irrigation.

  15. New insights on the propagation of the Near Inertial Waves (NIW) governing the bottom dynamic of the Western Ionian Sea (Eastern Mediterranean Sea).

    NASA Astrophysics Data System (ADS)

    Lo Bue, N.; Artale, V.; Marullo, S.; Marinaro, G.; Embriaco, D.; Favali, P.; Beranzoli, L.

    2017-12-01

    The past general idea that the ocean-deep circulation is in quasi-stationary motion, has conditioned the observations of deep layers for a long time, excluding them from the majority of the surveys around the ocean world and influencing studies on the deep ocean processes. After the pioneering work of Munk (1966) highlighting the importance of bottom mixing processes, an underestimation of these issue has continued to persist for decades, due also to the difficulty to make reliable observations in the abyssal layers. The real awareness about the unsteady state of the abyssal layers has only risen recently and encourages us to wonder how the deep mechanisms can induce an internal instability and, consequently, affect the ocean circulation. The NIWs are characterized by a frequency near the inertial frequency f and can be generated by a variety of mechanisms, including wind, nonlinear interactions wave-shear flow and wave-topography, and geostrophic adjustments. NIWs represent one of the main high-frequency variabilities in the ocean, and they contain around half the kinetic energy observed in the oceans (Simmons et al. 2012) appearing as a prominent peak rising well above the Garrett & Munk (1975) continuum internal wave spectrum. As such, they upset the mixing processes in the upper ocean and they can interact strongly with mesoscale and sub-mesoscale motions. Likewise, NIWs likely affect the mixing of the deep ocean in ways that are just beginning to be understood. The analysis carried out on yearly time series collected by the bottom observatory SN1, the Western Ionian node of EMSO (European Multidisciplinary Seafloor and water column Observatory) Research Infrastructure, provides new important understanding on the role of the NIWs in the abyssal ocean. Also, this analysis is very useful to shed light on the possible mechanism that can trigger deep processes such as the abyssal vortex chains found by Rubino et al. (2012) in the Ionian abyssal plain of the Eastern

  16. Plains Tectonics on Venus

    NASA Technical Reports Server (NTRS)

    Banerdt, W. B.; McGill, G. E.; Zuber, M. T.

    1996-01-01

    Tectonic deformation in the plains of Venus is pervasive, with virtually every area of the planet showing evidence for faulting or fracturing. This deformation can be classified into three general categories, defined by the intensity and areal extent of the surface deformation: distributed deformation, concentrated deformation, and local fracture patterns.

  17. Investigation of antarctic crust and upper mantle using MAGSAT and other geophysical data. M.S. Thesis. Final Report, Sep. 1979 - Aug. 1983

    NASA Technical Reports Server (NTRS)

    Bentley, C. R.; Ritzwoller, M. H.

    1983-01-01

    Data selection and reduction procedures are described by which scalar and vector magnetic anomaly maps are constructed. The scalar and vertical magnetic anomalies are believed to be generated mainly in the Earth's crust. The horizontal anomalies are believed to be mainly due to short-period field-aligned currents. The correlation of scalar magnetic anomalies with known oceanic structure is remarkable -- magnetic highs are associated with oceanic ridges and magnetic lows with abyssal plains. The correlation between anomalies and continental geology is not so clear.

  18. Antifriction coating of Cu-Fe-Al-Pb system for plain bearings

    NASA Astrophysics Data System (ADS)

    Kotenkov, Pavel; Kontsevoi, Yurii; Mejlakh, Anna; Pastukhov, Eduard; Shubin, Alexey; Goyda, Eduard; Sipatov, Ivan

    2017-09-01

    Aluminium, copper and their compounds are used in common as basis for antifriction coatings of plain bearings. Antifriction testing of plain bearings (based on Al and Cu) made by leading automotive manufacturers from Germany, Japan, USA, United Kingdom and Russia were carried out to make judicious selection of basis for development of new antifriction material. Testing was carried out using friction machine. It was defined that materials based on Cu provide better durability and robustness of plain bearings in comparison with Al based ones. The new antifriction composite coatings based on copper were developed taking into account the requirements specified for plain bearings of internal-combustion engine. Pilot samples of plain bearings with antifriction coatings of Cu-Fe-Al-Pb system were produced. The antifriction composite having Cu-5Fe-5Al5Fe2-10Pb (mass %) composition has demonstrated low friction factor and high wear-resistance. Metallographic analysis of pilot samples was carried out by means of optical and scanning electron microscopy.

  19. O Wakaga. Activities for Learning about the Plains Indians.

    ERIC Educational Resources Information Center

    Brewer, Linda Skinner

    A companion to The Mamook Book (ED 214 720), the student activity book teaches about Plains Indian cultures (in particular about Lakota life) through a series of activities such as: coloring panoramas of a Plains tipi encampment and a contemporary reservation; depicting historical and contemporary children; making a mobile; constructing a tipi and…

  20. Health Needs Assessment of Plain Populations in Lancaster County, Pennsylvania.

    PubMed

    Miller, Kirk; Yost, Berwood; Abbott, Christina; Thompson, Scottie; Dlugi, Emily; Adams, Zachary; Schulman, Meryl; Strauss, Nicole

    2017-02-01

    We performed a health needs assessment for three Plain communities in Lancaster County, Pennsylvania from a random sample of households. Compared with the general population of adults, Plain respondents were more likely to be married, to have children, and they had large families; they were more likely to drink well water, to eat fruit and vegetables, to drink raw milk, and to live on a farm. Plain respondents had better physical and mental health and were less likely to have been diagnosed with various medical conditions compared with the general population of adults in Lancaster County but Old Order Mennonite respondents were more likely to have been diagnosed compared with Old Order Amish respondents. Plain respondents usually have a regular doctor and often receive preventive care but Old Order Mennonite respondents were more likely to have a regular doctor, to receive preventive care, to have had their children vaccinated, and to receive routine dental care compared with Old Order Amish respondents. Despite their relative geographic and genetic isolation, and despite the small, relative differences noted, the health of Plain communities in Lancaster County is similar to that of other adults in the County.

  1. Agriculture on the Chaco Plain, Paraguay, South America

    NASA Technical Reports Server (NTRS)

    1990-01-01

    This view of extensive agriculture on the Chaco Plain, Paraguay, (22.5S, 60.5W) depicts the fertility of the soils between the Andes Mountains and the Paraguay - Parana Rivers in the northwestern Paraguay. The Gran Chaco Plain is flat landscape built up by sediments. Frontier settlements like Marsical Estigarribia, seen in the image, are dominated by agriculture along the stream courses that abound in the area.

  2. Types, harms and improvement of saline soil in Songnen Plain

    NASA Astrophysics Data System (ADS)

    Wang, Zhengjun; Zhuang, Jingjing; Zhao, Anping; Li, Xinxin

    2018-03-01

    Saline soil is an extremely difficult and modified soil, widely distributed around the world. According to UN-UNESCO and FAO, the world’s saline soil area is about 9.54×108hm2, and there is a growing trend, every year in 1.0×106-1.5×106hm2 speed growth, the effective utilization of land resources to the world is the most serious threat. The total area of saline-alkali land in China is about 9.91×107hm2, including the Songnen Plain, which is called one of the three major saline soil concentrations in the world. The Songnen plain is an important grain producing area in China, and the saline soil occupies most of the Songnen plain, so it is of great significance to study the saline soil and improvement in Songnen plain.

  3. Giant landslides and turbidity currents in the Agadir Canyon Region, NW-Africa

    NASA Astrophysics Data System (ADS)

    Krastel, Sebastian; Wynn, Russell B.; Stevenson, Christopher; Feldens, Peter; Mehringer, Lisa; Schürer, Anke

    2017-04-01

    Coring and drilling of the Moroccan Turbidite System off NW-Africa revealed a long sequence of turbidites, mostly sourced from the Moroccan continental margin and the volcanic Canary Islands. The largest individual flow deposits in the Moroccan Turbidite System contain sediment volumes >100 km3, although these large-scale events are relatively infrequent with a recurrence interval of 10,000 years (over the last 200,000 years). The largest siliciclastic flow in the last 200,000 years was the 'Bed 5 event', which transported 160 km3 of sediment up to 2000 km from the Agadir Canyon region to the southwest Madeira Abyssal Plain. While the Moroccan Turbidite System is extremely well investigated, almost no data from the source region, i.e. the Agadir Canyon, are available. Understanding why some submarine landslides remain as coherent blocks of sediment throughout their passage downslope, while others mix and disintegrate almost immediately after initial failure, is a major scientific challenge, which was addressed in the Agadir Canyon source region during RV Maria S. Merian Cruise MSM32 in late 2013. A major landslide area was identified 200 km south of the Agadir Canyon. A landslide was traced from this failure area to the Agadir Canyon. This landslide entered the canyon in about 2500 m water depth. Despite a significant increase in slope angle, the landslide did not disintegrate into a turbidity current when entering the canyon but moved on as landslide for at least another 200 km down the canyon. The age of the landslide ( 145 ka) does not correspond to any major turbidte deposit in the Moroccan Turbidite System, further supporting the fact that the landslide did not disintegrate into a major turbidity current. A core taken about 350 m above the thalweg in the head region of Agadir Canyon shows a single coarse-grained turbidite, which resembles the composition of the Bed 5 event in the Madeira Abyssal Plain. Hence, the Bed 5 turbidite originated as a failure in the

  4. Plastic pollution of the Kuril-Kamchatka Trench area (NW pacific)

    NASA Astrophysics Data System (ADS)

    Fischer, Viola; Elsner, Nikolaus O.; Brenke, Nils; Schwabe, Enrico; Brandt, Angelika

    2015-01-01

    During the German-Russian expedition KuramBio (Kuril-Kamchatka Biodiversity Studies) to the northwest Pacific Kuril-Kamchatka Trench and its adjacent abyssal plain, we found several kinds and sizes of plastic debris ranging from fishing nets and packaging to microplastic in the sediment of the deep-sea floor. Microplastics were ubiquitous in the smaller fractions of the box corer samples from every station from depths between 4869 and 5766 m. They were found on the abyssal plain and in the sediments of the trench slope on both sides. The amount of microplastics differed between the stations, with lowest concentration of 60 pieces per m2 and highest concentrations of more than 2000 pieces per m2. Around 75% of the microplastics (defined here as particles <1 mm) we isolated from the sediment samples were fibers. Other particles were paint chips or small cracked pieces of unknown origin. The Kuril-Kamchatka Trench area is known for its very rich marine fauna (Zenkevich, 1963). Yet we can only guess how these microplastics accumulated in the deep sea of the Kuril-Kamchatka Trench area and what consequences the microplastic itself and its adsorbed chemicals will have on this very special and rich deep-sea fauna. But we herewith present an evaluation of the different kinds of plastic debris we found, as a documentation of human impact into the deep sea of this region of the Northwest Pacific.

  5. Occurrence and variability of mining-related lead and zinc in the Spring River flood plain and tributary flood plains, Cherokee County, Kansas, 2009--11

    USGS Publications Warehouse

    Juracek, Kyle E.

    2013-01-01

    Historical mining activity in the Tri-State Mining District (TSMD), located in parts of southeast Kansas, southwest Missouri, and northeast Oklahoma, has resulted in a substantial ongoing input of cadmium, lead, and zinc to the environment. To provide some of the information needed to support remediation efforts in the Cherokee County, Kansas, superfund site, a 4-year study was begun in 2009 by the U.S. Geological Survey that was requested and funded by the U.S. Environmental Protection Agency. A combination of surficial-soil sampling and coring was used to investigate the occurrence and variability of mining-related lead and zinc in the flood plains of the Spring River and several tributaries within the superfund site. Lead- and zinc-contaminated flood plains are a concern, in part, because they represent a long-term source of contamination to the fluvial environment. Lead and zinc contamination was assessed with reference to probable-effect concentrations (PECs), which represent the concentrations above which adverse aquatic biological effects are likely to occur. The general PECs for lead and zinc were 128 and 459 milligrams per kilogram, respectively. The TSMD-specific PECs for lead and zinc were 150 and 2,083 milligrams per kilogram, respectively. Typically, surficial soils in the Spring River flood plain had lead and zinc concentrations that were less than the general PECs. Lead and zinc concentrations in the surficial-soil samples were variable with distance downstream and with distance from the Spring River channel, and the largest lead and zinc concentrations usually were located near the channel. Lead and zinc concentrations larger than the general or TSMD-specific PECs, or both, were infrequent at depth in the Spring River flood plain. When present, such contamination typically was confined to the upper 2 feet of the core and frequently was confined to the upper 6 inches. Tributaries with few or no lead- and zinc-mined areas in the basin—Brush Creek

  6. New Chronologies of Dune Activation Extracted from the Central Great Plains

    NASA Astrophysics Data System (ADS)

    Johnson, W. C.; Halfen, A. F.

    2011-12-01

    Recent investigations of dunefield activation histories in the Great Plains of North America have documented many long-duration, spatially-extensive, Holocene droughts. These "megadroughts" have been documented mostly in the larger dunefields of the Great Plains, e.g., the Nebraska Sand Hills, making it difficult for researchers to characterize these events region-wide. Several studies being conducted by the authors aim to extract a better spatial and temporal representation of megadroughts across the region by investigating smaller, less known dunefields of the Central Great Plains. Thus far, these studies have yielded new activation histories from three dunefields, the Kansas River, Hutchinson, and Arkansas Valley dunefields, which together span the precipitation gradient from eastern Kansas to eastern Colorado. While each of these dunefields have a unique history, collectively their activation chronologies yield new and important information on Holocene megadrought activity in the Great Plains, which may have been more spatially diverse and complex than previously thought. The Kansas River dunefield mantles a remnant high terrace of the lower Kansas River valley in the east-Central Great Plains and is one of the most easterly dunefields in the Great Plains. Optically stimulated luminescence (OSL) ages indicate dune activation last occurred ~36-31 ka, i.e., during MIS 3 between Heinrich Events 4 and 3 and was coincidental with loess deposition (Gillman Canyon Formation). The Kansas River dunefield also shows some evidence of minor activation during the middle Holocene, however this activity was likely limited to erosion of the dune surface and not full activation. About 200 km southwest of the Kansas River dunefield is the Hutchinson dunefield (HD), located immediately northeast of the Big Bend of the Arkansas River. OSL ages document dunefield-wide activity in the HD between ~1200 and 120 years ago, with peaks of activity centered after the Medieval Climatic

  7. Alcohol Warning Label Perceptions: Do Warning Sizes and Plain Packaging Matter?

    PubMed

    Al-Hamdani, Mohammed; Smith, Steven M

    2017-01-01

    There is a dearth of research on the effectiveness of stringent alcohol warning labels. Our experiment tested whether increasing the size of an alcohol health warning lowers product-based ratings. We examined whether plain packaging lowers ratings of alcohol products and the consumers who use them, increases ratings of bottle "boringness," and enhances warning recognition compared with branded packaging. A total of 440 adults (51.7% female) viewed one of three warning sizes (50%, 75%, or 90% of label surface) on either a plain or branded bottle of distilled spirits, wine, and beer. Participants also rated alcohol bottles on product-based (assessing the product itself), consumer-based (assessing perceptions of consumers of the product), and bottle boringness ratings, and then attempted to recognize the correct warning out of four choices. As expected, the size of warning labels lowered product-based ratings. Similarly, plain packaging lowered product-based and consumer-based ratings and increased bottle boringness but only for wine bottles. Further, plain packaging increased the odds of warning recognition on bottles of distilled spirits. This study shows that plain packaging and warning size (similar to the graphic warnings on cigarette packages) affect perceptions about alcohol bottles. It also shows that plain packaging increases the likelihood for correct health warning recognition, which builds the case for alcohol warning and packaging research and policy.

  8. Exploring geothermal structures in the Ilan Plain, Taiwan

    NASA Astrophysics Data System (ADS)

    Wang, Chien-Ying; Shih, Ruey-Chan; Chung, Chen-Tung; Huang, Ming-Zi; Kuo, Hsuan-Yu

    2017-04-01

    The Ilan Plain in northeast Taiwan is located at the southwestern tip of the Okinawa Trough, which extends westward into the Taiwan orogeny. The Ilan Plain covered by thick sediments is clipped by the Hsuehshan Range in the northern side and the Central Range in the southern side. High geothermal gradients with plenteous hot springs of this area may result from igneous intrusion associated with the back-arc spreading of the Okinawa Trough. In this study, we use reflection seismic survey to explore underground structures in the whole Ilan Plain, especially in SanShin, Wujie, and Lize area. We aim to find the relationship between underground structures and geothermal forming mechanism. The research uses reflection seismic survey to investigate the high geothermal gradient area with two mini-vibrators and 240-channel system. The total length of seismic lines is more than 30 kilometers. The results show that alluvial sediments covering the area about 400 600 meters thick and then thin out to the west in SanShin area. In SanShin , the Taiyaqiao anticline in Hsuehshan Range has entered the plain area and is bounded by the Zhuoshui fault (south) and the Zailian fault (north). In Wujie and Lize , Zhuoshui fault cut through a strong reflector which is the top of the gravel layer near the bottom of the alluvial layer, while the SanShin fault seems to cut near very shallow strata. These two faults are a strike-slip fault with a bit of normal fault component distributing over a range of 600 meters. In Ilan Plain, the geothermal forming mechanism is controlled by anticlines and faults. The hydrothermal solution which migrates upward along these anticline or fault zones to the shallow part causing high geothermal gradients in these areas.

  9. Coastal geomorphology of the Martian northern plains

    NASA Technical Reports Server (NTRS)

    Parker, Timothy J.; Gorsline, Donn S.; Saunders, Stephen R.; Pieri, David C.; Schneeberger, Dale M.

    1993-01-01

    The paper considers the question of the formation of the outflow channels and valley networks discovered on the Martian northern plains during the Mariner 9 mission. Parker and Saunders (1987) and Parker et al. (1987, 1989) data are used to describe key features common both in the lower reaches of the outflow channels and within and along the margins of the entire northern plains. It is suggested, that of the geological processes capable of producing similar morphologies on earth, lacustrine or marine deposition and subsequent periglacial modification offer the simplest and most consistent explanation for the suit of features found on Mars.

  10. Plain abdominal radiographs in acute medical emergencies: an abused investigation?

    PubMed

    Feyler, S; Williamson, V; King, D

    2002-02-01

    Plain abdominal radiographs are commonly requested for acute medical emergencies on patients with non-specific abdominal symptoms and signs. In this study 131 plain abdominal radiographs performed on the day of admission were prospectively analysed. In only 16 cases (12%) the reasons for requests conformed to the recommended guidelines by the Royal College of Radiologists. The reason for the request was stated in the case notes in only three cases. In 62 cases (47%), there was no comment made on the film by the requesting clinician. There was a discrepancy in the interpretation of the radiograph between the clinician and the radiologist in 31 cases (24%). The clinical management was influenced by plain abdominal radiographs in only nine cases (7%). The majority of plain abdominal radiographs requested on acute medical emergencies is inappropriate. There is a need to ensure guidelines are followed to prevent unnecessary exposure of patients to radiation as well as preventing expenditure on irrelevant investigations.

  11. Plain abdominal radiographs in acute medical emergencies: an abused investigation?

    PubMed Central

    Feyler, S; Williamson, V; King, D

    2002-01-01

    Plain abdominal radiographs are commonly requested for acute medical emergencies on patients with non-specific abdominal symptoms and signs. In this study 131 plain abdominal radiographs performed on the day of admission were prospectively analysed. In only 16 cases (12%) the reasons for requests conformed to the recommended guidelines by the Royal College of Radiologists. The reason for the request was stated in the case notes in only three cases. In 62 cases (47%), there was no comment made on the film by the requesting clinician. There was a discrepancy in the interpretation of the radiograph between the clinician and the radiologist in 31 cases (24%). The clinical management was influenced by plain abdominal radiographs in only nine cases (7%). The majority of plain abdominal radiographs requested on acute medical emergencies is inappropriate. There is a need to ensure guidelines are followed to prevent unnecessary exposure of patients to radiation as well as preventing expenditure on irrelevant investigations. PMID:11807192

  12. Plain language: a strategic response to the health literacy challenge.

    PubMed

    Stableford, Sue; Mettger, Wendy

    2007-01-01

    Low health literacy is a major challenge confronting American and international health organizations. Research in the past decade has documented the prevalence of limited literacy and limited health literacy skills among adults worldwide. This creates a major policy challenge: how to create text-based health information - a common method of health communication - that is accessible to the public. Plain language is a logical, flexible response. While touted by American, Canadian, and European health policy makers, adoption and promotion of plain language standards and skills in health-focused organizations have lagged. Most text-based health information continues to be too hard for most adults to read. Barriers to more rapid diffusion of plain language are reflected in a set of myths perpetuated by critics. These myths are identified and refuted. While plain language is only one of many broad-based solutions needed to address low health literacy, the benefits to everyone demand increased use by health organizations.

  13. Provenance of aeolian sands in the Hetao Plain, northwestern China

    NASA Astrophysics Data System (ADS)

    Yang, Xingchen; Cai, Maotang; Ye, Peisheng; Ye, Mengni; Li, Chenglu; Wu, Hang; Lu, Jing; Wang, Tao; Zhao, Zhirong; Luzhou, Yangfan; Liu, Chao

    2018-06-01

    Patches of aeolian sand are distributed throughout the Hetao Plain, which pose threats to farming and agriculture. Identification of the provenance of the aeolian sands may help with efforts to alleviate ecological stress in Inner Mongolia and in the paleoenvironmental interpretation of sandy sequences. This study uses geochemical data to determine the provenance of aeolian sands from the Hetao Plain. Provenance discrimination diagrams revealed that the aeolian sands were mainly derived from mixed source felsic granites and granodiorites, which have undergone weak sedimentary recycling. The chemical index of alteration and A-CN-K data indicated that the aeolian sediments were transported over a short distance. Comparison of trace element and rare earth element (REE) ratios of the aeolian sands with rock samples from potential source areas has revealed that aeolian sand deposits in the Hetao Plain were mainly derived from Sertengshan and Yellow River sediments. The Langshan and Ordos Plateau may represent additional sand sources for the Hetao Plain.

  14. Workshop on the Martian Northern Plains: Sedimentological, Periglacial, and Paleoclimatic Evolution

    NASA Technical Reports Server (NTRS)

    Kargel, Jeffrey S. (Editor); Moore, Jeffrey (Editor); Parker, Timothy (Editor)

    1993-01-01

    Papers that have been accepted for presentation at the Workshop on the Martian Northern Plains: Sedimentological, Periglacial, and Paleoclimatic Evolution, on 12-14 Aug. 1993 in Fairbanks, Alaska are included. Topics covered include: hydrological consequences of ponded water on Mars; morphological and morphometric studies of impact craters in the Northern Plains of Mars; a wet-geology and cold-climate Mars model: punctuation of a slow dynamics approach to equilibrium; the distribution of ground ice on Mars; and stratigraphy of the Martian Northern Plains.

  15. Plains tectonism on Venus: The deformation belts of Lavinia Planitia

    NASA Technical Reports Server (NTRS)

    Squyres, Steven W.; Jankowski, David G.; Simons, Mark; Solomon, Sean C.; Hager, Bradford H.; Mcgill, George E.

    1993-01-01

    High-resolution radar images from the Magellan spacecraft have revealed the first details of the morphology of the Lavinia Planitia region of Venus. A number of geologic units can be distinguished, including volcanic plains units with a range of ages. Transecting these plains over much of the Lavinia region are two types of generally orthogonal features that we interpret to be compressional wrinkle ridges and extensional grooves. The dominant tectonic features of Lavinia are broad elevated belts of intense deformation that transect the plains with complex geometry. They are many tens to a few hundred kilometers wide, as much as 1000 km long, and elevated hundreds of meters above the surrounding plains. Two classes of deformation belts are seen in the Lavinia region. 'Ridge belts' are composed of parallel ridges, each a few hundred meters in elevation, that we interpret to be folds. Typical fold spacings are 5-10 km. 'Fracture belts' are dominated instead by intense faulting, with faults in some instances paired to form narrow grabens. There is also some evidence for modest amounts of horizontal shear distributed across both ridge and fracture belts. Crosscutting relationships among the belts show there to be a range in belt ages. In western Lavinia, in particular, many ridge and fracture belts appear to bear a relationship to the much smaller wrinkle ridges and grooves on the surrounding plains: ridge morphology tends to dominate belts that lie more nearly parallel to local plains wrinkle ridges, and fracture morphology tends to dominate belts that lie more nearly parallel to local plains grooves. We use simple models to explore the formation of ridge and fracture belts. We show that convective motions in the mantle can couple to the crust to cause horizontal stresses of a magnitude sufficient to induce the formation of deformation belts like those observed in Lavinia. We also use the small-scale wavelengths of deformation observed within individual ridge belts to

  16. Young people's perceptions of cigarette packaging and plain packaging: an online survey.

    PubMed

    Moodie, Crawford; Ford, Allison; Mackintosh, Anne Marie; Hastings, Gerard

    2012-01-01

    In the United Kingdom, with most marketing channels prohibited, packaging is one of the few remaining ways that tobacco companies can promote their products. An online survey with young people aged 10-17 years (N = 658) was used to explore why youth choose cigarettes, perceptions of pack color, and perceptions of plain (nonbranded) cigarette packaging. Young people were also shown an image of 3 plain packs, which differed by shape and method of opening, and asked which they liked most and thought others their age would smoke. Price and what significant others smoke were key factors for choosing cigarettes, with packaging also an important influence. More than a third of the sample associated lighter pack color with weak tasting and less harmful cigarettes. Plain packs were rated negatively as were perceptions of plain pack users. One in 3 showed a preference for either a narrow "perfume type" plain pack or a plain "slide" pack that opened from the side, and 1 in 3 also thought that young people would smoke these packs. Packaging appears to both attract young people and mislead them about product strength and relative harm. Innovative pack construction (novel pack shape and method of opening) and the use of color are instrumental in these effects. The findings therefore suggest that any move to plain packaging should not only consider the benefits of removing branding (including color) but also of standardizing pack construction in terms of shape and method of opening.

  17. East China plains: a "basin" of ozone pollution.

    PubMed

    Zhao, Chun; Wang, Yuhang; Zeng, Tao

    2009-03-15

    Economic growth and associated pollution emissions in China are concentrated over three connected plains to the east In this work, we analyze an episode of highly elevated ozone over East China on June 9-14, 2004, using a 3-D chemical transport model. During this episode, the East China plains were under a high-pressure system, which suppressed the ventilation of pollutants from the boundary layer. Simulated ozone concentrations over a major fraction of East China reached high levels, all the way down to the Pearl River Delta region in the southern border. The convergence of pollutant emissions and population over the vast stretch of the geographically flat plains of East China makes the region susceptible to high-ozone exposure. During this episode, the high-03 region extended over an area >1 million km2, which hosts a population of >800 million people. Model results indicate that controlling anthropogenic NOx emissions effectively reduces the area with high-ozone exposure.

  18. Hydrogeologic Framework of the New Jersey Coastal Plain

    USGS Publications Warehouse

    Zapecza, Otto S.

    1989-01-01

    This report presents the results of a water-resources, oriented subsurface mapping program within the Coastal Plain of New Jersey. The occurrence and configuration of 15 regional hydrogeologic units have been defined, primarily on the basis of an interpretation of borehole geophysical data. The nine aquifers and six confining beds are composed of unconsolidated clay, silt, sand, and gravel and range in age from Cretaceous to Quaternary. Electric and gamma-ray logs from more than 1,000 Coastal Plain wells were examined. Of these, interpretive data for 302 sites were selected, on the basis of logged depth, quality of data, and data distribution, to prepare structure contour and thickness maps for each aquifer and a thickness map for each confining bed. These maps, together with 14 hydrogeologic sections, show the geometry, lateral extent, and vertical and horizontal relationships among the 15 hydrogeologic units. The hydrogeologic maps and sections show that distinct lower, middle, and upper aquifers are present within the Potomac, Raritan-Magothy aquifer system near the Delaware River from Burlington County to Salem County. Although the lower aquifer is recognized only in this area, the middle aquifer extends into the northeastern Coastal Plain of New Jersey, where it is stratigraphically equivalent to the Farrington aquifer. The upper aquifer extends throughout most of the New Jersey Coastal Plain and is stratigraphically equivalent to the Old Bridge aquifer in the northeastern Coastal Plain. The overlying Merchantville-Woodbury confining bed is the most regionally extensive confining bed within the New Jersey Coastal Plain. Its thickness ranges from less than 100 feet near the outcrop to more than 450 feet along the coast. The Englishtown aquifer system acts as a single aquifer throughout most of its subsurface extent, but it contains two water-bearing sands in pars of Monmouth and Ocean Counties. The overlying Marshalltown-Wenonah confining bed is a thin, leaky

  19. The Australian experience following plain packaging: the impact on tobacco branding.

    PubMed

    Greenland, Steven J

    2016-12-01

    Brands are critical to tobacco marketing. Industry stakeholders predicted that plain packaging, by removing key tangible branding dimensions, would restrict new products and brand differentiation. However, manufacturers respond innovatively to limit regulatory impact. This study investigates brand strategy following plain packaging's introduction to Australia. Brand portfolios were determined using 2006-15 tobacco ingredient reports. These detail the brand and variant names sold and are provided annually as part of a voluntary agreement between the Australian Government and leading manufacturers. Post-plain packaging brand ranges were verified using retail price lists and a supermarket retail audit using a method used previously to verify a period of pre-plain packaging data. The verification process identified some data inaccuracies from one manufacturer which resulted in the issuing of corrected data. After plain packaging the leading manufacturers continued with extensive brand ranges differentiated by price. All launched new products. While total brand numbers fell from 29 to 24, the mean number of variants for the leading 12 brands grew from 8.9 to 9.7. Substantial variant name modifications occurred with 50 new or modified names in 2012-13. Among leading brands, the incidence of variant colour names increased from 49.5 to 79.3%. New brands and variants were not inhibited by the introduction of plain packaging in Australia. After plain packaging, leading brand variant numbers expanded by 9 to 116 and colour variant names increased by 73.6% and became the norm-lighter colours (blue, gold and silver) dominated, perpetuating notions of less harmful cigarettes. [Correction added on 09 September 2016, after first online publication: The figures in the last sentence of the Abstract are now corrected from 'expanded by 116' to 'expanded by 9 to 116'.]. © 2016 Society for the Study of Addiction.

  20. Are plain radiographs sufficient to exclude cervical spine injuries in low-risk adults?

    PubMed

    Hunter, Benton R; Keim, Samuel M; Seupaul, Rawle A; Hern, Gene

    2014-02-01

    The routine use of clinical decision rules and three-view plain radiography to clear the cervical spine in blunt trauma patients has been recently called into question. In low-risk adult blunt trauma patients, can plain radiographs adequately exclude cervical spine injury when clinical prediction rules cannot? Four observational studies investigating the performance of plain radiographs in detecting cervical spine injury in low-risk adult blunt trauma patients were reviewed. The consistently poor performance of plain radiographs to rule out cervical spine injury in adult blunt trauma victims is concerning. Large, rigorously performed prospective trials focusing on low- or low/moderate-risk patients will be needed to truly define the utility of plain radiographs of the cervical spine in blunt trauma. Copyright © 2014 Elsevier Inc. All rights reserved.

  1. High Plains regional ground-water study

    USGS Publications Warehouse

    Dennehy, Kevin F.

    2000-01-01

    Over the last 25 years, industry and government have made large financial investments aimed at improving water quality across the Nation. Significant progress has been made; however, many water-quality concerns remain. In 1991, the U.S. Geological Survey (USGS) began implementing a full-scale National Water-Quality Assessment Program to provide consistent and scientifically sound information for managing the Nation's water resources. The goals of the NAWQA Program are to (1) describe current water-quality conditions for a large part of the Nation's freshwater streams and aquifers, (2) describe how water quality is changing over time, and (3) improve our understanding of the primary natural and human factors affecting water quality. Assessing the quality of water in every location in the Nation would not be practical; therefore, NAWQA Program studies are conducted within a set of areas called study units (fig. 1). These study units are composed of more than 50 important river and aquifer systems that represent the diverse geography, water resources, and land and water uses of the Nation. The High Plains Regional Ground-Water Study is one such study area, designed to address issues relevant to the High Plains Aquifer system while supplementing water-quality information collected in other study units across the Nation. Implementation of the NAWQA Program for the High Plains Regional Ground-Water Study area began in 1998.

  2. The High Plains: Land of Extremes.

    ERIC Educational Resources Information Center

    Capron, Ranel Stephenson; And Others

    1996-01-01

    Provides rich background information about unique High Plains ecosystems. Focuses on water, plant, animal, and energy resources. Describes hands-on activities related to ground water movement and energy resources. Contains 18 references. (DDR)

  3. Detailed Analysis of the Intra-Ejecta Dark Plains of Caloris Basin, Mercury

    NASA Astrophysics Data System (ADS)

    Buczkowski, D.; Seelos, K. D.

    2010-12-01

    The Caloris basin on Mercury is floored by light-toned plains and surrounded by an annulus of dark-toned material interpreted to be ejecta blocks and smooth, dark, ridged plains. Strangely, preliminary crater-counts indicate that these intra-ejecta dark plains are younger than the light-toned plains within the Caloris basin. This would imply a second, younger plains emplacement event, possibly involving lower albedo material volcanics, which resurfaced the original ejecta deposit. On the other hand, the dark plains may be pre-Caloris light plains covered by a thin layer of dark ejecta. Another alternative to the hypothesis of young, dark volcanism is the possibility that previous crater-counts have not thoroughly distinguished between superposed craters (fresh) and partly-buried craters (old) and therefore have not accurately determined the ages of the Caloris units. We here outline the tasks associated with a new mapping project of the Caloris basin, intended to improve our knowledge of the geology and geologic history of the basin, and thus facilitate an understanding of the thermal evolution of this region of Mercury. We will 1) classify craters based on geomorphology and infilling, 2) create a high-resolution map of the intra-ejecta dark plains, 3) perform crater counts of the intra-ejecta dark plains, the ejecta, and the Caloris floor light plains and 4) refine the stratigraphy of Caloris basin units. We will use new high resolution (200-300 m/p) imaging data from the MDIS instrument to create a new geomorphic map of the dark annulus around the Caloris basin. Known Caloris group formations will be mapped where identified and any new units will be defined and mapped as necessary. Specifically, we will delineate hummocks and smooth plains within the Odin formation and map them separately. We will look for unequivocal evidence of volcanic activity within the dark annulus and the Odin Formation, such as vents and flow lobes. The location of any filled craters will

  4. Hydrology and water budget for a forested atlantic coastal plain watershed, South Carolina

    Treesearch

    Scott V. Harder; Devendra M Amatya; Callahan Timothy J.; Carl C. Trettin; Hakkila Jon

    2007-01-01

    Increases in timber demand and urban development in the Atlantic Coastal Plain over the past decade have motivated studies on the hydrology, water quality, and sustainable management of coastal plain watersheds. However, studies on baseline water budgets are limited for the low-lying, forested watersheds of the Atlantic Coastal Plain. The purpose of this study was to...

  5. Hyrdology and water budget for a forested atlantic coastal plain watershed, South Carolina

    Treesearch

    Scott V. Harder; Devendra M. Amatya; Timothy J. Callahan; Carl C. Trettin; Jon Hakkila

    2007-01-01

    Increases in timber demand and urban development in the Atlantic Coastal Plain over the past decade have motivated studies on the hydrology, water quality, and sustainable management of coastal plain watersheds. However, studies on baseline water budgets are limited for the low-lying, forested watersheds of the Atlantic Coastal Plain. The purpose of this study was to...

  6. Intercrater Plains and Heavily Cratered Terrain

    NASA Image and Video Library

    2000-08-05

    This image, from NASA Mariner 10 spacecraft which launched in 1974, shows intercrater plains and heavily cratered terrain typical of much of Mercury outside the area affected by the formation of the Caloris basin.

  7. Arctic Refuge coastal plain terrestrial wildlife research summaries

    USGS Publications Warehouse

    Douglas, David C.; Reynolds, Patricia E.; Rhode, E.B.

    2002-01-01

    In 1980, when the U.S. Congress enacted the Alaska National Interest Lands Conservation Act (ANILCA), it also mandated a study of the coastal plain of the Arctic National Wildlife Refuge. Section 1002 of ANILCA stated that a comprehensive inventory of fish and wildlife resources would be conducted on 1.5 million acres of the Arctic Refuge coastal plain (1002 Area). Potential petroleum reserves in the 1002 Area were also to be evaluated from surface geological studies and seismic exploration surveys. Results of these studies and recommendations for future management of the Arctic Refuge coastal plain were to be prepared in a report to Congress.In 1987, the Department of the Interior published the Arctic National Wildlife Refuge, Alaska, Coastal Plain Resource Assessment - Report and Recommendations to the Congress of the United States and Final Environmental Impact Statement. This report to Congress identified the potential for oil and gas production (updated* most recently by the U.S. Geological Survey in 2001), described the biological resources, and evaluated the potential adverse effects to fish and wildlife resources. The 1987 report analyzed the potential environmental consequences of five management alternatives for the coastal plain, ranging from wilderness designation to opening the entire area to lease for oil and gas developement. The report's summary recommended opening the 1002 Area to an orderly oil and gas leasing program, but cautioned that adverse effects to some wildlife populations were possible.Congress did not act on this recommendation nor any other alternative for the 1002 Area, and scientists continued studies of key wildlife species and habitats on the coastal plain of the Arctic Refuge and surrounding areas. This report contains updated summaries of those scientific investigations of caribou, muskoxen, predators (grizzly bears, wolves, golden eagles), polar bears, snow geese, and their wildlife habitats.Contributions to this report were

  8. Regional dynamics of grassland change in the western Great Plains

    USGS Publications Warehouse

    Drummond, M.A.

    2007-01-01

    This paper examines the contemporary land-cover changes in two western Great Plains ecoregions between 1973 and 2000. Agriculture and other land uses can have a substantial effect on grassland cover that varies regionally depending on the primary driving forces of change. In order to better understand change, the rates, types, and causes of land conversion were examined for 1973, 1980, 1986, 1992, and 2000 using Landsat satellite data and a statistical sampling strategy. The overall estimated rate of land-cover change between 1973 and 2000 was 7.4% in the Northwestern Great Plains and 11.5% in the Western High Plains. Trends in both ecoregions have similarities, although the dynamics of change differ temporally depending on driving forces. Between 1973 and 1986, grassland cover declined when economic opportunity drove an expansion of agriculture. Between 1986 and 2000, grassland expanded as public policy and a combination of socioeconomic factors drove a conversion from agriculture to grassland. ?? 2007 Copyright by the Center for Great Plains Studies, University of Nebraska-Lincoln.

  9. Ice in the northern plains: Relic of a frozen ocean?

    NASA Technical Reports Server (NTRS)

    Lucchitta, B. K.

    1993-01-01

    Viking images revealed many features in the northern plains and along their boundary that early investigators believed to be formed by ice-related processes. The features are possible pingos, pseudocraters, table mountains and moberg ridges, thermokarst depressions, moraines, patterned ground, and lobate aprons that suggest viscous flow such as that of ice or rock glaciers. More recently, many of these features were reinterpreted as related to sedimentation in hypothetical former polar lakes, oceans, or alluvial plains or as shoreline features of associated water bodies. Some evidence that points toward the existence of former bodies of standing water in the northern plains, but is also consistent with the idea that these bodies were ice covered or completely frozen is reviewed.

  10. Plain and Rolled Images from Paired Fingerprint Cards

    National Institute of Standards and Technology Data Gateway

    NIST Plain and Rolled Images from Paired Fingerprint Cards (Web, free access)   NIST Special Database 29 is being distributed for use in development and testing fingerprint matching systems. The data consist of 216 ten-print fingerprint card pairs with both the rolled and plains (from a bottom of the fingerprint card) scanned at 19.7 pixels per mm. A newer version of the compression/decompression software on the CDROM can be found at the website http://www.nist.gov/itl/iad/ig/nigos.cfm as part of the NBIS package.

  11. Chemistry and mineralogy of pyrite-enriched sediments at a passive margin sulfide brine seep: abyssal Gulf of Mexico

    USGS Publications Warehouse

    Commeau, R.F.; Paull, C.K.; Commeau, J.A.; Poppe, L.J.

    1987-01-01

    Pyrite is rapidly accumulating at the contact between the Cretaceous limestones of the Florida Platform and the hemipelagic sediments of the abyssal Gulf of Mexico. Sediments sampled with the submersible "Alvin" in 3266 m of water are associated with a dense community of organisms that depend on chemosynthetic primary production as a food source. Analysis of the chemistry, mineralogy, and textural composition of these sediments indicate that iron sulfide mineralization is occurring at the seafloor within an anoxic micro-habitat sustained by the advection of hydrogen sulfide-charged saline brines from the adjacent platform. The chemosynthetic bacteria that directly overlie the sediments oxidize hydrogen sulfide for energy and provide elemental sulfur that reacts with iron monosulfide to form some of the pyrite. The sediments are mixtures of pyrite (??? 30 wt.%), BaSr sulfates (??? 4 wt.%), clays, and locally derived biogenic carbonates and are progressively being cemented by iron sulfides. Oxidation of hydrogen sulfide produces locally acidic conditions that corrode the adjacent limestones. Potential sources of S, H2S, Fe, Ba, and Sr are discussed. ?? 1987.

  12. Upscaling carbon fluxes over the Great Plains grasslands: Sinks and sources

    USGS Publications Warehouse

    Zhang, Li; Wylie, Bruce K.; Ji, Lei; Gilmanov, Tagir G.; Tieszen, Larry L.; Howar, Daniel M.

    2011-01-01

    Previous studies suggested that the grasslands may be carbon sinks or near equilibrium, and they often shift between carbon sources in drought years and carbon sinks in other years. It is important to understand the responses of net ecosystem production (NEP) to various climatic conditions across the U.S. Great Plains grasslands. Based on 15 grassland flux towers, we developed a piecewise regression model and mapped the grassland NEP at 250 m spatial resolution over the Great Plains from 2000 to 2008. The results showed that the Great Plains was a net sink with an averaged annual NEP of 24 ± 14 g C m−2 yr−1, ranging from a low value of 0.3 g C m−2 yr−1 in 2002 to a high value of 47.7 g C m−2 yr−1 in 2005. The regional averaged NEP for the entire Great Plains grasslands was estimated to be 336 Tg C yr−1 from 2000 to 2008. In the 9 year period including 4 dry years, the annual NEP was very variable in both space and time. It appeared that the carbon gains for the Great Plains were more sensitive to droughts in the west than the east. The droughts in 2000, 2002, 2006, and 2008 resulted in increased carbon losses over drought-affected areas, and the Great Plains grasslands turned into a relatively low sink with NEP values of 15.8, 0.3, 20.1, and 10.2 g C m−2 yr−1 for the 4 years, respectively.

  13. Volcanic Plains of Io Near Galai Patera

    NASA Technical Reports Server (NTRS)

    1983-01-01

    Io's volcanic plains are shown in this Voyager 1 image, which spans an area about 1030 km (640 miles) from left to right. North is about the 1:30 position. Numerous volcanic calderas and lava flows are visible here. The brown teardrop-shaped feature at left center is Galai Patera, a 100-km-long (62 mi) lava-flooded caldera (collapsed vent) of a volcano. The composition of Io's volcanic plains and lava flows has not been determined. The prevalent yellow, brown, and orange material may consist dominantly of sulfur with surface frosts of sulfur dioxide or of silicates (such as basalt) encrusted with sulfur and sulfur dioxide condensates. The whitish patches probably are freshly deposited SO2 frost.

  14. 49 CFR 215.109 - Defective plain bearing box: Journal lubrication system.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD FREIGHT CAR SAFETY STANDARDS Freight Car Components Suspension System § 215.109 Defective plain bearing box: Journal lubrication system. A railroad may not place or continue in service a car, if the car has a plain bearing box with a...

  15. 49 CFR 215.109 - Defective plain bearing box: Journal lubrication system.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD FREIGHT CAR SAFETY STANDARDS Freight Car Components Suspension System § 215.109 Defective plain bearing box: Journal lubrication system. A railroad may not place or continue in service a car, if the car has a plain bearing box with a...

  16. 49 CFR 215.109 - Defective plain bearing box: Journal lubrication system.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD FREIGHT CAR SAFETY STANDARDS Freight Car Components Suspension System § 215.109 Defective plain bearing box: Journal lubrication system. A railroad may not place or continue in service a car, if the car has a plain bearing box with a...

  17. 49 CFR 215.109 - Defective plain bearing box: Journal lubrication system.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD FREIGHT CAR SAFETY STANDARDS Freight Car Components Suspension System § 215.109 Defective plain bearing box: Journal lubrication system. A railroad may not place or continue in service a car, if the car has a plain bearing box with a...

  18. 49 CFR 215.109 - Defective plain bearing box: Journal lubrication system.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD FREIGHT CAR SAFETY STANDARDS Freight Car Components Suspension System § 215.109 Defective plain bearing box: Journal lubrication system. A railroad may not place or continue in service a car, if the car has a plain bearing box with a...

  19. Polygon-Cracked Plain

    NASA Technical Reports Server (NTRS)

    2005-01-01

    21 July 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a polygon-cracked plain in the south polar region of Mars. When this picture was acquired in April 2005, the surface was covered with seasonal carbon dioxide frost. Dark spots and streaks indicate areas where the frost had begun to change and sublime away.

    Location near: 86.8oS, 300.5oW Image width: width: 3 km (1.9 mi) Illumination from: upper left Season: Southern Spring

  20. Comparison of characteristics of chronic kidney diseases between Tibet plateau and plain areas

    PubMed Central

    Zhou, Yan; Deng, Yong-Ming; Li, Chuan; Gong, Yun-Bing; Mao, Zhi-Guo; Wu, Jun; Li, Su-Zhi; Liu, Zhi-Hong; Tang, Zheng

    2014-01-01

    Background: The purpose of the current study was to investigate the pathological characteristics of chronic kidney diseases in the Tibet plateau and the plain. Methods: 77 cases from the Tibet plateau and 154 cases from the plain of renal biopsied patients with chronic kidney diseases were compared in a randomized, and parallel controlled manner. Pathological characteristics were defined according to the standards of WHO and associated classifications. Results: The ration of sex was shown that most of patients in the plateau region were female, whereas those in the plain were male. The characteristics of pathological types were shown that the patients in the plateau region were primarily minimal change disease, but IgA nephropathy was rare; meanwhile, the proportional lupus nephritis (LN) ratio of the secondary glomerulonephritis in the plateau region was significantly lower than those in the plain region. Conclusions: The current data demonstrated that the most common kidney disease in the Tibet Plateau region is still the primary glomerulonephritis as the same as those in the plain region. However, the primary glomerular disease in the plateau region is minimal change disease, and the most common clinical manifestations are the nephrotic syndrome. The IgA nephropathy in the plain is the most frequent disease. In terms of the secondary renal diseases, Henoch-Schnolein purpura nephritis are dominated in the plateau region, whereas LN-based diseases are frequently found in the plain. There is a statistical significance existed between those two groups. PMID:25337266

  1. Tobacco branding, plain packaging, pictorial warnings, and symbolic consumption.

    PubMed

    Hoek, Janet; Gendall, Philip; Gifford, Heather; Pirikahu, Gill; McCool, Judith; Pene, Gina; Edwards, Richard; Thomson, George

    2012-05-01

    We use brand association and symbolic consumption theory to explore how plain cigarette packaging would influence the identities young adults cocreate with tobacco products. Group discussions and in-depth interviews with 86 young adult smokers and nonsmokers investigated how participants perceive tobacco branding and plain cigarette packaging with larger health warnings. We examined the transcript data using thematic analysis and explored how removing tobacco branding and replacing this with larger warnings would affect the symbolic status of tobacco brands and their social connotations. Smokers used tobacco brand imagery to define their social attributes and standing, and their connection with specific groups. Plain cigarette packaging usurped this process by undermining aspirational connotations and exposing tobacco products as toxic. Replacing tobacco branding with larger health warnings diminishes the cachet brand insignia creates, weakens the social benefits brands confer on users, and represents a potentially powerful policy measure.

  2. Small Craters Engulfed by Smooth Plains

    NASA Image and Video Library

    2000-08-05

    This double ring basin top center of image was photographed during NASA Mariner 10 second encounter and shows two craters about 30 km in diameter which have been engulfed by smooth plains on the floor of the inner ring.

  3. 41 CFR 102-2.140 - What elements of plain language appear in the FMR?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... MANAGEMENT REGULATION SYSTEM Plain Language Regulatory Style § 102-2.140 What elements of plain language... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false What elements of plain language appear in the FMR? 102-2.140 Section 102-2.140 Public Contracts and Property Management Federal...

  4. The case for the plain packaging of tobacco products.

    PubMed

    Freeman, Becky; Chapman, Simon; Rimmer, Matthew

    2008-04-01

    The Framework Convention on Tobacco Control (FCTC) requires nations that have ratified the convention to ban all tobacco advertising and promotion. In the face of these restrictions, tobacco packaging has become the key promotional vehicle for the tobacco industry to interest smokers and potential smokers in tobacco products. This paper reviews available research into the probable impact of mandatory plain packaging and internal tobacco industry statements about the importance of packs as promotional vehicles. It critiques legal objections raised by the industry about plain packaging violating laws and international trade agreements. Searches for available evidence were conducted within the internal tobacco industry documents through the online document archives; tobacco industry trade publications; research literature through the Medline and Business Source Premier databases; and grey literature including government documents, research reports and non-governmental organization papers via the Google internet search engine. Plain packaging of all tobacco products would remove a key remaining means for the industry to promote its products to billions of the world's smokers and future smokers. Governments have required large surface areas of tobacco packs to be used exclusively for health warnings without legal impediment or need to compensate tobacco companies. Requiring plain packaging is consistent with the intention to ban all tobacco promotions. There is no impediment in the FCTC to interpreting tobacco advertising and promotion to include tobacco packs.

  5. Long-term Agroecosystem Research in the Northern Great Plains.

    NASA Astrophysics Data System (ADS)

    Schmer, M.; Sanderson, M.; Liebig, M. A.; Wienhold, B.; Awada, T.; Papiernik, S.; Osborne, S.; Kemp, W.; Okalebo, J. A.; Riedall, W.

    2015-12-01

    The Northern Great Plains is the bread basket of the United States, accounting for a substantial portion of U.S. agricultural production. This region faces critical challenges regarding balancing food needs, resource conservation (e.g Ogallala aquifer), environmental concerns, and rural economy development. Developing transformative, multifunctional systems will require equally imaginative and efficient tools to help farmers manage complex agroecosystems in a rapidly changing climate. The Northern Plains long-term agroecosystem research (LTAR) site at Mandan, ND and the Platte River High Plains LTAR (ARS/University of Nebraska-Lincoln) at Lincoln, NE in collaboration with USDA-ARS research units in Brookings, SD and Fargo, ND are collaborating to address the grand challenge of providing and sustaining multiple service provisions from Northern Great Plains agroecosystems. We propose to attain these goals through sustainable intensification based on the adoption of conservation agriculture principles including reduced soil disturbance, livestock integration, and greater complexity and diversity in the cropping system. Here, we summarize new concepts these locations have pioneered in dynamic cropping systems, resource use efficiency, and agricultural management technologies. As part of the LTAR network, we will conduct long-term cross-site research to design and assess new agricultural practices and systems aimed at improving our understanding of decision making processes and outcomes across an array of agricultural systems.

  6. `Live' benthic foraminifera at an abyssal site in the equatorial Pacific nodule province: Abundance, diversity and taxonomic composition

    NASA Astrophysics Data System (ADS)

    Nozawa, Fusae; Kitazato, Hiroshi; Tsuchiya, Masashi; Gooday, Andrew J.

    2006-08-01

    Replicate sediment samples were obtained from 3 closely spaced stations in the Kaplan East (KE) area of the abyssal eastern Equatorial Pacific (˜15°N, 119°W; ˜4100 m water depth), just below the carbonate compensation depth. At each site, 2 (Stns 827, 838) or 3 (Stn 824) complete cores (57 mm i.d.) were subsampled using 2-3 cut-off syringes of 6.6 cm 3 cross-sectional area. The 0-1 cm sediment layers (>32 μm fraction) of these 20 subsamples together yielded 12,513 small, rose-Bengal stained benthic foraminifera dominated by agglutinated taxa, most of them morphologically simple monothalamous types or komokiaceans. Almost two-thirds (65%) of specimens were either obvious fragments, mainly of komokiaceans and tubular foraminifera, or single chambers or small groups of chambers believed to be fragments of very fragile komokiaceans. The remaining 4438 specimens (35%) were considered to be complete individuals. Most (78%) of these complete tests were indeterminate agglutinated spheres (termed 'psammosphaerids') that constituted 27.6% of all specimens (complete plus fragments). Complete individuals that could be assigned to either described or undescribed species accounted for 983 specimens (22% of complete tests=7.6% of all specimens); only 26 specimens (0.59% of complete individuals) were calcareous and these had invariably lost their tests through dissolution. Some groups exhibited considerable spatial heterogeneity. For example, 45% of the 3455 indeterminate psammosphaerids and 45% of the 3087 Komokiacean-like chambers occurred in single subcores. A total of 252 morphospecies was recognised; 168 were represented by complete individuals and 84 by fragments. There are clear differences between these Pacific assemblages and those from other oceans; in particular, psammosphaerids and isolated komokiacean chambers appear to be much more prevalent in the Pacific compared to the Atlantic Ocean. Some morphospecies present in Kaplan samples are known from the Atlantic

  7. 41 CFR 102-2.140 - What elements of plain language appear in the FMR?

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... language appear in the FMR? 102-2.140 Section 102-2.140 Public Contracts and Property Management Federal... MANAGEMENT REGULATION SYSTEM Plain Language Regulatory Style § 102-2.140 What elements of plain language appear in the FMR? The FMR is written in a “plain language” regulatory style. This style is easy to read...

  8. Optimisation and establishment of diagnostic reference levels in paediatric plain radiography

    NASA Astrophysics Data System (ADS)

    Paulo, Graciano do Nascimento Nobre

    Purpose: This study aimed to propose Diagnostic Reference Levels (DRLs) in paediatric plain radiography and to optimise the most frequent paediatric plain radiography examinations in Portugal following an analysis and evaluation of current practice. Methods and materials: Anthropometric data (weight, patient height and thickness of the irradiated anatomy) was collected from 9,935 patients referred for a radiography procedure to one of the three dedicated paediatric hospitals in Portugal. National DRLs were calculated for the three most frequent X-ray procedures at the three hospitals: chest AP/PA projection; abdomen AP projection; pelvis AP projection. Exposure factors and patient dose were collected prospectively at the clinical sites. In order to analyse the relationship between exposure factors, the use of technical features and dose, experimental tests were made using two anthropomorphic phantoms: a) CIRSTM ATOM model 705; height: 110cm, weight: 19kg and b) Kyoto kagakuTM model PBU-60; height: 165cm, weight: 50kg. After phantom data collection, an objective image analysis was performed by analysing the variation of the mean value of the standard deviation, measured with OsiriX software (Pixmeo, Switzerland). After proposing new exposure criteria, a Visual Grading Characteristic image quality evaluation was performed blindly by four paediatric radiologists, each with a minimum of 10 years of professional experience, using anatomical criteria scoring. Results: DRLs by patient weight groups have been established for the first time. ESAKP75 DRLs for both patient age and weight groups were also obtained and are described in the thesis. Significant dose reduction was achieved through the implementation of an optimisation programme: an average reduction of 41% and 18% on KAPP75 and ESAKP75, respectively for chest plain radiography; an average reduction of 58% and 53% on KAPP75 and ESAKP75, respectively for abdomen plain radiography; and an average reduction of 47% and

  9. Review: Recharge rates and chemistry beneath playas of the High Plains aquifer, USA

    NASA Astrophysics Data System (ADS)

    Gurdak, Jason J.; Roe, Cassia D.

    2010-12-01

    Playas are ephemeral, closed-basin wetlands that are hypothesized as an important source of recharge to the High Plains aquifer in central USA. The ephemeral nature of playas, low regional recharge rates, and a strong reliance on groundwater from the High Plains aquifer has prompted many questions regarding the contribution and quality of recharge from playas to the High Plains aquifer. As a result, there has been considerable scientific debate about the potential for water to infiltrate the relatively impermeable playa floors, travel through the unsaturated zone sediments that are tens of meters thick, and subsequently recharge the High Plains aquifer. This critical review examines previously published studies on the processes that control recharge rates and chemistry beneath playas. Reported recharge rates beneath playas range from less than 1.0 to more than 500 mm/yr and are generally 1-2 orders of magnitude higher than recharge rates beneath interplaya settings. Most studies support the conceptual model that playas are important zones of recharge to the High Plains aquifer and are not strictly evaporative pans. The major findings of this review provide science-based implications for management of playas and groundwater resources of the High Plains aquifer and directions for future research.

  10. Velocity and structural model of the Lower Tagus Basin according to the study of environmental seismic noise

    NASA Astrophysics Data System (ADS)

    Gomes Torres, Ricardo Jorge; Furtado, José Augusto; Gonçalves Silva, Hugo; Borges, José Fernando; Caldeira, Bento; Bezzeghoud, Mourad; Carvalho, João

    2013-04-01

    Along his history the Lower Tagus Valley (LTV) region was shaken by several earthquakes, some of them produced in large ruptures of offshore structures located southwest of the Portuguese coastline. Among these is the Lisbon earthquake of 1 November 1755 (M~8.5-8.7), and other moderates earthquakes that were produced by local sources such as the 1344 (M6.0), 1531 (M7.1) and 1909 (M6.0) earthquakes. Previous simulations [1] have shown high velocity amplification in the region. The model used in the simulations was updated from low to high resolution using all the new available geophysical and geotechnical data on the area (seismic reflection, aeromagnetic, gravimetric, deep wells and geological outcrops) [2]. To confirm this model in the areas where it was derived by potential field methods we use broadband ambient noise measurements collected in about 200 points along seven profiles on the LTV basin, six perpendicular and one parallel to the basin axis. We applied the horizontal to vertical (H/V) spectral ratio method [3] to the seismic noise profiles in order to estimate the distribution of amplification in the basin. The H/V curves obtained reveals the existence of two low frequency peaks centered on 0.2 and 1 Hz [4]. These peaks are strongly related with the thickness of Cenozoic and alluvial sediments. The velocity model obtained by inversion of the H/V curves is in good agreement with borehole data, and results obtained using seismic reflection and gravimetric methods. However, aeromagnetic data overestimates the depth of the base of Cenozoic in the areas where it overlies directly the paleozoic basement, which we attribute either to the existence of Mesozoic units or higher magnetic susceptibilities than expected for the Paleozoic. References: [1] Bezzeghoud, M., Borges, J.F., M., Caldeira (2011). Ground motion simulations of the SW Iberia margin: rupture directivity and earth structure effects. Natural Hazards, pages 1-17. doi:10.1007/s11069-011-9925-2 [2

  11. Plain packaging of cigarettes and smoking behavior: study protocol for a randomized controlled study.

    PubMed

    Maynard, Olivia M; Leonards, Ute; Attwood, Angela S; Bauld, Linda; Hogarth, Lee; Munafò, Marcus R

    2014-06-25

    Previous research on the effects of plain packaging has largely relied on self-report measures. Here we describe the protocol of a randomized controlled trial investigating the effect of the plain packaging of cigarettes on smoking behavior in a real-world setting. In a parallel group randomization design, 128 daily cigarette smokers (50% male, 50% female) will attend an initial screening session and be assigned plain or branded packs of cigarettes to smoke for a full day. Plain packs will be those currently used in Australia where plain packaging has been introduced, while branded packs will be those currently used in the United Kingdom. Our primary study outcomes will be smoking behavior (self-reported number of cigarettes smoked and volume of smoke inhaled per cigarette as measured using a smoking topography device). Secondary outcomes measured pre- and post-intervention will be smoking urges, motivation to quit smoking, and perceived taste of the cigarettes. Secondary outcomes measured post-intervention only will be experience of smoking from the cigarette pack, overall experience of smoking, attributes of the cigarette pack, perceptions of the on-packet health warnings, behavior changes, views on plain packaging, and the rewarding value of smoking. Sex differences will be explored for all analyses. This study is novel in its approach to assessing the impact of plain packaging on actual smoking behavior. This research will help inform policymakers about the effectiveness of plain packaging as a tobacco control measure. Current Controlled Trials ISRCTN52982308 (registered 27 June 2013).

  12. GLORIA mosaic of the Gulf of Alaska and the British Columbia margin: Deep-sea channels, margin deformation, and the Queen Charlotte fault

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

    Bruns, T.R.; Carlson, P.R.; Stevenson, A.J.

    1990-05-01

    GLORIA images collected from 1986 to 1989 show sea-floor morphology from the shelf break seaward to 400 km in the Gulf of Alaska and a 70-km-wide swath along British Columbia. Along the Aleutian convergent margin sediment is dominantly trapped in mid-slope basins, where few canyons reach the trench. Accretionary wedge structures range from highly discontinuous to long and continuous. The Yakutat transition margin is either extensively cut by dendritic drainages or, at sea-valley mouths, covered by glacially derived sediment. Young structures underlie the slope from Middleton Island to Pamplona Spur, but are absent from Pamplona Spur to Cross Sound. Alongmore » the southeast Alaska transform margin the Queen Charlotte fault is imaged as a narrow linear feature. The fault steps westward at Tuzo Wilson Knolls, which likely is a spreading ridge segment. Large anticlines lie seaward of and trend parallel to the fault. On the abyssal plain off the Shumagin margin inherited structural and bathymetric features trend parallel to magnetic anomalies, and trench parallel features reflect faulting as the ocean plate bends into the trench. To the north, three turbidite systems drain the margin. The Surveyor system begins between Pamplona Spur and Alsek Canyon and empties into the Aleutian Trench. The Chirikof system arises near Cross Sound and ends in turbidite fans south of the Kodiak-Bowie Seamount chain, a relic Chirikov channel that once carried sediment westward to the Aleutian Trench. The Mukluk and Horizon channels start along southeast Alaska and end 1,000 km away on the Tufts abyssal plain.« less

  13. Erosion and deposition on the eastern margin of the Bermuda Rise in the late Quaternary

    NASA Astrophysics Data System (ADS)

    McCave, I. N.; Hollister, C. D.; Laine, E. P.; Lonsdale, P. F.; Richardson, M. J.

    1982-05-01

    A near-bottom survey has been made on the Eastward Scarp (32°50'N, 57°30'W) of the Bermuda Rise, which rises 1150 m above the 5500-m deep Sohm Abyssal Plain in the western North Atlantic. The survey reveals evidence of erosion and deposition at present and in the late Quaternary by the deeper levels of the westward flowing Gulf Stream Return Flow. Four distinct regions of increasing bed gradient show increasing sediment smoothing and scour in the transition from plateau to abyssal plain. Bedforms observed are current crescents, crag and tail, triangular ripples, elongate mounds, transverse mud ripples, lineations, and furrows ranging from 10 to 1 m or less in depth, decreasing generally with bed gradient. Measured near-bottom current speeds are up to 20 cm s -1. Temperature structure on the lower, steep, slopes suggests that detachment of bottom mixed layers may occur there. Extensive net erosion appears to be confined to the lower steep slopes of the scarp. Reflection profiles (4 kHz) show that there has been erosion in areas thinly draped with recent sediments and in areas that show development of small scarps. The distribution of subsurface acoustic characteristics of the region corresponds broadly to the areas characterized by bed gradient and distinct sedimentation conditions. Subsurface hyperbolae, possibly caused by buried furrows, show furrow persistence through several tens of metres of deposition. Erosion occurs up to the top of the scarp during episodes of presumed stronger currents, which may correspond with intensified circulation during glacials.

  14. Geomorphology of the Iberian Continental Margin

    NASA Astrophysics Data System (ADS)

    Maestro, Adolfo; López-Martínez, Jerónimo; Llave, Estefanía; Bohoyo, Fernando; Acosta, Juan; Hernández-Molina, F. Javier; Muñoz, Araceli; Jané, Gloria

    2013-08-01

    The submarine features and processes around the Iberian Peninsula are the result of a complex and diverse geological and oceanographical setting. This paper presents an overview of the seafloor geomorphology of the Iberian Continental Margin and the adjacent abyssal plains. The study covers an area of approximately 2.3 million km2, including a 50 to 400 km wide band adjacent to the coastline. The main morphological characteristics of the seafloor features on the Iberian continental shelf, continental slope, continental rise and the surrounding abyssal plains are described. Individual seafloor features existing on the Iberian Margin have been classified into three main groups according to their origin: tectonic and/or volcanic, depositional and erosional. Major depositional and erosional features around the Iberian Margin developed in late Pleistocene-Holocene times and have been controlled by tectonic movements and eustatic fluctuations. The distribution of the geomorphological features is discussed in relation to their genetic processes and the evolution of the margin. The prevalence of one or several specific processes in certain areas reflects the dominant morphotectonic and oceanographic controlling factors. Sedimentary processes and the resulting depositional products are dominant on the Valencia-Catalán Margin and in the northern part of the Balearic Promontory. Strong tectonic control is observed in the geomorphology of the Betic and the Gulf of Cádiz margins. The role of bottom currents is especially evident throughout the Iberian Margin. The Galicia, Portuguese and Cantabrian margins show a predominance of erosional features and tectonically-controlled linear features related to faults.

  15. Climate vulnerabilities in the southern plains

    USDA-ARS?s Scientific Manuscript database

    The value of agricultural production in the Southern Plains exceeded $59 bil (2012 Agricultural Census) with livestock accounting for 58% of total agricultural sales. Crop and livestock commodities exceeding $1 bil include wheat, corn, horticultural crops, cotton, hay and forages, sorghum, soybean, ...

  16. Water Flow in the High Plains Aquifer in Northwestern Oklahoma

    USGS Publications Warehouse

    Luckey, Richard R.; Osborn, Noel I.; Becker, Mark F.; Andrews, William J.

    2000-01-01

    The High Plains is a major agricultural area, supported primarily by water from the High Plains aquifer, which is used to irrigate wheat and corn and to raise cattle and swine. The U.S. Geological Survey (USGS) and the Oklahoma Water Resources Board (OWRB) began a study of the High Plains aquifer in 1996. One purpose of the study was to develop a ground-water flow model that the OWRB could use to allocate the amount of water withdrawn from the a aquifer. The study area in Oklahoma covers all or parts of Beaver, Cimarron, Dewey, Ellis, Harper, Texas, and Woodward Counties. To provide appropriate hydrologic boundaries for the ground-water flow model, the study area was expanded to include parts of Colorado, Kansas, New Mexico, and Texas.

  17. 44 CFR 60.7 - Revisions of criteria for flood plain management regulations.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... flood plain management regulations. 60.7 Section 60.7 Emergency Management and Assistance FEDERAL EMERGENCY MANAGEMENT AGENCY, DEPARTMENT OF HOMELAND SECURITY INSURANCE AND HAZARD MITIGATION National Flood Insurance Program CRITERIA FOR LAND MANAGEMENT AND USE Requirements for Flood Plain Management Regulations...

  18. 44 CFR 60.7 - Revisions of criteria for flood plain management regulations.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... flood plain management regulations. 60.7 Section 60.7 Emergency Management and Assistance FEDERAL EMERGENCY MANAGEMENT AGENCY, DEPARTMENT OF HOMELAND SECURITY INSURANCE AND HAZARD MITIGATION National Flood Insurance Program CRITERIA FOR LAND MANAGEMENT AND USE Requirements for Flood Plain Management Regulations...

  19. 44 CFR 60.7 - Revisions of criteria for flood plain management regulations.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... flood plain management regulations. 60.7 Section 60.7 Emergency Management and Assistance FEDERAL EMERGENCY MANAGEMENT AGENCY, DEPARTMENT OF HOMELAND SECURITY INSURANCE AND HAZARD MITIGATION National Flood Insurance Program CRITERIA FOR LAND MANAGEMENT AND USE Requirements for Flood Plain Management Regulations...

  20. 44 CFR 60.7 - Revisions of criteria for flood plain management regulations.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... flood plain management regulations. 60.7 Section 60.7 Emergency Management and Assistance FEDERAL EMERGENCY MANAGEMENT AGENCY, DEPARTMENT OF HOMELAND SECURITY INSURANCE AND HAZARD MITIGATION National Flood Insurance Program CRITERIA FOR LAND MANAGEMENT AND USE Requirements for Flood Plain Management Regulations...

  1. Constructing a Home on the Range: Homemaking in Early-Twentieth-Century Plains Photograph Albums

    ERIC Educational Resources Information Center

    Dando, Christina E.

    2008-01-01

    For people living near the coasts or mountains of America, it must be hard to imagine longing for a "home on the plains"--but many Americans have had, and still have, a home on the Plains. The stereotypical American image of the Plains is flatness, austerity, emptiness. Not all would consider this an ideal landscape for home. So how did…

  2. Caanyon Mediated Cross-Slope Transport

    NASA Astrophysics Data System (ADS)

    Mihaly, S. F.; Cabrera De Leo, F.; Sastri, A. R.; Matabos, M.; Heesemann, M.; Ogata, B.

    2017-12-01

    Three current meter and water property stations along the west coast of Vancouver Island along with video and acoustic backscatter observations are used to gain insight into mechanisms of cross-slope transport. The setting is an eastern boundary current region with a active poleward flowing countercurrent. The significant effects of these currents flowing over a strongly incised continental slope along with cross-slope density flows are contrasted with the seasonally varying upwelling and downwelling regime. The video and acoustic backscatter enabled by Ocean Networks Canada's NEPTUNE observatory provide a view on the materials being transported between the abyssal plain and the continental shelf.

  3. Flood Plain Topography Affects Establishment Success of Direct-Seeded Bottomland Oaks

    Treesearch

    Emile S. Gardiner; John D. Hodges; T. Conner Fristoe

    2004-01-01

    Five bottomland oak species were direct seeded along a topographical gradient in a flood plain to determine if environmental factors related to relative position in the flood plain influenced seedling establishment and survival. Two years after installation of the plantation, seedling establishment rates ranged from 12±1.6 (mean ± standard error) percent for overcup...

  4. The Buffalo Commons: Great Plains Residents' Responses to a Radical Vision

    ERIC Educational Resources Information Center

    Rees, Amanda

    2005-01-01

    The American Great Plains has gained and shed various regional meanings since Euro-American exploration began. From a desert to a garden to a dust bowl to a breadbasket, this region's identity has shifted radically and dramatically over the last 200 years. In the mid-1980s unusual things were happening on the Plains that suggested yet another…

  5. Prediction of Tsunami Inundation in the City of Lisbon (portugal)

    NASA Astrophysics Data System (ADS)

    Baptista, M.; Miranda, J.; Omira, R.; Catalao Fernandes, J.

    2010-12-01

    Lisbon city is located inside the estuary of Tagus river, 20 km away from the Atlantic ocean. The city suffered great damage from tsunamis and its downtown was flooded at least twice in 1531 and 1755. Since the installation of the tide-gage network, in the area, three tsunamis caused by submarine earthquakes, were recorded in November 1941, February 1969 and May 1975. The most destructive tsunamis listed along Tagus Estuary are the 26th January 1531, a local tsunami event restricted to the Tagus Estuary, and the well known 1st November 1755 transoceanic event, both following highly destructive earthquakes, which deeply affected Lisbon. The economic losses due to the impact of the 1755 tsunami in one of Europe’s 18t century main harbor and commercial fleets were enormous. Since then the Tagus estuary suffered strong morphologic changes manly due to dredging works, construction of commercial and industrial facilities and recreational docks, some of them already projected to preserve Lisbon. In this study we present preliminary inundation maps for the Tagus estuary area in the Lisbon County, for conditions similar to the 1755 tsunami event, but using present day bathymetric and topographic maps. Inundation modelling is made using non linear shallow water theory and the numerical code is based upon COMCOT code. Nested grids resolutions used in this study are 800 m, 200 m and 50 m, respectively. The inundation is discussed in terms of flow depth, run up height, maximum inundation area and current flow velocity. The effects of estuary modifications on tsunami propagation are also investigated.

  6. Deformation associated with ghost craters and basins in volcanic smooth plains on Mercury: Strain analysis and implications for plains evolution

    NASA Astrophysics Data System (ADS)

    Klimczak, Christian; Watters, Thomas R.; Ernst, Carolyn M.; Freed, Andrew M.; Byrne, Paul K.; Solomon, Sean C.; Blair, David M.; Head, James W.

    2012-09-01

    Since its insertion into orbit about Mercury in March 2011, the MESSENGER spacecraft has imaged most previously unseen regions of the planet in unprecedented detail, revealing extensive regions of contiguous smooth plains at high northern latitudes and surrounding the Caloris basin. These smooth plains, thought to be emplaced by flood volcanism, are populated with several hundred ghost craters and basins, nearly to completely buried impact features having rims for which the surface expressions are now primarily rings of deformational landforms. Associated with some ghost craters are interior groups of graben displaying mostly polygonal patterns. The origin of these graben is not yet fully understood, but comparison with numerical models suggests that the majority of such features are the result of stresses from local thermal contraction. In this paper, we highlight a previously unreported category of ghost craters, quantify extensional strains across graben-bearing ghost craters, and make use of graben geometries to gain insights into the subsurface geology of smooth plains areas. In particular, the style and mechanisms of graben development imply that flooding of impact craters and basins led to substantial pooling of lavas, to thicknesses of ˜1.5 km. In addition, surface strains derived from groups of graben are generally in agreement with theoretically and numerically derived strains for thermal contraction.

  7. 49 CFR 215.111 - Defective plain bearing.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ..., DEPARTMENT OF TRANSPORTATION RAILROAD FREIGHT CAR SAFETY STANDARDS Freight Car Components Suspension System § 215.111 Defective plain bearing. A railroad may not place or continue in service a car, if the car has...

  8. 49 CFR 215.111 - Defective plain bearing.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ..., DEPARTMENT OF TRANSPORTATION RAILROAD FREIGHT CAR SAFETY STANDARDS Freight Car Components Suspension System § 215.111 Defective plain bearing. A railroad may not place or continue in service a car, if the car has...

  9. 49 CFR 215.111 - Defective plain bearing.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., DEPARTMENT OF TRANSPORTATION RAILROAD FREIGHT CAR SAFETY STANDARDS Freight Car Components Suspension System § 215.111 Defective plain bearing. A railroad may not place or continue in service a car, if the car has...

  10. 49 CFR 215.111 - Defective plain bearing.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ..., DEPARTMENT OF TRANSPORTATION RAILROAD FREIGHT CAR SAFETY STANDARDS Freight Car Components Suspension System § 215.111 Defective plain bearing. A railroad may not place or continue in service a car, if the car has...

  11. 49 CFR 215.111 - Defective plain bearing.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ..., DEPARTMENT OF TRANSPORTATION RAILROAD FREIGHT CAR SAFETY STANDARDS Freight Car Components Suspension System § 215.111 Defective plain bearing. A railroad may not place or continue in service a car, if the car has...

  12. Outwash plains and thermokarst on Mars

    USGS Publications Warehouse

    Costard, F.M.; Kargel, J.S.

    1995-01-01

    The spatial distribution of different types of rampart craters on Mars suggests a hemispheric asymmetry in the distribution of ground ice. The northern plains, especially major topographic depressions near the terminations of outflow channels, have high percentages of rampart craters. Two of these basins, Acidalia and Utopia Planitiae, received extraordinarily large amounts of water and sediment from the Chryse and Elysium outflow channels. In both regions, the analysis of high-resolution Viking pictures (12 m/pixel) indicates a concentration of kilometer-scale depressions that are similar in size and form to thermokarstic features in Yakutia (Siberia) and parts of the arctic coastal plain of North America. Accordingly, we infer that (1) Utopia Planitia and Acidalia Planitia may contain thick, laterally continuous, ice-rich sedimentary deposits related to outflow channel-forming floods, and (2) these areas of Mars may have experienced thermokarstic processes similar to modern thermokarstic processes in some periglacial regions of Earth.

  13. Women's Life Course in Northern Plains Indian Societies: Achieving the Honored Rank of Old Lady.

    ERIC Educational Resources Information Center

    Kehoe, Alice B.

    Among Indian groups of the Northwestern Plains (Blackfoot, Plains Cree, Dakota, Plains Ojibwa), older persons are respected for the spiritual power they have obtained. Differences exist between the several ethnic groups, but in general they assume that attainment of maturity and then old age proves spiritual power and makes the elder a proper…

  14. 40 CFR 81.152 - Southern Coastal Plain Intrastate Air Quality Control Region.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 17 2011-07-01 2011-07-01 false Southern Coastal Plain Intrastate Air Quality Control Region. 81.152 Section 81.152 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Air Quality Control Regions § 81.152 Southern Coastal Plain Intrastate Air Quality Control Region. The...

  15. 40 CFR 81.149 - Northern Coastal Plain Intrastate Air Quality Control Region.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 18 2013-07-01 2013-07-01 false Northern Coastal Plain Intrastate Air Quality Control Region. 81.149 Section 81.149 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Air Quality Control Regions § 81.149 Northern Coastal Plain Intrastate Air Quality Control Region. The...

  16. 40 CFR 81.149 - Northern Coastal Plain Intrastate Air Quality Control Region.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 17 2010-07-01 2010-07-01 false Northern Coastal Plain Intrastate Air Quality Control Region. 81.149 Section 81.149 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Air Quality Control Regions § 81.149 Northern Coastal Plain Intrastate Air Quality Control Region. The...

  17. 40 CFR 81.152 - Southern Coastal Plain Intrastate Air Quality Control Region.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 18 2014-07-01 2014-07-01 false Southern Coastal Plain Intrastate Air Quality Control Region. 81.152 Section 81.152 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Air Quality Control Regions § 81.152 Southern Coastal Plain Intrastate Air Quality Control Region. The...

  18. 40 CFR 81.152 - Southern Coastal Plain Intrastate Air Quality Control Region.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 17 2010-07-01 2010-07-01 false Southern Coastal Plain Intrastate Air Quality Control Region. 81.152 Section 81.152 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Air Quality Control Regions § 81.152 Southern Coastal Plain Intrastate Air Quality Control Region. The...

  19. 40 CFR 81.152 - Southern Coastal Plain Intrastate Air Quality Control Region.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 18 2013-07-01 2013-07-01 false Southern Coastal Plain Intrastate Air Quality Control Region. 81.152 Section 81.152 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Air Quality Control Regions § 81.152 Southern Coastal Plain Intrastate Air Quality Control Region. The...

  20. 40 CFR 81.149 - Northern Coastal Plain Intrastate Air Quality Control Region.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 18 2012-07-01 2012-07-01 false Northern Coastal Plain Intrastate Air Quality Control Region. 81.149 Section 81.149 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Air Quality Control Regions § 81.149 Northern Coastal Plain Intrastate Air Quality Control Region. The...

  1. 40 CFR 81.152 - Southern Coastal Plain Intrastate Air Quality Control Region.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 18 2012-07-01 2012-07-01 false Southern Coastal Plain Intrastate Air Quality Control Region. 81.152 Section 81.152 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Air Quality Control Regions § 81.152 Southern Coastal Plain Intrastate Air Quality Control Region. The...

  2. 40 CFR 81.149 - Northern Coastal Plain Intrastate Air Quality Control Region.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 18 2014-07-01 2014-07-01 false Northern Coastal Plain Intrastate Air Quality Control Region. 81.149 Section 81.149 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Air Quality Control Regions § 81.149 Northern Coastal Plain Intrastate Air Quality Control Region. The...

  3. 40 CFR 81.149 - Northern Coastal Plain Intrastate Air Quality Control Region.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 17 2011-07-01 2011-07-01 false Northern Coastal Plain Intrastate Air Quality Control Region. 81.149 Section 81.149 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Air Quality Control Regions § 81.149 Northern Coastal Plain Intrastate Air Quality Control Region. The...

  4. Savannah River Region: Transition between the Gulf and Atlantic Coastal Plains. Proceedings

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

    Zullo, V.A.; Harris, W.B.; Price, V.

    1990-12-31

    The focus of the this conference of Coastal Plains geologists was on the Savannah River region of Georgia and South Carolina, and particularly on the geology of the US Department of Energy`s 300 square mile Savannah River Site (SRS) in western South Carolina. Current geological studies indicate that the Mesozoic-Cenozoic section in the Savannah River region is transitional between that of the Gulf Coastal Plain to the southwest and that of the Atlantic Coastal Plain to the northeast. With the transitional aspect of the region as its theme, the first session was devoted to overviews of Cretaceous and Paleogene geologymore » in the Gulf and Atlantic Coastal Plains. Succeeding presentations and resulting discussions dealt with more specific problems in structural, lithostratigraphic, hydrological, biostratigraphic, and cyclostratigraphic analysis, and of correlation to standard stratigraphic frameworks. For these conference proceedings, individual papers have been processed separately for the Energy Data Base.« less

  5. Study on the Groundwater Vulnerability Assessment in Sanjiang Plain in Northeast China

    NASA Astrophysics Data System (ADS)

    Tang, Y.; Tang, W. K.; Liu, C.

    2012-12-01

    The Sanjiang Plain is located in eastern part of China's Heilongjiang Province.It's total area is 109 000 km2, with cultivated land area being 3.6677 million hm2. It is a major national commodity grain base. Rice planting area in Sanjiang Plain has been increasing year by year. Groundwater exploitation is increasing rapidly as a result of rapid increase of paddy field area. It is necessary to research and analyze spatial diversity of groundwater pollution vulnerability for Sanjiang Plain, so as to fulfill the goal of integrated planning, rational utilization of land and water resource, avoiding or minimizing groundwater contamination, and protecting grain security of China. Based on the commonly used DRASTIC method internationally, and according to hydrogeology, land use and other characteristics of Sanjiang Plain, this paper establishes groundwater vulnerability assessment index system. Since the Sanjiang Plain is an area that gives priority to agriculture, and impact of agricultural land and agricultural activity on groundwater vulnerability can not be ignored. Two indicators of agricultural land use rate (L) and population density (P) are increased in the DRASTC index system, the remaining 5 indicators are groundwater depth (D), aquifer net recharge(R), aquifer media type (A), soil type(S), aquifer hydraulic conductivity (C). Taking ArcGis as a calculation analysis platform to assess groundwater vulnerability of the Sanjiang Plain, by using hierarchical analysis method of the fuzzy mathematics method to calculate each index weigh of evaluation vulnerability. This paper applies 6 levels of assessment standard as follows: vulnerability index DI <2 stands for not vulnerable; 2 8 stands for extremely vulnerable. Groundwater vulnerably contaminated area is delineated based on the groundwater vulnerability spatial

  6. Boulder Strewn Plain in Northern Utopia Planitia

    NASA Image and Video Library

    2010-03-31

    This image taken by NASA Mars Reconnaissance Orbiter in the Cydnus Rupes region, shows that the northern plains of Mars are rock and boulder strewn landscapes otherwise devoid of major features except a few impact craters.

  7. Premature deterioration of jointed plain concrete pavements.

    DOT National Transportation Integrated Search

    2011-04-29

    Six sections of jointed plain concrete pavements (JPCP)s throughout the state were selected as candidates for the evaluation of premature deterioration. The data used in performing the evaluation included manual and historic automated distress survey...

  8. Premature deterioration of jointed plain concrete pavements.

    DOT National Transportation Integrated Search

    2011-04-29

    Six sections of jointed plain concrete pavements (JPCP)s throughout the state were selected as : candidates for the evaluation of premature deterioration. The data used in performing the evaluation included manual : and historic automated distress su...

  9. Digital radiographic imaging transfer: comparison with plain radiographs.

    PubMed

    Averch, T D; O'Sullivan, D; Breitenbach, C; Beser, N; Schulam, P G; Moore, R G; Kavoussi, L R

    1997-04-01

    Advances in digital imaging and computer display technology have allowed development of clinical teleradiographic systems. There are limited data assessing the effectiveness of such systems when applied to urologic pathology. In an effort to appraise the effectiveness of teleradiology in identifying renal calculi, the accuracy of findings on transmitted radiographic images were compared with those made when viewing the actual plain film. Plain films (KUB) were obtained from 26 patients who presented to the radiology department to rule out urinary calculous disease. The films were digitalized by a radiograph scanner into ARCNEMA-2 file format, compressed by a NASA algorithm, and transferred via a 28.8-kbps modern over standard telephone lines to a remote section 25 miles away, where they were decompressed and viewed on a 1600 x 1200-pixel monitor. Two attending urologists and two endourologic fellows were randomized to read either the transmitted image or the original radiograph with minimal clinical history provided. Of the 26 plain radiographic films, 24 were correctly interpreted by the fellows and 25 by the attending physicians (92% and 96% accuracy, respectively) for a total accuracy of 94% with no statistical difference (p = 0.16). After compression, all but one of the digital images were transferred successfully. The attending physicians correctly interpreted 24 of the 25 digital images (96%), whereas the fellows were correct on 21 interpretations (84%), resulting in a total 90% accuracy with a significant difference between the groups (p < or = 0.04). Overall, no statistical difference between the interpretations of the plain film and the digital image was revealed (p = 0.21). Using available technology, KUB images can be transmitted to a remote site, and the location of a stone can be determined correctly. Higher accuracy is demonstrated by experienced surgeons.

  10. Hydraulic and hydrologic aspects of flood-plain planning

    USGS Publications Warehouse

    Wiitala, S.W.; Jetter, K.R.; Sommerville, Alan J.

    1961-01-01

    The valid incentives compelling occupation of the flood plain, up to and eve n into the stream channel, undoubtedly have contributed greatly to the development of the country. But the result has been a heritage of flood disaster, suffering, and enormous costs. Flood destruction awakened a consciousness toward reduction and elimination of flood hazards, originally manifested in the protection of existing developments. More recently, increased knowledge of the problem has shown the impracticability of permitting development that requires costly flood protect/on. The idea of flood zoning, or flood-plain planning, has received greater impetus as a result of this realization. This study shows how hydraulic and hydrologic data concerning the flood regimen of a stream can be used in appraising its flood potential and the risk inherent in occupation of its flood plain. The approach involves the study of flood magnitudes as recorded or computed; flood frequencies based1 on experience shown by many years of gaging-station record; use of existing or computed stagedischarge relations and flood profiles; and, where required, the preparation of flood-zone maps to show the areas inundated by floods of several magnitudes and frequencies. The planner can delineate areas subject to inundation by floods o* specific recurrence intervals for three conditions: (a) for the immediate vicinity of a gaging station; (b) for a gaged stream at a considerable distance from a gaging station; and (c) for an ungaged stream. The average depth for a flood of specific frequency can be estimated on the basis of simple measurements of area of drainage basin, width of channel, and slope of streambed. This simplified approach should be useful in the initial stages of flood-plain planning. Brief discussions are included on various types of flood hazards, the effects of urbanization on flood runoff, and zoning considerations.

  11. Plain cigarette packs do not exert Pavlovian to instrumental transfer of control over tobacco-seeking

    PubMed Central

    Hogarth, Lee; Maynard, Olivia M; Munafò, Marcus R

    2015-01-01

    Aims To gain insight into the potential impact of plain tobacco packaging policy, two experiments were undertaken to test whether ‘prototype’ plain compared with branded UK cigarette pack stimuli would differentially elicit instrumental tobacco-seeking in a nominal Pavlovian to instrumental transfer (PIT) procedure. Design, Setting and Participants Two experiments were undertaken at the University of Bristol UK, with a convenience sample of adult smokers (experiment 1, n = 23, experiment 2, n = 121). Measurement In both experiments, smokers were trained on a concurrent choice procedure in which two responses earned points for cigarettes and chocolate, respectively, before images of branded and plain packs were tested for capacity to elicit the tobacco-seeking response in extinction. The primary outcome was percentage choice of the tobacco- over the chocolate-seeking response in plain pack, branded pack and no-stimulus conditions. Findings Both experiments found that branded packs primed a greater percentage of tobacco-seeking (overall mean = 62%) than plain packs (overall mean = 53%) and the no-stimulus condition (overall mean = 52%; Ps ≤ 0.01, ŋp2s ≥ 0.16), and that there was no difference in percentage tobacco-seeking between plain packs and the no-stimulus condition (Ps ≥ 0.17, ŋp2s ≤ 0.04). Plain tobacco packs showed an overall 9% reduction in the priming of a tobacco choice response compared to branded tobacco packs. Conclusions Plain packaging may reduce smoking in current smokers by degrading cue-elicited tobacco-seeking. PMID:25292280

  12. Age determinations and Earth-based multispectral observations of lunar light plains

    NASA Technical Reports Server (NTRS)

    Koehler, U.; Jaumann, R.; Neukum, G.

    1993-01-01

    The history of light plains still remains doubtful, but there are good arguments - mainly obtained by age determinations and supported by multispectral observations - for an endogenic (magmatic) instead of an (exclusively) impact related origin. Light plains are characterized by smooth areas with an albedo lower than the surrounding highlands (12 - 13 percent), but significantly higher than maria (5 - 6 percent). Before Apollo 16 a volcanic source has been supposed, but analysis of returned samples (highly brecciated and metamorphosed rocks) favored an impact ejecta related origin. Among the currently discussed models are formation by ejecta sedimentation from multi-ringed basins, formation by secondary and tertiary cratering action of ballistically ejected material during the formation of multi-ringed basins, in situ formation by impact melt of large events, and premare (crypto-) volcanism basalts covered by a thin ejecta cover; younger impacts penetrated the ejecta surface to create the dark haloed craters. To find arguments in favor or against these ideas the chronology of light plains is of major importance. Obviously a genetic relationship between the evolution of light plains and the basin forming impacts can be possible only if the events of emplacement features happened simultaneously.

  13. Ground-water use in the coastal plain of Maryland, 1900-1980

    USGS Publications Warehouse

    Wheeler, J.C.; Wilde, F.D.

    1989-01-01

    This report presents groundwater withdrawal data from 1900 through 1980 for Maryland counties lying with the Coastal Plain physiographic province, as well as a summary section for the total Maryland Coastal Plain. The types of water use included are domestic, military, water supplier, industrial/commercial, and irrigation. The data were obtained from state and county reports, biannual pumpage reports submitted to the Maryland Water Resources Administration, communication with individual owners, and estimates based on existing published data. The amount of groundwater withdrawn from aquifers in the Maryland Coastal Plain in 1900 was approximately 26 million gallons per day (Mgal/d) compared to nearly 134 Mgal/d in 1980. Jurisdictions withdrawing more than 10 Mgal/d for most of the 80-year period were Anne Arundel and Baltimore Counties and Baltimore City. The greatest withdrawals for most of the early part of the period were for domestic and industrial/commercial uses; however, water-supplier use dominated after 1965. Groundwater use for irrigation became important in the Coastal Plain around 1960 and increased steadily from approximately 2 Mgal/d in 1960 to nearly 12 Mgal/d in 1980. (USGS)

  14. Flood plain and channel dynamics of the Quinault and Queets Rivers, Washington, USA

    USGS Publications Warehouse

    O'Connor, J. E.; Jones, M.A.; Haluska, T.L.

    2003-01-01

    Observations from this study and previous studies on the Queets River show that channel and flood-plain dynamics and morphology are affected by interactions between flow, sediment, and standing and entrained wood, some of which likely involve time frames similar to 200–500-year flood-plain half-lives. On the upper Quinault River and Queets River, log jams promote bar growth and consequent channel shifting, short-distance avulsions, and meander cutoffs, resulting in mobile and wide active channels. On the lower Quinault River, large portions of the channel are stable and flow within vegetated flood plains. However, locally, channel-spanning log jams have caused channel avulsions within reaches that have been subsequently mobile for several decades. In all three reaches, log jams appear to be areas of conifer germination and growth that may later further influence channel and flood-plain conditions on long time scales by forming flood-plain areas resistant to channel migration and by providing key members of future log jams. Appreciation of these processes and dynamics and associated temporal and spatial scales is necessary to formulate effective long-term approaches to managing fluvial ecosystems in forested environments.

  15. Radiation dose and magnification in pelvic X-ray: EOS™ imaging system versus plain radiographs.

    PubMed

    Chiron, P; Demoulin, L; Wytrykowski, K; Cavaignac, E; Reina, N; Murgier, J

    2017-12-01

    In plain pelvic X-ray, magnification makes measurement unreliable. The EOS™ (EOS Imaging, Paris France) imaging system is reputed to reproduce patient anatomy exactly, with a lower radiation dose. This, however, has not been assessed according to patient weight, although both magnification and irradiation are known to vary with weight. We therefore conducted a prospective comparative study, to compare: (1) image magnification and (2) radiation dose between the EOS imaging system and plain X-ray. The EOS imaging system reproduces patient anatomy exactly, regardless of weight, unlike plain X-ray. A single-center comparative study of plain pelvic X-ray and 2D EOS radiography was performed in 183 patients: 186 arthroplasties; 104 male, 81 female; mean age 61.3±13.7years (range, 24-87years). Magnification and radiation dose (dose-area product [DAP]) were compared between the two systems in 186 hips in patients with a mean body-mass index (BMI) of 27.1±5.3kg/m 2 (range, 17.6-42.3kg/m 2 ), including 7 with morbid obesity. Mean magnification was zero using the EOS system, regardless of patient weight, compared to 1.15±0.05 (range, 1-1.32) on plain X-ray (P<10 -5 ). In patients with BMI<25, mean magnification on plain X-ray was 1.15±0.05 (range, 1-1.25) and, in patients with morbid obesity, 1.22±0.06 (range, 1.18-1.32). The mean radiation dose was 8.19±2.63dGy/cm 2 (range, 1.77-14.24) with the EOS system, versus 19.38±12.37dGy/cm 2 (range, 4.77-81.75) with plain X-ray (P<10 -4 ). For BMI >40, mean radiation dose was 9.36±2.57dGy/cm 2 (range, 7.4-14.2) with the EOS system, versus 44.76±22.21 (range, 25.2-81.7) with plain X-ray. Radiation dose increased by 0.20dGy with each extra BMI point for the EOS system, versus 0.74dGy for plain X-ray. Magnification did not vary with patient weight using the EOS system, unlike plain X-ray, and radiation dose was 2.5-fold lower. 3, prospective case-control study. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  16. Historical Influences on Contemporary Tobacco Use by Northern Plains and Southwestern American Indians

    PubMed Central

    2016-01-01

    There are great differences in smoking- and tobacco-related mortality between American Indians on the Northern Plains and those in the Southwest that are best explained by (1) ecological differences between the two regions, including the relative inaccessibility and aridity of the Southwest and the lack of buffalo, and (2) differences between French and Spanish Indian relations policies. The consequence was the disruption of inter- and intratribal relations on the Northern Plains, where as a response to disruption the calumet (pipe) ceremony became widespread, whereas it did not in the Southwest. Tobacco was, thus, integrated into social relationships with religious sanctions on the Northern Plains, which increased the acceptability of commercial cigarettes in the 20th century. Smoking is, therefore, more deeply embedded in religious practices and social relationships on the Northern Plains than in the Southwest. PMID:26691134

  17. 44 CFR 60.7 - Revisions of criteria for flood plain management regulations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... § 60.7 Revisions of criteria for flood plain management regulations. From time to time part 60 may be... 44 Emergency Management and Assistance 1 2010-10-01 2010-10-01 false Revisions of criteria for flood plain management regulations. 60.7 Section 60.7 Emergency Management and Assistance FEDERAL...

  18. Geology of the Gusec cratered plains from the Spirit rover transverse

    NASA Technical Reports Server (NTRS)

    Golombek, M. P.; Crumpler, L. S.; Grant, J. A.; Greely, R.; Cabrol, N. A.; Parker, T. J.; Rice, J. W., Jr.; Ward, J. G.; Arvidson, R. E.; Moersch, J. E.; hide

    2006-01-01

    The cratered plains of Gusev traversed by Spirit are generally low-relief rocky plains dominated by impact and eolian processes. Ubiquitous shallow, soil-filled, circular depressions, called hollows, are modified impact craters. Rocks are dark, fine-grained basalts, and the upper 10 m of the cratered plains appears to be an impact-generated regolith developed over intact basalt flows. Systematic field observations across the cratered plains identified vesicular clasts and rare scoria similar to original lava flow tops, consistent with an upper inflated surface of lava flows with adjacent collapse depressions. Crater and hollow morphometry are consistent with most being secondaries. The size frequency distribution of rocks >0.1 m diameter generally follows exponential functions similar to other landing sites for total rock abundances of 5-35%. Systematic clast counts show that areas with higher rock abundance and more large rocks have higher thermal inertia. Plains with lower thermal inertia have fewer rocks and substantially more pebbles that are well sorted and evenly spaced, similar to a desert pavement or lag. Eolian bed forms (ripples and wind tails) have coarse surface lags, and many are dust covered and thus likely inactive. Deflation of the surface _5-25 cm likely exposed two-toned rocks and elevated ventifacts and transported fines into craters creating the hollows. This observed redistribution yields extremely slow average erosion rates of _0.03 nm/yr and argues for very little long-term net change of the surface and a dry and desiccating environment similar to today's since the Hesperian (or _3 Ga).

  19. 44 CFR 60.12 - Flood plain management criteria for State-owned properties in special hazard areas.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... MITIGATION National Flood Insurance Program CRITERIA FOR LAND MANAGEMENT AND USE Requirements for State Flood Plain Management Regulations § 60.12 Flood plain management criteria for State-owned properties in... 44 Emergency Management and Assistance 1 2012-10-01 2011-10-01 true Flood plain management...

  20. 44 CFR 60.12 - Flood plain management criteria for State-owned properties in special hazard areas.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... MITIGATION National Flood Insurance Program CRITERIA FOR LAND MANAGEMENT AND USE Requirements for State Flood Plain Management Regulations § 60.12 Flood plain management criteria for State-owned properties in... 44 Emergency Management and Assistance 1 2014-10-01 2014-10-01 false Flood plain management...

  1. 44 CFR 60.12 - Flood plain management criteria for State-owned properties in special hazard areas.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... MITIGATION National Flood Insurance Program CRITERIA FOR LAND MANAGEMENT AND USE Requirements for State Flood Plain Management Regulations § 60.12 Flood plain management criteria for State-owned properties in... 44 Emergency Management and Assistance 1 2013-10-01 2013-10-01 false Flood plain management...

  2. 44 CFR 60.12 - Flood plain management criteria for State-owned properties in special hazard areas.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... MITIGATION National Flood Insurance Program CRITERIA FOR LAND MANAGEMENT AND USE Requirements for State Flood Plain Management Regulations § 60.12 Flood plain management criteria for State-owned properties in... 44 Emergency Management and Assistance 1 2010-10-01 2010-10-01 false Flood plain management...

  3. 44 CFR 60.12 - Flood plain management criteria for State-owned properties in special hazard areas.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... MITIGATION National Flood Insurance Program CRITERIA FOR LAND MANAGEMENT AND USE Requirements for State Flood Plain Management Regulations § 60.12 Flood plain management criteria for State-owned properties in... 44 Emergency Management and Assistance 1 2011-10-01 2011-10-01 false Flood plain management...

  4. Geologic Map of the Santa Barbara Coastal Plain Area, Santa Barbara County, California

    USGS Publications Warehouse

    Minor, Scott A.; Kellogg, Karl S.; Stanley, Richard G.; Gurrola, Larry D.; Keller, Edward A.; Brandt, Theodore R.

    2009-01-01

    This report presents a newly revised and expanded digital geologic map of the Santa Barbara coastal plain area at a compilation scale of 1:24,000 (one inch on the map to 2,000 feet on the ground)1 and with a horizontal positional accuracy of at least 20 m. The map depicts the distribution of bedrock units and surficial deposits and associated deformation underlying and adjacent to the coastal plain within the contiguous Dos Pueblos Canyon, Goleta, Santa Barbara, and Carpinteria 7.5' quadrangles. The new map supersedes an earlier preliminary geologic map of the central part of the coastal plain (Minor and others, 2002; revised 2006) that provided coastal coverage only within the Goleta and Santa Barbara quadrangles. In addition to new mapping to the west and east, geologic mapping in parts of the central map area has been significantly revised from the preliminary map compilation - especially north of downtown Santa Barbara in the Mission Ridge area - based on new structural interpretations supplemented by new biostratigraphic data. All surficial and bedrock map units, including several new units recognized in the areas of expanded mapping, are described in detail in the accompanying pamphlet. Abundant new biostratigraphic and biochronologic data based on microfossil identifications are presented in expanded unit descriptions of the marine Neogene Monterey and Sisquoc Formations. Site-specific fault kinematic observations embedded in the digital map database are more complete owing to the addition of slip-sense determinations. Finally, the pamphlet accompanying the present report includes an expanded and refined summary of stratigraphic and structural observations and interpretations that are based on the composite geologic data contained in the new map compilation. The Santa Barbara coastal plain is located in the western Transverse Ranges physiographic province along an east-west-trending segment of the southern California coastline about 100 km (62 mi) northwest

  5. Dynamics of playa lakes in the Texas High Plains

    NASA Technical Reports Server (NTRS)

    Reeves, C. C., Jr. (Principal Investigator)

    1972-01-01

    The author has identified the following significant results. Regional viewing of ERTS-1 imagery around the test sites shows that storm paths can be accurately traced and a count made of the number of intermittent lake basins filled by the storm. Therefore, during wet years ERTS-type imagery can be used to conduct a reliable count of the tens of thousands of natural lake basins on the southern High Plains which contain water. This type of regional overview of water filled basins in the normally arid southern High Plains is illustrated by bands 6 and 7, ERTS E-1078-16524.

  6. 17 CFR 240.15d-20 - Plain English presentation of specified information.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 17 Commodity and Securities Exchanges 3 2010-04-01 2010-04-01 false Plain English presentation of specified information. 240.15d-20 Section 240.15d-20 Commodity and Securities Exchanges SECURITIES AND... Regulations Under the Securities Exchange Act of 1934 Other Reports § 240.15d-20 Plain English presentation of...

  7. 17 CFR 240.13a-20 - Plain English presentation of specified information.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 17 Commodity and Securities Exchanges 3 2010-04-01 2010-04-01 false Plain English presentation of specified information. 240.13a-20 Section 240.13a-20 Commodity and Securities Exchanges SECURITIES AND... Regulations Under the Securities Exchange Act of 1934 Other Reports § 240.13a-20 Plain English presentation of...

  8. Investigation into Fretting Fatigue Under Cyclic Contact Load and in Conjunction with Plain Fatigue of Titanium Alloy

    DTIC Science & Technology

    2008-03-01

    by plain fatigue and the process kept alternating or finishing all fretting fatigue cycles first followed by plain fatigue...fatigue and the process kept alternating or finishing all fretting fatigue cycles first followed by plain fatigue. 127  6.2.2. Phase Difference...component’s life. Figure 1.2 illustrates the process of combination of fretting fatigue and plain fatigue, by using three parts. The first part of this figure

  9. A decade of investigations on groundwater arsenic contamination in Middle Ganga Plain, India.

    PubMed

    Saha, Dipankar; Sahu, Sudarsan

    2016-04-01

    Groundwater arsenic (As) load in excess of drinking limit (50 µg L(-1)) in the Gangetic Plains was first detected in 2002. Though the menace was known since about two decades from the downstream part of the plains in the Bengal Basin, comprising of Lower Ganga Plain and deltaic plains of Ganga-Brahmaputra-Meghna River system, little thought was given to its possible threat in the upstream parts in the Gangetic Plains beyond Garo-Rajmahal Hills. The contamination in Bengal Basin has become one of the extensively studied issues in the world and regarded as the severest case of health hazard in the history of mankind. The researches and investigations in the Gangetic Plains during the last decade (2003-2013) revealed that the eastern half of the plains, also referred as Middle Ganga Plain (MGP), is particularly affected by contamination, jeopardising the shallow aquifer-based drinking water supply. The present paper reviews researches and investigations carried out so far in MGP by various research institutes and government departments on wide array of issues of groundwater As such as its spatio-temporal variation, mobilisation paths, water level behaviour and flow regime, configuration of contaminated and safe aquifers and their recharge mechanism. Elevated conc. of groundwater As has been observed in grey and dark grey sediments of Holocene age (Newer Alluvium) deposited in a fluvio-lacustrine environment in the floodplain of the Ganga and most of its northern tributaries from Himalayas. Older Alluvium, comprising Pleistocene brownish yellow sediment, extending as deeper aquifers in Newer Alluvium areas, is low in groundwater As. Similarities and differences on issues between the MGP and the Bengal Basin have been discussed. The researches point towards the mobilisation process as reductive dissolution of iron hydroxide coating, rich in adsorbed As, mediated by microbial processes. The area is marked with shallow water level (<8.0 m below ground) with ample

  10. The value of plain abdominal radiographs in management of abdominal emergencies in Luth.

    PubMed

    Ashindoitiang, J A; Atoyebi, A O; Arogundade, R A

    2008-01-01

    The plain abdominal x-ray is still the first imaging modality in diagnosis of acute abdomen. The aim of this study was to find the value of plain abdominal x-ray in the management of abdominal emergencies seen in Lagos university teaching hospital. The accurate diagnosis of the cause of acute abdominal pain is one of the most challenging undertakings in emergency medicine. This is due to overlapping of clinical presentation and non-specific findings of physical and even laboratory data of the multifarious causes. Plain abdominal radiography is one investigation that can be obtained readily and within a short period of time to help the physician arrive at a correct diagnosis The relevance of plain abdominal radiography was therefore evaluated in the management of abdominal emergencies seen in Lagos over a 12 month period (April 2002 to March 2003). A prospective study of 100 consecutively presenting patients with acute abdominal conditions treated by the general surgical unit of Lagos University Teaching Hospital was undertaken. All patients had supine and erect abdominal x-ray before any therapeutic intervention was undertaken. The diagnostic features of the plain films were compared with final diagnosis to determine the usefulness of the plain x-ray There were 54 males and 46 females (M:F 1.2:1). Twenty-four percent of the patients had intestinal obstruction, 20% perforated typhoid enteritis; gunshot injuries and generalized peritonitis each occurred in 13%, blunt abdominal trauma in 12%, while 8% and 10% had acute appendicitis and perforated peptic ulcer disease respectively. Of 100 patients studied, 54% had plain abdominal radiographs that showed positive diagnostic features. Plain abdominal radiograph showed high sensitivity in patients with intestinal obstruction 100% and perforated peptic ulcer 90% but was less sensitive in patients with perforated typhoid, acute appendicitis, and blunt abdominal trauma and generalized peritonitis. In conclusion, this study

  11. Looking out Across the Martian Polar Plains

    NASA Image and Video Library

    2008-05-26

    This image shows the vast plains of the northern polar region of Mars, as seen by NASA Phoenix Mars Lander shortly after touching down on the Red Planet. The flat landscape is strewn with tiny pebbles and shows polygonal cracking.

  12. Landscape-scale patterns of fire and drought on the high plains, USA

    Treesearch

    Paulette Ford; Charles Jackson; Matthew Reeves; Benjamin Bird; Dave Turner

    2015-01-01

    We examine 31 years (1982-2012) of temperature, precipitation and natural wildfire occurrence data for Federal and Tribal lands to determine landscape-scale patterns of drought and fire on the southern and central High Plains of the western United States. The High Plains states of Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas and...

  13. Death, Murder, and Mayhem: Stories of Violence and Healing on the Plains

    ERIC Educational Resources Information Center

    Maher, Susan Naramore

    2009-01-01

    Unexpected, dramatic stories of death have left deep marks on the physical landscape and in the cultural psyche since humans first began to weave narrative from the Plains. When scholars and writers converged in Omaha, Nebraska for the 34th Interdisciplinary Symposium of the Center for Great Plains Center, many stories received scholarly and…

  14. Volcanism of the Eastern Snake River Plain, Idaho: A comparative planetary geology-guidebook

    NASA Technical Reports Server (NTRS)

    Greeley, R.; King, J. S.

    1977-01-01

    The Planetary Geology Field Conference on the central Snake River Plain was conceived and developed to accomplish several objectives. Primarily, field conferences are sponsored by the National Aeronautics and Space Administration to draw attention to aspects of terrestrial geology that appear to be important in interpreting the origin and evolution of extraterrestrial planetary surfaces. Another aspect is to present results of recent research in a region. A final objective of this conference is to bring together investigators of diverse backgrounds who share a common interest in the Snake River Plain. The Snake River Plain appears to be similar in surface morphology to many volcanic regions on the Moon, Mars, and possibly Mercury. Therefore, the Snake River Plain, in combination with the relatively good state of preservation, the lack of forests or other heavy vegetation, and the good network of jeep trails, is an area nearly ideal for analog studies.

  15. Saturated thickness of the High Plains regional aquifer in 1980, northwestern Oklahoma

    USGS Publications Warehouse

    Havens, John S.

    1982-01-01

    During 1978, the U.S. Geological Survey began a 5-year study of the High Plains regional aquifer system to provide hydrologic information for evaluation of the effects of long-term development of the aquifer and to develop computer models for prediction of aquifer response to alternative changes in ground-water management (Weeks, 1978). This report is one of a series presenting hydrologic information of the High Plains aquifer in Oklahoma. The 1980 saturated thickness of the High Plains regional aquifer in Oklahoma is shown for the eastern area (plate 1), consisting of Harper, Ellis, Woodward, Dewey, and Roger Mills Counties, and for the Panhandle area (plate 2), consisting of Cimarron, Texas, and Beaver Counties.

  16. International collaborative study for the calibration of proposed International Standards for thromboplastin, rabbit, plain, and for thromboplastin, recombinant, human, plain.

    PubMed

    van den Besselaar, A M H P; Chantarangkul, V; Angeloni, F; Binder, N B; Byrne, M; Dauer, R; Gudmundsdottir, B R; Jespersen, J; Kitchen, S; Legnani, C; Lindahl, T L; Manning, R A; Martinuzzo, M; Panes, O; Pengo, V; Riddell, A; Subramanian, S; Szederjesi, A; Tantanate, C; Herbel, P; Tripodi, A

    2018-01-01

    Essentials Two candidate International Standards for thromboplastin (coded RBT/16 and rTF/16) are proposed. International Sensitivity Index (ISI) of proposed standards was assessed in a 20-centre study. The mean ISI for RBT/16 was 1.21 with a between-centre coefficient of variation of 4.6%. The mean ISI for rTF/16 was 1.11 with a between-centre coefficient of variation of 5.7%. Background The availability of International Standards for thromboplastin is essential for the calibration of routine reagents and hence the calculation of the International Normalized Ratio (INR). Stocks of the current Fourth International Standards are running low. Candidate replacement materials have been prepared. This article describes the calibration of the proposed Fifth International Standards for thromboplastin, rabbit, plain (coded RBT/16) and for thromboplastin, recombinant, human, plain (coded rTF/16). Methods An international collaborative study was carried out for the assignment of International Sensitivity Indexes (ISIs) to the candidate materials, according to the World Health Organization (WHO) guidelines for thromboplastins and plasma used to control oral anticoagulant therapy with vitamin K antagonists. Results Results were obtained from 20 laboratories. In several cases, deviations from the ISI calibration model were observed, but the average INR deviation attributabled to the model was not greater than 10%. Only valid ISI assessments were used to calculate the mean ISI for each candidate. The mean ISI for RBT/16 was 1.21 (between-laboratory coefficient of variation [CV]: 4.6%), and the mean ISI for rTF/16 was 1.11 (between-laboratory CV: 5.7%). Conclusions The between-laboratory variation of the ISI for candidate material RBT/16 was similar to that of the Fourth International Standard (RBT/05), and the between-laboratory variation of the ISI for candidate material rTF/16 was slightly higher than that of the Fourth International Standard (rTF/09). The candidate materials

  17. Water in orthopyroxene from abyssal spinel peridotites of the East Pacific Rise (ODP Leg 147: Hess Deep)

    NASA Astrophysics Data System (ADS)

    Hesse, Kirsten T.; Gose, Jürgen; Stalder, Roland; Schmädicke, Esther

    2015-09-01

    Abyssal spinel peridotites from Hess Deep, East Pacific Rise (ODP Leg 147) were investigated concerning their major, minor, and trace element mineral chemistry and the incorporation of structural water in orthopyroxene. The rocks are partially serpentinized harzburgites containing primary minerals of olivine, orthopyroxene, clinopyroxene, and spinel. Orthopyroxene is enstatitic with Mg# (Mg/(Mg + Fe)) between 0.90 and 0.92 and Al2O3 from 0.5 to 2.9 wt.%. The residual harzburgite experienced high degrees of melt removal in the spinel peridotite stability field. The average degree of partial melting was calculated to be 17.5% (range: 16.4-17.8%). Trace element data of ortho- and clinopyroxenes reflect this strong depletion, characteristic for the restitic nature of abyssal peridotites. Mantle re-equilibration temperatures around 1000 °C indicate that, after melt extraction and before exhumation to the ocean floor, the rocks experienced significant cooling in the spinel peridotite facies. Water contents of orthopyroxene range from 86 to 233 wt. ppm H2O with an average concentration of 142 wt. ppm H2O. These results represent the first data on water contents in the sub-pacific mantle obtained by direct measurements of sub-oceanic peridotite. The water contents are not related to mineral chemistry, stratigraphy, melting degree, mantle equilibrium conditions or oxidation state. Calculated post-melt peridotite water contents vary between 40 and 100 wt. ppm H2O. Compared to Mid-Atlantic Ridge peridotites, the East Pacific Rise samples of Leg 147 contain somewhat lower water concentrations than samples from Leg 153 and considerably higher contents than those of Leg 209 (Gose et al., 2009; Schmädicke et al., 2011). In Leg 147, the strongest OH absorbtion band occurs at 3420 cm- 1, wheras orthopyroxene from MAR peridotite (Legs 153 and 209) has its strongest absorbtion band at 3566 and 3522 cm- 1. The mantle equilibrium temperature of Leg 147 peridotites is lower than that

  18. SDI increases water use efficiency of grain crops in the Southern High Plains

    USDA-ARS?s Scientific Manuscript database

    In the semi-arid Southern High Plains, nearly all irrigation water is derived from the declining High Plains (Ogallala) aquifer. As well capacities likewise decline, one tactic for continued irrigation is to install subsurface drip irrigation (SDI) systems with zones sized to accommodate the limited...

  19. Drawn by the Bison: Late Prehistoric Native Migration into the Central Plains

    ERIC Educational Resources Information Center

    Ritterbush, Lauren W.

    2002-01-01

    Popular images of the Great Plains frequently portray horse-mounted Indians engaged in dramatic bison hunts. The importance of these hunts is emphasized by the oft-mentioned dependence of the Plains Indians on bison. This animal served as a source of not only food but also materials for shelter, clothing, containers, and many other necessities of…

  20. Fluvial terraces of the Little River Valley, Atlantic Coastal Plain, North Carolina

    Treesearch

    Bradley Suther; David Leigh; George Brook

    2011-01-01

    An optically-stimulated luminescence (OSL) and radiocarbon chronology is presented for fluvial terraces of the Little River, a tributary to the Cape Fear River that drains 880 km2 of the Sandhills Province of the upper Coastal Plain of North Carolina. This study differs from previous work in the southeastern Atlantic Coastal Plain in that numerical age estimates are...

  1. Quantitative characterization of the small-scale fracture patterns on the plains of Venus

    NASA Technical Reports Server (NTRS)

    Sammis, Charles G.; Bowman, David D.

    1995-01-01

    The objectives of this research project were to (1) compile a comprehensive database of the occurrence of regularly spaced kilometer scale lineations on the volcanic plains of Venus in an effort to verify the effectiveness of the shear-lag model developed by Banerdt and Sammis (1992), and (2) develop a model for the formation of irregular kilometer scale lineations such as typified in the gridded plains region of Guinevere Planitia. Attached to this report is the paper 'A Tectonic Model for the Formation of the Gridded Plains on Guinevere Planitia, Venus, and Implications for the Elastic Thickness of the Lithosphere'.

  2. Optimization of microbial detoxification for an aquatic mercury-contaminated environment.

    PubMed

    Figueiredo, Neusa L; Canário, João; Serralheiro, Maria Luísa; Carvalho, Cristina

    2017-01-01

    Mercury (Hg) reduction performed by microorganisms is well recognized as a biological means for remediation of contaminated environment. Recently, studies demonstrated that Hg-resistant microorganisms of Tagus Estuary are involved in metal reduction processes. In the present study, aerobic microbial community isolated from a highly Hg-contaminated area of Tagus Estuary was used to determine the optimization of the reduction process in conditions such as the contaminated ecosystem. Factorial design methodology was employed to examine the influence of glucose, sulfate, iron, and chloride on Hg reduction. In the presence of several concentrations of these elements, microbial community reduced Hg in a range of 37-61% of the initial 0.1 mg/ml Hg 2+ levels. The response prediction through central composite design showed that the increase of sulfate concentration led to an optimal response in Hg reduction by microbial community, while the rise in chloride levels markedly decreased metal reduction. Iron may exert antagonistic effects depending upon the media composition. These results are useful in understanding the persistence of Hg contamination in Tagus Estuary after inactivation of critical industrial units, as well as data might also be beneficial for development of new bioremediation strategies either in Tagus Estuary and/or in other Hg-contaminated aquatic environments.

  3. Unique Microbial Phylotypes in Namib Desert Dune and Gravel Plain Fairy Circle Soils.

    PubMed

    van der Walt, Andries J; Johnson, Riegardt M; Cowan, Don A; Seely, Mary; Ramond, Jean-Baptiste

    2016-08-01

    Fairy circles (FCs) are barren circular patches of soil surrounded by grass species. Their origin is poorly understood. FCs feature in both the gravel plains and the dune fields of the Namib Desert. While a substantial number of hypotheses to explain the origin and/or maintenance of fairy circles have been presented, none are completely consistent with either their properties or their distribution. In this study, we investigated the hypothesis that FC formation in dunes and gravel plains is due to microbial phytopathogenesis. Surface soils from five gravel plain and five dune FCs, together with control soil samples, were analyzed using high-throughput sequencing of bacterial/archaeal (16S rRNA gene) and fungal (internal transcribed spacer [ITS] region) phylogenetic markers. Our analyses showed that gravel plain and dune FC microbial communities are phylogenetically distinct and that FC communities differ from those of adjacent vegetated soils. Furthermore, various soil physicochemical properties, particularly the pH, the Ca, P, Na, and SO4 contents, the soil particle size, and the percentage of carbon, significantly influenced the compositions of dune and gravel plain FC microbial communities, but none were found to segregate FC and vegetated soil communities. Nevertheless, 9 bacterial, 1 archaeal, and 57 fungal phylotypes were identified as FC specific, since they were present within the gravel plain and dune FC soils only, not in the vegetated soils. Some of these FC-specific phylotypes were assigned to taxa known to harbor phytopathogenic microorganisms. This suggests that these FC-specific microbial taxa may be involved in the formation and/or maintenance of Namib Desert FCs. Fairy circles (FCs) are mysterious barren circular patches of soil found within a grass matrix in the dune fields and gravel plains of the Namib Desert. Various hypotheses attempting to explain this phenomenon have been proposed. To date, however, none have been successful in fully

  4. Geothermal alteration of basaltic core from the Snake River Plain, Idaho

    NASA Astrophysics Data System (ADS)

    Sant, Christopher J.

    The Snake River Plain is located in the southern part of the state of Idaho. The eastern plain, on which this study focuses, is a trail of volcanics from the Yellowstone hotspot. Three exploratory geothermal wells were drilled on the Snake River Plain. This project analyzes basaltic core from the first well at Kimama, north of Burley, Idaho. The objectives of this project are to establish zones of geothermal alteration and analyze the potential for geothermal power production using sub-aquifer resources on the axial volcanic zone of the Snake River Plain. Thirty samples from 1,912 m of core were sampled and analyzed for clay content and composition using X-ray diffraction. Observations from core samples and geophysical logs are also used to establish alteration zones. Mineralogical data, geophysical log data and physical characteristics of the core suggest that the base of the Snake River Plain aquifer at the axial zone is located 960 m below the surface, much deeper than previously suspected. Swelling smectite clay clogs pore spaces and reduces porosity and permeability to create a natural base to the aquifer. Increased temperatures favor the formation of smectite clay and other secondary minerals to the bottom of the hole. Below 960 m the core shows signs of alteration including color change, formation of clay, and filling of other secondary minerals in vesicles and fractured zones of the core. The smectite clay observed is Fe-rich clay that is authigenic in some places. Geothermal power generation may be feasible using a low temperature hot water geothermal system if thermal fluids can be attained near the bottom of the Kimama well.

  5. Spatial Distribution and Morphology of Sediments in Texas Southern High Plains Playa Wetlands

    USDA-ARS?s Scientific Manuscript database

    Playas are depressional geomorphic features on the U.S. High Plains and about 20,000 Southern High Plains playa wetlands serve as runoff catchment basins, which are thought to be focal points of Ogallala aquifer recharge. Sediments in playas can alter biodiversity services, impede aquifer recharge,...

  6. Great Plains Project: at worst a $1. 7 billion squeeze

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

    Maize, K.

    1983-04-11

    On January 29, 1982, seeking a loan guarantee for its coal-to-gas synfuels project, Great Plains Gasification Associates told the Department of Energy that they expected to reap $1.2 billion in net income to the partnership during the first 10 years of the venture. On March 31, 1983, Great Plains treasurer Rodney Boulanger had a different projection: a horrific loss of $773 million in the first decade. The Great Plains project, with construction 50% complete, is being built near Beulah, ND. The project has a design capacity of 137.5 million cubic feet a day of SNG. Great Plains' analysis assumes thatmore » the plant will operate at 70% of design capacity in 1985, 77% in 1986, 84% in 1987 and 91% thereafter. The company projects the total project cost at $2.1 billion, consisting of plant costs of $1.9 billion and coal mine costs of $156 million. In originally projecting a cumulative net income of better than $1 billion, the partners anticipated running losses in only three of the first 10 years, and cash distributions from the project of $893 million during the first decade. Under the new projections, even in the best case, the first four years would show losses and there would be no distribution to the partners. In the worst case, the project would run in the red every year for the first 10 years.« less

  7. Wintering Golden Eagles on the coastal plain of South Carolina

    DOE PAGES

    Vukovich, Mark; Turner, Kelsey L.; Grazia, Tracy E.; ...

    2015-10-01

    Golden Eagles (Aquila chrysaetos) are rare winter residents in eastern North America, with most found along the Appalachian Mountains and few reported on the coastal plain of the Carolinas. We used remote cameras baited with wild pig (Sus scrofa) and white-tailed deer (Odocoileus virginianus) carcasses to detect, age, and individually identify Golden Eagles on the U.S. Department of Energy’s Savannah River Site on the coastal plain of South Carolina. We identified eight individual Golden Eagles during the winters of 2013–2014 and 2014–2015, with one detected during both winters. We detected eagles for 19 and 66 calendar days during the wintersmore » of 2013–2014 and 2014–2015, respectively, with two adult eagles detected for 30 and 31 calendar days in 2014–2015. Eagles typically scavenged on carcasses for a few days, left, and then returned when cameras were baited with another carcass, suggesting they had remained in the area. These observations suggest that large tracts of forests on the coastal plain may be important wintering areas for some Golden Eagles and, further, that other areas in the coastal plain of the southeastern United States may also harbor wintering eagles. Identification of wintering areas of Golden Eagles in the east will be an important step in the conservation of this protected species, and camera traps baited with carcasses can be an effective tool for such work.« less

  8. Wintering Golden Eagles on the coastal plain of South Carolina

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

    Vukovich, Mark; Turner, Kelsey L.; Grazia, Tracy E.

    Golden Eagles (Aquila chrysaetos) are rare winter residents in eastern North America, with most found along the Appalachian Mountains and few reported on the coastal plain of the Carolinas. We used remote cameras baited with wild pig (Sus scrofa) and white-tailed deer (Odocoileus virginianus) carcasses to detect, age, and individually identify Golden Eagles on the U.S. Department of Energy’s Savannah River Site on the coastal plain of South Carolina. We identified eight individual Golden Eagles during the winters of 2013–2014 and 2014–2015, with one detected during both winters. We detected eagles for 19 and 66 calendar days during the wintersmore » of 2013–2014 and 2014–2015, respectively, with two adult eagles detected for 30 and 31 calendar days in 2014–2015. Eagles typically scavenged on carcasses for a few days, left, and then returned when cameras were baited with another carcass, suggesting they had remained in the area. These observations suggest that large tracts of forests on the coastal plain may be important wintering areas for some Golden Eagles and, further, that other areas in the coastal plain of the southeastern United States may also harbor wintering eagles. Identification of wintering areas of Golden Eagles in the east will be an important step in the conservation of this protected species, and camera traps baited with carcasses can be an effective tool for such work.« less

  9. Identification of possible recent water/lava source vents in the Cerberus plains: Stratigraphic andcrater count age constraints

    NASA Astrophysics Data System (ADS)

    Thomas, Rebecca J.

    2013-04-01

    In order to investigate sources of lava and water to the Cerberus plains of Mars, geomorphological mapping on High Resolution Imaging Science Experiment (HiRISE) images was carried out to reveal the history of activity of fissures and pits which lie upstream of channels and deposits associated with a wrinkle ridge near Cerberus Fossae. The fissures and pits are superbly exposed and imaged, and flows and channels emanate directly from them, interpreted as clear evidence that these are vents. The mapping establishes stratigraphic relationships between the plains and the channels and deposits originating from the vents, establishing the vent history. For example, to the south of the wrinkle ridge, both incised channels and leveed flows extend onto the southern plain and are clearly the final phase of plains-forming activity. Conversely, to the north, vent-sourced channels only incise the plain close to the ridge—beyond that, they are overlain by large-scale regional flows that appear to have originated from the direction of Athabasca Valles. In the southeast, there is evidence of contemporaneity between vent-sourced activity and large-scale plains-forming flow that was not sourced from the vents, indicating that activity here was part of a broader process of Cerberus plains formation from multiple sources. Crater counts show all the activity to be Late Amazonian, with the latest activity tentatively dating to circa 11 Ma. Thus, this study implies that very recent outflows from these vents contributed to the formation of the Cerberus plains and constrains the timing and local flow direction of plains-forming deposits from other sources.

  10. 49 CFR 215.113 - Defective plain bearing wedge.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD FREIGHT CAR SAFETY STANDARDS Freight Car Components... car, if a plain bearing wedge on that car is— (a) Missing; (b) Cracked; (c) Broken; or (d) Not located...

  11. 49 CFR 215.113 - Defective plain bearing wedge.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD FREIGHT CAR SAFETY STANDARDS Freight Car Components... car, if a plain bearing wedge on that car is— (a) Missing; (b) Cracked; (c) Broken; or (d) Not located...

  12. 49 CFR 215.113 - Defective plain bearing wedge.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD FREIGHT CAR SAFETY STANDARDS Freight Car Components... car, if a plain bearing wedge on that car is— (a) Missing; (b) Cracked; (c) Broken; or (d) Not located...

  13. 49 CFR 215.113 - Defective plain bearing wedge.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD FREIGHT CAR SAFETY STANDARDS Freight Car Components... car, if a plain bearing wedge on that car is— (a) Missing; (b) Cracked; (c) Broken; or (d) Not located...

  14. 49 CFR 215.113 - Defective plain bearing wedge.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD FREIGHT CAR SAFETY STANDARDS Freight Car Components... car, if a plain bearing wedge on that car is— (a) Missing; (b) Cracked; (c) Broken; or (d) Not located...

  15. Precipitation Dynamical Downscaling Over the Great Plains

    NASA Astrophysics Data System (ADS)

    Hu, Xiao-Ming; Xue, Ming; McPherson, Renee A.; Martin, Elinor; Rosendahl, Derek H.; Qiao, Lei

    2018-02-01

    Detailed, regional climate projections, particularly for precipitation, are critical for many applications. Accurate precipitation downscaling in the United States Great Plains remains a great challenge for most Regional Climate Models, particularly for warm months. Most previous dynamic downscaling simulations significantly underestimate warm-season precipitation in the region. This study aims to achieve a better precipitation downscaling in the Great Plains with the Weather Research and Forecast (WRF) model. To this end, WRF simulations with different physics schemes and nudging strategies are first conducted for a representative warm season. Results show that different cumulus schemes lead to more pronounced difference in simulated precipitation than other tested physics schemes. Simply choosing different physics schemes is not enough to alleviate the dry bias over the southern Great Plains, which is related to an anticyclonic circulation anomaly over the central and western parts of continental U.S. in the simulations. Spectral nudging emerges as an effective solution for alleviating the precipitation bias. Spectral nudging ensures that large and synoptic-scale circulations are faithfully reproduced while still allowing WRF to develop small-scale dynamics, thus effectively suppressing the large-scale circulation anomaly in the downscaling. As a result, a better precipitation downscaling is achieved. With the carefully validated configurations, WRF downscaling is conducted for 1980-2015. The downscaling captures well the spatial distribution of monthly climatology precipitation and the monthly/yearly variability, showing improvement over at least two previously published precipitation downscaling studies. With the improved precipitation downscaling, a better hydrological simulation over the trans-state Oologah watershed is also achieved.

  16. Snake River Plain FORGE Well Data for USGS-142

    DOE Data Explorer

    Robert Podgorney

    2015-11-23

    Well data for the USGS-142 well located in eastern Snake River Plain, Idaho. This data collection includes lithology reports, borehole logs, and photos of rhyolite core samples. This collection of data has been assembled as part of the site characterization data used to develop the conceptual geologic model for the Snake River Plain site in Idaho, as part of phase 1 of the Frontier Observatory for Research in Geothermal Energy (FORGE) initiative. They were assembled by the Snake River Geothermal Consortium (SRGC), a team of collaborators that includes members from national laboratories, universities, industry, and federal agencies, lead by the Idaho National Laboratory (INL).

  17. Regional implications of heat flow of the Snake River Plain, Northwestern United States

    NASA Astrophysics Data System (ADS)

    Blackwell, D. D.

    1989-08-01

    The Snake River Plain is a major topographic feature of the Northwestern United States. It marks the track of an upper mantle and crustal melting event that propagated across the area from southwest to northeast at a velocity of about 3.5 cm/yr. The melting event has the same energetics as a large oceanic hotspot or plume and so the area is the continental analog of an oceanic hotspot track such as the Hawaiian Island-Emperor Seamount chain. Thus, the unique features of the area reflect the response of a continental lithosphere to a very energetic hotspot. The crust is extensively modified by basalt magma emplacement into the crust and by the resulting massive rhyolite volcanism from melted crustal material, presently occurring at Yellowstone National Park. The volcanism is associated with little crustal extension. Heat flow values are high along the margins of the Eastern and Western Snake River Plains and there is abundant evidence for low-grade geothermal resources associated with regional groundwater systems. The regional heat flow pattern in the Western Snake River Plains reflects the influence of crustal-scale thermal refraction associated with the large sedimentary basin that has formed there. Heat flow values in shallow holes in the Eastern Snake River Plains are low due to the Snake River Plains aquifer, an extensive basalt aquifer where water flow rates approach 1 km/yr. Below the aquifer, conductive heat flow values are about 100 mW m -2. Deep holes in the region suggest a systematic eastward increase in heat flow in the Snake River Plains from about 75-90 mW m -2 to 90-110 mW m -2. Temperatures in the upper crust do not behave similarly because the thermal conductivity of the Plio-Pleistocene sedimentary rocks in the west is lower than that in the volcanic rocks characteristic of the Eastern Snake River Plains. Extremely high heat loss values (averaging 2500 mW m -2) and upper crustal temperatures are characteristic of the Yellowstone caldera.

  18. Great plains regional climate assessment technical report

    USDA-ARS?s Scientific Manuscript database

    The Great Plains region (GP) plays important role in providing food and energy to the economy of the United States. Multiple climatic and non-climatic stressors put multiple sectors, livelihoods and communities at risk, including agriculture, water, ecosystems and rural and tribal communities. The G...

  19. Skip-row Planting Patterns Stabilize Corn Grain Yields in the Central Great Plains

    USDA-ARS?s Scientific Manuscript database

    The highly variable climate of the Central Great Plains makes dryland corn (Zea mays) production a risky enterprise. Twenty-three field trials were conducted across the Central Great Plains from 2004 through 2006 to quantify the effect of various skip-row planting patterns and plant populations on g...

  20. Socioeconomically disadvantaged smokers' ratings of plain and branded cigarette packaging: an experimental study.

    PubMed

    Guillaumier, Ashleigh; Bonevski, Billie; Paul, Chris; Durkin, Sarah; D'Este, Catherine

    2014-02-06

    This study aimed to test the potential impact of plain packaging for cigarettes on brand appeal among highly socioeconomically disadvantaged smokers using the new design for cigarettes implemented in Australia, which combines plain packaging with larger health warning labels. A 2×2 factorial design trial embedded within a cross-sectional computer touchscreen survey. Data were collected between March and December 2012. Socially disadvantaged welfare aid recipients were recruited through a large Social and Community Service Organisation in New South Wales, Australia. N=354 smokers. The majority of the sample had not completed high school (64%), earned less than $A300/week (55%) and received their income from Government payments (95%). Participants were randomised to one of the four different pack conditions determined by brand name: Winfield versus Benson & Hedges, and packaging type: branded versus plain. Participants were required to rate their assigned pack on measures of brand appeal and purchase intentions. Plain packaging was associated with significantly reduced smoker ratings of 'positive pack characteristics' (p<0.001), 'positive smoker characteristics' (p=0.003) and 'positive taste characteristics' (p=0.033) in the Winfield brand name condition only. Across the four pack conditions, no main differences were found for 'negative smoker characteristics' (p=0.427) or 'negative harm characteristics' (p=0.411). In comparison to plain packaging, the presentation of branded packaging was associated with higher odds of smokers' purchase intentions (OR=2.18, 95% CI 1.34 to 3.54; p=0.002). Plain packs stripped of branding elements, featuring larger health warning labels, were associated with reduced positive cigarette brand image and purchase intentions among highly socioeconomically disadvantaged smokers.

  1. A New Boundary for the High Plains - Ogallala Aquifer Complex

    NASA Astrophysics Data System (ADS)

    Haacker, E. M.; Nozari, S.; Kendall, A. D.

    2017-12-01

    In the semi-arid Great Plains, water is the key ingredient for crop growth: the difference between meager yields for many crops and an agricultural bonanza. The High Plains-Ogallala Aquifer complex (HPA) underlies 452,000 square kilometers of the region, and over 95% of water withdrawn from the aquifer is used for irrigation. Much of the HPA is being pumped unsustainably, and since the region is heavily reliant on this resource for its social and economic health, the High Plains has been a leader in groundwater management planning. However, the geographic boundary of the High Plains region fails to reflect the hydrogeological realities of the aquifer. The current boundary, recognizable from countless textbooks and news articles, is only slightly modified from a version from the 1980's, and largely follows the physiographic borders of the High Plains - defined by surface features such as escarpments and rivers - rather than the edges of water-bearing sediment sufficient for high-volume pumping. This is supported by three lines of evidence: hydrogeological observations from the original aquifer boundary determination; the extent of irrigated land, as estimated by MODIS-MIrAD data; and statistical estimates of saturated thickness, incorporating improved maps of the aquifer base and an additional 35 years of water table measurements. In this project, new maps of saturated thickness are used to create an updated aquifer boundary, which conforms with the standard definition of an aquifer as a package of sediment that yields enough water to be economically pumped. This has major implications for social and physical models, as well as water planning and estimates of sustainability for the HPA. Much of the area of the HPA that has been labeled `sustainable' based upon estimates of recharge relative to pumping estimates falls outside the updated aquifer boundary. In reality, the sustainably-pumped area of this updated aquifer boundary is far smaller—a fact that if more

  2. Geomorphic evidence for an eolian contribution to the formation of the Martian northern plains

    NASA Technical Reports Server (NTRS)

    Zimbelman, J. R.

    1993-01-01

    The northern plains of Mars have many morphologic characteristics that are uncommon or absent on the rest of the planet. Mariner 9 and Viking images obtained north of latitude 30 deg N revealed 'smooth' and 'mottled' plains of an uncertain origin. Some or all of the northern plains were interpreted to consist of lava plains intermixed with eolian and volcanic materials thick eolian mantles that buried portions of the mid latitudes periglacial deposits resulting from the presence of ground ice and as water-transported sediments derived from fluvial runoff, lacustrine deposition in standing bodies of water, or glacial runoff. The highest-resolution Viking images show many intriguing details that may provide clues to the origin of this complex and distinctive terrain. Some of the informative features present in the best Viking images, comparing the observations to what may be expected from various hypotheses of formation, are reviewed. While the results are not conclusive for any single hypothesis, eolian processes have played a major role in the erosion (and possibly deposition) of the materials that make up the surface exposures in the Martian northern plains.

  3. Surface-compositional Properties of Lava Plains in Syria-Thaumasia Block, Mars

    NASA Astrophysics Data System (ADS)

    Huang, J.; Xiao, L.; Kraft, M. D.; Christensen, P. R.; Edwards, C. S.; Ruff, S. W.; Dohm, J.

    2012-12-01

    Mars has a long and complex volcanic history (Greeley and Spudis, 1981; Carr, 2006). Among abundant plain-style volcanism and various edifices, Tharsis bulge is a prominent and long-lasting (Werner, 2009) volcanic province. However, there is little report about compositional variations before and after Tharsis uplift. The Syria- Thaumasia block (STB) is a complex tectono-volcanic province related to the Tharsis bulge. Understanding its formation is critical to characterizing the early history and planetary evolution of Mars. The STB lies at the southern edge of Tharsis bulge. It consists of lava plains (Syria, Solis, Sinai and Thaumasia Plana) bounded by an arcuate region of higher topography (Thaumasia Highlands, Melas Dorsa and Coprates Rise) and Valles Marineris to the north. Previous work on surface thermophysical properties (Christensen, 1988; Jakosky et al., 2000; Putzig and Mellon, 2007) and visible/near infrared and thermal infrared remote sensing spectroscopic compositional analysis (Bandfield, 2000; Bibring et al., 2006; Rogers and Christensen, 2007) had been done only in a global scale, but regional study of both surface thermophysical properties and compositions for each of the distinct lava plains in STB is lacking. In this study, we characterize a variety of volcanic features, including lava tubes, channels and their relationships with wrinkle ridges within lava plains using THEMIS infrared data (100 m/pixel: Christensen et al., 2004), CTX data (6 m/pixel: Malin et al., 2007) and HiRISE data (25 cm/pixel: McEwen et al., 2007). We assessed the surface thermophysical properties and compositions of lava plains using TES data (Christensen et al., 2001). The geomorphic features imply the lava emplacement mechanisms, while their relationships indicate the chronologic relationships between Tharsis uplift and lava emplacement. The compositional results show variations within the lava plains (Table 1), while the thermophysical results show the compositional

  4. Cerberus Plains: A most excellent Pathfinder landing site

    NASA Technical Reports Server (NTRS)

    Plescia, Jeff B.

    1994-01-01

    The Cerberus Plains in southeastern Elysium and western Amazonis cover greater than 10(exp 5) sq km, extending an east-west distance of approximately 3000 km and a north-south distance of up to 700 km near 195 deg. Crater numbers are 89 plus or minus 15 craters greater than 1 km/10(exp 6) sq km, indicating a stratigraphic age of Upper Amazonian and an absolute age of 200-500 Ma. The material forming the surface is referred to as the Cerberus Formation. The two ideas postulated about the unit's origin are fluvial and volcanic. Regardless of which interpretation is correct, the Cerberus Plains is an important candidate for a pathfinder landing site because it represents the youngest major geologic event (be it fluvial or volcanic) on Mars.

  5. Geodatabase compilation of hydrogeologic, remote sensing, and water-budget-component data for the High Plains aquifer, 2011

    USGS Publications Warehouse

    Houston, Natalie A.; Gonzales-Bradford, Sophia L.; Flynn, Amanda T.; Qi, Sharon L.; Peterson, Steven M.; Stanton, Jennifer S.; Ryter, Derek W.; Sohl, Terry L.; Senay, Gabriel B.

    2013-01-01

    The High Plains aquifer underlies almost 112 million acres in the central United States. It is one of the largest aquifers in the Nation in terms of annual groundwater withdrawals and provides drinking water for 2.3 million people. The High Plains aquifer has gained national and international attention as a highly stressed groundwater supply primarily because it has been appreciably depleted in some areas. The U.S. Geological Survey has an active program to monitor the changes in groundwater levels for the High Plains aquifer and has documented substantial water-level changes since predevelopment: the High Plains Groundwater Availability Study is part of a series of regional groundwater availability studies conducted to evaluate the availability and sustainability of major aquifers across the Nation. The goals of the regional groundwater studies are to quantify current groundwater resources in an aquifer system, evaluate how these resources have changed over time, and provide tools to better understand a systems response to future demands and environmental stresses. The purpose of this report is to present selected data developed and synthesized for the High Plains aquifer as part of the High Plains Groundwater Availability Study. The High Plains Groundwater Availability Study includes the development of a water-budget-component analysis for the High Plains completed in 2011 and development of a groundwater-flow model for the northern High Plains aquifer. Both of these tasks require large amounts of data about the High Plains aquifer. Data pertaining to the High Plains aquifer were collected, synthesized, and then organized into digital data containers called geodatabases. There are 8 geodatabases, 1 file geodatabase and 7 personal geodatabases, that have been grouped in three categories: hydrogeologic data, remote sensing data, and water-budget-component data. The hydrogeologic data pertaining to the northern High Plains aquifer is included in three separate

  6. 7 CFR 650.25 - Flood-plain management.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Agriculture Regulations of the Department of Agriculture (Continued) NATURAL RESOURCES CONSERVATION SERVICE... human life, health, and property in ways that are environmentally sensitive. Most flood plains are... management will be provided by the NRCS technical service centers (§ 600.3 of this part). (2) NRCS state...

  7. Contrasting soils and landscapes of the Piedmont and Coastal Plain, eastern United States

    USGS Publications Warehouse

    Markewich, H.W.; Pavich, M.J.; Buell, G.R.

    1990-01-01

    The Piedmont and Coastal Plain physiographic provinces comprise 80 percent of the Atlantic Coastal states from New Jersey to Georgia. The provinces are climatically similar. The soil moisture regime is udic. The soil temperature regime is typically thermic from Virginia through Georgia, although it is mesic at altitudes above 400 m in Georgia and above 320 m in Virginia. The soil temperature regime is mesic for the Piedmont and Coastal Plain from Maryland through New Jersey. The tightly folded, structurally complex crystalline rocks of the Piedmont and the gently dipping "layer-cake" clastic sedimentary rocks and sediments of the Coastal Plain respond differently to weathering, pedogenesis, and erosion. The different responses result in two physiographically contrasting terrains; each has distinctive near-surface hydrology, regolith, drainage morphology, and morphometry. The Piedmont is predominantly an erosional terrain. Interfluves are as narrow as 0.5 to 2 km, and are convex upward. Valleys are as narrow as 0.1 to 0.5 km and generally V-shaped in cross section. Alluvial terraces are rare and discontinuous. Soils in the Piedmont are typically less than 1 m thick, have less sand and more clay than Coastal Plain soils, and generally have not developed sandy epipedons. Infiltration rates for Piedmont soils are low at 6-15 cm/h. The soil/saprolite, soil/rock, and saprolite/rock boundaries are distinct (can be placed within 10 cm) and are characterized by ponding and/or lateral movement of water. Water movement through soil into saprolite, and from saprolite into rock, is along joints, foliation, bedding planes and faults. Soils and isotopic data indicate residence times consistent with a Pleistocene age for most Piedmont soils. The Coastal Plain is both an erosional and a constructional terrain. Interfluves commonly are broader than 2 km and are flat. Valleys are commonly as wide as 1 km to greater than 10 km, and contain numerous alluvial and estuarine terrace

  8. Coastal inundation risk assessment due to subsidence and sea level rise in a Mediterranean alluvial plain (Volturno coastal plain - southern Italy)

    NASA Astrophysics Data System (ADS)

    Ciro Aucelli, Pietro Patrizio; Di Paola, Gianluigi; Incontri, Pietro; Rizzo, Angela; Vilardo, Giuseppe; Benassai, Guido; Buonocore, Berardino; Pappone, Gerardo

    2017-11-01

    Interdisciplinary studies of the last years highlight that the Italian coasts are significantly subject to retreat and to inundation by sea ingression due to natural and anthropic causes. In this study, the effects of future relative sea level have been evaluated for the Volturno River Plain, one of the widest coastal plain in southern Italy. The plain is characterized by high economical and ecological value, for the presence of farm activities, tourist structures and wetland protected zones. The study area is potentially prone to coastal flooding due to its very low topography and because it is affected by a severe subsidence, which emphasize the local effect of sea level rise due to the ongoing climate changes. In accordance with the guidelines of the MEDFLOOD project, the areas prone to inundation in the years 2065 and 2100 have been evaluated by comparing the future topographical information and expected relative sea level scenarios. The local Vertical Ground Displacements have been derived by PS-InSAR processing data whilst the mean values of the scenarios RCP 2.6 and RCP 8.5 provided by the IPCC (2014) have been used as future sea level projections in 2065 and 2100. The PS-InSar data elaboration shows that the area affected by subsidence corresponds to 35% of the Volturno plain and that the annual rate of the phenomenon ranges between -1 and -25 mm/yr. The inundation analysis, based on the classification of the areas in four hazard classes, indicates that in 2065 the zones located below the sea level will increase approximately of 50% respect to the present conditions, while between 2065 and 2100 the increase can be at least of 60% (IPCC, RCP 8.5 scenarios). Considering the socio-economical and ecological exposure, evaluated following the EUROSION project guidelines, the coastal flooding risk maps have been produced. Almost 8.2 km2 and 14.4 km2 of the investigated area has to be considered subject to very high marine inundation risk in 2065 and 2100

  9. Groundwater declines are linked to changes in Great Plains stream fish assemblages

    USGS Publications Warehouse

    Prekins, Joshuah S.; Gido, Keith B.; Falke, Jeffrey A.; Fausch, Kurt D.; Crockett, Harry; Johnson, Eric R.; Sanderson, John

    2017-01-01

    Groundwater pumping for agriculture is a major driver causing declines of global freshwater ecosystems, yet the ecological consequences for stream fish assemblages are rarely quantified. We combined retrospective (1950–2010) and prospective (2011–2060) modeling approaches within a multiscale framework to predict change in Great Plains stream fish assemblages associated with groundwater pumping from the United States High Plains Aquifer. We modeled the relationship between the length of stream receiving water from the High Plains Aquifer and the occurrence of fishes characteristic of small and large streams in the western Great Plains at a regional scale and for six subwatersheds nested within the region. Water development at the regional scale was associated with construction of 154 barriers that fragment stream habitats, increased depth to groundwater and loss of 558 km of stream, and transformation of fish assemblage structure from dominance by large-stream to small-stream fishes. Scaling down to subwatersheds revealed consistent transformations in fish assemblage structure among western subwatersheds with increasing depths to groundwater. Although transformations occurred in the absence of barriers, barriers along mainstem rivers isolate depauperate western fish assemblages from relatively intact eastern fish assemblages. Projections to 2060 indicate loss of an additional 286 km of stream across the region, as well as continued replacement of large-stream fishes by small-stream fishes where groundwater pumping has increased depth to groundwater. Our work illustrates the shrinking of streams and homogenization of Great Plains stream fish assemblages related to groundwater pumping, and we predict similar transformations worldwide where local and regional aquifer depletions occur.

  10. Groundwater declines are linked to changes in Great Plains stream fish assemblages.

    PubMed

    Perkin, Joshuah S; Gido, Keith B; Falke, Jeffrey A; Fausch, Kurt D; Crockett, Harry; Johnson, Eric R; Sanderson, John

    2017-07-11

    Groundwater pumping for agriculture is a major driver causing declines of global freshwater ecosystems, yet the ecological consequences for stream fish assemblages are rarely quantified. We combined retrospective (1950-2010) and prospective (2011-2060) modeling approaches within a multiscale framework to predict change in Great Plains stream fish assemblages associated with groundwater pumping from the United States High Plains Aquifer. We modeled the relationship between the length of stream receiving water from the High Plains Aquifer and the occurrence of fishes characteristic of small and large streams in the western Great Plains at a regional scale and for six subwatersheds nested within the region. Water development at the regional scale was associated with construction of 154 barriers that fragment stream habitats, increased depth to groundwater and loss of 558 km of stream, and transformation of fish assemblage structure from dominance by large-stream to small-stream fishes. Scaling down to subwatersheds revealed consistent transformations in fish assemblage structure among western subwatersheds with increasing depths to groundwater. Although transformations occurred in the absence of barriers, barriers along mainstem rivers isolate depauperate western fish assemblages from relatively intact eastern fish assemblages. Projections to 2060 indicate loss of an additional 286 km of stream across the region, as well as continued replacement of large-stream fishes by small-stream fishes where groundwater pumping has increased depth to groundwater. Our work illustrates the shrinking of streams and homogenization of Great Plains stream fish assemblages related to groundwater pumping, and we predict similar transformations worldwide where local and regional aquifer depletions occur.

  11. Groundwater declines are linked to changes in Great Plains stream fish assemblages

    PubMed Central

    Perkin, Joshuah S.; Gido, Keith B.; Falke, Jeffrey A.; Fausch, Kurt D.; Crockett, Harry; Johnson, Eric R.; Sanderson, John

    2017-01-01

    Groundwater pumping for agriculture is a major driver causing declines of global freshwater ecosystems, yet the ecological consequences for stream fish assemblages are rarely quantified. We combined retrospective (1950–2010) and prospective (2011–2060) modeling approaches within a multiscale framework to predict change in Great Plains stream fish assemblages associated with groundwater pumping from the United States High Plains Aquifer. We modeled the relationship between the length of stream receiving water from the High Plains Aquifer and the occurrence of fishes characteristic of small and large streams in the western Great Plains at a regional scale and for six subwatersheds nested within the region. Water development at the regional scale was associated with construction of 154 barriers that fragment stream habitats, increased depth to groundwater and loss of 558 km of stream, and transformation of fish assemblage structure from dominance by large-stream to small-stream fishes. Scaling down to subwatersheds revealed consistent transformations in fish assemblage structure among western subwatersheds with increasing depths to groundwater. Although transformations occurred in the absence of barriers, barriers along mainstem rivers isolate depauperate western fish assemblages from relatively intact eastern fish assemblages. Projections to 2060 indicate loss of an additional 286 km of stream across the region, as well as continued replacement of large-stream fishes by small-stream fishes where groundwater pumping has increased depth to groundwater. Our work illustrates the shrinking of streams and homogenization of Great Plains stream fish assemblages related to groundwater pumping, and we predict similar transformations worldwide where local and regional aquifer depletions occur. PMID:28652354

  12. Nontuberculous mycobacteria in the environment of Hranice Abyss, the world's deepest flooded cave (Hranice karst, Czech Republic).

    PubMed

    Pavlik, Ivo; Gersl, Milan; Bartos, Milan; Ulmann, Vit; Kaucka, Petra; Caha, Jan; Unc, Adrian; Hubelova, Dana; Konecny, Ondrej; Modra, Helena

    2018-06-06

    Nontuberculous mycobacteria (NTM) are widely distributed in the environment. On one hand, they are opportunistic pathogens for humans and animals, and on the other hand, they are effective in biodegradation of some persistent pollutants. Following the recently recorded large abundance of NTM in extreme geothermal environments, the aim of the study was to ascertain the occurrence of NTM in the extreme environment of the water zone of the Hranice Abyss (HA). The HA mineral water is acidic, with large concentrations of free CO 2 , and bacterial slimes creating characteristic mucilaginous formations. Both culture and molecular methods were used to compare the mycobacterial diversity across the linked but distinct ecosystems of HA and the adjacent Zbrašov Aragonite Caves (ZAC) with consideration of their pathogenic relevance. Six slowly growing NTM species (M. arupense, M. avium, M. florentinum, M. gordonae, M. intracellulare) and two rapidly growing NTM species (M. mucogenicum, M. sediminis) were identified in the water and in the dry zones at both sites. Proteobacteria were dominant in all the samples from both the HA and the ZAC. The bacterial microbiomes of the HA mineral water and HA slime were similar, but both differed from the microbiome in the ZAC mineral water. Actinobacteria, a phylum containing mycobacteria, was identified in all the samples at low proportional abundance. The majority of the detected NTM species belong among environmental opportunistic pathogens.

  13. Southern Great Plains Safety Orientation

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

    Schatz, John

    2014-05-01

    Welcome to the Atmospheric Radiation Measurement (ARM) Climate Research Facility (ARM) Southern Great Plains (SGP) site. This U.S. Department of Energy (DOE) site is managed by Argonne National Laboratory (ANL). It is very important that all visitors comply with all DOE and ANL safety requirements, as well as those of the Occupational Safety and Health Administration (OSHA), the National Fire Protection Association, and the U.S. Environmental Protection Agency, and with other requirements as applicable.

  14. Nature, distribution, and origin of Titan’s Undifferentiated Plains

    USGS Publications Warehouse

    Lopes, Rosaly; Malaska, M. J.; Solomonidou, A.; Le, Gall A.; Janssen, M.A.; Neish, Catherine D.; Turtle, E.P.; Birch, S. P. D.; Hayes, A.G.; Radebaugh, J.; Coustenis, A.; Schoenfeld, A.; Stiles, B.W.; Kirk, Randolph L.; Mitchell, K.L.; Stofan, E.R.; Lawrence, K. J.; ,

    2016-01-01

    The Undifferentiated Plains on Titan, first mapped by Lopes et al. (Lopes, R.M.C. et al., 2010. Icarus, 205, 540–588), are vast expanses of terrains that appear radar-dark and fairly uniform in Cassini Synthetic Aperture Radar (SAR) images. As a result, these terrains are often referred to as “blandlands”. While the interpretation of several other geologic units on Titan – such as dunes, lakes, and well-preserved impact craters – has been relatively straightforward, the origin of the Undifferentiated Plains has remained elusive. SAR images show that these “blandlands” are mostly found at mid-latitudes and appear relatively featureless at radar wavelengths, with no major topographic features. Their gradational boundaries and paucity of recognizable features in SAR data make geologic interpretation particularly challenging. We have mapped the distribution of these terrains using SAR swaths up to flyby T92 (July 2013), which cover >50% of Titan’s surface. We compared SAR images with other data sets where available, including topography derived from the SARTopo method and stereo DEMs, the response from RADAR radiometry, hyperspectral imaging data from Cassini’s Visual and Infrared Mapping Spectrometer (VIMS), and near infrared imaging from the Imaging Science Subsystem (ISS). We examined and evaluated different formation mechanisms, including (i) cryovolcanic origin, consisting of overlapping flows of low relief or (ii) sedimentary origins, resulting from fluvial/lacustrine or aeolian deposition, or accumulation of photolysis products created in the atmosphere. Our analysis indicates that the Undifferentiated Plains unit is consistent with a composition predominantly containing organic rather than icy materials and formed by depositional and/or sedimentary processes. We conclude that aeolian processes played a major part in the formation of the Undifferentiated Plains; however, other processes (fluvial, deposition of photolysis products) are likely to

  15. Creep of plain weave polymer matrix composites

    NASA Astrophysics Data System (ADS)

    Gupta, Abhishek

    Polymer matrix composites are increasingly used in various industrial sectors to reduce structural weight and improve performance. Woven (also known as textile) composites are one class of polymer matrix composites with increasing market share mostly due to their lightweight, their flexibility to form into desired shape, their mechanical properties and toughness. Due to the viscoelasticity of the polymer matrix, time-dependent degradation in modulus (creep) and strength (creep rupture) are two of the major mechanical properties required by engineers to design a structure reliably when using these materials. Unfortunately, creep and creep rupture of woven composites have received little attention by the research community and thus, there is a dire need to generate additional knowledge and prediction models, given the increasing market share of woven composites in load bearing structural applications. Currently, available creep models are limited in scope and have not been validated for any loading orientation and time period beyond the experimental time window. In this thesis, an analytical creep model, namely the Modified Equivalent Laminate Model (MELM), was developed to predict tensile creep of plain weave composites for any orientation of the load with respect to the orientation of the fill and warp fibers, using creep of unidirectional composites. The ability of the model to predict creep for any orientation of the load is a "first" in this area. The model was validated using an extensive experimental involving the tensile creep of plain weave composites under varying loading orientation and service conditions. Plain weave epoxy (F263)/ carbon fiber (T300) composite, currently used in aerospace applications, was procured as fabrics from Hexcel Corporation. Creep tests were conducted under two loading conditions: on-axis loading (0°) and off-axis loading (45°). Constant load creep, in the temperature range of 80-240°C and stress range of 1-70% UTS of the

  16. Slab-controlled Tectonomagmatism of the Pacific Northwest: A Holistic view of Columbia River, High Lava Plains, and Snake River Plain/Yellowstone Volcanism

    NASA Astrophysics Data System (ADS)

    James, D. E.; Fouch, M. J.; Long, M. D.; Druken, K. A.; Wagner, L. S.; Chen, C.; Carlson, R. W.

    2012-12-01

    We interpret post-20 Ma tectonomagmatism across the U.S. Pacific Northwest in the context of subduction related processes. While mantle plume models have long enjoyed favor as an explanation for the post 20-Ma magmatism in the region, conceptually their support has hinged almost entirely on two major features: (1) Steens/Columbia River flood basalt volcanism (plume head); and (2) The Snake River Plain/Yellowstone hotspot track (plume tail). Recent work, synthesized in this presentation, suggests that these features are more plausibly the result of mantle dynamical processes driven by southerly truncation of the Farallon/Juan de Fuca subduction zone and slab detachment along the evolving margin of western North America (Long et al., 2012; James et al., 2011). Plate reconstructions indicate that shortening of the subduction zone by the northward migration of the Mendocino triple junction resulted in a significant increase in the rate of trench retreat and slab rollback ca 20 Ma. Both numerical modeling and physical tank experiments in turn predict large-scale mantle upwelling and flow around the southern edge of the rapidly retreating slab, consistent both with the observed Steens/Columbia River flood volcanism and with the strong E-W mantle fabric observed beneath the region of the High Lava Plains of central and eastern Oregon. The High Lava Plains and Snake River Plain time-progressive volcanism began concurrently about 12 Ma, but along highly divergent tracks and characterized by strikingly different upper mantle structure. Crustal and upper mantle structure beneath the High Lava Plains exhibits evidence typical of regional extension; i.e. thin crust, flat and sharp Moho, and an uppermost mantle with low velocities but otherwise largely devoid of significant vertical structure. In contrast, the Snake River Plain exhibits ultra-low mantle velocities to depths of about 180 km along the length of the hotspot track. Seismic images of the upper mantle in the depth

  17. Groundwater availability in the Atlantic Coastal Plain of North and South Carolina

    USGS Publications Warehouse

    Campbell, Bruce G.; Coes, Alissa L.

    2010-01-01

    The Atlantic Coastal Plain aquifers and confining units of North and South Carolina are composed of crystalline carbonate rocks, sand, clay, silt, and gravel and contain large volumes of high-quality groundwater. The aquifers have a long history of use dating back to the earliest days of European settlement in the late 1600s. Although extensive areas of some of the aquifers have or currently (2009) are areas of groundwater level declines from large-scale, concentrated pumping centers, large areas of the Atlantic Coastal Plain contain substantial quantities of high-quality groundwater that currently (2009) are unused. Groundwater use from the Atlantic Coastal Plain aquifers in North Carolina and South Carolina has increased during the past 60 years as the population has increased along with demands for municipal, industrial, and agricultural water needs. While North Carolina and South Carolina work to increase development of water supplies in response to the rapid growth in these coastal populations, both States recognize that they are facing a number of unanswered questions regarding availability of groundwater supplies and the best methods to manage these important supplies. An in-depth assessment of groundwater availability of the Atlantic Coastal Plain aquifers of North and South Carolina has been completed by the U.S. Geological Survey Groundwater Resources Program. This assessment includes (1) a determination of the present status of the Atlantic Coastal Plain groundwater resources; (2) an explanation for how these resources have changed over time; and (3) development of tools to assess the system's response to stresses from potential future climate variability. Results from numerous previous investigations of the Atlantic Coastal Plain by Federal and State agencies have been incorporated into this effort. The primary products of this effort are (1) comprehensive hydrologic datasets such as groundwater levels, groundwater use, and aquifer properties; (2) a

  18. Distribution of breeding shorebirds on the Arctic Coastal Plain of Alaska

    USGS Publications Warehouse

    Johnson, J.A.; Lanctot, Richard B.; Andres, B.A.; Bart, J.R.; Brown, S.C.; Kendall, S.J.; Payer, David C.

    2007-01-01

    Available information on the distribution of breeding shorebirds across the Arctic Coastal Plain of Alaska is dated, fragmented, and limited in scope. Herein, we describe the distribution of 19 shorebird species from data gathered at 407 study plots between 1998 and 2004. This information was collected using a single-visit rapid area search technique during territory establishment and early incubation periods, a time when social displays and vocalizations make the birds highly detectable. We describe the presence or absence of each species, as well as overall numbers of species, providing a regional perspective on shorebird distribution. We compare and contrast our shorebird distribution maps to those of prior studies and describe prominent patterns of shorebird distribution. Our examination of how shorebird distribution and numbers of species varied both latitudinally and longitudinally across the Arctic Coastal Plain of Alaska indicated that most shorebird species occur more frequently in the Beaufort Coastal Plain ecoregion (i.e., closer to the coast) than in the Brooks Foothills ecoregion (i.e., farther inland). Furthermore, the occurrence of several species indicated substantial longitudinal directionality. Species richness at surveyed sites was highest in the western portion of the Beaufort Coastal Plain ecoregion. The broad-scale distribution information we present here is valuable for evaluating potential effects of human development and climate change on Arctic-breeding shorebird populations. ?? The Arctic Institute of North America.

  19. Estimating Groundwater Development area in Jianan Plain using Standardized Groundwater Index

    NASA Astrophysics Data System (ADS)

    Yu, Chang Hsiang; Haw, Lee Cheng

    2017-04-01

    Taiwan has been facing severe water crises in recent years owing to the effects of extreme weather conditions. Changes in precipitation patterns have also made the drought phenomenon increasingly prominent, which has indirectly affected groundwater recharge. Hence, in the present study, long-term monitoring data were collected from the study area of the Jianan plain. The standardized groundwater index (SGI) and was then used to analyse the region's drought characteristics. To analyse the groundwater level by using SGI, making SGI180 groundwater level be the medium water crises, and SGI360 groundwater level be the extreme water crises. Through the different water crises signal in SGI180 and SGI360, we divide groundwater in Jianan plain into two sections. Thereby the water crises indicators establishing groundwater level standard line in Jianan Plain, then using the groundwater level standard line to find the study area where could be groundwater development area in Jianan plain. Taking into account relatively more water scarcity in dry season, so the study screen out another emergency backup groundwater development area, but the long-term groundwater development area is still as a priority development area. After finding suitable locations, groundwater modeling systems(GMS) software is used to simulate our sites to evaluate development volume. Finally, the result of study will help the government to grasp the water shortage situation immediately and solve the problem of water resources deployment.

  20. Plain film measurement error in acute displaced midshaft clavicle fractures

    PubMed Central

    Archer, Lori Anne; Hunt, Stephen; Squire, Daniel; Moores, Carl; Stone, Craig; O’Dea, Frank; Furey, Andrew

    2016-01-01

    Background Clavicle fractures are common and optimal treatment remains controversial. Recent literature suggests operative fixation of acute displaced mid-shaft clavicle fractures (DMCFs) shortened more than 2 cm improves outcomes. We aimed to identify correlation between plain film and computed tomography (CT) measurement of displacement and the inter- and intraobserver reliability of repeated radiographic measurements. Methods We obtained radiographs and CT scans of patients with acute DMCFs. Three orthopedic staff and 3 residents measured radiographic displacement at time zero and 2 weeks later. The CT measurements identified absolute shortening in 3 dimensions (by subtracting the length of the fractured from the intact clavicle). We then compared shortening measured on radiographs and shortening measured in 3 dimensions on CT. Interobserver and intraobserver reliability were calculated. Results We reviewed the fractures of 22 patients. Bland–Altman repeatability coefficient calculations indicated that radiograph and CT measurements of shortening could not be correlated owing to an unacceptable amount of measurement error (6 cm). Interobserver reliability for plain radiograph measurements was excellent (Cronbach α = 0.90). Likewise, intraobserver reliabilities for plain radiograph measurements as calculated with paired t tests indicated excellent correlation (p > 0.05 in all but 1 observer [p = 0.04]). Conclusion To establish shortening as an indication for DMCF fixation, reliable measurement tools are required. The low correlation between plain film and CT measurements we observed suggests further research is necessary to establish what imaging modality reliably predicts shortening. Our results indicate weak correlation between radiograph and CT measurement of acute DMCF shortening. PMID:27438054

  1. Identification of possible recent water/lava source fissures in the Cerberus Plains: stratigraphic and crater count age constraints

    NASA Astrophysics Data System (ADS)

    Thomas, Rebecca J.

    2013-04-01

    The Cerberus plains are one of the youngest surfaces on Mars. They are thought to have been formed by lava and/or water flows, but there is considerable debate regarding the source of this material. Much of the material forming the western plains, including the Athabasca Valles outflow channels, appears to have flowed from the region of the Cerberus Fossae graben system [1,2,3] and limited areas forming the eastern plains may have been erupted by low shield volcanoes [4,5]. However, flow of material from west to east is obstructed by a ridge centred on 157°E, 7°N and, prior to this study, vents which might be the source of fluid of a low enough viscosity to form the majority of the flat eastern plains had not been identified. We studied new HiRISE (25cm/px, High Resolution Science Imaging Experiment) images of the ridge between the east and west plains and observed possible source vents for this material: the ridge is cut by a series of pits and fissures which lie at the heads of flows and channels extending towards the surrounding plains. In order to establish the stratigraphic relationships between the vents and plains, this study produced large scale geomorphological maps based on the HiRISE images. The mapping showed that both incised channels and leveed flows extend onto the plain to the south of the ridge and that these were the final phase of plains-forming activity in that region. Conversely, to the north, ridge-sourced deposits only form the plains surface close to the ridge - beyond that, they are overlain by large-scale regional flows that appear to have originated from the direction of Athabasca Valles. In the southeast, a large-scale flow which does not emanate from this ridge forms the plains surface, but there is evidence that the youngest outflow activity from the ridge was contemporaneous with emplacement of this unit. We also performed crater counts to age-date the surfaces and these indicate that plains-forming and ridge-sourced units are of a

  2. Wrinkle ridges, stress domains, and kinematics of venusian plains

    NASA Technical Reports Server (NTRS)

    Mcgill, George E.

    1993-01-01

    Wrinkle ridges are nearly ubiquitous landforms on the plains of Venus. By analogy with similar structures on other planets, venusian wrinkle ridges are inferred to trend normal to the direction of maximum principal compression in the crust, an inference that is verified by geometrical relationships with positive and negative relief features on Venus. Because plains are the dominant terrain on Venus, wrinkle ridges provide an excellent opportunity to determine the orientations of shallow crustal principal stress trajectories over most of the planet. In most places there are two or more sets of wrinkle ridges, and commonly one of these persists over a large area, defining a regional stress domain. Intersection relationships indicate that these domains differ in age.

  3. Snake River Plain FORGE Well Data for WO-2

    DOE Data Explorer

    Robert Podgorney

    1991-07-29

    Well data for the WO-2 well located in eastern Snake River Plain, Idaho. This data collection includes lithology reports, borehole logs, temperature at depth data, neutron density and gamma data, and rock strength parameters for the WO-2 well. This collection of data has been assembled as part of the site characterization data used to develop the conceptual geologic model for the Snake River Plain site in Idaho, as part of phase 1 of the Frontier Observatory for Research in Geothermal Energy (FORGE) initiative. They were assembled by the Snake River Geothermal Consortium (SRGC), a team of collaborators that includes members from national laboratories, universities, industry, and federal agencies, lead by the Idaho National Laboratory (INL).

  4. Soil suitability for hardwoods in Coastal Plains

    Treesearch

    W. M. Broadfoot; J. S. McKnight

    1962-01-01

    The Coastal Plain soil area occupies the major portion of Mississippi east of the Delta and Loess areas. In general, the soils are sandy, acid, and lacking in natural fertility, but on the alluvial soils moisture and drainage relations appear sufficient to support good growth of some tree species.

  5. 7 CFR 650.25 - Flood-plain management.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 6 2013-01-01 2013-01-01 false Flood-plain management. 650.25 Section 650.25 Agriculture Regulations of the Department of Agriculture (Continued) NATURAL RESOURCES CONSERVATION SERVICE... management will be provided by the NRCS technical service centers (§ 600.3 of this part). (2) NRCS state...

  6. Hydrologic and geochemical characterization of the Santa Rosa Plain watershed, Sonoma County, California

    USGS Publications Warehouse

    Nishikawa, Tracy

    2013-01-01

    The Santa Rosa Plain is home to approximately half of the population of Sonoma County, California, and faces growth in population and demand for water. Water managers are confronted with the challenge of meeting the increasing water demand with a combination of water sources, including local groundwater, whose future availability could be uncertain. To meet this challenge, water managers are seeking to acquire the knowledge and tools needed to understand the likely effects of future groundwater development in the Santa Rosa Plain and to identify efficient strategies for surface- and groundwater management that will ensure the long-term viability of the water supply. The U.S. Geological Survey, in cooperation with the Sonoma County Water Agency and other stakeholders in the area (cities of Cotati, Rohnert Park, Santa Rosa, and Sebastopol, town of Windsor, Cal-American Water Company, and the County of Sonoma), undertook this study to characterize the hydrology of the Santa Rosa Plain and to develop tools to better understand and manage the groundwater system. The objectives of the study are: (1) to develop an updated assessment of the hydrogeology and geochemistry of the Santa Rosa Plain; (2) to develop a fully coupled surface-water and groundwater-flow model for the Santa Rosa Plain watershed; and (3) to evaluate the potential hydrologic effects of alternative groundwater-management strategies for the basin. The purpose of this report is to describe the surface-water and groundwater hydrology, hydrogeology, and water-quality characteristics of the Santa Rosa Plain watershed and to develop a conceptual model of the hydrologic system in support of the first objective. The results from completing the second and third objectives will be described in a separate report.

  7. Socioeconomically disadvantaged smokers’ ratings of plain and branded cigarette packaging: an experimental study

    PubMed Central

    Guillaumier, Ashleigh; Bonevski, Billie; Paul, Chris; Durkin, Sarah; D'Este, Catherine

    2014-01-01

    Objectives This study aimed to test the potential impact of plain packaging for cigarettes on brand appeal among highly socioeconomically disadvantaged smokers using the new design for cigarettes implemented in Australia, which combines plain packaging with larger health warning labels. Design A 2×2 factorial design trial embedded within a cross-sectional computer touchscreen survey. Data were collected between March and December 2012. Setting Socially disadvantaged welfare aid recipients were recruited through a large Social and Community Service Organisation in New South Wales, Australia. Participants N=354 smokers. The majority of the sample had not completed high school (64%), earned less than $A300/week (55%) and received their income from Government payments (95%). Interventions Participants were randomised to one of the four different pack conditions determined by brand name: Winfield versus Benson & Hedges, and packaging type: branded versus plain. Participants were required to rate their assigned pack on measures of brand appeal and purchase intentions. Results Plain packaging was associated with significantly reduced smoker ratings of ‘positive pack characteristics’ (p<0.001), ‘positive smoker characteristics’ (p=0.003) and ‘positive taste characteristics’ (p=0.033) in the Winfield brand name condition only. Across the four pack conditions, no main differences were found for ‘negative smoker characteristics’ (p=0.427) or ‘negative harm characteristics’ (p=0.411). In comparison to plain packaging, the presentation of branded packaging was associated with higher odds of smokers’ purchase intentions (OR=2.18, 95% CI 1.34 to 3.54; p=0.002). Conclusions Plain packs stripped of branding elements, featuring larger health warning labels, were associated with reduced positive cigarette brand image and purchase intentions among highly socioeconomically disadvantaged smokers. PMID:24503299

  8. The effect of cigarette branding and plain packaging on female youth in the United Kingdom.

    PubMed

    Hammond, David; Daniel, Samantha; White, Christine M

    2013-02-01

    Cigarette packaging is the most prominent form of tobacco marketing remaining in countries such as the United Kingdom. The current study examined perceptions of cigarette packaging among female youth and the potential impact of "plain" cigarette packaging regulations. A national sample of 947 16- to 19-year-old female subjects in the United Kingdom completed an online survey. Participants were randomized to view 10 cigarette packs designed according to one of four experimental conditions: fully branded female packs, the same packs without descriptor words, the same packs without brand imagery or descriptors ("plain" packs), and branded non-female brands. Participants rated packs on measures of appeal and health risk, positive smoker image, and completed a behavioral pack selection task. Plain packs were rated as the least appealing and worse tasting compared with all other conditions. Plain packs were also associated with fewer false beliefs about health risks compared with branded packs. Removing brand descriptors from packs significantly reduced measures of appeal and taste, particularly for brands with flavor descriptors, such as cherry and vanilla. Plain packs were significantly less likely to be associated with positive images, such as glamour, sophistication, and slimness. Most importantly, respondents were significantly less likely to accept a pack of cigarettes when offered only plain versus branded packs (p = .026). Marketing in the form of pack branding remains a potent tool for increasing the appeal of tobacco products to young women. The findings provide empirical support for plain cigarette packaging regulations in Australia to be implemented in 2012. Copyright © 2013 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

  9. Groundwater depletion and sustainability of irrigation in the US High Plains and Central Valley

    USGS Publications Warehouse

    Scanlon, Bridget R.; Faunt, Claudia; Longuevergne, Laurent; Reedy, Robert C.; Alley, William M.; McGuire, Virginia L.; McMahon, Peter B.

    2012-01-01

    Aquifer overexploitation could significantly impact crop production in the United States because 60% of irrigation relies on groundwater. Groundwater depletion in the irrigated High Plains and California Central Valley accounts for ∼50% of groundwater depletion in the United States since 1900. A newly developed High Plains recharge map shows that high recharge in the northern High Plains results in sustainable pumpage, whereas lower recharge in the central and southern High Plains has resulted in focused depletion of 330 km3 of fossil groundwater, mostly recharged during the past 13,000 y. Depletion is highly localized with about a third of depletion occurring in 4% of the High Plains land area. Extrapolation of the current depletion rate suggests that 35% of the southern High Plains will be unable to support irrigation within the next 30 y. Reducing irrigation withdrawals could extend the lifespan of the aquifer but would not result in sustainable management of this fossil groundwater. The Central Valley is a more dynamic, engineered system, with north/south diversions of surface water since the 1950s contributing to ∼7× higher recharge. However, these diversions are regulated because of impacts on endangered species. A newly developed Central Valley Hydrologic Model shows that groundwater depletion since the 1960s, totaling 80 km3, occurs mostly in the south (Tulare Basin) and primarily during droughts. Increasing water storage through artificial recharge of excess surface water in aquifers by up to 3 km3 shows promise for coping with droughts and improving sustainability of groundwater resources in the Central Valley.

  10. Groundwater depletion and sustainability of irrigation in the US High Plains and Central Valley

    USGS Publications Warehouse

    Scanlon, Bridget R.; Faunt, Claudia C.; Longuevergne, Laurent; Reedy, Robert C.; Alley, William M.; McGuire, Virginia L.; McMahon, Peter B.

    2012-01-01

    Aquifer overexploitation could significantly impact crop production in the United States because 60% of irrigation relies on groundwater. Groundwater depletion in the irrigated High Plains and California Central Valley accounts for ~50% of groundwater depletion in the United States since 1900. A newly developed High Plains recharge map shows that high recharge in the northern High Plains results in sustainable pumpage, whereas lower recharge in the central and southern High Plains has resulted in focused depletion of 330 km3 of fossil groundwater, mostly recharged during the past 13,000 y. Depletion is highly localized with about a third of depletion occurring in 4% of the High Plains land area. Extrapolation of the current depletion rate suggests that 35% of the southern High Plains will be unable to support irrigation within the next 30 y. Reducing irrigation withdrawals could extend the lifespan of the aquifer but would not result in sustainable management of this fossil groundwater. The Central Valley is a more dynamic, engineered system, with north/south diversions of surface water since the 1950s contributing to ~7× higher recharge. However, these diversions are regulated because of impacts on endangered species. A newly developed Central Valley Hydrologic Model shows that groundwater depletion since the 1960s, totaling 80 km3, occurs mostly in the south (Tulare Basin) and primarily during droughts. Increasing water storage through artificial recharge of excess surface water in aquifers by up to 3 km3 shows promise for coping with droughts and improving sustainability of groundwater resources in the Central Valley.

  11. Groundwater depletion and sustainability of irrigation in the US High Plains and Central Valley

    PubMed Central

    Scanlon, Bridget R.; Faunt, Claudia C.; Longuevergne, Laurent; Reedy, Robert C.; Alley, William M.; McGuire, Virginia L.; McMahon, Peter B.

    2012-01-01

    Aquifer overexploitation could significantly impact crop production in the United States because 60% of irrigation relies on groundwater. Groundwater depletion in the irrigated High Plains and California Central Valley accounts for ∼50% of groundwater depletion in the United States since 1900. A newly developed High Plains recharge map shows that high recharge in the northern High Plains results in sustainable pumpage, whereas lower recharge in the central and southern High Plains has resulted in focused depletion of 330 km3 of fossil groundwater, mostly recharged during the past 13,000 y. Depletion is highly localized with about a third of depletion occurring in 4% of the High Plains land area. Extrapolation of the current depletion rate suggests that 35% of the southern High Plains will be unable to support irrigation within the next 30 y. Reducing irrigation withdrawals could extend the lifespan of the aquifer but would not result in sustainable management of this fossil groundwater. The Central Valley is a more dynamic, engineered system, with north/south diversions of surface water since the 1950s contributing to ∼7× higher recharge. However, these diversions are regulated because of impacts on endangered species. A newly developed Central Valley Hydrologic Model shows that groundwater depletion since the 1960s, totaling 80 km3, occurs mostly in the south (Tulare Basin) and primarily during droughts. Increasing water storage through artificial recharge of excess surface water in aquifers by up to 3 km3 shows promise for coping with droughts and improving sustainability of groundwater resources in the Central Valley. PMID:22645352

  12. Graphic warning labels on plain cigarette packs: will they make a difference to adolescents?

    PubMed

    McCool, Judith; Webb, Lisa; Cameron, Linda D; Hoek, Janet

    2012-04-01

    Graphic warning labels and plain cigarette packaging are two initiatives developed to increase quit behaviour among smokers. Although a little is known about how adolescents interpret graphic warning labels, very few studies have examined how plain cigarette packaging would affect adolescents' perceptions of cigarette smoking and smoking behaviour. We explored how teens interpret and respond to graphic warning labels and the plain packaging of cigarettes, to assess the potential these strategies may offer in deterring smoking initiation. Twelve focus group interviews with a sample of 80 14-16 year old students from a diverse range of schools in Auckland, New Zealand were undertaken between June and August 2009. Textual analysis revealed that graphic warning labels may influence adolescents by reiterating a negative image of smokers. Graphic warning on a plain cigarette pack increased the attention paid to graphic warning labels and the overall perceptions of harm caused by cigarette smoking, and reduced the social appeal of cigarette smoking. This research offers evidence on how adolescents are appraising and interpreting graphic warning labels, and explores how dominant appraisals may affect the role graphic warning labels play in preventing smoking. Not only would plain cigarette packaging enhance the salience and impact of graphic warning labels, but it would potentially bolster the overall message that cigarette smoking is harmful. In the context of a comprehensive tobacco control programme, graphic warning labels on plain cigarette packaging present an explicit message about the risks (to health and image) associated with cigarette smoking. Copyright © 2012 Elsevier Ltd. All rights reserved.

  13. Changes in water levels and storage in the High Plains Aquifer, predevelopment to 2009

    USGS Publications Warehouse

    McGuire, V.L.

    2011-01-01

    The High Plains aquifer underlies 111.8 million acres (175,000 square miles) in parts of eight States - Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming. The area overlying the High Plains aquifer is one of the primary agricultural regions in the Nation. Water-level declines began in parts of the High Plains aquifer soon after the onset of substantial irrigation with groundwater from the aquifer (about 1950 and termed "predevelopment" in this fact sheet). By 1980, water levels in the High Plains aquifer in parts of Texas, Oklahoma, and southwestern Kansas had declined more than 100 feet (ft) (Luckey and others, 1981). In 1987, in response to declining water levels, Congress directed the U.S. Geological Survey (USGS), in collaboration with numerous Federal, State, and local water-resources entities, to assess and track water-level changes in the aquifer. This fact sheet summarizes changes in water levels and drainable water in storage in the High Plains aquifer from predevelopment to 2009. Drainable water in storage is the fraction of water in the aquifer that will drain by gravity and can be withdrawn by wells. The remaining water in the aquifer is held to the aquifer material by capillary forces and generally cannot be withdrawn by wells. Drainable water in storage is termed "water in storage" in this report. A companion USGS report presents more detailed and technical information about water-level and storage changes in the High Plains aquifer during this period (McGuire, 2011).

  14. Austenite grain growth kinetics in Al-killed plain carbon steels

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

    Militzer, M.; Giumelli, A.; Hawbolt, E.B.

    1996-11-01

    Austenite grain growth kinetics have been investigated in three Al-killed plain carbon steels. Experimental results have been validated using the statistical grain growth model by Abbruzzese and Luecke, which takes pinning by second-phase particles into account. It is shown that the pinning force is a function of the pre-heat-treatment schedule. Extrapolation to the conditions of a hot-strip mill indicates that grain growth occurs without pinning during conventional processing. Analytical relations are proposed to simulate austenite grain growth for Al-killed plain carbon steels for any thermal path in a hot-strip mill.

  15. Geochemistry of shallow ground water in coastal plain environments in the southeastern United States: Implications for aquifer susceptibility

    USGS Publications Warehouse

    Tesoriero, A.J.; Spruill, T.B.; Eimers, J.L.

    2004-01-01

    Ground-water chemistry data from coastal plain environments have been examined to determine the geochemical conditions and processes that occur in these areas and assess their implications for aquifer susceptibility. Two distinct geochemical environments were studied to represent a range of conditions: an inner coastal plain setting having more well-drained soils and lower organic carbon (C) content and an outer coastal plain environment that has more poorly drained soils and high organic C content. Higher concentrations of most major ions and dissolved inorganic and organic C in the outer coastal plain setting indicate a greater degree of mineral dissolution and organic matter oxidation. Accordingly, outer coastal plain waters are more reducing than inner coastal plain waters. Low dissolved oxygen (O2) and nitrate (NO 3-) concentrations and high iron (Fe) concentrations indicate that ferric iron (Fe (III)) is an important electron acceptor in this setting, while dissolved O2 is the most common terminal electron acceptor in the inner coastal plain setting. The presence of a wide range of redox conditions in the shallow aquifer system examined here underscores the importance of providing a detailed geochemical characterization of ground water when assessing the intrinsic susceptibility of coastal plain settings. The greater prevalence of aerobic conditions in the inner coastal plain setting makes this region more susceptible to contamination by constituents that are more stable under these conditions and is consistent with the significantly (p<0.05) higher concentrations of NO3- found in this setting. Herbicides and their transformation products were frequently detected (36% of wells sampled), however concentrations were typically low (<0.1 ??g/L). Shallow water table depths often found in coastal plain settings may result in an increased risk of the detection of pesticides (e.g., alachlor) that degrade rapidly in the unsaturated zone.

  16. Reducing pain in acute herpes zoster with plain occlusive dressings: a case report.

    PubMed

    Keegan, David A

    2015-04-25

    The pain of acute herpes zoster (shingles) is severe and difficult to control. The medications used to control pain have a variety of important and potentially serious side effects. To the best of my knowledge, this is the first case report of using a plain topical occlusive dressing to reduce the pain of herpes zoster, avoiding the use of medication. A 40-year-old Caucasian man and a qualified physician (the author), developed a dermatomal vesicular rash consistent with herpes zoster. Applying plain topical occlusive dressings reduced the severity of his pain to an ignorable level. Plain topical occlusive dressings provide effective pain relief for acute herpes zoster, thereby avoiding the risks accompanying medication use.

  17. Do abyssal scavengers use phytodetritus as a food resource? Video and biochemical evidence from the Atlantic and Mediterranean

    NASA Astrophysics Data System (ADS)

    Jeffreys, Rachel M.; Lavaleye, Marc S. S.; Bergman, Magda J. N.; Duineveld, Gerard C. A.; Witbaard, Rob

    2011-04-01

    Deep-sea benthic communities derive their energetic requirements from overlying surface water production, which is deposited at the seafloor as phytodetritus. Benthic invertebrates are the primary consumers of this food source, with deep-sea fish at the top of the trophic hierarchy. Recently, we demonstrated with the use of baited cameras that macrourid fish rapidly respond to and feed vigorously on large plant food falls mimicked by spinach ( Jeffreys et al., 2010). Since higher plant remains are scarce in the deep-sea, with the exception of canyons, where terrestrial material has been observed, these results led us to ask if a more commonly documented plant material i.e. phytodetritus might form a food source for deep-sea fish and mobile scavenging megafauna. We simulated a phytodetritus dump at the seafloor in two contrasting environments (1) the NE Atlantic where carpets of phytodetritus have been previously observed and (2) the oligotrophic western Mediterranean, where the deposition of phytodetritus at the seafloor is a rare occurrence. We recorded the response of the scavenging fauna using an in situ benthic lander equipped with baited time-lapse cameras. In the NE Atlantic at 3000 m, abyssal macrourids and cusk-eels were observed ingesting the phytodetritus. The phytodetrital patch was significantly diminished within 2 h. Abundance estimates calculated from first arrival times of macrourids at the phytodetrital patch in the Atlantic corresponded with abundance estimates from video-transect indicating that fish were attracted to the scent of phytodetrital bait. In contrast to this, in the western Mediterranean at 2800 m a single macrourid was observed investigating the phytodetrital patch but did not feed from it. The phytodetrital patch was significantly diminished within 6.5 h as a result of mainly invertebrate activity. At 1900 m, Lepidion lepidion was observed near the lander and the bait, but did not feed. The phytodetrital patch remained intact until

  18. Perceptions of plain packaging among young adult roll-your-own smokers in France: a naturalistic approach.

    PubMed

    Gallopel-Morvan, Karine; Moodie, Crawford; Eker, Figen; Beguinot, Emmanuelle; Martinet, Yves

    2015-03-01

    We explored, for the first time, young adult roll-your-own smokers' response to using plain packaging in real-world settings. Naturalistic research was employed, where 133 French young adult smokers (18-25 years of age) used plain roll-your-own packs for 10 days; the plain packs they were provided with contained their usual brand of rolling tobacco and displayed the name of their usual brand. Participants were recruited in five cities in France (Paris, Marseille, Metz, Nantes, Toulouse) and completed two questionnaires to measure their response to their own branded packs and the plain packs. Both questionnaires assessed pack perceptions, brand attachment, product perceptions (eg, taste, quality, natural), feelings about smoking (satisfying, pleasurable), feelings when using the pack in front of others (embarrassment, image), warning response (credibility, awareness of risks) and smoking-related behaviour (eg, consumption, quitting). Compared to their own fully branded packs, plain packs were associated with less positive pack and product perceptions, lower brand attachment and less positive feelings about smoking and feelings when using the pack in front of others. Participants were also more likely to report feeling like reducing consumption and quitting when using the plain packs, and more likely to feel like missing out on rolling a cigarette. No significant differences between the two pack types (plain and branded) were found in terms of credibility of warnings and perceptions of level of tar. The study suggests that the impacts of plain packaging for roll-your-own cigarette smokers are the same as for smokers of factory-made cigarettes. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  19. The potential impact of plain packaging of cigarette products among Brazilian young women: an experimental study

    PubMed Central

    2012-01-01

    Background Tobacco use is responsible for 5.4 million deaths every year worldwide and is a leading cause of preventable death. The burden of these deaths is rapidly shifting to low and middle-income countries, such as Brazil. Brazil has prohibited most forms of tobacco advertising; however, the cigarette pack remains a primary source of marketing. The current study examined how tobacco packaging influences brand appeal and perceptions of health risk among young women in Brazil. Methods A between-subjects experiment was conducted in which 640 Brazilian women aged 16–26 participated in an online survey. Participants were randomized to view 10 cigarette packages according to one of three experimental conditions: standard branded packages, the same packs without brand imagery (“plain packaging”), or the same packs without brand imagery or descriptors (e.g., flavors). Participants rated packages on perceived appeal, taste, health risk, smoothness, and smoker attributes. Finally, participants were shown a range of branded and plain packs from which they could select one as a free gift, which constituted a behavioral measure of appeal. Results Branded packs were rated as significantly more appealing, better tasting, and smoother on the throat than plain packs. Branded packs were also associated with a greater number of positive smoker attributes including style and sophistication, and were perceived as more likely to be smoked by females than the plain packs. Removing descriptors from the plain packs further decreased the ratings of appeal, taste and smoothness, and also reduced associations with positive attributes. In the pack offer, participants were three times more likely to select branded packs than plain packs. Conclusions Plain packaging and removal of descriptors may reduce the appeal of smoking for youth and young adults, and consequently reduce smoking susceptibility. Overall, the findings provide support for plain packaging regulations, such as those in

  20. The potential impact of plain packaging of cigarette products among Brazilian young women: an experimental study.

    PubMed

    White, Christine M; Hammond, David; Thrasher, James F; Fong, Geoffrey T

    2012-09-04

    Tobacco use is responsible for 5.4 million deaths every year worldwide and is a leading cause of preventable death. The burden of these deaths is rapidly shifting to low and middle-income countries, such as Brazil. Brazil has prohibited most forms of tobacco advertising; however, the cigarette pack remains a primary source of marketing. The current study examined how tobacco packaging influences brand appeal and perceptions of health risk among young women in Brazil. A between-subjects experiment was conducted in which 640 Brazilian women aged 16-26 participated in an online survey. Participants were randomized to view 10 cigarette packages according to one of three experimental conditions: standard branded packages, the same packs without brand imagery ("plain packaging"), or the same packs without brand imagery or descriptors (e.g., flavors). Participants rated packages on perceived appeal, taste, health risk, smoothness, and smoker attributes. Finally, participants were shown a range of branded and plain packs from which they could select one as a free gift, which constituted a behavioral measure of appeal. Branded packs were rated as significantly more appealing, better tasting, and smoother on the throat than plain packs. Branded packs were also associated with a greater number of positive smoker attributes including style and sophistication, and were perceived as more likely to be smoked by females than the plain packs. Removing descriptors from the plain packs further decreased the ratings of appeal, taste and smoothness, and also reduced associations with positive attributes. In the pack offer, participants were three times more likely to select branded packs than plain packs. Plain packaging and removal of descriptors may reduce the appeal of smoking for youth and young adults, and consequently reduce smoking susceptibility. Overall, the findings provide support for plain packaging regulations, such as those in Australia.

  1. Intercrater Plains and Heavily Cratered Terrain - First Encounter

    NASA Image and Video Library

    2000-01-18

    Intercrater plains and heavily cratered terrain typical of much of Mercury outside the area affected by the formation of the Caloris basin are shown in this image taken during the NASA Mariner 10 first encounter with Mercury in 1974.

  2. Vascular flora of saline lakes in the southern high plains of Texas and eastern New Mexico

    USGS Publications Warehouse

    Rosen, David J.; Conway, Warren C.; Haukos, David A.; Caskey, Amber D.

    2013-01-01

    Saline lakes and freshwater playas form the principal surface hydrological feature of the High Plains of the Southern Great Plains. Saline lakes number less than 50 and historically functioned as discharge wetlands with relatively consistent water availability due to the presence of one or more springs. Currently, less than ten saline lakes contain functional springs. A survey of vascular plants at six saline lakes in the Southern High Plains of northwest Texas and one in eastern New Mexico during May and September 2009 resulted in a checklist of 49 species representing 16 families and 40 genera. The four families with the most species were Asteraceae (12), Amaranthaceae (8), Cyperaceae (5), and Poaceae (12). Non-native species (Bromus catharticus, Poa compressa, Polypogon monspeliensis, Sonchus oleraceus, Kochia scoparia, and Tamarix ramosissima) accounted for 10% of the total species recorded. Whereas nearly 350 species of vascular plants have been identified in playas in the Southern High Plains, saline lakes contain a fraction of this species richness. The Southern High Plains saline lake flora is regionally unique, containing taxa not found in playas, with species composition that is more similar to temperate desert wetlands of the Intermountain Region and Gulf Coastal Plain of North America.

  3. 18 CFR 801.8 - Flood plain management and protection.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ..., welfare, safety and property, and to sustain economic development. (c) To foster sound flood plain controls, as an essential part of water resources management, the Commission shall: (1) Encourage and...

  4. Allostratigraphy of the U.S. middle Atlantic continental margin; characteristics, distribution, and depositional history of principal unconformity-bounded upper Cretaceous and Cenozoic sedimentary units

    USGS Publications Warehouse

    Poag, C. Wylie; Ward, Lauck W.

    1993-01-01

    Publication of Volumes 93 and 95 ('The New Jersey Transect') of the Deep Sea Drilling Project's Initial Reports completed a major phase of geological and geophysical research along the middle segment of the U. S. Atlantic continental margin. Relying heavily on data from these and related published records, we have integrated outcrop, borehole, and seismic-reflection data from this large area (500,000 km^2 ) to define the regional allostratigraphic framework for Upper Cretaceous and Cenozoic sedimentary rocks. The framework consists of 12 alloformations, which record the Late Cretaceous and Cenozoic depositional history of the contiguous Baltimore Canyon trough (including its onshore margin) and Hatteras basin (northern part). We propose stratotype sections for each alloformation and present a regional allostratigraphic reference section, which crosses these basins from the inner edge of the coastal plain to the inner edge of the abyssal plain. Selected supplementary reference sections on the coastal plain allow observation of the alloformations and their bounding unconformities in outcrop. Our analyses show that sediment supply and its initial dispersal on the middle segment of the U. S. Atlantic margin have been governed, in large part, by hinterland tectonism and subsequently have been modified by paleoclimate, sea-level changes, and oceanic current systems. Notable events in the Late Cretaceous to Holocene sedimentary evolution of this margin include (1) development of continental-rise depocenters in the northern part of the Hatteras basin during the Late Cretaceous; (2) the appear ance of a dual shelf-edge system, a marked decline in siliciclastic sediment accumulation rates, and widespread acceleration of carbonate production during high sea levels of the Paleogene; (3) rapid deposition and progradation of thick terrigenous delta complexes and development of abyssal depocenters during the middle Miocene to Quaternary interval; and (4) deep incision of the

  5. 78 FR 49684 - Safety Zone, Brandon Road Lock and Dam to Lake Michigan Including Des Plaines River, Chicago...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-15

    ...-AA00 Safety Zone, Brandon Road Lock and Dam to Lake Michigan Including Des Plaines River, Chicago... the Safety Zone; Brandon Road Lock and Dam to Lake Michigan including Des Plaines River, Chicago... the Safety Zone; Brandon Road Lock and Dam to Lake Michigan including Des Plaines River, Chicago...

  6. Summary of the Snake River plain Regional Aquifer-System Analysis in Idaho and eastern Oregon

    USGS Publications Warehouse

    Lindholm, G.F.

    1993-01-01

    The 15,600 sq mi Snake River Plain in southern Idaho and eastern Oregon was studied as part of the U.S. Geological Survey's Regional Aquifer-System Analysis program. Quaternary basalt of the Snake River Group underlies most of the 10,800 square mile eastern plain and constitutes the most productive aquifers. Transmissivity of the upper 200 feet of the basalt aquifer commonly ranges from 100,000 to 1,000,000 square feet per day. Vertical hydraulic conductivity is several orders of magnitude lower than horizontal hydraulic conductivity and is related to the degree of jointing. Alluvial sand and gravel in the Boise River valley constitutes the most productive aquifers in the 4,800 square mile western plain. Along much of its length, the Snake River gains groundwater. Between Milner and King Hill, the river gained 4.7 million acre-ft in 1980, most as spring flow from the north side. The chemical composition of groundwater in the plain is essentially the same as that in streams and ground- water from tributary drainage basins. The use of surface water for irrigation for 100 years has caused major changes in the hydrologic system on the plain. During that time, recharge on the main part of the eastern plain increased about 70 percent, discharge about 80 percent. In 1980, about 8.9 million acre-ft of Snake River water was diverted and 2.3 million acre-ft of groundwater was pumped from 5,300 wells for irrigation.

  7. Snake River Plain FORGE Well Data for INEL-1

    DOE Data Explorer

    Robert Podgorney

    1979-03-01

    Well data for the INEL-1 well located in eastern Snake River Plain, Idaho. This data collection includes caliper logs, lithology reports, borehole logs, temperature at depth data, neutron density and gamma data, full color logs, fracture analysis, photos, and rock strength parameters for the INEL-1 well. This collection of data has been assembled as part of the site characterization data used to develop the conceptual geologic model for the Snake River Plain site in Idaho, as part of phase 1 of the Frontier Observatory for Research in Geothermal Energy (FORGE) initiative. They were assembled by the Snake River Geothermal Consortium (SRGC), a team of collaborators that includes members from national laboratories, universities, industry, and federal agencies, lead by the Idaho National Laboratory (INL).

  8. Stem Cubic-Foot Volume Tables for Tree Species in the Upper Coastal Plain

    Treesearch

    Alexander Clark; Ray A. Souter

    1996-01-01

    Stemwood cubic-foot volume inside bark tables are presented for 11 species and 8 species groups based on equations used to estimate timber sale volumes on national forests in the Upper Coastal Plain. Tables are based on form class measurement data for 521 trees sampled in the Upper Coastal Plain and taper data collected across the South. A series of tables is...

  9. The characteristics of hydrogeochemical zonation of groundwater in inland plain

    NASA Astrophysics Data System (ADS)

    Xin-yu, HOU; Li-ting, XING; Yi, YANG; Wen-jing, ZHANG; Guang-yao, CHI

    2018-05-01

    To find out the hydrochemical zoning of groundwaterin the inland plain, taking Jiyang plain as an example, based on mathematical statistics, ion ratio coefficient and isotopic analysis method, the characteristics of water chemical composition and its zoning at different depths of 500m were studied. The result shows: ①The groundwater flow system in the study area can be divided into local flow system, intermediate flow system and regional flow system. ②The hydrochemical type of shallow groundwater is complex. The hydrochemical types of middle confined water are mainly ClṡSO4—MgṡNa and SO4ṡCl—NaṡMg. The deep confined water is mainly HCO3. ③The TDS of shallow groundwater increases gradually along the direction of groundwater flow. ④The shallow saltwater and freshwater are alternately distributed in horizontal direction, and saltwater is distributed sporadically in the interfluve area with sporadic punctate or banded, and hydrochemical types are mainly ClṡSO4—NaṡMgṡCa. Conclusion: Groundwater in the study area is affected by complicated hydrogeochemical action, mainly in the form of filtration, cation exchange and evaporation. The inland plain area is characterized by hydrogeochemical zonation in horizontal and vertical.

  10. Groundwater Vulnerability Assessment of the Pingtung Plain in Southern Taiwan.

    PubMed

    Liang, Ching-Ping; Jang, Cheng-Shin; Liang, Cheng-Wei; Chen, Jui-Sheng

    2016-11-23

    In the Pingtung Plain of southern Taiwan, elevated levels of NO₃ - -N in groundwater have been reported. Therefore, efforts for assessing groundwater vulnerability are required as part of the critical steps to prevent and control groundwater pollution. This study makes a groundwater vulnerability assessment for the Pingtung Plain using an improved overlay and index-based DRASTIC model. The improvement of the DRASTIC model is achieved by reassigning the weighting coefficients of the factors in this model with the help of a discriminant analysis statistical method. The analytical results obtained from the improved DRASTIC model provide a reliable prediction for use in groundwater vulnerability assessment to nitrate pollution and can correctly identify the groundwater protection zones in the Pingtung Plain. Moreover, the results of the sensitivity analysis conducted for the seven parameters in the improved DRASTIC model demonstrate that the aquifer media (A) is the most sensitive factor when the nitrate-N concentration is below 2.5 mg/L. For the cases where the nitrate-N concentration is above 2.5 mg/L, the aquifer media (A) and net recharge (R) are the two most important factors.

  11. 78 FR 36091 - Safety Zone, Brandon Road Lock and Dam to Lake Michigan Including Des Plaines River, Chicago...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-17

    ... Zone, Brandon Road Lock and Dam to Lake Michigan Including Des Plaines River, Chicago Sanitary and Ship...; Brandon Road Lock and Dam to Lake Michigan including Des Plaines River, Chicago Sanitary and Ship Canal... the Safety Zone; Brandon Road Lock and Dam to Lake Michigan including Des Plaines River, Chicago...

  12. 77 FR 65478 - Safety Zone, Brandon Road Lock and Dam to Lake Michigan including Des Plaines River, Chicago...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-29

    ...-AA00 Safety Zone, Brandon Road Lock and Dam to Lake Michigan including Des Plaines River, Chicago... the Safety Zone; Brandon Road Lock and Dam to Lake Michigan including Des Plaines River, Chicago... segment of the Safety Zone; Brandon Road Lock and Dam to Lake Michigan including Des Plaines River...

  13. 77 FR 60044 - Safety Zone, Brandon Road Lock and Dam to Lake Michigan Including Des Plaines River, Chicago...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-02

    ...-AA00 Safety Zone, Brandon Road Lock and Dam to Lake Michigan Including Des Plaines River, Chicago... the Safety Zone; Brandon Road Lock and Dam to Lake Michigan including Des Plaines River, Chicago... segment of the Safety Zone; Brandon Road Lock and Dam to Lake Michigan including Des Plaines River...

  14. 76 FR 65609 - Safety Zone, Brandon Road Lock and Dam to Lake Michigan including Des Plaines River, Chicago...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-24

    ... Zone, Brandon Road Lock and Dam to Lake Michigan including Des Plaines River, Chicago Sanitary and Ship...; Brandon Road Lock and Dam to Lake Michigan including Des Plaines River, Chicago Sanitary and Ship Canal...; Brandon Road Lock and Dam to Lake Michigan including Des Plaines River, Chicago Sanitary and Ship Canal...

  15. MAP OF ECOREGIONS OF THE MISSISSIPPI ALLUVIAL PLAIN

    EPA Science Inventory

    The ecoregions of The Mississippi Alluvial Plain (73) have been identified, mapped, and described and provide a geographic structure for environmental resources research, assessment, monitoring, and management. This project is part of a larger effort by the U.S. EPA to create a ...

  16. Plains Culture Area. Native American Curriculum Series.

    ERIC Educational Resources Information Center

    Ross, Cathy; Fernandes, Roger

    One in a series of Native American instructional materials, this booklet introduces elementary students to the tribes of the plains culture area, extending from the Rocky Mountains to the Mississippi River and from Texas to Canada. Written in simple language, the booklet begins with a brief description of the region--its extreme climate and the…

  17. Groundwater recharge and chemical evolution in the southern High Plains of Texas, USA

    NASA Astrophysics Data System (ADS)

    Fryar, Alan; Mullican, William; Macko, Stephen

    2001-11-01

    The unconfined High Plains (Ogallala) aquifer is the largest aquifer in the USA and the primary water supply for the semiarid southern High Plains of Texas and New Mexico. Analyses of water and soils northeast of Amarillo, Texas, together with data from other regional studies, indicate that processes during recharge control the composition of unconfined groundwater in the northern half of the southern High Plains. Solute and isotopic data are consistent with a sequence of episodic precipitation, concentration of solutes in upland soils by evapotranspiration, runoff, and infiltration beneath playas and ditches (modified locally by return flow of wastewater and irrigation tailwater). Plausible reactions during recharge include oxidation of organic matter, dissolution and exsolution of CO2, dissolution of CaCO3, silicate weathering, and cation exchange. Si and 14C data suggest leakage from perched aquifers to the High Plains aquifer. Plausible mass-balance models for the High Plains aquifer include scenarios of flow with leakage but not reactions, flow with reactions but not leakage, and flow with neither reactions nor leakage. Mechanisms of recharge and chemical evolution delineated in this study agree with those noted for other aquifers in the south-central and southwestern USA. Résumé. L'aquifère libre des Hautes Plaines (Ogallala) est le plus vaste aquifère des états-Unis et la ressource de base pour l'eau potable de la région semi-aride du sud des Hautes Plaines du Texas et du Nouveau-Mexique. Des analyses de l'eau et des sols prélevés au nord-est d'Amarillo (Texas), associées à des données provenant d'autres études dans cette région, indiquent que des processus intervenant au cours de l'infiltration contrôlent la composition de l'eau de la nappe libre dans la moitié septentrionale du sud des Hautes Plaines. Les données chimiques et isotopiques sont compatibles avec une séquence de précipitation épisodique, avec la reconcentration en solut

  18. 18 CFR 801.8 - Flood plain management and protection.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... nonstructural nature for the protection of flood plains subject to frequent flooding. (3) Assist in the study and classification of flood prone lands to ascertain the relative risk of flooding, and establish...

  19. 18 CFR 801.8 - Flood plain management and protection.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... nonstructural nature for the protection of flood plains subject to frequent flooding. (3) Assist in the study and classification of flood prone lands to ascertain the relative risk of flooding, and establish...

  20. 18 CFR 801.8 - Flood plain management and protection.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... nonstructural nature for the protection of flood plains subject to frequent flooding. (3) Assist in the study and classification of flood prone lands to ascertain the relative risk of flooding, and establish...

  1. Pluto Majestic Mountains, Frozen Plains and Foggy Hazes

    NASA Image and Video Library

    2015-09-17

    Just 15 minutes after its closest approach to Pluto on July 14, 2015, NASA's New Horizons spacecraft looked back toward the sun and captured this near-sunset view of the rugged, icy mountains and flat ice plains extending to Pluto's horizon. The smooth expanse of the informally named icy plain Sputnik Planum (right) is flanked to the west (left) by rugged mountains up to 11,000 feet (3,500 meters) high, including the informally named Norgay Montes in the foreground and Hillary Montes on the skyline. To the right, east of Sputnik, rougher terrain is cut by apparent glaciers. The backlighting highlights more than a dozen layers of haze in Pluto's tenuous but distended atmosphere. The image was taken from a distance of 11,000 miles (18,000 kilometers) to Pluto; the scene is 780 miles (1,250 kilometers) wide. http://photojournal.jpl.nasa.gov/catalog/PIA19948

  2. Age of fracturing and mesa development in the Elysium Area, northern Martian plains

    NASA Technical Reports Server (NTRS)

    Mcgill, George E.

    1987-01-01

    One of the fundamental questions of Martian crustal history is the origin of the crustal dichotomy between northern plains and southern highlands. Hypotheses for the origin of the dichotomy may be constrained by global scale, geophysical considerations, or by detailed geological studies of the genesis and relative ages of materials and landforms in the northern plains of Mars and along the boundary between the plains and the highlands. This abstract summarizes progress on one aspect of a long-range geological study intended to constrain hypotheses for the dichotomy by tracing the history of the northern plains from the most recent events backward -- essentially the same approach used to understand old events in Earth history. Both the giant impact and the mantle convection models for the crustal dichotomy imply a major coeval fracturing event. As has been known for some time, the present dichotomy boundary lies well south of its original position, at least in some places. Nevertheless, there is severe fracturing of this present dichotomy boundary in many places. The specific objectives of this study are to determine the ages of fracturing along the present dichotomy boundary.

  3. 76 FR 2829 - Safety Zone, Brandon Road Lock and Dam to Lake Michigan Including Des Plaines River, Chicago...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-18

    ... Zone, Brandon Road Lock and Dam to Lake Michigan Including Des Plaines River, Chicago Sanitary and Ship...; Brandon Road Lock and Dam to Lake Michigan including Des Plaines River, Chicago Sanitary and Ship Canal... enforce a segment of the Safety Zone; Brandon Road Lock and Dam to Lake Michigan including Des Plaines...

  4. 77 FR 20295 - Safety Zone, Brandon Road Lock and Dam to Lake Michigan including Des Plaines River, Chicago...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-04

    ... Zone, Brandon Road Lock and Dam to Lake Michigan including Des Plaines River, Chicago Sanitary and Ship...; Brandon Road Lock and Dam to Lake Michigan including Des Plaines River, Chicago Sanitary and Ship Canal... enforce a segment of the Safety Zone; Brandon Road Lock and Dam to Lake Michigan including Des Plaines...

  5. 77 FR 35854 - Safety Zone, Brandon Road Lock and Dam to Lake Michigan Including Des Plaines River, Chicago...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-15

    ... Zone, Brandon Road Lock and Dam to Lake Michigan Including Des Plaines River, Chicago Sanitary and Ship...; Brandon Road Lock and Dam to Lake Michigan including Des Plaines River, Chicago Sanitary and Ship Canal... enforce a segment of the Safety Zone; Brandon Road Lock and Dam to Lake Michigan including Des Plaines...

  6. 75 FR 52462 - Safety Zone, Brandon Road Lock and Dam to Lake Michigan Including Des Plaines River, Chicago...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-26

    ... Zone, Brandon Road Lock and Dam to Lake Michigan Including Des Plaines River, Chicago Sanitary and Ship...; Brandon Road Lock and Dam to Lake Michigan including Des Plaines River, Chicago Sanitary and Ship Canal... enforce a segment of the Safety Zone; Brandon Road Lock and Dam to Lake Michigan including Des Plaines...

  7. 75 FR 73966 - Safety Zone, Brandon Road Lock and Dam to Lake Michigan Including Des Plaines River, Chicago...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-30

    ... Zone, Brandon Road Lock and Dam to Lake Michigan Including Des Plaines River, Chicago Sanitary and Ship...; Brandon Road Lock and Dam to Lake Michigan including Des Plaines River, Chicago Sanitary and Ship Canal... enforce a segment of the Safety Zone; Brandon Road Lock and Dam to Lake Michigan including Des Plaines...

  8. Morphology of Florida escarpment chemosynthetic brine seep community sites: deep-tow, seabeam, and GLORIA surveys

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

    Paull, C.K.; Spiess, F.N.; Curray, J.R.

    1988-02-01

    The Florida Escarpment near 26/degree/N was surveyed with Deep-Tow, Seabeam, and GLORIA in the area where chemosynthetic communities were discovered via ALVIN in the abyssal Gulf of Mexico. Seabeam bathymetry and GLORIA images indicate that the escarpment is a generally straight cliff with average slopes of about 45/degree/ from 2200 to more than 3250 m. The escarpment's face is cut by 2-km wide box canyons whose head walls are as steep as the intervening escarpment's face. The shapes of these canyons are difficult to explain with the traditional models of canyon formation. Sidescan sonar images and bottom photographs reveal thatmore » the escarpment's face is composed of a series of long, straight bedding-plain terraces which are truncated along nearly vertical orthogonal joints. Exposure of these truncated strata indicate the face of the escarpment is eroded. The contact between the basal escarpment and the flat-lying abyssal hemipelagic sediments is abrupt. Basal talus is uncommon because the abyssal floor is part of the distal Mississippi fan which is rapidly burying the escarpment. However, where talus occurs, it is in tongues of angular megabreccia of meter- and larger-sized blocks which indicate periodic catastrophic collapse. Sidescan images reveal bands of contrast in the reflective texture of the sea floor that extends 10-20 m from the base along more than 10% of the surveyed area. Photographic surveys show that these areas are associated with communities of abundant organisms. Apparently chemosynthetic communities line extensive sections of the escarpment base where reduced brines seep out into the sea floor. The morphology suggests joints and deep seeps are controlling factors in scarp retreat.« less

  9. Groundwater Pollution Sources Apportionment in the Ghaen Plain, Iran

    PubMed Central

    Berndtsson, Ronny; Adamowski, Jan; Sadatipour, Elaheh

    2018-01-01

    Although Iran’s Ghaen Plain provides saffron to much of the world, no regional groundwater quality (GQ) assessment has yet been undertaken. Given the region’s potential for saltwater intrusion and heavy metal contamination, it is important to assess the GQ and determine its main probable source of pollution (MPSP). Such knowledge would allow for informed mitigation or elimination of the potential adverse health effects of this groundwater through its use as drinking water, or indirectly as a result of the consumption of groundwater-irrigated crops. Total dissolved solids, sodium, and chloride in the water of the majority of 16 wells sampled within the region exceeded World Health Organization and Iranian permissible standards for drinking water. The groundwater proved to only be suitable for irrigating salt tolerant crops under good drainage conditions. Due to the precipitation of calcium carbonate in the water supply facilities, the water from all wells was deemed unsuitable for industrial purposes. Heavy metal pollution and contamination indices showed no groundwater contamination. Analysis of ionic ratios and the application of principal components analysis indicated the MPSP to be saltwater intrusion, with the geology subtending the plain, and to a lesser extent, anthropogenic activities. Reducing groundwater withdrawals, particularly those for agricultural production by using high performance irrigation methods could reduce saltwater intrusion and improve GQ in the Ghaen Plain. PMID:29361791

  10. Groundwater Pollution Sources Apportionment in the Ghaen Plain, Iran.

    PubMed

    Vesali Naseh, Mohammad Reza; Noori, Roohollah; Berndtsson, Ronny; Adamowski, Jan; Sadatipour, Elaheh

    2018-01-22

    Although Iran's Ghaen Plain provides saffron to much of the world, no regional groundwater quality (GQ) assessment has yet been undertaken. Given the region's potential for saltwater intrusion and heavy metal contamination, it is important to assess the GQ and determine its main probable source of pollution (MPSP). Such knowledge would allow for informed mitigation or elimination of the potential adverse health effects of this groundwater through its use as drinking water, or indirectly as a result of the consumption of groundwater-irrigated crops. Total dissolved solids, sodium, and chloride in the water of the majority of 16 wells sampled within the region exceeded World Health Organization and Iranian permissible standards for drinking water. The groundwater proved to only be suitable for irrigating salt tolerant crops under good drainage conditions. Due to the precipitation of calcium carbonate in the water supply facilities, the water from all wells was deemed unsuitable for industrial purposes. Heavy metal pollution and contamination indices showed no groundwater contamination. Analysis of ionic ratios and the application of principal components analysis indicated the MPSP to be saltwater intrusion, with the geology subtending the plain, and to a lesser extent, anthropogenic activities. Reducing groundwater withdrawals, particularly those for agricultural production by using high performance irrigation methods could reduce saltwater intrusion and improve GQ in the Ghaen Plain.

  11. A conceptual model to facilitate amphibian conservation in the northern Great Plains

    USGS Publications Warehouse

    Mushnet, David M.; Euliss, Ned H.; Stockwell, Craig A.

    2012-01-01

    As pressures on agricultural landscapes to meet worldwide resource needs increase, amphibian populations face numerous threats including habitat destruction, chemical contaminants, disease outbreaks, wetland sedimentation, and synergistic effects of these perturbations. To facilitate conservation planning, we developed a conceptual model depicting elements critical for amphibian conservation in the northern Great Plains. First, we linked upland, wetland, and landscape features to specific ecological attributes. Ecological attributes included adult survival; reproduction and survival to metamorphosis; and successful dispersal and recolonization. Second, we linked ecosystem drivers, ecosystem stressors, and ecological effects of the region to each ecological attribute. Lastly, we summarized information on these ecological attributes and the drivers, stressors, and effects that work in concert to influence the maintenance of viable and genetically diverse amphibian populations in the northern Great Plains. While our focus was on the northern Great Plains, our conceptual model can be tailored to other geographic regions and taxa.

  12. Quantifying potential yield and water-limited yield of summer maize in the North China Plain

    NASA Astrophysics Data System (ADS)

    Jiang, Mingnuo; Liu, Chaoshun; Chen, Maosi

    2017-09-01

    The North China Plain is a major food producing region in China, and climate change could pose a threat to food production in the region. Based on China Meteorological Forcing Dataset, simulating the growth of summer maize in North China Plain from 1979 to 2015 with the regional implementation of crop growth model WOFOST. The results showed that the model can reflect the potential yield and water-limited yield of Summer Maize in North China Plain through the calibration and validation of WOFOST model. After the regional implementation of model, combined with the reanalysis data, the model can better reproduce the regional history of summer maize yield in the North China Plain. The yield gap in Southeastern Beijing, southern Tianjin, southern Hebei province, Northwestern Shandong province is significant, these means the water condition is the main factor to summer maize yield in these regions.

  13. 27 CFR 9.144 - Texas High Plains.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...” 1954, revised 1975. (6) “Big Spring, Texas” 1954, revised 1975. (c) Boundary. The Texas High Plains...; (2) The boundary follows U.S. Route 180 east through Seminole, Texas and onto the Big Spring, Texas... the U.S.G.S. maps of Big Spring and Lubbock, Texas; (4) The boundary continues along the 3,000 foot...

  14. 27 CFR 9.144 - Texas High Plains.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...” 1954, revised 1975. (6) “Big Spring, Texas” 1954, revised 1975. (c) Boundary. The Texas High Plains...; (2) The boundary follows U.S. Route 180 east through Seminole, Texas and onto the Big Spring, Texas... the U.S.G.S. maps of Big Spring and Lubbock, Texas; (4) The boundary continues along the 3,000 foot...

  15. 27 CFR 9.144 - Texas High Plains.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...” 1954, revised 1975. (6) “Big Spring, Texas” 1954, revised 1975. (c) Boundary. The Texas High Plains...; (2) The boundary follows U.S. Route 180 east through Seminole, Texas and onto the Big Spring, Texas... the U.S.G.S. maps of Big Spring and Lubbock, Texas; (4) The boundary continues along the 3,000 foot...

  16. 27 CFR 9.144 - Texas High Plains.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...” 1954, revised 1975. (6) “Big Spring, Texas” 1954, revised 1975. (c) Boundary. The Texas High Plains...; (2) The boundary follows U.S. Route 180 east through Seminole, Texas and onto the Big Spring, Texas... the U.S.G.S. maps of Big Spring and Lubbock, Texas; (4) The boundary continues along the 3,000 foot...

  17. 27 CFR 9.144 - Texas High Plains.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...” 1954, revised 1975. (6) “Big Spring, Texas” 1954, revised 1975. (c) Boundary. The Texas High Plains...; (2) The boundary follows U.S. Route 180 east through Seminole, Texas and onto the Big Spring, Texas... the U.S.G.S. maps of Big Spring and Lubbock, Texas; (4) The boundary continues along the 3,000 foot...

  18. Juniper seed sources in the Great Plains

    Treesearch

    Richard A. Cunningham; Rudy M. King

    2000-01-01

    At age 10, 100% of eastern redcedar ( L.) and Rocky Mountain juniper ( Sarg.) trees from several seed sources throughout the Great Plains had survived. Seed sources from southeastern Texas had the poorest survival. Eastern redcedar trees from Kansas seed sources grew tallest, and trees from Montana and southeastern Texas seed sources were the shortest. Rocky Mountain...

  19. Prolonged carbonate diagenesis under an evolving late cenozoic climate; Nullarbor Plain, southern Australia

    NASA Astrophysics Data System (ADS)

    Miller, Cody R.; James, Noel P.; Bone, Yvonne

    2012-06-01

    The Nullarbor Plain in southern Australia, the largest areal karst on the globe, is a ~ 240,000 km2 uplifted succession of Cenozoic marine carbonates whose surface has been exposed for 14 to 15 m.y. The middle Miocene Nullarbor Limestone forms the upper surface of the plain and hosts a complex and prolonged record of meteoric diagenesis. Such a complete record offers unique insights into the effects of climate, tectonics, sea level, topography, and hydrology on the style and placement of numerous diagenetic events in flat low lying carbonate plains. Alteration took place during three broad phases comprising eight stages that are interpreted to have formed against a background of dramatic climate change. Middle Miocene phase one diagenesis took place under a humid climate and resulted in rapid mineral equilibration, calcite cementation, extensive karst development, and finally widespread lacustrine and palustrine sedimentation. Resultant palustrine sediments, especially terrestrial ooids, are now preserved at the surface and in underlying karst cavities. Latest middle Miocene to middle Pliocene phase two diagenesis occurred during a prolonged period (~ 8 m.y.) of temperate climate and resulted in initial deep cave dissolution during low sea levels and later shallow cave development in the course of a high sea level. Onset of a somewhat more arid climate in the latest Pliocene led to the development of the modern desolate landscape of the Plain. This final phase of diagenesis involved creation of solution pits filled with black limestone pebbles, open and closed dolines with associated colluvium fill, and pervasive pedogenic calcrete. The Nullarbor Plain demonstrates that low lying carbonate plains can have low surficial erosion rates, precisely record relative sea level positions, be able to have extensive caves with extended periods of arrested calcite precipitation, and finally host extensive terrestrial ooid deposits. The importance of this comprehensive

  20. Sulfide petrology and highly siderophile element geochemistry of abyssal peridotites: a coupled study of samples from the Kane Fracture Zone (45°W 23°20N, MARK area, Atlantic Ocean)

    NASA Astrophysics Data System (ADS)

    Luguet, Ambre; Lorand, Jean-Pierre; Seyler, Monique

    2003-04-01

    Nineteen samples from the Kane Fracture Zone have been studied for sulfide mineralogy and analyzed for S, Se, platinum-group elements (PGE), and Au to assess the effect of refertilization processes on the PGE systematics of abyssal peridotites. The lherzolites show broadly chondritic PGE ratios and sulfide modal abundances (0.01 to 0.03 wt%) consistent with partial melting models, although the few pyroxene-hosted sulfide inclusions and in situ LAM-ICPMS analyses provide evidence for in situ mobilization of a Cu-Ni-rich sulfide partial melt. The most refractory harzburgites (spinel Cr# > 29) are almost devoid of magmatic sulfides and show uniformly low Pd N/Ir N (<0.5) for variable Pt N/Ir N (0.8 to 1.2). The compatible behavior of Os, Ir, Ru, Rh, and Pt reflects the presence of primary Os-Ru alloys. Some harzburgites displaying petrographic evidence for refertilization by incremental melts en route to the surface are enriched in sulfides (up to 0.1 wt%). Some of these sulfides are concentrated in small veinlets of clinopyroxene and spinel crystallized from these melts. These S-rich harzburgites display superchondritic Pd N/Ir N (up to 2.04) positively correlated with sulfide modal contents. It is concluded that refertilization processes resulting in precipitation of metasomatic sulfides may significantly enhance Pd concentrations of abyssal peridotites while marginally affecting Pt (Pt N/Ir N ≤ 1.24) and Rh (Rh N/Ir N ≤ 1.23) as well. When the effects of such processes are screened out, our database suggests PGE relative abundances in the DMM (Depleted MORB Mantle; MORB: Mid-Ocean Ridge) within the uncertainty range of chondritic meteorites, without evidence of superchondritic Pt/Ir and/or Rh/Ir ratios.

  1. Plain abdominal radiography in acute abdominal pain; past, present, and future

    PubMed Central

    Gans, Sarah L; Stoker, Jaap; Boermeester, Marja A

    2012-01-01

    Several studies have demonstrated that a diagnosis based solely on a patient’s medical history, physical examination, and laboratory tests is not reliable enough, despite the fact that these aspects are essential parts of the workup of a patient presenting with acute abdominal pain. Traditionally, imaging workup starts with abdominal radiography. However, numerous studies have demonstrated low sensitivity and accuracy for plain abdominal radiography in the evaluation of acute abdominal pain as well as various specific diseases such as perforated viscus, bowel obstruction, ingested foreign body, and ureteral stones. Computed tomography, and in particular computed tomography after negative ultrasonography, provides a better workup than plain abdominal radiography alone. The benefits of computed tomography lie in decision-making for management, planning of a surgical strategy, and possibly even avoidance of negative laparotomies. Based on abundant available evidence, major advances in diagnostic imaging, and changes in the management of certain diseases, we can conclude that there is no place for plain abdominal radiography in the workup of adult patients with acute abdominal pain presenting in the emergency department in current practice. PMID:22807640

  2. Adolescents' perceptions of cigarette brand image: does plain packaging make a difference?

    PubMed

    Germain, Daniella; Wakefield, Melanie A; Durkin, Sarah J

    2010-04-01

    To examine the effect of plain packaging on adolescents' perceptions of cigarette packs, attributes of smokers, and expectations of cigarette taste, and to identify the effect of increasing the size of pictorial health warnings on appraisal of plain packs. We used a 5 (degree of plain packaging and graphic health warning)x 3 (brand type) between-subjects experimental design, using a Web-based methodology to expose adolescents to one randomly selected cigarette pack, during which respondents completed ratings. When brand elements such as color, branded fonts, and imagery were progressively removed from cigarette packs, adolescents perceived packs to be less appealing, rated attributes of a typical smoker of the pack less positively, and had more negative expectations of cigarette taste. Pack appeal was reduced even further when the size of the pictorial health warning on the most plain pack was increased from 30% to 80% of the pack face, with this effect apparent among susceptible nonsmokers, experimenters, and established smokers. Removing as much brand information from cigarette packs as possible is likely to reduce positive cigarette brand image associations among adolescents. By additionally increasing the size of pictorial health warnings, positive pack perceptions of those who are at greater risk of becoming regular addicted adult smokers are most likely to be reduced. Copyright 2010 Society for Adolescent Medicine. Published by Elsevier Inc. All rights reserved.

  3. Areas Contributing Recharge to Wells in the Tafuna-Leone Plain, Tutuila, American Samoa

    USGS Publications Warehouse

    Izuka, Scot K.; Perreault, Jeff A.; Presley, Todd K.

    2007-01-01

    To address the concerns about the potential for contamination of drinking-water wells in the Tafuna-Leone Plain, Tutuila, American Samoa, a numerical ground-water flow model was developed and used to delineate areas contributing recharge to the wells (ACRWs). Surveys and analyses were conducted to obtain or compile certain essential hydrogeologic information needed for the model, such as groundwater production statistics, ground-water levels under current production, and an assessment of the distribution of groundwater recharge. The ground-water surveys indicate that total production from all wells in the Tafuna-Leone Plain between 1985 and 2005 averaged 6.1 Mgal/d and showed a gradual increase. A synoptic survey indicates that current water levels in the Tafuna-Leone Plain are highest near its inland boundary, decrease toward the coast, and are slightly depressed in high-production well fields. Ground-water levels showed little effect from the increased production because hydraulic conductivites are high and withdrawal is small relative to recharge. Analysis of ground-water recharge using a soil water-budget analysis indicates that the Tafuna-Leone Plain and adjacent areas receive about 280 Mgal/d of water from rainfall, of which 24 percent runs off to the ocean, 26 percent is removed by evapotranspiration, and 50 percent goes to ground-water recharge. Ground-water recharge per unit area is generally higher at the mountain crests than at the coast, but the highest recharge per unit area is in the mountain-front recharge zone at the juncture between the Tafuna-Leone Plain and the adjacent mountains. Surface water from the mountains also contributes to ground-water recharge in the eastern Tafuna-Leone Plain, in a process analogous to mountain-front recharge described in arid areas. Analysis of stream-gage data indicates that in the mountains of Tutuila, ground water discharges and contributes substantially to the total flow of the streams. In contrast, multiple

  4. Plains South of Valles Marineris

    NASA Image and Video Library

    2017-03-28

    This enhanced-color sample reveals the incredible diversity of landforms on some Martian plains that appear bland and uniform at larger scales. Here we see layers, small channels suggesting water flow, craters, and indurated sand dunes. The map is projected here at a scale of 25 centimeters (9.8 inches) per pixel. [The original image scale is 25.7 centimeters (10.1 inches) per pixel (with 1 x 1 binning); objects on the order of 77 centimeters (30.3 inches) across are resolved.] North is up. http://photojournal.jpl.nasa.gov/catalog/PIA21573

  5. Crustal thickness and composition beneath the High Lava Plains of Eastern Oregon from teleseismic receiver functions

    NASA Astrophysics Data System (ADS)

    Eagar, K. C.; Fouch, M. J.; James, D. E.; Carlson, R. W.

    2009-12-01

    The nature of the crust beneath the High Lava Plains of eastern Oregon is fundamental for understanding the origins of widespread Cenozoic volcanism in the region. Eruptions of flood basalts in the southern Cascadian back arc peaked ~17-15 Ma, and were followed by distributed bimodal volcanism along two perpendicular migrating tracks; the Snake River Plain and the High Lava Plains. The orientations of eruptive centers have led to several competing hypotheses about their cause, including a deep mantle plume, slab retreat and asthenospheric inflow, lithospheric delamination, and lithospheric extension. The goal of this project is to constrain the nature, geometry, and depth of the Moho across the High Lava Plains, which will shed light on questions regarding crustal influence on melt generation and differentiation and the degree of magmatic underplating. In this study, we analyze teleseismic receiver functions from 118 stations of the High Lava Plains temporary broadband array, 34 nearby EarthScope/USArray stations, and 5 other regional broadband stations to determine bulk crustal features of thickness (H) and Vp/Vs ratio (κ). Applying the H-κ stacking method, we search for the best-fitting solution of timing predictions for direct and multiple P-to-S conversions from the Moho interface. Converting Vp/Vs to Poisson ratio, which is dependent primarily upon rock composition, allows for comparison with other direct geological observations. Preliminary results show that the crust of the High Lava Plains is relatively thin (~31 km) with a very sharp gradient to thicker crust (~42 km) at the western edge of the Owyhee Plateau in southwestern Idaho. This gradient is co-located with the western margin of Precambrian North America and is in the vicinity of the Jordan Craters volcanic center. The sharp topography of the Moho might have been a factor in melt migration beneath this area. West of the High Lava Plains, the crust thickens to ~40 km into the Cascade volcanic arc

  6. The Main Factors of Uranium Accumulation in the Ishim Plain Saline Lakes (Western Siberia)

    NASA Astrophysics Data System (ADS)

    Vladimirov, A. G.; Krivonogov, S. K.; Karpov, A. V.; Nikolaeva, I. V.; Razvorotneva, L. I.; Kolpakova, M. N.; Moroz, E. N.

    2018-04-01

    Hydrochemical analysis of the high-salinity lakes in the Ishim Plain (>250-300 g/L) located at the border with the Northern Kazakhstan uranium ore province is performed. The studies have shown that the main factor of concentration and redistribution of uranium in the lake basins of the Ishim Plain are the processes of intense salt deflation causing sanding of lakes and uranium depletion in the near-surface layer of the bottom deposits. The correlation between the hydroxide forms of uranium binding in the bottom lacustrine deposits of the Ishim Plain and the coffinite composition of the Semizbai deposit makes it possible to consider this province to be promising for the discovery of hydromineral uranium deposits.

  7. Quaternary sedimentary processes on the northwestern African continental margin - An integrated study using side-scan sonar, high-resolution profiling, and core data

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

    Masson, D.G.; Huggett, Q.J.; Weaver, P.P.E.

    1991-08-01

    Side-scan sonar data, cores, and high-resolution profiles have been used to produce an integrated model of sedimentation for the continental margin west of the Canary Islands. Long-range side-scan sonar (GLORIA) data and a grid of 3.5-kHz profiles, covering some 200,000 km{sup 2} allow a regional appraisal of sedimentation. More detailed studies of selected areas have been undertaken using a new 30 kHz deep-towed side-scan sonar (TOBI) developed by the U.K. Institute of Oceanographic Sciences. Sediment cores have been used both to calibrate acoustic facies identified on sonographs and for detailed stratigraphic studies. The most recent significant sedimentation event in themore » area is to Saharan Sediment Slide, which carried material from the upper continental slope off West Africa to the edge of the Madeira Abyssal Plain, a distance of some 1000 km. The authors data shows the downslope evolution of the debris flow. Near the Canaries, it is a 20-m-thick deposit rafting coherent blocks of more than 1 km diameter; side-scan records show a strong flow-parallel fabric on a scale of tens of meters. On the lower slope, the debris flow thins to a few meters, the flow fabric disappears, and the rafted blocks decrease to meters in diameter. Side-scan data from the lower slope show that the Saharan Slide buries an older landscape of turbidity current channels, typically 1 km wide and 50 m deep. Evidence from the Madeiran Abyssal Plain indicates a history of large but infrequent turbidity currents, the emplacement of which is related to the effects of sea level changes on the northwest African margin.« less

  8. Overview of the sedimentological processes in the western North Atlantic

    NASA Astrophysics Data System (ADS)

    Benetti, S.; Weaver, P.; Wilson, P.

    2003-04-01

    The sedimentary processes operating within the western North Atlantic continental margin include both along-slope sediment transport, which builds sediment drifts and waves, and down-slope processes involving mass wasting. Sedimentation along a large stretch of the margin (north of 32°N) has been heavily influenced by processes that occurred during glacial times (e.g. cutting of canyons and infilling of abyssal plains) when large volumes of sediment were supplied to the shelf edge either by ice grounded on continental shelves or river discharge. The large area of sea floor occupied by depositional basins and abyssal plains testifies to the dominance of turbidity currents. The widespread presence of slide complexes in this region has been related to earthquakes and melting of gas hydrates. South of 32°N, because of the low sediment supply from rivers even during glacial times and the reduced sedimentation due to the erosive effects of the Gulf Stream, few canyon systems and slides are observed and Tertiary sediment cover is thin and irregular. Turbidity currents filled re-entrant basins in the Florida-Bahama platform. Tectonic activity is primarily responsible for the overall morphology and sedimentation pattern along the Caribbean active margin. Along the whole margin, the reworking of bottom sediments by deep-flowing currents seems to be particularly active during interglacials. To some extent this observation must reflect the diminished effect of downslope transport during interglacials, but our data also contribute to the debate over changes in deep water circulation strength on glacial-interglacial timescales. Strong bottom circulation, an open basin system and high sediment supply have led to the construction of large elongate contourite drifts, mantled by smaller scale bedforms. These drifts are mostly seen in regions protected or distant from the masking influence of turbidity currents and sediment mass movements.

  9. Seafloor geomorphology and geology of the Kingman Reef-Palmyra Atoll region, Central Pacific Ocean

    NASA Astrophysics Data System (ADS)

    Eakins, Barry; Barth, Ginger; Scheirer, Dan; Mosher, Dave; Armstrong, Andy

    2017-04-01

    Kingman Reef and Palmyra Atoll are the exposed summits of two seamounts within the Line Islands Volcanic Chain in the Central Pacific Ocean. Both are U.S. Territories, and the Exclusive Economic Zone around the islands was partially surveyed in 1991 with GLORIA sidescan sonar and seismic reflection profiling. New multibeam swath sonar surveys were conducted in 2010, 2015, and 2016 around the islands, in support of U.S. Extended Continental Shelf investigations. Numerous transits through the region by research vessels have collected additional multibeam swath sonar data. We present new, detailed maps of bathymetry, sidescan sonar imagery, geology, and sediment isopachs of the seafloor surrounding the islands, and how these have informed our understanding of the islands' margins. The islands are the last subaerial remnants of a complex, horse-shoe-shaped volcanic platform spanning roughly 200 km in diameter. The elevated platform from which the seamounts arise comprises at least 10 individual volcanic centers that have heights exceeding 3000m above the nearby abyssal plains. Gravity modeling suggests that the elevated platform is compensated by thickened crust. Strong carbonate caps and voluminous sediment accumulations flanking the platform indicate that the volcanoes were once shallow-water or emergent systems. These systems produced vast quantities of carbonate sediment that were shed to a deep interior basin to the east of Palmyra Atoll, and to nearby abyssal plains. The identification of mass failures, sediment reworking and bedforms, and channel networks provide evidence for extensive sedimentary processes around these volcanic centers. Analysis of the seamounts atop the elevated platform and in the seamount province to the northwest shows that flat-topped seamounts ("guyots") are principally found at depths shallower than 1300 meters, while peaked seamounts are almost exclusively found at greater depths. This constrains the amount of regional subsidence that

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

    Gough, M.A.; Fauzi, R.; Mantoura, C.

    The vascular land plant biopolymers lignin and cutin were surveyed in the surface sediments of coastal and open ocean waters by controlled alkaline CuO oxidation/reaction. Two contrasting oceanic regimes were studied: the northwest Mediterranean (NWM) Sea, which receives significant particulate terrigenous debris through riverine discharge; and the northeast Atlantic (NEA) Ocean, with poorly characterized terrestrial carbon inputs. In the NWM products of lignin and cutin co-occurred at all stations, elevated levels (ca. 0.5-3.0 mg lignin phenols/100 mg organic carbon; ca. 0.01-0.09 mg cutin acids/100 mg organic carbon) were observed for near-shore deltaic and shelf sediments. The influence of terrestrial landmore » plant inputs extended across the shelf and through the slope to the abyssal plain, providing molecular evidence for advective offshore transfer of terrestrial carbon. Mass balance estimates for the basin suggest riverine inputs account for the majority of surface sedimentary ligin/cutin, most of which (>90%) is deposited on the shelf. Products of CuO oxidation of lignin and cutin were also detected in NEA surface sediments, at levels comparable to those observed for the NWM continental slope, and were detectable at low concentrations in the sediments of the abyssal plains (>4,000 m depth). While atmospheric deposition of lignin/cutin-derived material cannot be discounted in this open ocean system, lateral advective transfer of enriched shelf sediments is inferred as a possible transport process. A progressive enrichment in cutin-derived material relative to lignin was observed offshore, with evidence of an increase in the degree of oxidative alteration of lignin residues. Preliminary mass balance calculations applied to the global ocean margin suggest riverine sources of both particulate lignin and cutin are important and that most (>95%) deposition of recognizable land plant biopolymers occurs in shelf seas. 74 refs., 7 figs., 5 tabs.« less

  11. The future of irrigation on the High Plains

    USDA-ARS?s Scientific Manuscript database

    The future of irrigation on the U.S. High Plains was examined through the lens of past changes in water supply and innovations in irrigation technology, management and agronomy. The innovations have greatly increased the efficiency of water application and use, and the agricultural productivity of t...

  12. Introducing Plain Language Principles to Business Communication Students

    ERIC Educational Resources Information Center

    Greer, Rachelle R.

    2012-01-01

    In response to current federal mandates requiring selected businesses and government agencies to use plain language (PL) when reporting information to the public, this article advocates the introduction of PL principles into current business communication curricula. Despite recent PL mandates and advances, many current business textbooks and…

  13. REGIONALIZATION OF THE WESTERN CORN BELT PLAINS ECOREGION

    EPA Science Inventory

    As part of a larger effort to study the fate and transport of agrichemicals in the midwestern United States, the U.S. Environmental Protection Agency commissioned a study of spatial variability within the Western Corn Belt Plains ecoregion. he objective of this study was to syste...

  14. Summary of the Snake River plain Regional Aquifer-System Analysis in Idaho and eastern Oregon

    USGS Publications Warehouse

    Lindholm, G.F.

    1996-01-01

    Regional aquifers underlying the 15,600-square-mile Snake River Plain in southern Idaho and eastern Oregon was studied as part of the U.S. Geological Survey's Regional Aquifer-System Analysis program. The largest and most productive aquifers in the Snake River Plain are composed of Quaternary basalt of the Snake River Group, which underlies most of the 10,8000-square-mile eastern plain. Aquifer tests and simulation indicate that transmissivity of the upper 200 feet of the basalt aquifer in the eastern plain commonly ranges from about 100,000 to 1,000,000 feet squared per day. However, transmissivity of the total aquifer thickness may be as much as 10 million feet squared per day. Specific yield of the upper 200 feet of the aquifer ranges from about 0.01 to 0.20. Average horizontal hydraulic conductivity of the upper 200 feet of the basalt aquifer ranges from less than 100 to 9,000 feet per day. Values may be one to several orders of magnitude higher in parts in individual flows, such as flow tops. Vertical hydraulic conductivity is probably several orders of magnitude lower than horizontal hydraulic conductivity and is generally related to the number of joints. Pillow lava in ancestral Snake River channels has the highest hydraulic conductivity of all rock types. Hydraulic conductivity of the basalt decreases with depth because of secondary filling of voids with calcite and silica. An estimated 80 to 120 million acre-feet of water is believed to be stored in the upper 200 feet of the basalt aquifer in the eastern plain. The most productive aquifers in the 4,800-square-mile western plain are alluvial sand and gravel in the Boise River valley. Although aquifer tests indicate that transmissivity of alluvium in the Boise River valley ranges from 5,000 to 160,000 feet squared per day, simulation suggests that average transmissivity of the upper 500 feet is generally less than 20,000 feet squared per day. Vertically averaged horizontal hydraulic conductivity of the upper

  15. 77 FR 1082 - Call for Nominations for the Carrizo Plain National Monument Advisory Council, California

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-09

    ...The Bureau of Land Management (BLM) is soliciting nominations from the public to fill four positions on the Carrizo Plain National Monument Advisory Committee (MAC). MAC members provide advice and recommendations to the BLM on the management of public lands in the Carrizo Plain National Monument.

  16. Does climatic variability influence agricultural land prices under differing uses? The Texas High Plains case

    USDA-ARS?s Scientific Manuscript database

    The Texas High Plains faces projections of increasing temperature and declining precipitation in the future on account of its semi-arid climate. This research evaluated the impact of climatic variability on agricultural land prices under different land uses in the Texas High Plains, employing the Ri...

  17. Frozen Plains in the Heart of Pluto Heart

    NASA Image and Video Library

    2015-07-17

    At center left of Pluto vast heart-shaped feature "Tombaugh Regio" -- lies a vast, craterless plain that appears to be no more than 100 million years old, and is possibly still being shaped by geologic processes as seen by NASA New Horizons spacecraft. This frozen region is north of Pluto's icy mountains and has been informally named Sputnik Planum (Sputnik Plain), after Earth's first artificial satellite. The surface appears to be divided into irregularly-shaped segments that are ringed by narrow troughs. Features that appear to be groups of mounds and fields of small pits are also visible. This image was acquired by the Long Range Reconnaissance Imager (LORRI) on July 14 from a distance of 48,000 miles (77,000 kilometers). Features as small as one-half mile (1 kilometer) across are visible. The blocky appearance of some features is due to compression of the image. http://photojournal.jpl.nasa.gov/catalog/PIA19841

  18. BIOLOGICAL INTEGRITY IN MID-ATLANTIC COASTAL PLAINS HEADWATER STREAMS

    EPA Science Inventory

    The objective of this study was to assess the applicability of landscape metrics, in conjunction with stream water quality to estimate the biological integrity of headwater streams in the Mid-Atlantic Coastal Plains using multivariate techniques.

  19. 78 FR 17653 - Upper Great Plains Wind Energy Draft Programmatic Environmental Impact Statement (DOE/EIS-0408)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-22

    ... infrastructure development, including siting wind turbines, access roads, underground collector lines, overhead... Wildlife Service Upper Great Plains Wind Energy Draft Programmatic Environmental Impact Statement (DOE/EIS... Plains Wind Energy Draft Programmatic Environmental Impact Statement (Draft [[Page 17654

  20. Artesian water in the Malabar coastal plain of southern Kerala, India

    USGS Publications Warehouse

    Taylor, George C.; Ghosh, P.K.

    1964-01-01

    The present report is based on a geological and hydrological reconnaissance during 1954 of the Malabar Coastal Plain and adjacent island area of southern Kerala to evaluate the availability of ground water for coastal villages and municipalities and associated industries and the potentialities for future development. The work was done in cooperation with the Geological Survey of India and under the auspices of the U.S. Technical Cooperation Mission to India. The State of Kerala, which lies near the southern tip of India and along the eastern shore of the Caspian Sea, contains a total area of 14,937 square miles. The eastern part of the state is s rugged mountainous highland which attains altitudes of more than 6,000 feet. This highland descends westward through piedmont upland to s narrow coastal plain, which reaches a maximum width of about 16 miles in the latitude of Shertalli. A tropical monsoon rain-forest climate prevails in most of Kerala, and annual rainfall ranges from 65 to 130 inches in the southern part of the coastal plain to as much a 200 inches in the highland. The highland and piedmont upland tracts of Kerala are underlain by Precambrian meamorphic and igneous rocks belonging in large parabola-the so-called Charnockite Series. Beneath ahe coastal plain are semiconsolidated asunconsolidated sedimentary deposits whose age ranges from Miocene to Recent. These deposits include sofa sandstone and clay shale containing some marl or limestone and sand, and clay and pea containing some gravel. The sofa sandstone, sand, and gravel beds constitute important aquifers a depths ranging from a few tens of feet to 400 feet or more below the land surface. The shallow ground war is under water-able or unconfined conditions, but the deeper aquifers contain water under artesian pressure. Near the coast, drilled wells tapping the deeper aquifers commonly flow with artesian heads as much as 10 to 12 feet above the land surface. The draft from existing wells in the

  1. A comparison of the regional slope characteristics of Venus and earth - Implications for geologic processes on Venus

    NASA Technical Reports Server (NTRS)

    Sharpton, V. L.; Head, J. W., III

    1986-01-01

    The range of 3 degree by 3 degree regional slopes of the Earth and Venus is similar (approximately 0.0-2.4 degrees), although the surface distribution of these values differs significantly. On earth, cratonic and abyssal plains form extensive regions of 0.0 degree slope. Within these regions a variety of features (mid-ocean ridges, volcanic island chains, subduction zones, and floded mountains) have regional slope characteristics influenced by seafloor spreading and plate recycling, as well as an active weathering regime. The plains provinces of Venus are much more rugged than earth's plains and are marked by numerous closely spaced circular and linear features (0.1-0.2 degree regional slope) concentrated into broad linear zones of global extent. Although Venus highlands are bounded by narrow zones of relatively steep slope, the margins of Aphrodite Terra and Beta Regio are not as steep as earth's continental margins and appear to be best developed parallel to the trends of major chasmata within these regions. Ishtar Terra's margins are significantly steeper and more continuous than other highland margins and are comparable to passive margins on earth. The Venus highlands do not contain appreciable smooth, flat interior regions, implying that highland topography is not significantly modified by erosion or deposition.

  2. Plain-water intake and risk of type 2 diabetes in young and middle-aged women1234

    PubMed Central

    Pan, An; Malik, Vasanti S; Schulze, Matthias B; Manson, JoAnn E; Willett, Walter C

    2012-01-01

    Background: The replacement of caloric beverages such as sugar-sweetened beverages (SSBs) and fruit juices with noncaloric beverages such as plain water has been recommended for diabetes prevention. Objective: We evaluated the relation of plain-water intake and the substitution of plain water for SSBs and fruit juices with incident type 2 diabetes (T2D) in US women. Design: We prospectively followed 82,902 women in the Nurses’ Health Study II who were free of diabetes, cardiovascular disease, or cancer at baseline. Diet, including various beverages, was assessed by using validated food-frequency questionnaires and updated every 4 y. Incident T2D was confirmed by using a validated supplementary questionnaire. We used a 4-y lagged analysis to minimize reverse causation (ie, increased water consumption that was due to early stage of diabetes). Results: During 1,115,427 person-years of follow-up, we documented 2718 incident T2D cases. Plain-water intake was not associated with T2D risk in the multivariable-adjusted model that included age, BMI, diet, and lifestyle factors; RRs (95% CIs) across categories (<1, 1, 2–3, 4–5, and ≥6 cups/d) were 1.00, 0.93 (0.82, 1.05), 0.93 (0.83, 1.05), 1.09 (0.96, 1.24), and 1.06 (0.91, 1.23), respectively (P-trend = 0.15). We estimated that the replacement of 1 serving SSBs and fruit juices/d by 1 cup plain water/d was associated with 7% (3%, 11%) and 8% (2%, 13%) lower risk of T2D, respectively. Conclusions: Plain-water intake, per se, was not significantly associated with risk of T2D. However, substitution of plain water for SSBs or fruit juices was estimated to be associated with modestly lower risk of T2D. PMID:22552035

  3. Cigarette packaging and health warnings: the impact of plain packaging and message framing on young smokers

    PubMed Central

    Mays, Darren; Niaura, Raymond S.; Evans, W. Douglas; Hammond, David; Luta, George; Tercyak, Kenneth P.

    2014-01-01

    Objective This study examined the impact of pictorial cigarette warning labels, warning label message framing, and plain cigarette packaging on young adult smokers’ motivation to quit. Methods Smokers ages 18–30 (n=740) from a consumer research panel were randomized to one of four experimental conditions where they viewed online images of 4 cigarette packs with warnings about lung disease, cancer, stroke/heart disease, and death, respectively. Packs differed across conditions by warning message framing (gain versus loss) and packaging (branded versus plain). Measures captured demographics, smoking behavior, covariates, and motivation to quit in response to cigarette packs. Results Pictorial warnings about lung disease and cancer generated the strongest motivation to quit across conditions. Adjusting for pre-test motivation and covariates, a message framing by packaging interaction revealed gain-framed warnings on plain packs generated greater motivation to quit for lung disease, cancer, and mortality warnings (p < 0.05), compared with loss-framed warnings on plain packs. Conclusions Warnings combining pictorial depictions of smoking-related health risks with text-based messages about how quitting reduces risks may achieve better outcomes among young adults, especially in countries considering or implementing plain packaging regulations. PMID:24420310

  4. Energy transfer in the Congo deep-sea fan: From terrestrially-derived organic matter to chemosynthetic food webs

    NASA Astrophysics Data System (ADS)

    Pruski, A. M.; Decker, C.; Stetten, E.; Vétion, G.; Martinez, P.; Charlier, K.; Senyarich, C.; Olu, K.

    2017-08-01

    Large amounts of recent terrestrial organic matter (OM) from the African continent are delivered to the abyssal plain by turbidity currents and accumulate in the Congo deep-sea fan. In the recent lobe complex, large clusters of vesicomyid bivalves are found all along the active channel in areas of reduced sediment. These soft-sediment communities resemble those fuelled by chemoautotrophy in cold-seep settings. The aim of this study was to elucidate feeding strategies in these macrofaunal assemblages as part of a greater effort to understand the link between the inputs of terrestrially-derived OM and the chemosynthetic habitats. The biochemical composition of the sedimentary OM was first analysed in order to evaluate how nutritious the available particulate OM is for the benthic macrofauna. The terrestrial OM is already degraded when it reaches the final depositional area. However, high biopolymeric carbon contents (proteins, carbohydrates and lipids) are found in the channel of the recent lobe complex. In addition, about one to two thirds of the nitrogen can be assigned to peptide-like material. Even if this soil-derived OM is poorly digestible, turbiditic deposits contain such high amounts of organic carbon that there is enough biopolymeric carbon and proteacinous nitrogen to support dense benthic communities that contrast with the usual depauperate abyssal plains. Stable carbon and nitrogen isotopes and fatty acid biomarkers were then used to shed light on the feeding strategies allowing the energy transfer from the terrestrial OM brought by the turbidity currents to the abyssal food web. In the non-reduced sediment, surface detritivorous holothurians and suspension-feeding poriferans rely on detritic OM, thereby depending directly on the turbiditic deposits. The sulphur-oxidising symbiont bearing vesicomyids closely depend on the reprocessing of OM with methane and sulphide as final products. Their carbon and nitrogen isotopic signatures vary greatly among sites

  5. Small benthic size classes along the N.W. European Continental Margin: spatial and temporal variability in activity and biomass

    NASA Astrophysics Data System (ADS)

    Pfannkuche, O.; Soltwedel, T.

    1998-12-01

    In the context of the European OMEX Programme this investigation focused on gradients in the biomass and activity of the small benthic size spectrum along a transect across the Goban Spur from the outer Celtic Sea into Porcupine Abyssal Plain. The effects of food pulses (seasonal, episodic) on this part of the benthic size spectrum were investigated. Sediments sampled during eight expeditions at different seasons covering a range from 200 m to 4800 m water depth were assayed with biochemical bulk measurements: determinations of chloroplastic pigment equivalents (CPE), the sum of chlorophyll a and its breakdown products, provide information concerning the input of phytodetrital matter to the seafloor; phospholipids were analyzed to estimate the total biomass of small benthic organisms (including bacteria, fungi, flagellata, protozoa and small metazoan meiofauna). A new term `small size class biomass' (SSCB) is introduced for the biomass of the smallest size classes of sediment-inhabiting organisms; the reduction of fluorescein-di-acetate (FDA) was determined to evaluate the potential activity of ester-cleaving bacterial exoenzymes in the sediment samples. At all stations benthic biomass was predominantly composed of the small size spectrum (90% on the shelf; 97-98% in the bathyal and abyssal parts of the transect). Small size class biomass (integrated over a 10 cm sediment column) ranged from 8 g C m -2 on the shelf to 2.1 g C m -2 on the adjacent Porcupine Abyssal Plain, exponentially decreasing with increasing water depth. However, a correlation between water depth and SSCB, macrofauna biomass as well as metazoan meiofauna biomass exhibited a significantly flatter slope for the small size classes in comparison to the larger organisms. CPE values indicated a pronounced seasonal cycle on the shelf and upper slope with twin peaks of phytodetrital deposition in mid spring and late summer. The deeper stations seem to receive a single annual flux maximum in late summer

  6. Groundwater-abstraction induced land subsidence and groundwater regulation in the North China Plain

    NASA Astrophysics Data System (ADS)

    Guo, H.; Wang, L.; Cheng, G.; Zhang, Z.

    2015-11-01

    Land subsidence can be induced when various factors such as geological, and hydrogeological conditions and intensive groundwater abstraction combine. The development and utilization of groundwater in the North China Plain (NCP) bring great benefits, and at the same time have led to a series of environmental and geological problems accompanying groundwater-level declines and land subsidence. Subsidence occurs commonly in the NCP and analyses show that multi-layer aquifer systems with deep confined aquifers and thick compressible clay layers are the key geological and hydrogeological conditions responsible for its development in this region. Groundwater overdraft results in aquifer-system compaction, resulting in subsidence. A calibrated, transient groundwater-flow numerical model of the Beijing plain portion of the NCP was developed using MODFLOW. According to available water supply and demand in Beijing plain, several groundwater regulation scenarios were designed. These different regulation scenarios were simulated with the groundwater model, and assessed using a multi-criteria fuzzy pattern recognition model. This approach is proven to be very useful for scientific analysis of sustainable development and utilization of groundwater resources. The evaluation results show that sustainable development of groundwater resources may be achieved in Beijing plain when various measures such as control of groundwater abstraction and increase of artificial recharge combine favourably.

  7. 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.

  8. The vertical structure of upper ocean variability at the Porcupine Abyssal Plain during 2012-2013

    NASA Astrophysics Data System (ADS)

    Damerell, Gillian M.; Heywood, Karen J.; Thompson, Andrew F.; Binetti, Umberto; Kaiser, Jan

    2016-05-01

    This study presents the characterization of variability in temperature, salinity and oxygen concentration, including the vertical structure of the variability, in the upper 1000 m of the ocean over a full year in the northeast Atlantic. Continuously profiling ocean gliders with vertical resolution between 0.5 and 1 m provide more information on temporal variability throughout the water column than time series from moorings with sensors at a limited number of fixed depths. The heat, salt and dissolved oxygen content are quantified at each depth. While the near surface heat content is consistent with the net surface heat flux, heat content of the deeper layers is driven by gyre-scale water mass changes. Below ˜150m, heat and salt content display intraseasonal variability which has not been resolved by previous studies. A mode-1 baroclinic internal tide is detected as a peak in the power spectra of water mass properties. The depth of minimum variability is at ˜415m for both temperature and salinity, but this is a depth of high variability for oxygen concentration. The deep variability is dominated by the intermittent appearance of Mediterranean Water, which shows evidence of filamentation. Susceptibility to salt fingering occurs throughout much of the water column for much of the year. Between about 700-900 m, the water column is susceptible to diffusive layering, particularly when Mediterranean Water is present. This unique ability to resolve both high vertical and temporal variability highlights the importance of intraseasonal variability in upper ocean heat and salt content, variations that may be aliased by traditional observing techniques.

  9. Mapping the spatio-temporal evolution of irrigation in the Coastal Plain of Georgia, USA

    Treesearch

    Marcus D. Williams; Christie M.S. Hawley; Marguerite Madden; J. Marshall Shepherd

    2017-01-01

    This study maps the spatial and temporal evolution of acres irrigated in the Coastal Plain of Georgia over a 38 year period. The goal of this analysis is to create a time-series of irrigated areas in the Coastal Plain of Georgia at a sub-county level. From 1976 through 2013, Landsat images were obtained and sampled at four year intervals to manually...

  10. The Tempe volcanic province of Mars and comparisons with the Snake River Plains of Idaho

    NASA Technical Reports Server (NTRS)

    Plescia, J. B.

    1981-01-01

    The Tempe volcanic region of Mars, a relatively low plain of probable basaltic flood lava affinity, is shown to be comparable in many respects to features of the Snake River Plains of Idaho, including both scale and type of features observed. Superimposed upon the Tempe plain are a variety of features that appear structurally controlled, along an orientation of N60 deg E; comprising low shields, irregular hills that may be silicic domes, and possible composite cones. The Tempe/Snake River match is held to be the first in which direct comparison can be made between Martian and terrestrial geologic-geomorphic features without encountering problems of scale.

  11. 18. PLAIN OFFICE; SHOWS WOODWORK AND WALL TREATMENT. ROOM 2662, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    18. PLAIN OFFICE; SHOWS WOODWORK AND WALL TREATMENT. ROOM 2662, SECOND FLOOR, SOUTH SIDE. - Hughes Aircraft Company, Processing & Electronics Building, 6775 Centinela Avenue, Los Angeles, Los Angeles County, CA

  12. Simulation of Degraded Properties of 2D plain Woven C/SiC Composites under Preloading Oxidation Atmosphere

    NASA Astrophysics Data System (ADS)

    Chen, Xihui; Sun, Zhigang; Sun, Jianfen; Song, Yingdong

    2017-12-01

    In this paper, a numerical model which incorporates the oxidation damage model and the finite element model of 2D plain woven composites is presented for simulation of the oxidation behaviors of 2D plain woven C/SiC composite under preloading oxidation atmosphere. The equal proportional reduction method is firstly proposed to calculate the residual moduli and strength of unidirectional C/SiC composite. The multi-scale method is developed to simulate the residual elastic moduli and strength of 2D plain woven C/SiC composite. The multi-scale method is able to accurately predict the residual elastic modulus and strength of the composite. Besides, the simulated residual elastic moduli and strength of 2D plain woven C/SiC composites under preloading oxidation atmosphere show good agreements with experimental results. Furthermore, the preload, oxidation time, temperature and fiber volume fractions of the composite are investigated to show their influences upon the residual elastic modulus and strength of 2D plain woven C/SiC composites.

  13. Dynamics of cultural transmission in Native Americans of the high Great Plains.

    PubMed

    Lycett, Stephen J

    2014-01-01

    Culture is a phenomenon shared by all humans. Attempts to understand how dynamic factors affect the origin and distribution of cultural elements are, therefore, of interest to all humanity. As case studies go, understanding the distribution of cultural elements in Native American communities during the historical period of the Great Plains would seem a most challenging one. Famously, there is a mixture of powerful internal and external factors, creating-for a relatively brief period in time-a seemingly distinctive set of shared elements from a linguistically diverse set of peoples. This is known across the world as the "Great Plains culture." Here, quantitative analyses show how different processes operated on two sets of cultural traits among nine High Plains groups. Moccasin decorations exhibit a pattern consistent with geographically-mediated between-group interaction. However, group variations in the religious ceremony of the Sun Dance also reveal evidence of purifying cultural selection associated with historical biases, dividing down ancient linguistic lines. The latter shows that while the conglomeration of "Plains culture" may have been a product of merging new ideas with old, combined with cultural interchange between groups, the details of what was accepted, rejected or elaborated in each case reflected preexisting ideological biases. Although culture may sometimes be a "melting pot," the analyses show that even in highly fluid situations, cultural mosaics may be indirectly shaped by historical factors that are not always obvious.

  14. [The plain packaging of tobacco products: a new strategy for tobacco control].

    PubMed

    Rey-Pino, Juan Miguel; Nerín, Isabel; Lacave-García, Ma Blanca

    There is evidence that global tobacco smoking control policies contribute to decrease the prevalence of smoking among populations, so there is a need to effectively implement different measures in a coordinated way. The plain packaging and labelling of tobacco products is one of the measures proposed by the World Health Organisation Framework Convention on Tobacco Control. At the moment, leading countries are implementing this tobacco control measure, which involves a plain packaging for all tobacco products, i.e., the absence of any promotional or communication tool in the packaging, except the name of the brand, appearing with a standardised font, size, colour and placing in the pack. Australia was the first country to implement this measure in 2012 and recently other countries are legislating and approving it. In Spain, tobacco legislation (2005 and 2010), was an important advance in tobacco control policies. The introduction of plain packaging in Spain would mean the next step in the development of a global strategy for fighting this significant health problem. The aim of this article is to synthesise in a structured manner the role that the packaging of tobacco products has within marketing and communication strategies, as well as to describe the potential effects that the plain packaging has on some aspects of smoking behaviour, according to current literature. Copyright © 2016 SESPAS. Publicado por Elsevier España, S.L.U. All rights reserved.

  15. Ground-water withdrawals from the Coastal Plain of New Jersey, 1956-1980

    USGS Publications Warehouse

    Vowinkel, E.F.

    1984-01-01

    Withdrawals and site data for wells with a pump capacity of 100 ,000 gallons per day or greater in the Coastal Plain of New Jersey are stored in computer files for 1956-80. The data are aggregated by computer into tables, graphs and maps to show the distribution of ground-water withdrawals. Withdrawals are reported by type of use and aquifer for each county in the Coastal Plain. Public-supply wells withdraw the largest quantity of ground water in the Coastal Plain, followed by industrial and agricultural wells. In 1980 public-supply withdrawals were about 280 million gallons per day; the maximum monthly rate was about 355 million gallons per day in July, and the lowest was about 215 million gallons per day in February. Average industrial withdrawals were about 65 million gallons per day. Ground-water withdrawals used for agriculture vary significantly during the year. In 1980, about 75 percent of the agricultural withdrawals occurred from June through September. Several aquifers are used as sources of water supply in the Coastal Plain. Five regional aquifers are the major sources of water for public-supply, industrial, or agricultural use. In decreasing order of withdrawals in 1980, in million gallons per day, they are: The Potomac-Raritan-Magothy aquifer system, 243; Kirkwood-Cohansey aquifer system, 70; Atlantic City 800-foot sand, 21; Englishtown aquifer, 12; and the Wenonah-Mount Laurel aquifer system, 5. (USGS)

  16. Plain Language Summary: Adult Sinusitis (Sinus Infection).

    PubMed

    Caspersen, Leslie A; Walter, Lindsey M; Walsh, Sandra A; Rosenfeld, Richard M; Piccirillo, Jay F

    2015-08-01

    This plain language summary serves as an overview in explaining sinusitis (pronounced sign-you-side-tis). The purpose of this plain language summary is to provide patients with standard language explaining their condition in an easy-to-read format. This summary applies to those 18 years of age or older with sinusitis. The summary is featured as an FAQ (frequently asked question) format. The summary addresses how to manage and treat sinusitis symptoms. Adult sinusitis is often called a sinus infection. A healthcare provider may refer to a sinus infection as rhinosinusitis (pronounced rhi-no-sign-you-side-tis). This includes the nose as well as the sinuses in the name. A sinus infection is the swelling of the sinuses and nasal cavity.The summary is based on the published 2015 "Clinical Practice Guideline: Adult Sinusitis." The evidence-based guideline includes research to support more effective diagnosis and treatment of adult sinus infections. The guideline was developed as a quality improvement opportunity for managing sinus infections by creating clear recommendations to use in medical practice. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2015.

  17. How New Zealand Consumers Respond to Plain English.

    ERIC Educational Resources Information Center

    Campbell, Nittaya

    1999-01-01

    Considers how New Zealand has seen a need for providing readily understandable business and government documents. Reports a psycholinguistic study testing the level of consumer comprehension of bank contracts, and the effect of using plain English to rewrite them. Finds that the most effective means of enhancing comprehension was that which…

  18. A Reverse Taxonomic Approach to Assess Macrofaunal Distribution Patterns in Abyssal Pacific Polymetallic Nodule Fields

    PubMed Central

    Janssen, Annika; Kaiser, Stefanie; Meißner, Karin; Brenke, Nils; Menot, Lenaick; Martínez Arbizu, Pedro

    2015-01-01

    Heightened interest in the exploitation of deep seafloor minerals is raising questions on the consequences for the resident fauna. Assessing species ranges and determination of processes underlying current species distributions are prerequisites to conservation planning and predicting faunal responses to changing environmental conditions. The abyssal central Pacific nodule belt, located between the Clarion and Clipperton Fracture Zones (CCZ), is an area prospected for mining of polymetallic nodules. We examined variations in genetic diversity and broad-scale connectivity of isopods and polychaetes across the CCZ. Faunal assemblages were studied from two mining claims (the eastern German and French license areas) located 1300 km apart and influenced by different productivity regimes. Using a reverse taxonomy approach based on DNA barcoding, we tested to what extent distance and large-scale changes in environmental parameters lead to differentiation in two macrofaunal taxa exhibiting different functions and life-history patterns. A fragment of the mitochondrial gene Cytochrome Oxidase Subunit 1 (COI) was analyzed. At a 97% threshold the molecular operational taxonomic units (MOTUs) corresponded well to morphological species. Molecular analyses indicated high local and regional diversity mostly because of large numbers of singletons in the samples. Consequently, variation in composition of genotypic clusters between sites was exceedingly large partly due to paucity of deep-sea sampling and faunal patchiness. A higher proportion of wide-ranging species in polychaetes was contrasted with mostly restricted distributions in isopods. Remarkably, several cryptic lineages appeared to be sympatric and occurred in taxa with putatively good dispersal abilities, whereas some brooding lineages revealed broad distributions across the CCZ. Geographic distance could explain variation in faunal connectivity between regions and sites to some extent, while assumed dispersal

  19. Genetic variation in ponderosa pine: A 15-year test of provenances in the Great Plains

    Treesearch

    David F. Van Haverbeke

    1986-01-01

    Survival was highest and height growth greatest in ponderosa pine provenances from northcentral Nebraska, southwest South Dakota, and the High Plains region. Genotype x environment interaction was minimal in central and northern Great Plains plantations. Age/age correlations indicate provenances expressing superior height growth can be identified after 5 or 10 years....

  20. Microbicidal effects of plain soap vs triclocarban-based antibacterial soap.

    PubMed

    Kim, S A; Rhee, M S

    2016-11-01

    The aim of this study was to determine the bactericidal effects of plain and antibacterial soap. The bactericidal effects of plain and antibacterial soap containing 0.3% triclocarban were examined against 10 Gram-positive and 10 Gram-negative bacterial strains after exposure at 22°C and 40°C for 20 s. Gram-negative bacteria were more susceptible to both soaps than Gram-positive bacteria. However, with one exception (Enterococcus faecalis ATCC 19433 at 40°C), there was no significant difference between the effects of medicated and non-medicated soap at either temperature. Triclocarban in soap does not lead to a meaningful reduction in bacterial levels during use. Copyright © 2016 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.