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Sample records for river watercourse barents

  1. Water quality of the Luján river, a lowland watercourse near the metropolitan area of Buenos Aires (Argentina).

    PubMed

    Castañé, Patricia M; Sánchez-Caro, Aníbal; Salibián, Alfredo

    2015-10-01

    Luján river is a lowland watercourse which runs 130 km before flowing into the Río de la Plata Estuary, and receives a mixture of domestic and industrial wastewaters originating at its margins. In order to know the physicochemical profile of its surface water, 36 physical-chemical variables were analyzed in samples collected seasonally between 2004 and 2006 at three sampling stations. The results obtained through the principal component analysis (PCA) suggest that the variations in water quality are explained by natural components (soluble salts; metals), nonpoint inputs (nutrients), and anthropogenic (organic and bacterial) and industrial (toxic heavy metals) pollutants. The cases did not fit a clear spatial or seasonal pattern when plotted against the first two PCA axes. The three water quality indices calculated gave middle scores; Sampling station 1 gave a baseline for the comparison of the river's water quality along its course while Sampling station 3 (downriver) was the most degraded. A variety of pollution pulses reach and affect the watercourse downstream. Cities' sewage discharges into the river seem to be the major polluting factor, together with natural metals and other solutes loads that are present from the headwaters. The results may be useful for the development of local and regional mitigation and remediation programs regarding toxic and eutrophying loads in the upper basin of the river. PMID:26407859

  2. Geology of Barents Sea

    SciTech Connect

    Riis, F.; Vollset, J.

    1984-09-01

    The Barents Sea is situated on the continental shelf between Norway, the Spitsbergen Islands, and Novaya Zemlya. The main structural framework of the area was formed during the Caledonian and Hercynian orogenies, whereas the western parts were reactivated by the Kimmerian and Alpine orogenies. Because of the complex opening of the Greenland Norwegian Sea, important tertiary reactivation of Mesozoic normal faults occurred along southwest-northeast-trending systems of wrench faults. Owing to substantial erosion in the late Tertiary, the subsidence history and thermal development are more difficult to unravel in this area than in other places along the Norwegian Shelf. The erosion products were deposited in a huge sedimentary wedge extending onto the oceanic crust. The hydrocarbon discoveries in the Troms area in the southern part of the Barents Sea are encouraging for further exploration. However, the petroleum potential for large areas is not well known at this stage.

  3. Protozoa interaction with aquatic invertebrate: interest for watercourses biomonitoring.

    PubMed

    Palos Ladeiro, M; Bigot, A; Aubert, D; Hohweyer, J; Favennec, L; Villena, I; Geffard, A

    2013-02-01

    Toxoplasma gondii, Cryptosporidium parvum, and Giardia duodenalis are human waterborne protozoa. These worldwide parasites had been detected in various watercourses as recreational, surface, drinking, river, and seawater. As of today, water protozoa detection was based on large water filtration and on sample concentration. Another tool like aquatic invertebrate parasitism could be used for sanitary and environmental biomonitoring. In fact, organisms like filter feeders could already filtrate and concentrate protozoa directly in their tissues in proportion to ambient concentration. So molluscan shellfish can be used as a bioindicator of protozoa contamination level in a site since they were sedentary. Nevertheless, only a few researches had focused on nonspecific parasitism like protozoa infection on aquatic invertebrates. Objectives of this review are twofold: Firstly, an overview of protozoa in worldwide water was presented. Secondly, current knowledge of protozoa parasitism on aquatic invertebrates was detailed and the lack of data of their biological impact was pointed out. PMID:23001759

  4. Barents Tour for Geotourists

    NASA Astrophysics Data System (ADS)

    Pihlaja, Jouni; Johansson, Peter; Lauri, Laura

    2015-04-01

    Barents Tour for Geotourists is a guidebook for a circular route locating in northern Finland, northern Norway and north-western Russia. The targets along the route are all connected with different aspects of geology: there are localities presenting rare rock types and minerals, potholes, gorges, eskers, raised beaches and palsa mires. Total number of sites along the route is 26, 14 of them are locating in Finland, 4 in Norway and 8 in the Kola Peninsula, Russia. In addition to geological information on the sites, the guidebook features directions and information on local tourism services in four languages: English, Finnish, Russian and Norwegian. Good examples of the geological sites in northern Finland are the potholes at Aholanvaara, Salla. The largest pothole is called the "Drinking pot". With a diameter of 15.5 m and a depth of 9.5 m it is the largest known pothole in Finland. One famous target in northern Finland is also the Gold Prospector Museum and geological nature trail at Tankavaara, Sodankylä. The museum has an impressive mineral and jewellery stone collection and it is the only international museum in the world displaying past and present items of gold panning and prospecting. The Khibiny Tundra is the largest mountain massif on the Kola Peninsula, Russia. These mountains are best known for their unique landscapes, geology and mineralogy. With an experienced guide, minerals like apatite, nepheline, titanite, eudialyte and lamprophyllite can be found there. In north-eastern Norway, the palsas at Øvre Neiden and Færdesmyra are examples of a specific mire type in the cold climate area. The palsa mires are characterized by the presence of 2-5 m high peat mounds that consist of interleaved peat and ice layers. The route was planned and implemented in the ABCGheritage project (Arctic Biological, Cultural and Geological Heritage) partly funded by the Kolarctic ENPI CBC program of the European Union. The guidebook was written by researchers of the

  5. Environmental impacts of human action in watercourses

    NASA Astrophysics Data System (ADS)

    Antunes do Carmo, J. S.

    2014-10-01

    The economic, social and environmental conditions of various European river basins and estuarine systems have changed dramatically in the last decades as a consequence of anthropogenic effects, and they will go on changing in the years to come due to increasing human pressure. Particularly in Portugal, various river-estuary systems have undergone several human interventions, notably engineering works to restore considerable stretches of channels and river banks. Whenever the characteristics and natural evolution of a river are altered as a result of human intervention there is an environmental impact. In other words, it is understood that differences can be observed between any present situation that is the result of the evolution of an environment after human intervention, and the natural situation that would have existed if this type of intervention had not taken place, taking into account our previous knowledge of the situation. A thorough understanding of the fluvial processes and new strategies are needed to develop a multifunctional use structure, which must take into account the many-faceted aims of sustainable development. This paper provides a brief description of the nature and distribution of the direct and indirect types of impact arising out of building and operating large dams, as well as some specific points that should be taken into consideration. It also reflects on the way in which the problem of extracting inert material from water environments has been dealt with in Portugal and offers a brief technical contribution which, although qualitative, provides a basic record and explanation of the consequences of significant interventions in water environments that have not been properly assessed or have not taken other mitigating circumstances into consideration.

  6. Storm surges formation in the White and Barents Seas

    NASA Astrophysics Data System (ADS)

    Arkhipkin, Victor; Dobrolyubov, Sergey; Korablina, Anastasia; Myslenkov, Stanislav

    2016-04-01

    Investigation of storm surges in the Arctic seas are of high priority in Russia due to the active development of offshore oil and gas, construction of facilities in the coastal zone, as well as for the safety of navigation. It is important to study the variability of surges, to predict this phenomena and subsequent economic losses, thus including such information into the Russian Arctic Development Program 2020. Surges in the White and Barents Seas are caused mainly by deep cyclones of two types: "diving" from the north (88% of all cyclones) and western. The average height of the storm surges in the White Sea is 0.6-0.9 m. An average duration of storm surges is about 80 hours. Mathematical modeling is used to analyze the characteristics of storm surges formation in the Dvina Bay of the White Sea, and in the Varandey village on the Barents Sea coast. Calculating storm surge heights in the White and Barents seas is performed using the ADCIRC model on an unstructured grid with a step from 20 km in the Barents Sea to 100 m in the White Sea. Unstructured grids allowed keeping small features of the coastline of the White and Barents seas, small islands and shallow banks, and assessing their impact on the development and transformation of wind-generated waves. The ADCIRC model used data of wind field reanalysis CFSv2. The storm surges were simulated for the time period from 1979 to 2010 and included scenarios with / without direct atmospheric pressure forcing, waves and tides. Numerical experiments have revealed distribution of storm surges in channels of the Northern Dvina River delta. The storm surges spreads in the model from the north-north-west of the Dvina Bay. As storm surge moves from the wellhead to the seaside estuary of the Northern Dvina (district Solombala), its height increases from 0.5 to 2 m. We also found a non-linear interaction of the surge and tide during the phase of surge destruction. This phenomenon is the highest in the period of low water, and the

  7. The UN Convention on International Watercourses and integrated water management: A bridge built

    NASA Astrophysics Data System (ADS)

    Tzatzaki, Vasiliki-Maria

    2008-11-01

    The UN Convention on the Law of the Non Navigational Uses of International Watercourses incorporates principles regarding the management of international water resources. The most important principles are the duty of the riparian states to cooperate, not to cause significant harm, to protect the aquatic environment and to utilize the watercourses reasonably and equitably. The lack of hierarchy between these principles signifies that the necessary step for the sound management of shared natural resources is an integrated approach, which takes into account economic development, human needs and environmental protection. Moreover, the UN Convention proved to be useful for the International Court of Justice (hereinafter ICJ) in the settlement of the Gabcikovo- Nagymaros dispute between Hungary and Slovakia for the Danube River. The Court highlighted the importance of the Convention by reminding the riparian states of their obligation to abide by its principles. On the other hand, the ICJ has used the principles of the Convention in the pending case of Pulp Mills between Uruguay and Argentina. This paper is going to show that the UN Convention is an international legal framework with general guidelines in order to create regional conventions, which promotes integrated water management as a solution to the emerging challenges of international water law and potential future conflicts.

  8. Anthropogenic influence of small urban watercourses - Case study from the Czech Republic

    NASA Astrophysics Data System (ADS)

    Svobodova, Eva; Jakubinsky, Jiri; Bacova, Radka; Kubicek, Petr; Herber, Vladimir

    2013-04-01

    Rivers and streams in the urban areas are losing natural environmental values. There is especially small watercourses issue, where there exists the lack of river management and interest of municipalities. The main used methods are based on the field research of river landscape, mapping and inventory of anthropogenic landforms and determination of Channel Capacity Coefficient (CCC). We establish the list of anthropogenic landforms, which we divide to the five categories - industrial, agrarian, urban, transport network, and water management structures. Values of the channel morphologic parameters - width of channel, width of riverbed, and the degree of countersink - are measured for Channel Capacity Coefficient calculation. Pattern of objects shrinking transverse profile and limiting the smooth flow are investigated beside the morphological features. Resulting from the application of these theoretical methods are several practical outputs. Firstly, we construct thematic grid cell monitoring maps (a) count of anthropogenic landforms in the floodplain; (b) weighted average of landform, whose weight was determined on the basis of their influence on the impact of floods. Secondly, we identify pattern distribution of the watercourses channel capacity in the selected study areas. Thirdly, we confirm existence of the urban stream syndrome which is characterized by consistently observed ecological degradation of brooks. The main symptoms of degradation are the altered channel morphology, occurrence of flashfloods, and the rate of ecological stability. Above mentioned characteristics were applied in two different catchments in the Czech Republic - the Leskava Brook and the Lacnovsky Brook. Both streams flow through the urban area in the diverse natural conditions and with various historical development. The Leskava Brook is situated in the southern part of Brno in the Southern Moravia, and the Lacnovsky Brook, lies in the northern part of Svitavy town on the border of Moravia

  9. The role of watercourse versus overland dispersal and niche effects on ostracod distribution in Mediterranean streams (eastern Iberian Peninsula)

    NASA Astrophysics Data System (ADS)

    Castillo-Escrivà, Andreu; Rueda, Juan; Zamora, Laia; Hernández, Ramón; Moral, Mónica del; Mesquita-Joanes, Francesc

    2016-05-01

    The processes behind the heterogeneous distribution of species involve a combination of environmental and spatial effects. In the spatial context, stream networks constitute appropriate systems to compare the relative importance of two dispersal modes in aquatic organisms: overland and watercourse dispersal. In the present study, we analyzed the distribution of ostracod species in a river network in the eastern Iberian Peninsula, with variation partitioning between environmental and spatial factors, using Moran and Asymmetric Eigenvector Maps (MEMs, AEMs) as spatial variables. Our aims were to determine the relative importance of environmental and spatial control and to compare the importance of overland and watercourse dispersal for species distribution of passively-dispersing aquatic organisms. Our results suggest that watercourse was the most important dispersal mode, favoring mass-effects. The role of species sorting was significant and related to temperature, stream width and water quality, measured as a biotic index (IBMWP). These results stress the major importance of connectivity, besides niche-related factors, in structuring riverine communities of passively-dispersing aquatic organisms.

  10. Investigation of watercourses by comparison of successive historical map surveys of Western Hungary

    NASA Astrophysics Data System (ADS)

    Kovács, Gábor

    2010-05-01

    The Second (Timár et al., 2006) and Third Military Survey (Biszak et al., 2007) of the Habsburg Empire, completed in the 19th century (1806-69 and 1869-87), can be very useful in different scientific investigations because of their accuracy and data content. The mapmakers used geodetic projections and survey technologies provided high accuracy. Therefore, scientists can use these maps and the represented objects in retrospective studies. The streams were drawn with very thin lines that also ascertain the high accuracy of their location. Previous study used the Second Military Survey to examine the neotectonic evaluation of the western part of the Pannonian Basin, bordered by Pinka, Rába and Répce Rivers (Kovács, 2010). The watercourses, especially alluvial ones, react very sensitively to tectonic forcing (Schumm & Khan, 1972; Ouchi, 1985). However, the present-day course of the creeks and rivers are mostly regulated, therefore they are unsuitable for such studies. The watercourses have reconstructed from maps surveyed prior to the main water control measures. The Second Military Survey was a perfect source for such studies. The investigated streams were free meandering ones. They could flood their banks, and only natural levees were present. After georeferencing the maps of the area, the streams were digitized, and their sinuosity values were computed. Where significant sinuosity changes have been detected along the streams, it can be considered as indicators of differential uplift or subsidence of the bedrock/alluvium. The goal of this study is to decide the character of several stream sections: were they free meandering ones or not? Some of the sections are antecedent ones, especially at the Vas Mountain at the present Austrian-Hungarian border. If the shapes of the watercourses on the different surveys are almost the same, the sinuosity refers to a prior, forced state of the stream. After digitizing the watercourses on the Third Military Survey sheets, some

  11. WATER QUALITY STATUS REPORT, CROOKED RIVER, IDAHO COUNTY IDAHO, 1987

    EPA Science Inventory

    Crooked River (17060305), a primary anadromous fisheries resource, is located approximately 120 miles southeast of Lewiston, Idaho. Dredging operations between 1936 and 1948 left large piles of gravel in the natural watercourse, causing the river to meander. Impoundments of wat...

  12. Assessment of 137Cs and 90Sr Fluxes in the Barents Sea

    NASA Astrophysics Data System (ADS)

    Matishov, Gennady; Usiagina, Irina; Kasatkina, Nadezhda; Ilin, Gennadii

    2014-05-01

    On the basis of published and own data the annual balance of radionuclide income/outcome was assessed for 137Cs and 90Sr in the Barents Sea for the period from 1950s to the presnt. The scheme of the isotope balance calculation in the Barents Sea included the following processes:atmospheric fallout; river run-off; liquid radioactive wastes releases, income from the Norwegian and the White Seas; outflow to the adjacent areas through the Novaya Zemlya straits and the transects Svalbard-Franz Josef Land and Franz Josef Land-Novaya Zemlya; radioactive decay. According to the multiyear dynamics, the inflow of 137Cs and 90Sr to the Barents Sea was significantly preconditioned by currents from the Norwegian Sea. Three peaks of 137Cs and 90Sr isotope concentrations were registered for the surface waters on the western border of the Barents Sea. The first one was observed in the mid-1960s and was conditioned by testing of nuclear weapons. The increase of isotope concentrations in 1975 and 1980 was preconditioned by the discharge of atomic waste by the Sellafield nuclear reprocessing plant. Nowadays, after the sewage disposal plant was built, the annual discharge of nuclear waste from Sellafield plant is low. The Norwegian Sea was a major source of 137Cs and 90Sr isotope income into the Barents Sea for the period of 1960-2014. Currently, the transborder transfer of 90Sr and 137Cs from the Norwegian Sea into the Barents Sea constitutes about 99% of income for each element. Atmospheric precipitation had a major impact in the 1950-1960s after the testing of the nuclear weapons, and in 1986 after the accident at Chernobyl Nuclear Power Station. In 1963, the atmospheric precipitation of 137Cs reached 1050 TBq; and that of 90Sr, 630 TBq. In 1986, a significant amount of 137Cs inflow (up to 1010 TBq/year) was registered. The 137Cs isotope income exceeded the 90Sr income in the 1960s-1980s, and equal amounts penetrated into the Barents Sea from the Norwegian Sea in the 1990s. Before

  13. Sourcing sediment loss to watercourses at catchment scale using a novel tracing-tracking framework

    NASA Astrophysics Data System (ADS)

    Collins, Adrian; Zhang, Yusheng; Walling, Des; Black, Kevin

    2010-05-01

    Although traditional sediment tracing approaches provide valuable information for characterising key generic sediment sources, Catchment Officers working as part of the England Catchment Sensitive Farming Delivery Initiative (ECSFDI) frequently require higher resolution evidence to assist better the targeting of mitigation options. Accordingly, a novel framework combining conventional sediment source fingerprinting and a dual signature tracking method has recently been used to improve the resolution of sediment source information for contrasting priority catchments. Conventional geochemical tracing incorporating revised mass balance modelling is used to provide information on the relative significance of generic sediment sources such as grassland or arable surface soils, damaged road verges and channel banks/subsurface sources and to provide a framework for the spatial extrapolation of tracking data. Particle tracking using fluorescent-magnetic grains is used to elucidate sediment loss from key components of the primary generic sources, characterised, for example, as poached gateways or cattle tracks and wider areas of general poaching damage in grass fields, wheeling or inter-wheeling areas in arable fields and poached or fluvial-eroded channel banks. The insertion of high-strength magnets in watercourses ensures that the tracking component links sediment loss from seeded areas to river channels as opposed to providing edge-of-field information. Uncertainty and prior information are explicitly recognised by the novel framework. Key words: sediment sources; catchment scale; fingerprinting; tracking; uncertainty; prior information

  14. The influence of the annual invasive plant, Impatiens glandulifera, on the sediment dynamics of inland watercourses in temperate regions

    NASA Astrophysics Data System (ADS)

    Dalvi, Shrutika; Greenwood, Philip

    2016-04-01

    Impatiens glandulifera (Common English Name - Himalayan Balsam) is a non native annual and highly invasive plant that was introduced into parts of Europe from the Himalaya during the nineteenth century as a colourful adornment to parks and gardens. This Plant colonises areas along the river banks, preferably wet, depositional sites, and displaces natural vegetation. The plant is killed by cold weather. The leaves area of riverbank previously occupied by the plant extremely vulnerable to soil erosion until new plant germinates in the following spring. Research work undertaken in the northwest Switzerland and the soutwestern United Kingdom established s link between accelerated soil erosion caused by Impatiens glandulifera and its detrimental impact on native biodiversity of riparian zone of river catchment area. This study focueses on the potential impact of such erosion on sediment quality. A priory reasoning suggests that the preference of Impatiens glandulifera on young depsotional sites near watercourses affects sediment quality. In this study, the results of a soil quality analysis along Impatiens glandulifera-contaminated river banks is presented. Soil physical and chemical properties are compared to non-affected sites to assess the potential impact of preferential erosion on water quality. In addtiion, soil surface profile (SSP) measuring based on by erosion pins, a micro profile bridge and a digital calliper at different selected locations along the riparian zone of river catchment area is used to determine erosion rates and determine sediment transfer from the riparian zone into the rivers.

  15. The eutrophication history of a naturally eutrophic watercourse

    NASA Astrophysics Data System (ADS)

    Tammelin, Mira; Kauppila, Tommi

    2015-04-01

    For efficient inland water protection, it is essential to know the natural states of lakes or, at least, the reference conditions before intensive human impact. The estimation of the natural state is particularly difficult for geologically anomalous areas, where naturally eutrophic lakes are located within nutrient-poorer regions. This is because of the lack of monitoring data and pristine reference lakes and the poor functioning of regional paleoecological nutrient models in such anomalous areas. A paleoecological model that is specifically targeted to the anomalously eutrophic area, however, could be used to interpret the eutrophication histories and natural states of the naturally eutrophic lakes in that area. We applied a targeted paleoecological diatom-total phosphorus transfer function to examine the natural eutrophy and eutrophication history of a central basin and two upstream lakes of the anomalously nutrient-rich Iisalmi watercourse in Eastern Finland. In addition to the nutrient reconstruction based on stratigraphic diatom samples, we studied chrysophyte cyst to diatom ratio, taxonomic diversity and the magnetic susceptibility of the sediment core to find further evidence for possible changes in the lakes and their catchments. The results show that the three lakes are naturally eutrophic with average background total phosphorus levels between 40 μg/l - 60 μg/l. However, human-induced eutrophication has also affected the lakes, which can be seen as rapid changes in the diatom assemblages and magnetic susceptibility between the sediment depths of 40 cm and 90 cm. The modeled lake water total phosphorus concentration has increased less abruptly, approximately 20 μg/l altogether, and the reconstructions of the top sediments mainly correspond well with the water quality observations of the last few decades. The results of this study indicate that a targeted paleoecological nutrient model can be used to interpret the natural state and the eutrophication

  16. Prioritization of contaminated watercourses using an integrated biomarker approach in caged carp.

    PubMed

    Schoenaers, Sébastjen; Vergauwen, Lucia; Hagenaars, An; Vanhaecke, Lynn; AbdElgawad, Hamada; Asard, Han; Covaci, Adrian; Bervoets, Lieven; Knapen, Dries

    2016-08-01

    Because of the ever increasing complexity of environmental contamination profiles, there are limitations to the use of analytical pollutant measurements for monitoring and prioritization of watercourses. The potential of biomarkers has been debated for many years, especially in laboratory settings, but there is a need for studies evaluating these approaches in the field. We evaluated the usefulness of a selection of biomarkers, mostly indicators of general physiological status and common stress responses such as oxidative stress, to discriminate among environmental pollution profiles, with the aim of prioritizing contaminated watercourses for targeted remediation efforts. To this end, juvenile common carp (Cyprinus carpio Lin.) were exposed in cages in the field to Flemish watercourses with varying pollution profiles. After six weeks of exposure, the bioaccumulation of key pollutants was measured, and a set of organismal, biochemical and transcriptional endpoints was determined in several tissue types. After data integration a discrete set of 14 parameters was identified, that could successfully distinguish all watercourses from each other. We show that an integrated biomarker approach, mainly targeting common stress responses, can offer the resolving power to discriminate among environmentally relevant exposure scenarios, and a means to prioritize watercourses for targeted remediation. PMID:27153115

  17. Chemical composition of lake sediments along a pollution gradient in a Subarctic watercourse.

    PubMed

    Dauvalter, Vladimir; Kashulin, Nikolay; Sandimirov, Sergey; Terentjev, Petr; Denisov, Dmitry; Amundsen, Per-Arne

    2011-01-01

    Sediment cores were collected from seven lakes in the Subarctic Pasvik watercourse, polluted by sewage waters and air emissions from the Pechenganickel Metallurgical Company, in order to study chemical composition and estimate the intensity of pollution by taking into account background concentration of elements and the vertical and spatial distribution of their contents in cores and surficial layers of sediments. Sediment samples were analysed by atomic-absorption spectrophotometry for 18 elements (Ni, Cu, Co, Zn, Cd, Pb, Hg, As, Cr, Sr, Mn, Fe, Ca, Mg, Na, K, Al, P). Maximum concentrations of all investigated heavy metals (Ni, Cu, Co, Zn, Cd, Pb, Hg, As) were found in the surficial sediment layers of Lake Kuetsjarvi situated directly below the metallurgic smelters. Decreased contents of heavy metals were observed in surficial sediment layers further downstream in the Pasvik watercourse, although pollution remained rather high. Considerable increase in the contents of the heavy metals emitted into the atmosphere in significant amounts by the Pechenganickel Company (Ni, Cu, Co, Zn), was not observed in surficial sediment layers of lakes upstream in the watercourse polluted only by air contamination and household sewage, but substantial increase of the concentrations of chalcophile elements (Pb, Cd, Hg, As) was revealed. The increase in P contents towards the sediment surface in some lakes may suggest a development of eutrophication processes. Our studies reveal that the metallurgic processing of the Pechenganickel Company has resulted in comprehensive heavy metal pollution and contaminations of lakes sediments in the Inari-Pasvik watercourse. The pollution impact on the sediments is most severe in Lake Kuetsjarvi in the vicinity of the smelters, intermediate in lake localities in the main watercourse downstream the metallurgic enterprises and least in lake localities in the upstream part of the watercourse. PMID:21847792

  18. Halocline water formation in the Barents Sea

    NASA Technical Reports Server (NTRS)

    Steele, Michael; Morison, James H.; Curtin, Thomas B.

    1995-01-01

    Hydrographic data from the first phase of the Coordinated Eastern Arctic Experiment (CEAREX) are analyzed. The data consist of temperature and salinity measurements made by a ship-based conductivity-temperature-depth (CTD) instrument and by a drifting SALARGOS buoy. These data were collected in the autumn and early winter of 1988-1989 in the northern Barents Sea, mostly in ice-covered conditions and then across the marginal ice zone (MIZ). The data show that relatively warm, salty water of Atlantic origin is modified by air cooling and ice melting to produce lighter water that has properties identical to (lower) halocline water found in the Arctic Ocean. This occurs mostly at the MIZ and to a lesser degree within the ice pack itself. At the MIZ the halocline water subjects underneath the lighter meltwater that resides directly under the ice pack; geostrophic velocity calculations indicate that it then turns eastward and flows toward the Kara Sea, in keeping with previous chemical tracer analyses. A rough calculation reveals that the amount of halocline water formed in this way in the Barents Sea and Fram Strait is 30-50% of that formed by ice growth in eastern Arctic polynyas.

  19. Locating the Caledonian Deformation Front in the Western Barents Sea

    NASA Astrophysics Data System (ADS)

    Shulgin, Alexey; Aarseth, Iselin; Faleide, Jan-Inge; Mjelde, Rolf; Huismans, Ritske

    2016-04-01

    The crustal architecture of the Paleozoic sedimentary basins and the underlying basement is still not fully understood in the Western Barents Sea region. It has been proposed that the major basins have developed along the structural framework inherited from the early Devonian Caledonian orogeny. However, the location of the Caledonian suture zone and its orientation and the extent of the deformation front are still poorly constrained and are ambiguous in the Barents Sea. Two orientations of the Caledonian Deformation Front (CDF) have been proposed earlier: north-south (from the potential fields data) and southwest-northeast (from seismic data). Knowledge of the spatial extent and orientation of the CDF has a major effect on our understanding of the evolution of the Barents Sea and provides important constrains on the basin-basement interaction. In 2014 a marine seismic experiment was conducted in the Western Barents Sea. One of the goals of the experiment is to discriminate between two proposed models and to constrain the location of the Caledonian Deformation front offshore northern Norway. We present the joint interpretation of collocated newly collected wide-angle seismic data (Ocean Bottom Seismometers) and reprocessing of the reflection seismic dataset (Multi-channel seismics) collected in the mid 80's, using modern computational techniques. The two seismic methods provide best resolution at different depth ranges, and in our modeling we combine the results from the two methods to constrain the location of the CDF along transect running Northwest-Southeast across the Western Barents Sea.

  20. Postglacial paleoceanographic environments in the Barents and Baltic seas

    NASA Astrophysics Data System (ADS)

    Ivanova, E. V.; Murdmaa, I. O.; Emelyanov, E. M.; Seitkalieva, E. A.; Radionova, E. P.; Alekhina, G. N.; Sloistov, S. M.

    2016-01-01

    This paper presents reconstructions of ice sheet boundaries, lacustrine and marine paleobasins, as well as the connections of the Barents and Baltic seas with the North Atlantic from the Last Glacial Maximum to the Holocene. The reconstructions are based on original and published data obtained from the northern and western parts of the Barents Sea and Baltic depressions with account for the available regional schematic maps of deglaciation. The early deglaciation of the Scandinavian-Barents ice sheet culminated with the Bølling-Allerød interstadial (14.5-12.9 cal ka BP), which was characterized by a more vigorous Atlantic meridional overturning circulation (AMOC) and a corresponding increase in surface Atlantic water inflow into the Barents Sea through deep troughs. The Baltic Ice Lake (BIL) remained a dammed-up isolated basin during deglaciation from 16.0 to 11.7 cal ka BP. In the Younger Dryas (YD), the lake drained into the North Sea and was replaced by a brackish Yoldia Sea (YS) at the beginning of the Holocene (Preboreal, 11.7-10.7 cal ka BP), due to a limited connection between two basins through the Närke Strait. In the Barents Sea, the next increase in the Atlantic water influx into the deep basins corresponded to terminal YD and Preboreal events with a culmination in the Early Holocene. The Yoldia Sea became a lake again during the next stage, the Ancylus (~10.7-8.8 cal ka BP). Atlantic water inflow both into the Barents and Baltic seas varied during the Holocene, with a maximum contribution in the Early Holocene, when the Littorina Sea (LS, 8-4 cal ka BP) connection with the North Sea via the Danish Straits was formed to replace the Ancylus Lake. The recent, post-Littorina stage (PS, the last 4 cal ka) of the Baltic Sea evolution began in the Late Holocene.

  1. Assessment of Undiscovered Petroleum Resources of the Barents Sea Shelf

    USGS Publications Warehouse

    Klett, Timothy R.; Gautier, Donald L.

    2009-01-01

    Four geologic provinces of the Barents Sea shelf were assessed for undiscovered crude oil, natural gas, and natural gas liquid or condensate resources as part of the U.S. Geological Survey's Circum-Arctic Oil and Gas Resource Appraisal. Using a geology-based methodology, the mean undiscovered, conventional, technically recoverable petroleum resources in the Barents Sea Shelf are estimated to be more than 76 billion barrels of oil equivalent, which includes approximately 11 billion barrels of crude oil, 380 trillion cubic feet of natural gas, and 2 billion barrels of natural gas liquids.

  2. Total and organic mercury in Barents sea pelagic fish

    SciTech Connect

    Joiris, C.R.; Ali, I.B.; Hoisbeek, L. Bossicart, M.; Tapia, G.

    1995-11-01

    One of the main questions, when studying mercury levels in natural samples, is to define how far the measured concentrations correspond to natural- or background-levels or to actual contamination due to human activities. To establish background pristine levels of Hg in the marine environment, areas of very low human activities are often proposed. Arctic and Antarctic waters, together with deep oceans waters, are best suited and provide themselves for such studies. Barents Sea areas were used in this study, even if the existence of an important atmospheric transport of Hg probably caused an increase of Hg levels at a global scale. Instead of analyzing mercury from the very low concentrations in sea water, it is much easier to identify it from the higher concentrations which organisms, used as bioindicators, have built up in their tissues. By using these bioindicators to study the bioavailable fraction of the stable residues, one also integrates small scale temporal and spatial variations. Pelagic fish were used in this work to study the ecotoxicology of Hg in the Barents Sea. This study has been made possible due to recent access of the Barents Sea to western scientists and it is to serve as a complement to existing studies by the same team in the Greenland and Norwegian seas, and the southwestern part of the Barents Sea. 19 refs., 4 figs., 2 tabs.

  3. Late Weichselian to Holocene paleoenvironments in the Barents Sea

    NASA Astrophysics Data System (ADS)

    Ivanova, Elena V.; Murdmaa, Ivar O.; Duplessy, Jean-Claude; Paterne, Martine

    2002-11-01

    Paleoceanographic changes since the Late Weichselian have been studied in three sediment cores raised from shelf depressions along a north-south transect across the central Barents Sea. AMS radiocarbon dating offers a resolution of several hundred years for the Holocene. The results of lithological and micropaleontological study reveal the response of the Barents Sea to global climatic changes and Atlantic water inflow. Four evolutionary stages were distinguished. The older sediments are moraine deposits. The destruction of the Barents Sea ice sheet during the beginning of the deglaciation in response to climate warming and sea level rise resulted in proximal glaciomarine sedimentation. Then, the retreat of the glacier front to archipelagoes during the main phase of deglaciation caused meltwater discharge and restricted iceberg calving. Fine-grained distal glaciomarine sediments were deposited from periodic near-bottom nepheloid flows and the area was almost permanently covered with sea ice. The dramatic change in paleoenvironment occurred near the Pleistocene/Holocene boundary when normal marine conditions ultimately established resulting in a sharp increase of biological productivity. This event was diachronous and started prior to 10 14C ka BP in the southern and about 9.2 14C ka in the northern Barents Sea. Variations in sediment supply, paleoproductivity, sea-ice conditions, and Atlantic water inflow controlled paleoenvironmental changes during the Holocene.

  4. Technological challenges for hydrocarbon production in the Barents Sea

    SciTech Connect

    Gudmestad, O.T.; Strass, P.

    1995-02-01

    Technological challenges for hydrocarbon production in the Barents Sea relate mainly to the climatic conditions (ice and icebergs), to the relatively deep water of the area, and to the distance to the market for transportation of gas. It is suggested that environmental conditions must be carefully mapped over a sufficiently long period to get reliable statistics for the area.

  5. High temperatures in the Barents Sea in 2013

    NASA Astrophysics Data System (ADS)

    Chepurin, Gennady; Carton, James

    2014-05-01

    During this past summer SST in the Barents Sea of the Eurasian Arctic reached its highest value since satellite infrared measurements began in 1981, with multi-satellite Pathfinder anomalies exceeding 4°C (3.5°C if a temporal warming trend is removed). The anomalies which began to develop in the Barents Sea in May and gradually expanded into the Kara Sea during the summer, largely subsided by November. This warming of the Eurasian side of the Arctic is in striking contrast to the pattern of warming in 2007 when the Pacific side of the Arctic was warm and the Barents Sea was cool. The shift of SST anomalies across the Arctic has potentially important consequences for meteorological conditions in this region. Indeed atmospheric conditions this past summer were also anomalous, with unusually clear skies and August surface winds shifting from the expected northerly direction to westerly. The causes of the summer 2013 anomalous warming are complex. In the seasonal heat budget of the Barents Sea convergence of heat is important due to the eastward advection and surfacing of warm, salty Atlantic Water, and is balanced by surface cooling in winter. In spring of this year the Barents Sea ice retreat came early in the north and east, one impact of which was a greater opportunity for high solar absorption into the surface ocean (ice-albedo feedback) and high air humidity. To quantify the net surface heating contribution we present results from the NCEP and ERA Interim atmospheric reanalyses, and scatterometer winds, while to estimate the potential ocean contribution we examine ocean heat convergence in ocean models. The current results suggest that the anomalous conditions were forced by both anomalous surface fluxes, particularly net solar radiation, and ocean heat convergence due to anomalous transport of Atlantic Water.

  6. Mining, metallurgy and the historical origin of mercury pollution in lakes and watercourses in Central Sweden.

    PubMed

    Bindler, Richard; Yu, Ruilian; Hansson, Sophia; Classen, Neele; Karlsson, Jon

    2012-08-01

    In Central Sweden an estimated 80% of the lakes contain fish exceeding health guidelines for mercury. This area overlaps extensively with the Bergslagen ore region, where intensive mining of iron ores and massive sulfide ores occurred over the past millennium. Although only a few mines still operate today, thousands of mineral occurrences and mining sites are documented in the region. Here, we present data on long-term mercury pollution in 16 sediment records from 15 lakes, which indicate that direct release of mercury to lakes and watercourses was already significant prior to industrialization (watercourses, which suggests that the present-day problem of elevated mercury concentrations in the Bergslagen region can trace its roots back to historical mining. PMID:22731612

  7. Modeling transfer of 137Cs fallout in a large Finnish watercourse.

    PubMed

    Korhonen, R

    1990-10-01

    In the Finnish environment, lakes provide very important transfer pathways for various pollutants. In this study, a large watercourse was modeled using the dynamic compartment model DETRA. The model includes a fish model for roach, nonpredatory and predatory perches, and pike. Transfer of 137Cs fallout deposited onto the Kymijoki drainage area after the Chernobyl accident was calculated using the model. In the model, fallout was assumed to consist of a soluble and insoluble component, behaving differently in the environment. Model predictions were compared with measured concentrations. Lake Päijänne, the largest lake of the watercourse, was studied most extensively. Calculated concentrations in lake water were consistent with measured concentrations. However, calculated concentrations in fish were lower than measured concentrations. To test the model by using additional experimental data, transfer of nuclear weapons testing fallout was also calculated. The processes that cause the rather rapid removal of 137Cs from lake water need to be studied further using more detailed data. In the long term, runoff and resuspension of sedimentary material were considered to be important in causing concentrations in lake water. PMID:2398012

  8. Input of pharmaceuticals through coastal surface watercourses into a Mediterranean lagoon (Mar Menor, SE Spain): sources and seasonal variations.

    PubMed

    Moreno-González, R; Rodríguez-Mozaz, S; Gros, M; Pérez-Cánovas, E; Barceló, D; León, V M

    2014-08-15

    The seasonal occurrence and distribution of 69 pharmaceuticals along coastal watercourses during 6 sampling campaigns and their input through El Albujón watercourse to the Mar Menor lagoon were determined by UPLC-MS-MS, considering a total of 115 water samples. The major source of pharmaceuticals running into this watercourse was an effluent from the Los Alcazares WWTP, although other sources were also present (runoffs, excess water from irrigation, etc.). In this urban and agriculturally influenced watercourse different pharmaceutical distribution profiles were detected according to their attenuation, which depended on physicochemical water conditions, pollutant input variation, biodegradation and photodegradation rates of pollutants, etc. The less recalcitrant compounds in this study (macrolides, β-blockers, etc.) showed a relevant seasonal variability as a consequence of dissipation processes (degradation, sorption, etc.). Attenuation was lower, however, for diclofenac, carbamazepine, lorazepam, valsartan, sulfamethoxazole among others, due to their known lower degradability and sorption onto particulate matter, according to previous studies. The maximum concentrations detected were higher than 1000 ng L(-1) for azithromycin, clarithromycin, valsartan, acetaminophen and ibuprofen. These high concentration levels were favored by the limited dilution in this low flow system, and consequently some of them could pose an acute risk to the biota of this watercourse. Considering data from 2009 to 2010, it has been estimated that a total of 11.3 kg of pharmaceuticals access the Mar Menor lagoon annually through the El Albujón watercourse. The highest proportion of this input corresponded to antibiotics (46%), followed by antihypertensives (20%) and diuretics (18%). PMID:24840281

  9. Environmental regulation of bivalve growth in the southern Barents Sea: A combined ecological and geochemical approach

    NASA Astrophysics Data System (ADS)

    Carroll, M. L.; Johnson, B. J.; Henkes, G. A.; McMahon, K. W.; Voronkov, A.; Ambrose, W. G., Jr.; Denisenko, S. G.

    2009-04-01

    Ecological and geochemical analyses of bivalve shells provide potentially complimentary information on patterns and drivers of natural variability in Arctic marine populations, yet are rarely considered together. We analyzed growth rates and shell geochemistry of the Greenland Smooth Cockle (Serripes groenlandicus) from the southern Barents Sea between 1882 and 1968. Growth, stable isotope (oxygen and carbon), and trace elemental (Mg, Sr, Ba, Mn) patterns were linked to environmental variations on weekly to decadal scales. Standardized growth rates exhibited multi-year periodicity inversely related to the North Atlantic Oscillation Index (NAO) and positively related to river discharge. Up to 60% of the interannual variability in Ba/Ca could be explained by variations in river discharge at stations closest to the rivers, but the relationship disappeared at a more distant location. Stable isotope data (18O, 13C), and Sr/Ca patterns suggest that bivalve growth ceases at elevated temperatures during the fall and recommences at the coldest temperatures in the early spring, implying that food, rather than temperature, is the primary driver of the annual growth cycle. Combining annually-integrated growth results and higher resolution geochemical results thus elucidated the annual growth cycle of an Arctic bivalve and mechanisms of biophysical coupling over a range of temporal and spatial scales.

  10. Grounding zone wedges, Kveithola Trough (NW Barents Sea)

    NASA Astrophysics Data System (ADS)

    Rebesco, Michele; Urgeles, Roger; Özmaral, Asli; Hanebuth, Till; Caburlotto, Andrea; Hörner, Tanja; Lantzsch, Hendrik; LLopart, Juame; Lucchi, Renata; Skøtt Nicolaisen, Line; Giacomo, Osti; Sabbatini, Anna; Camerlenghi, Angelo

    2014-05-01

    Swath bathymetry within Kveithola Trough (NW Barents Sea) shows a seafloor characterized by E-W trending megascale glacial lineations (MSGLs) overprinted by transverse Grounding Zone Wedges (GZWs), which give the trough a stair profile (Rebesco et al., 2011). GZWs are formed by deposition of subglacial till at temporarily stable ice-stream fronts in between successive episodic retreats (Rüther et al., 2012; Bjarnadóttir et al., 2012). Sub-bottom data show that present-day morphology is largely inherited from palaeo-seafloor topography of GZWs, which is draped by a deglacial to early Holocene glaciomarine sediments (about 15 m thick). The ice stream that produced such subglacial morphology was flowing from East to West inside Kveithola Trough during Last Glacial Maximum. Its rapid retreat was likely associated with progressive lift-offs, and successive rapid melting of the grounded ice, induced by the eustatic sea-level rise (Lucchi et al., 2013). References: Bjarnadóttir, L.R., Rüther, D.C., Winsborrow, M.C.M., Andreassen, K., 2012. Grounding-line dynamics during the last deglaciation of Kveithola, W Barents Sea, as revealed by seabed geomorphology and shallow seismic stratigraphy. Boreas, 42, 84-107. Lucchi R.G., et al. 2013. Postglacial sedimentary processes on the Storfjorden and Kveithola TMFs: impact of extreme glacimarine sedimentation. Global and Planetary Change, 111, 309-326. Rebesco, M., et al. 2011. Deglaciation of the Barents Sea Ice Sheet - a swath bathymetric and subbottom seismic study from the Kveitehola Trough. Marine Geology, 279, 141-14. Rüther, D.C., Bjarnadóttir, L.R., Junttila, J., Husum, K., Rasmussen, T.L., Lucchi, R.G., Andreassen, K., 2012. Pattern and timing of the north-western Barents Sea Ice Sheet deglaciation and indications of episodic Holocene deposition. Boreas 41, 494-512.

  11. Food webs and carbon flux in the Barents Sea

    NASA Astrophysics Data System (ADS)

    Wassmann, Paul; Reigstad, Marit; Haug, Tore; Rudels, Bert; Carroll, Michael L.; Hop, Haakon; Gabrielsen, Geir Wing; Falk-Petersen, Stig; Denisenko, Stanislav G.; Arashkevich, Elena; Slagstad, Dag; Pavlova, Olga

    2006-10-01

    Within the framework of the physical forcing, we describe and quantify the key ecosystem components and basic food web structure of the Barents Sea. Emphasis is given to the energy flow through the ecosystem from an end-to-end perspective, i.e. from bacteria, through phytoplankton and zooplankton to fish, mammals and birds. Primary production in the Barents is on average 93 g C m -2 y -1, but interannually highly variable (±19%), responding to climate variability and change (e.g. variations in Atlantic Water inflow, the position of the ice edge and low-pressure pathways). The traditional focus upon large phytoplankton cells in polar regions seems less adequate in the Barents, as the cell carbon in the pelagic is most often dominated by small cells that are entangled in an efficient microbial loop that appears to be well coupled to the grazing food web. Primary production in the ice-covered waters of the Barents is clearly dominated by planktonic algae and the supply of ice biota by local production or advection is small. The pelagic-benthic coupling is strong, in particular in the marginal ice zone. In total 80% of the harvestable production is channelled through the deep-water communities and benthos. 19% of the harvestable production is grazed by the dominating copepods Calanus finmarchicus and C. glacialis in Atlantic or Arctic Water, respectively. These two species, in addition to capelin ( Mallotus villosus) and herring ( Clupea harengus), are the keystone organisms in the Barents that create the basis for the rich assemblage of higher trophic level organisms, facilitating one of the worlds largest fisheries (capelin, cod, shrimps, seals and whales). Less than 1% of the harvestable production is channelled through the most dominating higher trophic levels such as cod, harp seals, minke whales and sea birds. Atlantic cod, seals, whales, birds and man compete for harvestable energy with similar shares. Climate variability and change, differences in recruitment

  12. Temporal Dynamics of Top Predators Interactions in the Barents Sea

    PubMed Central

    Durant, Joël M.; Skern-Mauritzen, Mette; Krasnov, Yuri V.; Nikolaeva, Natalia G.; Lindstrøm, Ulf; Dolgov, Andrey

    2014-01-01

    The Barents Sea system is often depicted as a simple food web in terms of number of dominant feeding links. The most conspicuous feeding link is between the Northeast Arctic cod Gadus morhua, the world's largest cod stock which is presently at a historical high level, and capelin Mallotus villosus. The system also holds diverse seabird and marine mammal communities. Previous diet studies may suggest that these top predators (cod, bird and sea mammals) compete for food particularly with respect to pelagic fish such as capelin and juvenile herring (Clupea harengus), and krill. In this paper we explored the diet of some Barents Sea top predators (cod, Black-legged kittiwake Rissa tridactyla, Common guillemot Uria aalge, and Minke whale Balaenoptera acutorostrata). We developed a GAM modelling approach to analyse the temporal variation diet composition within and between predators, to explore intra- and inter-specific interactions. The GAM models demonstrated that the seabird diet is temperature dependent while the diet of Minke whale and cod is prey dependent; Minke whale and cod diets depend on the abundance of herring and capelin, respectively. There was significant diet overlap between cod and Minke whale, and between kittiwake and guillemot. In general, the diet overlap between predators increased with changes in herring and krill abundances. The diet overlap models developed in this study may help to identify inter-specific interactions and their dynamics that potentially affect the stocks targeted by fisheries. PMID:25365430

  13. Temporal dynamics of top predators interactions in the Barents Sea.

    PubMed

    Durant, Joël M; Skern-Mauritzen, Mette; Krasnov, Yuri V; Nikolaeva, Natalia G; Lindstrøm, Ulf; Dolgov, Andrey

    2014-01-01

    The Barents Sea system is often depicted as a simple food web in terms of number of dominant feeding links. The most conspicuous feeding link is between the Northeast Arctic cod Gadus morhua, the world's largest cod stock which is presently at a historical high level, and capelin Mallotus villosus. The system also holds diverse seabird and marine mammal communities. Previous diet studies may suggest that these top predators (cod, bird and sea mammals) compete for food particularly with respect to pelagic fish such as capelin and juvenile herring (Clupea harengus), and krill. In this paper we explored the diet of some Barents Sea top predators (cod, Black-legged kittiwake Rissa tridactyla, Common guillemot Uria aalge, and Minke whale Balaenoptera acutorostrata). We developed a GAM modelling approach to analyse the temporal variation diet composition within and between predators, to explore intra- and inter-specific interactions. The GAM models demonstrated that the seabird diet is temperature dependent while the diet of Minke whale and cod is prey dependent; Minke whale and cod diets depend on the abundance of herring and capelin, respectively. There was significant diet overlap between cod and Minke whale, and between kittiwake and guillemot. In general, the diet overlap between predators increased with changes in herring and krill abundances. The diet overlap models developed in this study may help to identify inter-specific interactions and their dynamics that potentially affect the stocks targeted by fisheries. PMID:25365430

  14. Structural evolution and petroleum potential of the Norwegian Barents Sea

    SciTech Connect

    Nilsen, K.T.

    1995-08-01

    The tectonic history of the Norwegian Barents Sea has provided potential hydrocarbon traps in clastic reservoirs associated with rotated fault blocks, compressional anticlines and salt domes. Significant stratigraphic potential also resides in Paleozoic carbonates. Drilling in the Hammerfest Basin has yielded large gas discoveries in rotated fault blocks, but other trapping concepts remain relatively untested. The undrilled arm north of 74{degrees} 30 minutes N, currently being mapped by the Norwegian Petroleum Directorate using exclusive seismic and geological data from shallow boreholes, represents a significant area for future exploration. Prospectivity is critically dependent on the scaling of traps following Neogene uplift of large areas of the Barents platform. The area is dominated by structural trends inherited from the Caledonian and older orogens. Carboniferous rifting established a system of half grabens and intervening highs, followed by late Permian faulting in the west which initiated regional subsidence continuing into the early Jurassic. Fault reactivation in early Triassic times triggered salt diapirism and provided structural control for the formation of Triassic shelf margins. During the late Jurassic-early Cretaceous western basins underwent tectonic subsidence, while the northeastern platform arm was subject to gentle compression. In the late Cretaceous salt was reactivated in the Nordkapp Basin and compressional structures developed west of the Loppa High. Further subsidence of the western basins was promoted by late Mesozoic and early Tertiary transtensional movements along the North Atlantic rift system. Subsequent regional compression in these basins, and basin inversion east of the Loppa High, are of post-Eocene age.

  15. Tectonics and hydrocarbon potential of the Barents Megatrough

    SciTech Connect

    Baturin, D.; Vinogradov, A.; Yunov, A. )

    1991-08-01

    Interpretation of geophysical data shows that the geological structure of the Eastern Barents Shelf, named Barents Megatrough (BM), extends sublongitudinally almost from the Baltic shield to the Franz Josef Land archipelago. The earth crust within the axis part of the BM is attenuated up to 28-30 km, whereas in adjacent areas its thickness exceeds 35 km. The depression is filled with of more than 15 km of Upper Paleozoic, Mesozoic, and Cenozoic sediments overlying a folded basement of probable Caledonian age. Paleozoic sediments, with exception of the Upper Permian, are composed mainly of carbonates and evaporites. Mesozoic-Cenozoic sediments are mostly terrigenous. The major force in the development of the BM was due to extensional tectonics. Three rifting phases are recognizable: Late Devonian-Early Carboniferous, Early Triassic, and Jurassic-Early Cretaceous. The principal features of the geologic structure and evolution of the BM during the late Paleozoic-Mesozoic correlate well with those of the Sverdup basin, Canadian Arctic. Significant quantity of Late Jurassic-Early Cretaceous basaltic dikes and sills were intruded within Triassic sequence during the third rifting phase. This was probably the main reason for trap disruption and hydrocarbon loss from Triassic structures. Lower Jurassic and Lower Cretaceous reservoir sandstones are most probably the main future objects for oil and gas discoveries within the BM. Upper Jurassic black shales are probably the main source rocks of the BM basin, as well as excellent structural traps for hydrocarbon fluids from the underlying sediments.

  16. Bivalves as indicators of environmental variation and potential anthropogenic impacts in the southern Barents Sea.

    PubMed

    Carroll, Michael L; Johnson, Beverly J; Henkes, Gregory A; McMahon, Kelton W; Voronkov, Andrey; Ambrose, William G; Denisenko, Stanislav G

    2009-01-01

    Identifying patterns and drivers of natural variability in populations is necessary to gauge potential effects of climatic change and the expected increases in commercial activities in the Arctic on communities and ecosystems. We analyzed growth rates and shell geochemistry of the circumpolar Greenland smooth cockle, Serripes groenlandicus, from the southern Barents Sea over almost 70 years between 1882 and 1968. The datasets were calibrated via annually-deposited growth lines, and growth, stable isotope (delta(18)O, delta(13)C), and trace elemental (Mg, Sr, Ba, Mn) patterns were linked to environmental variations on weekly to decadal scales. Standardized growth indices revealed an oscillatory growth pattern with a multi-year periodicity, which was inversely related to the North Atlantic Oscillation Index (NAO), and positively related to local river discharge. Up to 60% of the annual variability in Ba/Ca could be explained by variations in river discharge at the site closest to the rivers, but the relationship disappeared at a more distant location. Patterns of delta(18)O, delta(13)C, and Sr/Ca together provide evidence that bivalve growth ceases at elevated temperatures during the fall and recommences at the coldest temperatures in the early spring, with the implication that food, rather than temperature, is the primary driver of bivalve growth. The multi-proxy approach of combining the annually integrated information from the growth results and higher resolution geochemical results yielded a robust interpretation of biophysical coupling in the region over temporal and spatial scales. We thus demonstrate that sclerochronological proxies can be useful retrospective analytical tools for establishing a baseline of ecosystem variability in assessing potential combined impacts of climatic change and increasing commercial activities on Arctic communities. PMID:19394657

  17. Bivalves as indicators of environmental variation and potential anthropogenic impacts in the southern Barents Sea

    PubMed Central

    Carroll, Michael L.; Johnson, Beverly J.; Henkes, Gregory A.; McMahon, Kelton W.; Voronkov, Andrey; Ambrose, William G.; Denisenko, Stanislav G.

    2009-01-01

    Identifying patterns and drivers of natural variability in populations is necessary to gauge potential effects of climatic change and the expected increases in commercial activities in the Arctic on communities and ecosystems. We analyzed growth rates and shell geochemistry of the circumpolar Greenland smooth cockle, Serripes groenlandicus, from the southern Barents Sea over almost 70 years between 1882 and 1968. The datasets were calibrated via annually-deposited growth lines, and growth, stable isotope (δ18O, δ13C), and trace elemental (Mg, Sr, Ba, Mn) patterns were linked to environmental variations on weekly to decadal scales. Standardized growth indices revealed an oscillatory growth pattern with a multi-year periodicity, which was inversely related to the North Atlantic Oscillation Index (NAO), and positively related to local river discharge. Up to 60% of the annual variability in the Ba/Ca could be explained by variations in river discharge at the site closest to the rivers, but the relationship disappeared at a more distant location. Patterns of δ18O, δ13C, and Sr/Ca together provide evidence that bivalve growth ceases at elevated temperatures during the fall and recommences at the coldest temperatures in the early spring, with the implication that food, rather than temperature, is the primary driver of bivalve growth. The multi-proxy approach of combining the annually integrated information from the growth results and higher resolution geochemical results yielded a robust interpretation of biophysical coupling in the region over temporal and spatial scales. We thus demonstrate that sclerochronological proxies can be useful retrospective analytical tools for establishing a baseline of ecosystem variability in assessing potential combined impacts of climatic change and increasing commercial activities on Arctic communities. PMID:19394657

  18. Distribution of zooplankton in the Barents Sea in August 2006

    NASA Astrophysics Data System (ADS)

    Dvoretsky, V. G.; Dvoretsky, A. G.

    2010-12-01

    Forty-two mesozooplankton samples were collected in the Barents Sea during the cruise of the R/V Dal'nie Zelentsy in August 2006. In total, 72 taxa of planktic animals were found. The minimal average mesozooplankton abundance was noted in the Murmansk coastal waters in the south of the sea (154 ind./m3), while the maximal was noted in the Arctic waters (1533 ind./m3). The average wet biomass varied from 32 to 830 mg/m3. The zooplankton abundance and biomass exceeded the relevant average long-term parameters by 1.5-2 times and by 1.2-1.4 times, respectively. The mean biodiversity (Shannon's index) of the zooplankton communities was low: H' = 1.62 ± 0.104 bit/ind.

  19. Continent-ocean transition at the western Barents Sea/Svalbard continental margin

    SciTech Connect

    Eldholm, O.; Faleide, J.I.; Myhre, A.M.

    1987-12-01

    The change in crustal type at the western Barents Sea/Svalbard margin takes place over a narrow zone related to primary rift and shear structures reflecting the stepwise opening of the Greenland Sea. Regionally, the margin is composed of two large shear zones and a central rifted-margin segment. Local transtension and transpression at the plate boundary caused the early Cenozoic tectonism in Svalbard and the western Barents Sea, and might explain the prominent marginal gravity and velocity anomalies.

  20. The Lower Cretaceous strata in Svalbard and the Barents Sea; basin infill dynamics and palaeobathymetry

    NASA Astrophysics Data System (ADS)

    Midtkandal, Ivar; Faleide, Jan Inge; Evensen Dahlberg, Maria; Dimitriou, Myrsini; Petter Nystuen, Johan

    2014-05-01

    Data from cliff sections on Svalbard and seismic sections from the Barents Sea indicate an Early Cretaceous depositional system of far greater reach than the Svalbard archipelago, with a source area to the northwest of Svalbard and a basin deepening to the southeast in the western Barents Sea. Seismic imagery shows large-scale, low-angle clinoforms that demonstrate progradation of shallow-marine clastic deposits hundreds of kilometres into the present day Barents Sea, sourced from areas near the High Arctic Large Igneous Province (HALIP) to the northwest. Field data and seismic imagery are coupled to map architectural patterns that provide information on basin physiography and scale. The results of the study show that the sediment infill of the epicontinental basin was largely controlled by availability of accommodation space, and how the formation of localized syn- and post-depositional troughs and highs altered the position and orientation of the Early Cretaceous shoreline, and thereby its corresponding facies distribution. The Early Cretaceous accommodation space covering a wider part of the Barents Shelf, was created by regional subsidence of a possible deep-seated origin. In the SW Barents Sea additional accommodation space was formed by prominent rift events during Late Jurassic-Early Cretaceous times. Cenozoic uplift and erosion, increasing northwards, has removed most of the Lower Cretaceous strata in the NW Barents Sea. Thus, a direct tie between the prograding units in the southern Barents Sea and the exposed more proximal Lower Cretaceous strata on Svalbard is not possible. An on-going analysis of seismic profiles along with well data will provide new constraints for estimating palaeo-water depths and facies distribution for the Cretaceous in the Barents Sea.

  1. Change in Fish Community Structure in the Barents Sea

    PubMed Central

    Aschan, Michaela; Fossheim, Maria; Greenacre, Michael; Primicerio, Raul

    2013-01-01

    Change in oceanographic conditions causes structural alterations in marine fish communities, but this effect may go undetected as most monitoring programs until recently mainly have focused on oceanography and commercial species rather than on whole ecosystems. In this paper, the objective is to describe the spatial and temporal changes in the Barents Sea fish community in the period 1992–2004 while taking into consideration the observed abundance and biodiversity patterns for all 82 observed fish species. We found that the spatial structure of the Barents Sea fish community was determined by abiotic factors such as temperature and depth. The observed species clustered into a deep assemblage, a warm water southern assemblage, both associated with Atlantic water, and a cold water north-eastern assemblage associated with mixed water. The latitude of the cold water NE and warm water S assemblages varied from year to year, but no obvious northward migration was observed over time. In the period 1996–1999 we observed a significant reduction in total fish biomass, abundance, mean fish weight, and a change in community structure including an increase in the pelagic/demersal ratio. This change in community structure is probably due to extremely cold conditions in 1996 impacting on a fish community exposed to historically high fishing rates. After 1999 the fish community variables such as biomass, abundance, mean weight, P/D ratio as well as community composition did not return to levels of the early 90s, although fishing pressure and climatic conditions returned to earlier levels. PMID:23658646

  2. Influence of the North Atlantic on climate change in the Barents Sea

    NASA Astrophysics Data System (ADS)

    Glok, Natalia; Alekseev, Genrikh; Smirnov, Aleksander; Vyasilova, Anastasia

    2015-04-01

    This study is based on the observations taken from the meteorological archives, satellite and historic visual observations of sea ice, global SST, data of water temperature in the upper layer on the section in the Barents Sea. For processing data was used factor analysis, calculation of correlation matrices with different delay between the Barents Sea and selected areas in North Atlantic. It is shown that the inflow of Atlantic water into the Barents Sea has a major influence on the climate of the region and its changes affect the variations of all climate characteristics. Decadal and interannual changes of air temperature in the Barents Sea are closely related (correlation over 0.8) with temperature of water, coming from the Norwegian Sea. The effect of these changes is seen in the air temperature in the Kara Sea. Atlantic water inflow especially impact on winter sea ice in the Barents Sea. The correlation between the average water temperature at section along the Kola meridian and sea ice extent in the Barents Sea in May reaches values of -0.86. To enhance the predictive capability established dependence, the study was extended to the area of the North Atlantic, where temperature anomalies are formed. In the North Atlantic from the equator to 80 ° N were identified 6 areas where the average annual SST anomalies are associated with SST anomalies and sea ice extent (SIE) in the Barents Sea. Detailed analysis with monthly SST from HadISST for 1951 - 2013 identified two areas with the greatest influence on the Barents Sea. One area is the northern region of the Gulf Stream and other is the equatorial region. The corresponding delays amounted to 26 months and 4-5 years. The relationship between changes AMO index, averaged over August-October, and SIE in the Barents Sea in January is evaluated. Correlation coefficient between them with 3 year delay is -0.54. Implemented study revealed the importance of teleconnection between SST anomalies in the North Atlantic and SST

  3. Two wind-driven modes of winter sea ice variability in the Barents Sea

    NASA Astrophysics Data System (ADS)

    Herbaut, Christophe; Houssais, Marie-Noëlle; Close, Sally; Blaizot, Anne-Cécile

    2015-12-01

    The interannual variability of the winter sea ice area in the Barents Sea is investigated using SMMR-SSM/I data and a coupled ocean-sea ice model over the period 1979-2012. Our analysis reveals that the sea ice area in the northern and eastern parts of the Barents Sea do not covary. This contrast in behavior allows us to associate two distinct modes of variability with these two regions, with the variability of the overall Barents Sea ice cover being predominantly captured by the northern mode. Both modes show a dominant, near in-phase response to the surface wind, both being associated with different spatial patterns. The northern mode emerges in response to northwesterly wind anomalies which favor the export of ice and surface polar water from the Arctic between Svalbard and Franz Josef Land. Atlantic Water temperature anomalies, formed concomitantly with northerly wind anomalies in the vicinity of the Barents Sea Opening, also influence the northern mode in the following winter. These temperature anomalies are linked to local convergence of the oceanic heat transport. The delayed influence of the ocean on the sea ice is found primarily in the northeastern Barents Sea and occurs through the re-emergence of the Atlantic water temperature anomalies at the surface in the following fall and winter. An ocean-to-atmosphere feedback initiated by October SST anomalies in the central Barents Sea is further identified. This feedback is hypothesized to enhance the sea ice response in the northern Barents Sea by promoting the formation of meridional wind anomalies. In contrast, the eastern mode of variability of the Barents Sea ice mainly responds to wind anomalies with a strong zonal component, and is less influenced by the Atlantic Water temperature variability than the northern mode. While our results clearly highlight a role of the ocean in the Barents Sea ice variability, this role appears to be more spatially restricted following the sudden northward retreat of the ice

  4. Human impact on dynamics of Barents and Kara Seas Coasts

    NASA Astrophysics Data System (ADS)

    Ogorodov, Stanislav

    2013-04-01

    The coasts of Barents and Kara Seas which are composed of unconsolidated deposits have poor erosion resistance qualities. In natural conditions such coasts may retreat with a rate of 1 to 2 m a year. Under the influence of human activities this rate can double and even triple. Over the last twenty years the human impact on the natural coastal geosystems has noticeably increased due to the latest oil and gas developments on the sea shelf and coasts of the Russian North. A range of facilities - oil custody terminals for drilling and production platforms, submerged pipelines, ports and other industrial features and residential infrastructure - are currently being operated in the coastal and shelf zones. In most of the cases no morphodynamic or lithodynamic features of the coastal zone had been taken into account during the construction or operation of these facilities. This results in a disturbance of the sediment transport in the coastal zone, which triggers active erosion of both the shore itself and the coastal slope beneath. The operated facilities themselves are then threatened as their destruction is possible and often no new facilities can be constructed in the disturbed area. The operating companies have to bear forced nonmanufacturing expenses to protect or move their facilities of oil and gas industry to new areas. We may cite here three instances for Barents and Kara Seas where human impact has already brought in negative effects. One of the examples is Varandey Coast of the Barents Sea. From 1979 to 2012 a deliberate destruction of the dune chain of the barrier beach by vehicle traffic and a removal of the beach material for construction needs led to a quick intensification of the coastal retreat here. And now, storm surges without hindrance penetrate inland for several kilometers. Let's move further east to the Kara Sea: on to Kharasavey Coast to the Yamal Peninsula. A large-scale extraction of sediments from the coastal slope has resulted in a depletion

  5. Deep suture zone in the North Barents Basin

    NASA Astrophysics Data System (ADS)

    Butsenko, Viktor; Kireev, Artem; Piskarev, Alexey; Savin, Vasily; Smirnov, Oleg

    2015-04-01

    Study of sedimentary basin evolution is a part of research for the forecast of oil and gas capacity of the North Barents shelf. Maps of potential fields anomalies are compiled on the basis of the latest geophysical databases, structural maps of the seismic horizons are analyzed, the location of sources of potential fields anomalies are calculated, 3D density and magnetic models of Earth's crust are constructed. Six seismic complexes are allocated in sedimentary cover structure: Devonian - Lower Carboniferous, Upper Carboniferous - Lower Permian, Mid Permian - Lower Triassic, Triassic - Lower Jurassic, Upper Jurassic - Lower Cretaceous, Lower Cretaceous - Quaternary. The research of lateral changes of allocated layers thickness gives an idea of sedimentation in the region on various time intervals. The structural and tectonic scheme of the region is made after analysis of new geologic-geophysical materials. Contact zones of heterogeneous blocks of the crystalline basement are marked, disjunctive dislocations in a sedimentary cover and the upper crust, and also zones of increase of sediments thickness in various seismic complexes are designated. The deep suture zone delimiting Mesozoic and Paleozoic sedimentary basins has the most important geological value among disjunctive zones of the region. This zone stretches along the Admiralty Arch in East part of the North Barents shelf and is marked by negative magnetic anomaly 30-50 km wide. In view of special tectonic value of the suture zone marked by this anomaly we have calculated the 3D magnetic crust model. The sedimentary layers of a model section is based on seismic data. As a result of modeling the studied anomaly of a magnetic field can be approximated by the block of basement rocks of the lowered magnetization (1.2 A/m). The surface of this block is located in a zone of anomaly at a depth of 12-14 km. The asymmetry of anomaly is accounted by an inclination to East of the borders of the block with low

  6. Basin evolution at the SW Barents Sea margin and its conjugate off NE Greenland

    NASA Astrophysics Data System (ADS)

    Faleide, Jan Inge; Wong, Po Wan; Helge Gabrielsen, Roy; Tsikalas, Filippos; Blaich, Olav A.; Planke, Sverre; Myklebust, Reidun

    2015-04-01

    The SW Barents Sea margin developed from a megashear zone which linked the Norwegian-Greenland Sea and the Artic Eurasia Basin during the initial Eocene opening. Within the dextral megashear system, a series of deep and narrow basins formed in the SW Barents Sea. These basins formed in response to multiple rift events and rapid differential subsidence. The distribution of salt structures both in the SW Barents Sea and on the conjugate NE Greenland margin reflects the Late Paleozoic basin configuration. Late Middle Jurassic to Early Cretaceous rifting affected all deep basins in the SW Barents Sea (e.g., Bjørnøya, Tromsø, Harstad and Sørvestsnaget basins) as on the mid-Norwegian margin and the conjugate NE Greenland margin. Following rifting, a wide region subsided and was covered by thick Cretaceous strata. Late Cretaceous-Paleocene rifting between Norway and Greenland was taken up within the megashear zone and pull-apart basins formed in the SW Barents Sea and in the Wandel Sea Basin in NE Greenland. Contraction/inversion formed structural highs separating distinct Late Cretaceous depocenters that continued to subside rapidly. The rifting culminated in crustal breakup and accretion of oceanic crust near the Paleocene-Eocene transition. NE Atlantic breakup was accompanied by large-scale igneous activity, which also affected parts of the SW Barents Sea margin. The sheared Senja FZ margin is segmented, each segment having different structural styles reflecting a complex interplay between the geometry of the sheared margin segments and the opening direction. A continental sliver was also cut off the SW Barents Sea margin, now forming the Greenland Ridge which is a protrusion of the NE Greenland margin. The continent-ocean transition is confined within a narrow zone, bounded by a characteristic marginal high along the Senja Fracture Zone. During Eocene, the Harstad and southern Sørvestsnaget basins developed as narrow, elongated, en echelon basins landward of the

  7. Link between anomalously cold winters in Russia and sea-ice decline in the Barents Sea

    NASA Astrophysics Data System (ADS)

    Semenov, V. A.

    2016-05-01

    There were several anomalously cold winter weather regimes in Russia in the early 21st century. These regimes were usually associated with a blocking anticyclone south of the Barents Sea. Numerical simulations with an atmospheric general circulation model (AGCM) using prescribed sea-ice concentration (SIC) data for different periods during the last 50 years showed that a rapid sea-ice area decline in the Barents Sea in the last decade could bring about the formation of such a blocking anticyclone and cooling over northern Eurasia. The SIC reduction in the former period, from the second half of the 1960s to the first half of the 1990s, results in a weaker response of opposite sign. This suggests a nonlinear atmospheric circulation response to the SIC reduction in the Barents Sea, which has been previously found in the idealized AGCM simulations. An impact of the Barents Sea SIC reduction on the North Atlantic Oscillation (NAO), in particular, on the formation of the anomalously low NAO index, is found. The results indicate an important role that the Barents Sea, a region with the largest variability of the ocean-atmosphere heat exchange in the Arctic in wintertime, plays in generating anomalous weather regimes in Russia.

  8. Observations of sea ice and icebergs in the western Barents Sea during the winter of 1987

    SciTech Connect

    Loeset, S.; Carstens, T.

    1995-12-31

    A multisensor ice data acquisition program for the western Barents Sea was carried out during three field campaigns in the mid winter and fall of 1987. The main purpose of the program was to obtain comprehensive information about the ice in the area at that time. The reasoning was that prior to any oil/gas exploration and production in the Barents Sea, the physical environment has to be quantitatively surveyed in order to ensure safe operations related to human safety, the regular operability and safety of the structure and protection of the environment. Prior to this field investigation program in 1987 data on sea ice and icebergs for engineering purposes for the western Barents Sea were meager. The present paper highlights some of the findings with emphasis on ice edge speeds, ice edge displacement and ice drift. For icebergs, the paper focuses on population, size distributions and geometric parameters.

  9. Polar low climatology over the Nordic and Barents seas based on satellite passive microwave data

    NASA Astrophysics Data System (ADS)

    Smirnova, Julia E.; Golubkin, Pavel A.; Bobylev, Leonid P.; Zabolotskikh, Elizaveta V.; Chapron, Bertrand

    2015-07-01

    A new climatology of polar lows over the Nordic and Barents seas for 14 seasons (1995/1996-2008/2009) is presented. For the first time in climatological studies of polar lows an approach based on satellite passive microwave data was adopted for polar low identification. A total of 637 polar lows were found in 14 extended winter seasons by combining total atmospheric water vapor content and sea surface wind speed fields retrieved from Special Sensor Microwave/Imager data. As derived, the polar low activity in the Norwegian and Barents Seas is found to be almost equal, and the main polar low genesis area is located northeastward of the North Cape. For the Barents Sea, a significant correlation is found between the number of polar lows and mean sea ice extent. Individual indicative polar low characteristics (i.e., diameter, lifetime, distance traveled, translation speed, and maximum wind speed) are also presented.

  10. Marine mammals' influence on ecosystem processes affecting fisheries in the Barents Sea is trivial.

    PubMed

    Corkeron, Peter J

    2009-04-23

    Some interpretations of ecosystem-based fishery management include culling marine mammals as an integral component. The current Norwegian policy on marine mammal management is one example. Scientific support for this policy includes the Scenario Barents Sea (SBS) models. These modelled interactions between cod, Gadus morhua, herring, Clupea harengus, capelin, Mallotus villosus and northern minke whales, Balaenoptera acutorostrata. Adding harp seals Phoca groenlandica into this top-down modelling approach resulted in unrealistic model outputs. Another set of models of the Barents Sea fish-fisheries system focused on interactions within and between the three fish populations, fisheries and climate. These model key processes of the system successfully. Continuing calls to support the SBS models despite their failure suggest a belief that marine mammal predation must be a problem for fisheries. The best available scientific evidence provides no justification for marine mammal culls as a primary component of an ecosystem-based approach to managing the fisheries of the Barents Sea. PMID:19126534

  11. Biomass of Scyphozoan Jellyfish, and Its Spatial Association with 0-Group Fish in the Barents Sea

    PubMed Central

    Eriksen, Elena; Prozorkevich, Dmitry; Trofimov, Aleksandr; Howell, Daniel

    2012-01-01

    An 0-group fish survey is conducted annually in the Barents Sea in order to estimate fish population abundance. Data on jellyfish by-catch have been recorded since 1980, although this dataset has never been analysed. In recent years, however, the ecological importance of jellyfish medusae has become widely recognized. In this paper the biomass of jellyfish (medusae) in 0–60 m depths is calculated for the period 1980–2010. During this period the climate changed from cold to warm, and changes in zooplankton and fish distribution and abundance were observed. This paper discusses the less well known ecosystem component; jellyfish medusae within the Phylum Cnidaria, and their spatial and temporal variation. The long term average was ca. 9×108 kg, with some years showing biomasses in excess of 5×109 kg. The biomasses were low during 1980s, increased during 1990s, and were highest in early 2000s with a subsequent decline. The bulk of the jellyfish were observed in the central parts of the Barents Sea, which is a core area for most 0-group fishes. Jellyfish were associated with haddock in the western area, with haddock and herring in the central and coastal area, and with capelin in the northern area of the Barents Sea. The jellyfish were present in the temperature interval 1°CBarents Sea jellyfish medusae; however their biomass has showed a recent moderate decline during years with record high temperatures in the Barents Sea. Jellyfish are undoubtedly an important component of the Barents Sea ecosystem, and the data presented here represent the best summary of jellyfish biomass and distribution yet published for the region. PMID:22457732

  12. An extended dynamical model of a geyser induced by inflow of gas (3) : effects of various friction loss in an underground watercourse

    NASA Astrophysics Data System (ADS)

    Kagami, H.

    2009-04-01

    We have proposed a mathematical model (a static model), a dynamical model and a modified dynamical model of a geyser induced by inflow of gas (a periodic bubbling spring) based on observation of Hirogawara Geyser (Yamagata, Japan)and model experiments of the geyser and have also proposed a combined model combining above 2 models. And numerical simulations of the modified dynamical model or the combined model reappear dynamics of spouting of geysers induced by inflow of gas and it becomes possible that parameters (volume of the underground space, depth of spouting hole and so on) under a geyser are estimated due to comparison between results of simulation and those of observation. Moreover we have verified above models through geological exploration, analysis of hot spring water and radioactive prospecting. Then we added evaporation effect of gas dissolved in hot spring water to the combined model. Then we expanded the combined model through adding effects of a complicated underground watercourse, that is, effects of watercourses' sudden expansion, sudden contraction, repeat of them and elbow shape to the combined model. As a result, though we could see change of spouting's amplitude, period and so on dependent on degrees of above effects, we could also see that these effects were much smaller than those of other parameters, that is, volume of the underground space, depth of spouting hole and so on. But in the case of such a long watercourse as a geyser's underground watercourse, an effect of friction loss between walls of the watercourse and hot spring water flowing along it is largest among the other effects concerning head loss. Therefore we have to consider above effect of friction loss when we discuss spouting dynamics of a geyser. In this study, we expand further above expanded model through adding effects of friction loss between walls of the watercourse and hot spring water during spouting to the combined model and estimate effects of it on spouting dynamics

  13. Impact of agricultural practices and river catchment characteristics on river and bathing water quality.

    PubMed

    Aitken, M N

    2003-01-01

    The objective was to investigate the potential risk of faecal indicator organism (FIO) bacteriological contamination of river catchments and coastal bathing waters from farm management practices and to develop practices to reduce the risk. A risk assessment on 117 farms was carried out in two river catchments in south-west Scotland. Manure storage facilities, farming practices, field conditions and catchment characteristics were assessed. River samples at 33 locations were regularly taken and analysed for FIOs. Available manure storage capacity and farm management practices are inadequate on a high proportion of farms and FIO contamination of watercourses was likely the result of effluent transported into watercourses due to non-collection or poor containment. In addition, surface run-off or leaching following land application of manure or intensive stocking in adverse conditions was a high risk on up to 50% of farms. The concentrations of FIOs in the streams of two sub-catchments with high livestock intensity was 4 to 8 times higher compared to the two sub-catchments which had a low livestock intensity. The majority of potential risks of agricultural pollution to watercourses may be eliminated through improved manure and dirty water management, forward planning of manure spreading activities and improved operational procedures. PMID:15137173

  14. Polychlorinated biphenyls in Barents and Greenland seas fish

    SciTech Connect

    Ali, I.B.; Joiris, C.R.; Holsbeek, J.L.

    1997-06-01

    PCBs are widespread, persistent organochlorines which have the potential for harmful biological effects. The number of possible congeners is 209, but few only are both prevalent and toxic. Commercially-produced PCBs (e.g. Aroclors) consist of mixtures containing between 50 and 90 congeners. According to the classification of PCBs based on potential toxicity, environmental prevalence and relative abundance in animal tissues, the number of environmentally threatening PCB congeners reduces to about 36, of which 25 account for 50 to 75% of the total PCBs in biological compartments. Their dispersion and accumulation through the ecosystem is reflected by their presence in air, snow, ice, fish, birds and mammals in the polar regions, in the surface and sub-surface water of oceans, in the atmosphere, and in a wide range of plankton, fish, and marine and terrestrial mammals including humans. It has been estimated that about 31% of the 1.2 million tons of PCBs that have been produced are still present in the environment. Seven major fish species collected in the Barents and Greenland seas have been studied in an attempt to answer the question raised by Ottar: {open_quotes}is the Arctic marine environment, as a result of its cold climate, a sink for semi-volatile organics, such as PCBs, PCDD/ PCDFs, organochlorine pesticides, polyaromatic hydrocarbons (PAHs) and metals, such as mercury, emitted in the mid-latitudes?{close_quotes}. This work is part of a broader ecotoxicological study on stable residues in European Arctic seas. 17 refs., 7 figs., 4 tabs.

  15. Does the invasive plant, Impatiens glandulifera promote soil erosion from riparian zones? An investigation on a small watercourse in northwest Switzerland

    NASA Astrophysics Data System (ADS)

    Greenwood, Philip; Kuhn, Nikolaus

    2013-04-01

    Impatiens glandulifera (common English name: Himalayan Balsam) was introduced into Europe in the mid-19th century, whereupon its invasive tendency has facilitated its expansion throughout many mainland European countries. Its rate of expansion can be attributed to certain lifecycle traits that allow it to become rapidly established and crowd-out many native floral species. Its preferred habitat includes damp, nutrient-rich soils that experience frequent natural disturbance, such as along riparian zones. Once present, nearby watercourses then inadvertently act as conduits that facilitate the movement of seeds downstream into un-colonised parts of a catchment. Once established, individual plants form discrete and often mono-cultural stands of dense vegetation that can typically range in area from a few m-2 to > 150 m-2. Impatiens glandulifera is cold-intolerant however, and in temperate countries rapidly dies when exposed to the first frosts of the season. Once die-back occurs, it is hypothesised that a reduction in the protection afforded to the underlying soil by the vegetation canopy will promote the mobilisation of material from areas contaminated with I. glandulifera at a greater rate that areas supporting indigeneous vgetation, due to their increased exposure to erosion processes. An investigation was conducted to test this hypothesis in a contaminated sub-catchment of the Birs River in northwest Switzerland. A measurement technique consisting of erosion pins, an erosion bridge and a digital caliper was employed to quantify changes in the soil profile, as this approach represented the least invasive way of repeatedly measuring through vegetation without undue disturbance. An initial soil surface profile was established at five contaminated sites in late summer 2012 before die-back occurred, as well as at five nearby reference sites where I. glandulifera was absent. All soil surface profiles were re-measured at ca. 25-day intervals and the average net change was

  16. Padus, Sandalus, Gens Fadiena. Underwater Surveys in Palaeo-Watercourses (ferrara District - Italy)

    NASA Astrophysics Data System (ADS)

    Bucci, G.

    2015-04-01

    In the ambit of our program of researches on ancient rivers in Ferrara hinterland (Italy), we have been joining a Scientific - Didactic Project between Soprintendenza per i Beni Archeologici dell'Emilia Romagna, Comune di Portomaggiore Assessorato alla Cultura, CMAS A.CDCI. - Confédération Mondiale des Activités Subaquatiques Federation ITA F07 - Associazione CMAS Diving Center Italia. The Project is focused on underwater archaeological surveys in ex quarry lakes, following the Rivers Padus and Sandalus between Voghiera, Gambulaga and Portomaggiore (Ferrara District). Here we are going to introduce our most recent results, after the last immersions and a 3D bathymetrical survey completed by echo-side scan sonar in Tramonto Lake at Gambulaga, explaining the connection with remote sensing investigations and direct surveys applied to underwater archaeology of the inland water. The main submerged structure individuated is a part of wooden dock on the left side of Padus, in front of the Necropolis of Fadieni (1st-3rd cent. A.D.). Thanks to the study of 183 finds coming from the lake, involving students and young collaborators of the Archaeological National Museum of Ferrara, we are reconstructing the ancient landscape between Proto-Imperial Age and Late Antique.

  17. Subglacial hydraulic conditions of the former Barents Sea Ice Sheet inferred from meltwater landforms

    NASA Astrophysics Data System (ADS)

    Shackleton, Calvin; Bjarnadóttir, Lilja; Winsborrow, Monica; Esteves, Mariana; Andreassen, Karin

    2016-04-01

    A large multibeam dataset acquired by the MAREANO programme covering over 24,000 km2 at 5 m horizontal resolution has uncovered abundant subglacial meltwater landforms in the central Barents Sea. These landforms provide unprecedented insights into the nature of hydrological systems operating at the bed of the former Barents Sea Ice Sheet, helping us to understand the subglacial environments of marine based ice sheets as a whole. Large sinuous features up to 3.5 km wide and over 40 km long, with depths up to 40 m are interpreted as braided tunnel valleys, which would have drained vast amounts of water at the base of the ice sheet. Dendritic channels are also common, up to 42 km long and 24 m deep, along with several anastomosing channels and numerous complex esker systems. These features document that a wide range of subglacial hydraulic conditions and a well-established meltwater system existed beneath the former Barents Sea Ice Sheet. In conjunction with mapping of glacial landforms, these meltwater features provide the basis for a reconstruction of the subglacial drainage systems in the central Barents Sea and their interaction with the dynamic activity of the overlying ice sheet.

  18. Norwegian petroleum resources with focus on challenges and opportunities in the Barents Sea

    SciTech Connect

    Aamodt, F.R.

    1995-12-31

    The Norwegian Continental Shelf can be subdivided into 3 different petroleum provinces: (1) the North Sea, (2) the Norwegian Sea including the Jan Mayen ridge, and (3) the Barents Sea including the islands of Svalbard. The majority of the fields and discoveries and most of the resources are located in the mature North Sea Basin. Significant resources are however also discovered in the Norwegian Sea and the Barents Sea. 39 fields are in production or decided to be developed while 3 fields are closed down. Approximately 70% of the discovered resources are located in these fields, of which some are gigantic in size (Statfjord, Ekofisk, Gullfaks, Oseberg, Troll and Snorre). Most of the remaining discoveries (134) are smaller in size and approximately 2/3 of the resources are gas. According to a recent study carried out by the Norwegian Petroleum Directorate the expected undiscovered Norwegian Petroleum Resources are assessed to be on the order of 3,5 billion Sm{sup 3} o.e. with a level of uncertainty ranging from 2 to 6 billion Sm{sup 3} o.e. 40% of the undiscovered petroleum resources are expected to be found as oil. These are the perspectives of the Norwegian Petroleum Resources. The resources of the Barents Sea is included in this perspective. The significance of the Barents Sea resources is not particularly important in the short-medium term perspective, but will be important in the longer perspective.

  19. On large outflows of Arctic sea ice into the Barents Sea

    NASA Technical Reports Server (NTRS)

    Kwok, Ron; Maslowski, Wieslaw; Laxon, Seymour W.

    2005-01-01

    Winter outflows of Arctic sea ice into the Barents Sea are estimated using a 10-year record of satellite ice motion and thickness. The mean winter volume export through the Svalbard/Franz Josef Land passage is 40 km3, and ranges from -280 km3 to 340 km3. A large outflow in 2003 is preconditioned by an unusually high concentration of thick perennial ice over the Nansen Basin at the end of the 2002 summer. With a deep atmospheric low situated over the eastern Barents Sea in winter, the result is an increased export of Arctic ice. The Oct-Mar ice area flux, at 110 x 10 to the third power km3, is not only unusual in magnitude but also remarkable in that >70% of the area is multiyear ice; the ice volume flux at340 km3 is almost one-fifth of the ice flux through the Fram Strait. Another large outflow of Arctic sea ice through this passage, comparable to that in 2003, is found in 1996. This southward flux of sea ice represents one of two major sources of freshwater in the Barents Sea; the other is the eastward flux of water via the Norwegian Coastal Current. The possible consequences of variable freshwater input on the Barents Sea hydrography and its impact on transformation of Atlantic Water en route to the Arctic Ocean are examined with a 25-year coupled ice-ocean model.

  20. An integrated approach to evaluate gas hydrate prospects in SW Barents Sea

    NASA Astrophysics Data System (ADS)

    Chand, Shyam; Knies, Jochen; Jensen, Henning; Baranwal, Soma; Klug, Martin

    2014-05-01

    The SW Barents Sea subsurface has undergone large changes in geomorphology due to the impact of glaciations on its surface and subsurface. Glacial erosion during Plio-Pleistocene removed large thickness of sediments from the seabed and opened up the faults causing basin wide spillage of hydrocarbon fluids. Pockmarks are widely distributed in the SW Barents Sea. Regional fault complexes such as the Ringvassøy Loppa Fault Complex are reported to be open pathways for fluids with the observation of large acoustic gas flares in the water column. We analysed selected gravity cores from Veslemøy high based on subsurface seismic amplitude anomalies and structural controls of fluid flow towards the seafloor. The subsurface fluid flow at Veslemøy high is observed to be controlled by the evolution history of the region. This includes 1) the morphology and orientation of regional faults, structural highs and basins, 2) the presence of lithological boundaries linked to the palaeo morphology of the region, 3) glacial and post glacial sediment thickness. Estimates of extractable organic matter and foraminifera influenced by microseeps at different levels of the post glacial sediments are related to fluid flow governed by the subsurface architecture of the sedimentary units. The fluid flow model is compared to other provinces of Barents Sea to evaluate the gas hydrate prospects of SW Barents Sea.

  1. New approach to oil and gas potential of Barents Sea and Timan-Pechora basin

    SciTech Connect

    Nevskaya, N.M.

    1995-12-01

    High temperatures at large depths of Barents shelf and Timan-Pechora basin cause the formation of homogeneous steam-liquid mixtures consisting of supercritical water and dissolved hydrocarbons. The analysis of thermobaric conditions allowed to distinguish the zones of possible hydrocarbon accumulation. The conclusions allow to make more precise future exploration.

  2. The Barents and Chukchi Seas: Comparison of two Arctic shelf ecosystems

    NASA Astrophysics Data System (ADS)

    Hunt, George L.; Blanchard, Arny L.; Boveng, Peter; Dalpadado, Padmini; Drinkwater, Kenneth F.; Eisner, Lisa; Hopcroft, Russ R.; Kovacs, Kit M.; Norcross, Brenda L.; Renaud, Paul; Reigstad, Marit; Renner, Martin; Skjoldal, Hein Rune; Whitehouse, Andy; Woodgate, Rebecca A.

    2013-01-01

    This paper compares and contrasts the ecosystems of the Barents and Chukchi Seas. Despite their similarity in a number of features, the Barents Sea supports a vast biomass of commercially important fish, but the Chukchi does not. Here we examine a number of aspects of these two seas to ascertain how they are similar and how they differ. We then indentify processes and mechanisms that may be responsible for their similarities and differences. Both the Barents and Chukchi Seas are high latitude, seasonally ice covered, Arctic shelf-seas. Both have strongly advective regimes, and receive water from the south. Water entering the Barents comes from the deep, ice-free and "warm" Norwegian Sea, and contains not only heat, but also a rich supply of zooplankton that supports larval fish in spring. In contrast, Bering Sea water entering the Chukchi in spring and early summer is cold. In spring, this Bering Sea water is depleted of large, lipid-rich zooplankton, thus likely resulting in a relatively low availability of zooplankton for fish. Although primary production on average is similar in the two seas, fish biomass density is an order of magnitude greater in the Barents than in the Chukchi Sea. The Barents Sea supports immense fisheries, whereas the Chukchi Sea does not. The density of cetaceans in the Barents Sea is about double that in the Chukchi Sea, as is the density of nesting seabirds, whereas, the density of pinnipeds in the Chukchi is about double that in the Barents Sea. In the Chukchi Sea, export of carbon to the benthos and benthic biomass may be greater. We hypothesize that the difference in fish abundance in the two seas is driven by differences in the heat and plankton advected into them, and the amount of primary production consumed in the upper water column. However, we suggest that the critical difference between the Chukchi and Barents Seas is the pre-cooled water entering the Chukchi Sea from the south. This cold water, and the winter mixing of the

  3. Investigating Streams and Rivers. An Interdisciplinary Curriculum Guide for Use with Mitchell and Stapp's "Field Manual for Water Quality Monitoring."

    ERIC Educational Resources Information Center

    Cromwell, Mare; And Others

    This guide contains 12 activities designed to encourage secondary school student inquiry, investigation, and action regarding local streams and rivers. The activities are sequential and organized into three topic areas. The first section consists of three activities that help orient students to their local watercourse. Students map a local…

  4. The Barents Sea polar front and water masses variability (1980-2011)

    NASA Astrophysics Data System (ADS)

    Oziel, L.; Sirven, J.; Gascard, J.-C.

    2015-03-01

    The polar front separates the warm and saline Atlantic Waters encountered in the western part of the Barents Sea from the cold and fresh Arctic Waters situated in the northern part. These water masses can mix together, mainly in the eastern part of the Barents Sea, generating dense waters in winter which can cascade into the Arctic Ocean to form the Artic Intermediate Waters. To study the interannual variability and evolution of these water masses and the fronts, we have merged data from the International Council for the Exploration of the Sea and the Arctic and Antarctic Research Institute and have built a new database which covers the period 1980-2011. The summer data is interpolated on a regular grid and a "Probability Density Function" method is used to show that the polar front splits into two branches east of 32° E where the topographic constraint weakens. Two fronts can then be defined: the "Northern Polar Front" is associated with strong salinity gradients and the "Southern Polar Front" with temperature gradients. They enclose the dense Barents Sea Water. The interannual variability of the water masses is apparent in the observed data and is linked to that of the ice cover. In contrast, the link with the Arctic Oscillation is not clear. However, results from a general circulation model suggest that such a link could be found if winter data were taken into account. A strong trend, which amplifies during the last decade, is also found: the Atlantic Water occupies a larger volume of the Barents Sea. This "Atlantification" could be accompanied by a northwards displacement of the southern polar front in the eastern part of the Barents Sea (which is suggested by a model based study) and a decrease of the volume occupied by the Arctic Waters.

  5. The Svalbard-Barents Sea ice-sheet - Historical, current and future perspectives

    NASA Astrophysics Data System (ADS)

    Ingólfsson, Ólafur; Landvik, Jon Y.

    2013-03-01

    The history of research on the Late Quaternary Svalbard-Barents Sea ice sheet mirrors the developments of ideas and the shifts of paradigms in glacial theory over the past 150 years. Since the onset of scientific research there in the early 19th Century, Svalbard has been a natural laboratory where ideas and concepts have been tested, and played an important (but rarely acknowledged) role in the break-through of the Ice Age theory in the 1870's. The history of how the scientific perception of the Svalbard-Barents sea ice sheet developed in the mid-20th Century also tells a story of how a combination of fairly scattered and often contradictory observational data, and through both deductive and inductive reasoning, could outline a major ice sheet that had left but few tangible fingerprints. Since the 1980's, with increased terrestrial stratigraphical data, ever more marine geological evidence and better chronological control of glacial events, our perception of the Svalbard-Barents Sea ice sheet has changed. The first reconstructions depicted it as a static, concentric, single-domed ice sheet, with ice flowing from an ice divide over the central northern Barents Sea that expanded and declined in response to large-scale, Late Quaternary climate fluctuations, and which was more or less in tune with other major Northern Hemisphere ice sheets. We now increasingly perceive it as a very dynamic, multidomed ice sheet, controlled by climate fluctuations, relative sea-level change, as well as subglacial topography, substrate properties and basal temperature. In this respect, the Svalbard-Barents Sea ice sheet will increasingly hold the key for understanding the dynamics and processes of how marine-based ice sheets build-up and decay.

  6. Deep seismic soundings on the 1-AP profile in the Barents Sea: Methods and results

    NASA Astrophysics Data System (ADS)

    Sakoulina, T. S.; Kashubin, S. N.; Pavlenkova, G. A.

    2016-07-01

    Profile 1-AP with a length of 1300 km intersects the Barents Sea from The Kola Peninsula to Franz Josef Land. The combined Common Depth Point (CDP) and Deep Seismic Sounding (DSS) seismic studies were carried out on this profile. The DSS measurements were conducted with the standalone bottom seismic stations with an interval of 5-20 km between them. The stations recorded the signals generated by the large air guns with a step of 250 m. Based on these data, the detailed P-velocity section of the Earth's crust and uppermost mantle have been constructed for the entire profile and the S-velocity section for its southern part. The use of a variety of methods for constructing the velocity sections enabled us to assess the capabilities of each method from the standpoint of the highest reliability and informativity of the models. The ray tracing method yielded the best results. The 1-PR profile crosses two large basins—the South Barents and North Barents ones, with the thickness of the sediments increasing from 8 to 10 km in the south to 12-15 km in the north. The Earth's crust pertains to the continental type along the entire profile. Its thickness averages 32 to 36 km and only increases to 43 km at the boundary between the two basins. The distinct change in the wave field at this boundary suggests the presence of a large deep fault in this zone. The high-velocity blocks are revealed in the crust of the South Barents basin, whereas the North Barents crust is characterized by relatively low velocities.

  7. Ecosystem structure and resilience—A comparison between the Norwegian and the Barents Sea

    NASA Astrophysics Data System (ADS)

    Yaragina, Natalia A.; Dolgov, Andrey V.

    2009-10-01

    Abundance and biomass of the most important fish species inhabited the Barents and Norwegian Sea ecosystems have shown considerable fluctuations over the last decades. These fluctuations connected with fishing pressure resulted in the trophic structure alterations of the ecosystems. Resilience and other theoretical concepts (top-down, wasp-waste and bottom-up control, trophic cascades) were viewed to examine different response of the Norwegian and Barents Sea ecosystems on disturbing forces. Differences in the trophic structure and functioning of Barents and Norwegian Sea ecosystems as well as factors that might influence the resilience of the marine ecosystems, including climatic fluctuation, variations in prey and predator species abundance, alterations in their regular migrations, and fishing exploitation were also considered. The trophic chain lengths in the deep Norwegian Sea are shorter, and energy transfer occurs mainly through the pelagic fish/invertebrates communities. The shallow Barents Sea is characterized by longer trophic chains, providing more energy flow into their benthic assemblages. The trophic mechanisms observed in the Norwegian Sea food webs dominated by the top-down control, i.e. the past removal of Norwegian Spring spawning followed by zooplankton development and intrusion of blue whiting and mackerel into the area. The wasp-waist response is shown to be the most pronounced effect in the Barents Sea, related to the position of capelin in the ecosystem; large fluctuations in the capelin abundance have been strengthened by intensive fishery. Closer links between ecological and fisheries sciences are needed to elaborate and test various food webs and multispecies models available.

  8. Satellite observations of seasonal and regional variability of particulate organic carbon concentration in the Barents Sea

    NASA Astrophysics Data System (ADS)

    Stramska, Malgorzata; Białogrodzka, Jagoda

    2016-04-01

    The Nordic and Barents Seas are of special interest for research on climate change, since they are located on the main pathway of the heat transported from low to high latitudes. Barents Sea is known to be an important area for formation of deep water and significant uptake from the atmosphere and sequestration of carbon dioxide (CO2). This region is characterized by supreme phytoplankton blooms and large amount of carbon is sequestered here due to biological processes. It is important to monitor the biological variability in this region in order to derive in depth understanding whether the size of carbon reservoirs and fluxes may vary as a result of climate change. In this presentation we analyze the 17 years (1998-2014) of particulate organic carbon (POC) concentration derived from remotely sensed ocean color. POC concentrations in the Barents Sea are among the highest observed in the global ocean with monthly mean concentrations in May exceeding 300 mg m‑3. The seasonal amplitude of POC concentration in this region is larger when compared to other regions in the global ocean. Our results indicate that the seasonal increase in POC concentration is observed earlier in the year and higher concentrations are reached in the southeastern part of the Barents Sea in comparison to the southwestern part. Satellite data indicate that POC concentrations in the southern part of the Barents Sea tend to decrease in recent years, but longer time series of data are needed to confirm this observation. This work was funded by the Norway Grants (NCBR contract No. 201985, project NORDFLUX). Partial support for MS comes from the Institute of Oceanology (IO PAN).

  9. Ice loading model for Glacial Isostatic Adjustment in the Barents Sea constrained by GRACE gravity observations

    NASA Astrophysics Data System (ADS)

    Root, Bart; Tarasov, Lev; van der Wal, Wouter

    2014-05-01

    The global ice budget is still under discussion because the observed 120-130 m eustatic sea level equivalent since the Last Glacial Maximum (LGM) can not be explained by the current knowledge of land-ice melt after the LGM. One possible location for the missing ice is the Barents Sea Region, which was completely covered with ice during the LGM. This is deduced from relative sea level observations on Svalbard, Novaya Zemlya and the North coast of Scandinavia. However, there are no observations in the middle of the Barents Sea that capture the post-glacial uplift. With increased precision and longer time series of monthly gravity observations of the GRACE satellite mission it is possible to constrain Glacial Isostatic Adjustment in the center of the Barents Sea. This study investigates the extra constraint provided by GRACE data for modeling the past ice geometry in the Barents Sea. We use CSR release 5 data from February 2003 to July 2013. The GRACE data is corrected for the past 10 years of secular decline of glacier ice on Svalbard, Novaya Zemlya and Frans Joseph Land. With numerical GIA models for a radially symmetric Earth, we model the expected gravity changes and compare these with the GRACE observations after smoothing with a 250 km Gaussian filter. The comparisons show that for the viscosity profile VM5a, ICE-5G has too strong a gravity signal compared to GRACE. The regional calibrated ice sheet model (GLAC) of Tarasov appears to fit the amplitude of the GRACE signal. However, the GRACE data are very sensitive to the ice-melt correction, especially for Novaya Zemlya. Furthermore, the ice mass should be more concentrated to the middle of the Barents Sea. Alternative viscosity models confirm these conclusions.

  10. Modern processes controlling the sea bed sediment formation in Barents Sea

    NASA Astrophysics Data System (ADS)

    Balanyuk, I.; Dmitrievsky, A.; Shapovalov, S.; Chaikina, O.; Akivis, T.

    2009-04-01

    The Barents Sea is one of the key regions for understanding of the postglacial history of the climate and circulation of the World Ocean. There are the limits of warm North Atlantic waters penetration to the Arctic and a zone of interaction between Atlantic and Arctic waters. The Barents Se's limits are the deep Norwegian Sea in the West, the Spitsbergen Island and the Franz Josef Land and the deep Nansen trough in the North, the Novaya Zemlya archipelago in the East and the North shore of Europe in the South. An analysis of Eurasian-Arctic continental margin shows correspondence between the rift systems of the shelf with those of the ocean. This relation can be observed in the central Arctic region. All the rift systems underlying the sediment basin are expressed in the sea bed relief as spacious and extensive graben valleys burnished by lobes. Two transverse trenches cross both shelf and continental slope, namely the Medvezhinsky trench between Norway and Spitsbergen in the West and the Franz Victoria trench between Spitsbergen and the Franz Josef Land in the North. The Barents and the Kara Seas are connected by the Kara Gate Strait and wide transverse trough of Saint Anna in the North-West. The recent assessment of the eolian solid sediment supply to the Barents Sea is about 0.904 tons. The Barents Sea as a whole should be considered as "starving" in terms of its feeding with solid sediment matter. Observations show the considerable part of the sea bottom to be free of Holocene sediment cover. The more ancient Quaternary units or bedrock can be seen at the bottom surface. This phenomenon is the most typical for arches of relatively shallow elevations. Thick accumulations of new sediments are connected with fjords. The amount of sea ice delivered from the Barents Sea to the Arctic Ocean is 35 km3 a year. This value should be added by iceberg delivery from the North island of Novaya Zemlya, the Franz Josef Land, the Spitsbergen Island and North Norway but most of

  11. Invasion genetics of vendace (Coregonus albula (L.)) in the Inari-Pasvik watercourse: revealing the origin and expansion pattern of a rapid colonization event

    PubMed Central

    Præbel, Kim; Gjelland, Karl Øystein; Salonen, Erno; Amundsen, Per-Arne

    2013-01-01

    Species invasions can have wide-ranging biological and socio-economic effects and are generally unwanted by legislation. Identification of the source population as well as the ecology and genetics of both the invader population and the receiving community is of crucial importance. The rapid invasion of a small coregonid fish vendace (Coregonus albula) in a major northern European subarctic watercourse has resulted in a labile ecological situation in the receiving community. The ecological impact of the invasion has been thoroughly documented, but the genetics of the invasion remains to be explored. We analyzed the genetic diversity and divergence patterns among the two possible source populations from southern Finnish Lapland and three colonists populations within the Inari-Pasvik watercourse using ten microsatellite loci in order to (i) identify the most likely source of the invasion, (ii) reveal the dispersal pattern and genetic structure of the secondary expansion, and (iii) to investigate whether the initial introduction and the secondary expansion were associated with founder effects. We revealed that repeated translocation of vendace from Lake Sinettäjärvi into a tributary lake of L. Inari in 1964–1966 is the most plausible source for the invasion. Both the initial introduction and the secondary expansion were found not to be associated with significant founder effects. The secondary expansion followed a stepping stone pattern and the source and colonist populations of this expansion have undergone rapid genetic divergence within a period of 15–35 years (ca. 8–17 generations). The rapid divergence may be contributed to lack of gene flow among the source and colonist populations due to the extensive hydroelectric damming in the watercourse. Multiple introductions and substantial genetic variation in combination with the boom-and-bust population development of the species thus likely counteracted the founder effects as well as fueled the rapid

  12. Ancient watercourses and biogeography of the Sahara explain the peopling of the desert

    PubMed Central

    Drake, Nick A.; Blench, Roger M.; Armitage, Simon J.; Bristow, Charlie S.; White, Kevin H.

    2011-01-01

    Evidence increasingly suggests that sub-Saharan Africa is at the center of human evolution and understanding routes of dispersal “out of Africa” is thus becoming increasingly important. The Sahara Desert is considered by many to be an obstacle to these dispersals and a Nile corridor route has been proposed to cross it. Here we provide evidence that the Sahara was not an effective barrier and indicate how both animals and humans populated it during past humid phases. Analysis of the zoogeography of the Sahara shows that more animals crossed via this route than used the Nile corridor. Furthermore, many of these species are aquatic. This dispersal was possible because during the Holocene humid period the region contained a series of linked lakes, rivers, and inland deltas comprising a large interlinked waterway, channeling water and animals into and across the Sahara, thus facilitating these dispersals. This system was last active in the early Holocene when many species appear to have occupied the entire Sahara. However, species that require deep water did not reach northern regions because of weak hydrological connections. Human dispersals were influenced by this distribution; Nilo-Saharan speakers hunting aquatic fauna with barbed bone points occupied the southern Sahara, while people hunting Savannah fauna with the bow and arrow spread southward. The dating of lacustrine sediments show that the “green Sahara” also existed during the last interglacial (∼125 ka) and provided green corridors that could have formed dispersal routes at a likely time for the migration of modern humans out of Africa. PMID:21187416

  13. An overview of the ecosystems of the Barents and Norwegian Seas and their response to climate variability

    NASA Astrophysics Data System (ADS)

    Loeng, Harald; Drinkwater, Ken

    2007-11-01

    The principal features of the marine ecosystems in the Barents and Norwegian Seas and some of their responses to climate variations are described. The physical oceanography is dominated by the influx of warm, high-salinity Atlantic Waters from the south and cold, low-salinity waters from the Arctic. Seasonal ice forms in the Barents Sea with maximum coverage typically in March-April. The total mean annual primary production rates are similar in the Barents and Norwegian Seas (80-90 g C m -2), although in the Barents, the production is higher in the Atlantic than in the ice covered Arctic Waters. The zooplankton is dominated by Calanus species, C. finmarchicus in the Atlantic Waters of the Norwegian and Barents Seas, and C. glacialis in the Arctic Waters of the Barents Sea. The fish species in the Norwegian Sea are mostly pelagics such as herring ( Clupea harengus) and blue whiting ( Micromesistius poutassou), while in the Barents Sea there are both pelagics (capelin ( Mallotus villosus Mülle r), herring, and polar cod ( Boreogadus saida Lepechin)) and demersals (cod ( Gadus morhua L.) and haddock ( Melanogrammus aeglefinus)). The latter two species spawn in the Norwegian Sea along the slope edge (haddock) or along the coast (cod) and drift into the Barents Sea. Marine mammals and seabirds, although comprising only a relatively small percentage of the biomass and production in the region, play an important role as consumers of zooplankton and small fish. While top-down control by predators certainly is significant within the two regions, there is also ample evidence of bottom-up control. Climate variability influences the distribution of several fish species, such as cod, herring and blue whiting, with northward shifts during extended warm periods and southward movements during cool periods. Climate-driven increases in primary and secondary production also lead to increased fish production through higher abundance and improved growth rates.

  14. Demersal fish assemblages and spatial diversity patterns in the Arctic-Atlantic transition zone in the Barents Sea.

    PubMed

    Johannesen, Edda; Høines, Åge S; Dolgov, Andrey V; Fossheim, Maria

    2012-01-01

    Direct and indirect effects of global warming are expected to be pronounced and fast in the Arctic, impacting terrestrial, freshwater and marine ecosystems. The Barents Sea is a high latitude shelf Sea and a boundary area between arctic and boreal faunas. These faunas are likely to respond differently to changes in climate. In addition, the Barents Sea is highly impacted by fisheries and other human activities. This strong human presence places great demands on scientific investigation and advisory capacity. In order to identify basic community structures against which future climate related or other human induced changes could be evaluated, we analyzed species composition and diversity of demersal fish in the Barents Sea. We found six main assemblages that were separated along depth and temperature gradients. There are indications that climate driven changes have already taken place, since boreal species were found in large parts of the Barents Sea shelf, including also the northern Arctic area. When modelling diversity as a function of depth and temperature, we found that two of the assemblages in the eastern Barents Sea showed lower diversity than expected from their depth and temperature. This is probably caused by low habitat complexity and the distance to the pool of boreal species in the western Barents Sea. In contrast coastal assemblages in south western Barents Sea and along Novaya Zemlya archipelago in the Eastern Barents Sea can be described as diversity "hotspots"; the South-western area had high density of species, abundance and biomass, and here some species have their northern distribution limit, whereas the Novaya Zemlya area has unique fauna of Arctic, coastal demersal fish. (see Information S1 for abstract in Russian). PMID:22545093

  15. Demersal Fish Assemblages and Spatial Diversity Patterns in the Arctic-Atlantic Transition Zone in the Barents Sea

    PubMed Central

    Johannesen, Edda; Høines, Åge S.; Dolgov, Andrey V.; Fossheim, Maria

    2012-01-01

    Direct and indirect effects of global warming are expected to be pronounced and fast in the Arctic, impacting terrestrial, freshwater and marine ecosystems. The Barents Sea is a high latitude shelf Sea and a boundary area between arctic and boreal faunas. These faunas are likely to respond differently to changes in climate. In addition, the Barents Sea is highly impacted by fisheries and other human activities. This strong human presence places great demands on scientific investigation and advisory capacity. In order to identify basic community structures against which future climate related or other human induced changes could be evaluated, we analyzed species composition and diversity of demersal fish in the Barents Sea. We found six main assemblages that were separated along depth and temperature gradients. There are indications that climate driven changes have already taken place, since boreal species were found in large parts of the Barents Sea shelf, including also the northern Arctic area. When modelling diversity as a function of depth and temperature, we found that two of the assemblages in the eastern Barents Sea showed lower diversity than expected from their depth and temperature. This is probably caused by low habitat complexity and the distance to the pool of boreal species in the western Barents Sea. In contrast coastal assemblages in south western Barents Sea and along Novaya Zemlya archipelago in the Eastern Barents Sea can be described as diversity “hotspots”; the South-western area had high density of species, abundance and biomass, and here some species have their northern distribution limit, whereas the Novaya Zemlya area has unique fauna of Arctic, coastal demersal fish. (see Information S1 for abstract in Russian). PMID:22545093

  16. Application of ground penetrating radar (GPR) to delineate clay layers in wetlands. A case study in the Soto Grande and Soto Chico watercourses, Doñana (SW Spain)

    NASA Astrophysics Data System (ADS)

    Gómez-Ortiz, D.; Martín-Crespo, T.; Martín-Velázquez, S.; Martínez-Pagán, P.; Higueras, H.; Manzano, M.

    2010-10-01

    The potential utility of ground penetrating radar (GPR) in delineating the geometry of clay layers under two watercourses of the Doñana National Park (SW Spain) has been checked. The interpretation of the GPR profiles, calibrated with piezometers, shows the presence of two clay layer roughly continuous along some 2 km. The work allowed to gain insight about the watercourses relationship with groundwater. Up to now, watercourses in the area have been associated as a matter of fact to the intersection of the water table with the topography. But this work shows the existence of shallow, roughly continuous clay layers under the watercourses that may generate perched phreatic levels even if the regional water table is too deep to crop out. Thus, the GPR proved to be very helpful and suitable in supporting hydrogeological studies in wetlands.

  17. Barents Sea Paleozoic basement and basin configurations: Crustal structure from deep seismic and potential field data

    NASA Astrophysics Data System (ADS)

    Aarseth, Iselin; Mjelde, Rolf; Breivik, Asbjørn Johan; Huismans, Ritske; Faleide, Jan Inge

    2016-04-01

    The Barents Sea is underlain by at least two different basement domains; the Caledonian in the west and the Timanian in the east. The transition between these two domains is not well constrained and contrasting interpretations have been published recently. Interpretations of new high-quality magnetic data covering most of the SW Barents Sea has challenged the Late Paleozoic basin configurations in the western and central Barents Sea as outlined in previous studies. Two regional ocean bottom seismic (OBS) profiles were acquired in 2014. This new dataset crosses the two major directions of Caledonian deformation proposed by different authors: N-S direction and SW-NE direction. Of particular importance are the high velocity anomalies related to Caledonian eclogites, revealing the location of Caledonian suture zones in the northern Barents Sea. One of the main objectives with this project is to locate the main Caledonian suture in the western Barents Sea, as well as the possible Barentsia-Baltica suture postulated further eastwards. The collapse of the Caledonian mountain range predominantly along these suture zones is expected to be tightly linked to the deposition of large thicknesses of Devonian erosional products, and later rifting is expected to be influenced by inheritance of Caledonian trends. The P-wave travel-time modelling is done by use of a combined ray-tracing and inversion scheme, and gravity- and magnetic modelling will be used to augment the seismic model. The preliminary results indicate high P-wave velocities (mostly over 4 km/s) close to the seafloor as well as high velocity (around 6 km/s) zones at shallow depths which are interpreted as volcanic sills. The crustal transects reveal areas of complex geology and velocity inversions. A low seismic impedance contrast between the sedimentary section and top crystalline basement makes identification of this interface uncertain. Depth to Moho mostly lies around 30 km, except in an area of rapid change in

  18. The Barents Sea frontal zones and water masses variability (1980-2011)

    NASA Astrophysics Data System (ADS)

    Oziel, L.; Sirven, J.; Gascard, J.-C.

    2016-01-01

    The polar front separates the warm and saline Atlantic Water entering the southern Barents Sea from the cold and fresh Arctic Water located in the north. These water masses can mix together (mainly in the center of the Barents Sea), be cooled by the atmosphere and receive salt because of brine release; these processes generate dense water in winter, which then cascades into the Arctic Ocean to form the Arctic Intermediate Water. To study the interannual variability and evolution of the frontal zones and the corresponding variations of the water masses, we have merged data from the International Council for the Exploration of the Sea and the Arctic and Antarctic Research Institute and have built a new database, which covers the 1980-2011 period. The summer data were interpolated on a regular grid. A probability density function is used to show that the polar front splits into two branches east of 32° E where the topographic constraint weakens. Two fronts can then be identified: the Northern Front is associated with strong salinity gradients and the Southern Front with temperature gradients. Both fronts enclose the denser Barents Sea Water. The interannual variability of the water masses is apparent in the observed data and is linked to that of the ice cover. The frontal zones variability is found by using data from a general circulation model. The link with the atmospheric variability, represented here by the Arctic Oscillation, is not clear. However, model results suggest that such a link could be validated if winter data were taken into account. A strong trend appears: the Atlantic Water (Arctic Water) occupies a larger (smaller) volume of the Barents Sea. This trend amplifies during the last decade and the model study suggests that this could be accompanied by a northwards displacement of the Southern Front in the eastern part of the Barents Sea. The results are less clear for the Northern Front. The observations show that the volume of the Barents Sea Water

  19. Seasonal variation of pharmaceutical concentrations in a river/lake system in Eastern Finland.

    PubMed

    Meierjohann, Axel; Brozinski, Jenny-Maria; Kronberg, Leif

    2016-03-01

    In this study, the concentrations of 15 pharmaceuticals were monitored during four seasons (February, May, July, and November 2010) along a 32 km stretch of a highly wastewater polluted watercourse (River Rakkolanjoki, Lake Haapajärvi) in Eastern Finland. The aim was to study the seasonal variation in the elimination of the pharmaceuticals and the stability of the compounds along the watercourse. The analysis was carried out using a liquid chromatography tandem mass spectrometry (LC-MS/MS) method combined with extraction and preconcentration on HLB solid phase extraction (SPE) cartridges. Pharmaceutical concentrations were determined at 9 points along the watercourse, and loads and removal of parent compounds were calculated using flow data from the discharge point and the last sampling point. The pharmaceuticals were found in concentrations ranging from low ng l(-1) to low μg l(-1) values at the discharge point and at concentrations of 0-556 ng l(-1) at the last sampling point. The rate of elimination of the pharmaceutical load was significantly higher in May and July than in February and November. There were clear differences in the stability of the individual compounds along the watercourse. Carbamazepine was not eliminated during any season, while ibuprofen, ketoprofen and sertraline were fully eliminated over the studied stretch of river during the summer months. Other compounds showed continuous elimination independent of the season, indicating different elimination paths, such as sorption, biodegradation and phototransformation, for the studied compounds. PMID:26822330

  20. Marine sedimentary record of Meltwater Pulse 1a along the NW Barents Sea continental margin

    NASA Astrophysics Data System (ADS)

    Giulia Lucchi, Renata; Sagnotti, Leonardo; Camerlenghi, Angelo; Macrì, Patrizia; Rebesco, Michele; Pedrosa, Maria Teresa; Giorgetti, Giovanna

    2016-04-01

    The upper continental slope of the Storfjorden-Kveithola Trough Mouth Fans (NW Barents Sea) contains a several m-thick late Pleistocene sequence of plumites composed of laminated mud interbedded with sand/silt layers. Radiocarbon ages revealed that deposition occurred during about 130 years at a very high sedimentation rate of 3.4 cm a-1, at about 7 km from the present shelf break. Palaeomagnetic and rock magnetic analyses confirm the existence of a prominent, short-living sedimentary event. The plumites appear laterally continuous and were correlated with the sedimentary sequences described west of Svalbard and neighbouring glacial depositional systems representing a major event at regional scale appointed to correspond to the deep-sea sedimentary record of Meltwater Pulse-1a. We also present new sedimentological and geochemical insights, and multi-beam data adding information on the palaeoenvironmental characteristics during MWP-1a and ice sheet decay in the NW Barents Sea.

  1. Paleotemperature regime studies of the Barents Sea sediments through spontaneous fission-track analysis

    SciTech Connect

    Il`chenko, V.L.

    1995-09-01

    The results obtained are compared to earlier data on vitrinite reflectance and the catagenetic alteration grade of disseminated organic matter studied in samples from the same boreholes and stratigraphic intervals. Accessory apatite from terricrenous sediments is usable as a geothermometer of higher sensitivity than that based on epigenetic alterations of organic matter. The fission-track analysis data on the paleothermal history of terrigenous sediments from the South Barents Depression are presented. Apatite from six offshore boreholes in the South Barents shelf (Severo-Guliaev, Kurentsov, Murman, Severo-Kil`din, Shtokman, and Ludlov fields) is studied. Paleotemperature values lying within or beyond the upper limit of the oil-productive thermal interval are considered important factors stimulating the generation of hydrocarbons.

  2. A study of oceanic surface heat fluxes in the Greenland, Norwegian, and Barents Seas

    NASA Technical Reports Server (NTRS)

    Hakkinen, Sirpa; Cavalieri, Donald J.

    1989-01-01

    This study examines oceanic surface heat fluxes in the Norwegian, Greenland, and Barents seas using the gridded Navy Fleet Numerical Oceanography Central surface analysis and the First GARP Global Experiment (FGGE) IIc cloudiness data bases. Monthly and annual means of net and turbulent heat fluxes are computed for the FGGE year 1979. The FGGE IIb data base consisting of individual observations provides particularly good data coverage in this region for a comparison with the gridded Navy winds and air temperatures. The standard errors of estimate between the Navy and FGGE IIb winds and air temperatures are 3.6 m/s and 2.5 C, respectively. The computations for the latent and sensible heat fluxes are based on bulk formulas with the same constant heat exchange coefficient of 0.0015. The results show extremely strong wintertime heat fluxes in the northern Greenland Sea and especially in the Barents Sea in contrast to previous studies.

  3. South and North Barents Triassic-Jurassic total petroleum system of the Russian offshore Arctic

    USGS Publications Warehouse

    Lindquist, Sandra J.

    1999-01-01

    One major gas-prone petroleum system characterizes the sparsely explored South and North Barents Basin Provinces of the Russian Arctic in the eastern Barents Sea. More than 13 billion barrels of oil equivalent (79 trillion cubic feet of gas) known ultimately recoverable gas reserves in seven fields were sourced from Triassic marine and continental shales and stored in Jurassic (97%) and Triassic (3%) marine and continental sandstone reservoir rocks. The basins contain 18-20 kilometers of pre-Upper Permian carbonate and post-Upper Permian siliciclastic sedimentary fill. Late Permian-Triassic(?) rifting and subsidence resulted in the deposition of as much as 9 kilometers of Triassic strata, locally injected with sills. Rapidly buried Lower Triassic source rocks generated hydrocarbons as early as Late Triassic into stratigraphic traps and structural closures that were modified periodically. Thermal cooling and deformation associated with Cenozoic uplift impacted seal integrity and generation processes, modified traps, and caused gas expansion and remigration.

  4. Seasonal and annual dynamics of particulate carbon flux in the Barents Sea

    SciTech Connect

    Wassmann, P. ); Slagstad, D. )

    1993-08-01

    Mathematical modelling was used to explore the seasonal and annual variability of primary, new and secondary production as well as sedimentation between 72[degrees] and 80[degrees]N in the central Barents Sea during the years 1981 to 1983. 1981 and 1982 were years with extensive ice coverage while 1983 experienced little sea-ice. The phyto-plankton [open quotes]spring[close quotes] bloom started usually in April/May at about 75[degrees]N and was delayed from May/June in the south to August/September in the north as a function of thermal stratification and sea-ice dynamics. The model indicates that several, simultaneous spring bloom events, separated in space, can be found, especially during years with low ice coverage. The annual estimates of primary production, secondary production and sedimentation decreased on average from 73, 7.3 and 48 to 18, 1.8 and 9 gCm[sup [minus]2] year[sup [minus]1] between the southern and the northern part of the Barents Sea respectively. The annual estimates of particular carbon flux were much higher in 1983 compared to 1981-1982, especially in the north where up to 6 times higher rates were calculated for 1983. The number of zooplankton species present in spring in the southern Barents Sea is governed by over-wintering success, but probably also influenced by advection of Atlantic water. The model was run for Atlantic water with 10,000, 3,000 or none copepods per m[sup 2] present in March, indicating that sedimentation can vary between 38 and 61 gCm[sup [minus]2] year[sup [minus]1] due to zooplankton grazing alone. This suggests that the supply of organic carbon to the aphotic zone of the Barents Sea is only partly determined by the strength and duration of phytoplankton blooms, but strongly influenced by zooplankton dynamics. 49 refs., 6 figs., 3 tabs.

  5. Constraining Earth's Rheology of the Barents Sea Using Grace Gravity Change Observations

    NASA Astrophysics Data System (ADS)

    van der Wal, W.; Root, B. C.; Tarasov, L.

    2014-12-01

    The Barents Sea region was ice covered during last glacial maximum and experiences Glacial Isostatic Adjustment (GIA). Because of the limited amount of relevant geological and geodetic observations, it is difficult to constrain GIA models for this region. With improved ice sheet models and gravity observations from GRACE, it is possible to better constrain Earth rheology. This study aims to constrain the upper mantle viscosity and elastic lithosphere thickness from GRACE data in the Barents Sea region. The GRACE observations are corrected for current ice melting on Svalbard, Novaya Zemlya and Frans Joseph Land. A secular trend in gravity rate trend is estimated from the CSR release 5 GRACE data for the period of February 2003 to July 2013. Furthermore, long wavelength effects from distant large mass balance signals such as Greenland ice melting are filtered out. A new high-variance set of ice loading histories from calibrated glaciological modeling are used in the GIA modeling as it is found that ICE-5G over-estimates the observed GIA gravity change in the region. It is found that the rheology structure represented by VM5a results in over-estimation of the observed gravity change in the region for all ice sheet chronologies investigated. Therefore, other rheological Earth models were investigated. The best fitting upper mantle viscosity and elastic lithosphere thickness in the Barents Sea region are 4 (±0.5)*10^20 Pas and 110 (±20) km, respectively. The GRACE satellite mission proves to be a useful constraint in the Barents Sea Region for improving our knowledge on the upper mantle rheology.

  6. Modeling dynamics and thermodynamics of icebergs in the Barents Sea from 1987 to 2005

    NASA Astrophysics Data System (ADS)

    Keghouche, I.; Counillon, F.; Bertino, L.

    2010-12-01

    A modeling study of iceberg drift characteristics in the Barents and Kara seas for the period 1987-2005 is presented. Maps of iceberg density and potential locations subject to grounding complement sparse existing oceanographic and aerial field survey campaigns. The model suggests preferential pathways from the most important calving sources. Icebergs originating from Franz Josef Land have the largest spread over the domain. Simulations confirm the previously observed seasonal cycle of the southernmost extent of the icebergs. Strong interannual variability of the iceberg extent with a weak decreasing trend occurs, similar to the observed sea ice extent. Analysis of the atmospheric forcing reveals that years with anomalous northerly winds enhance the southward iceberg extension. Northerly winds also have a positive delayed impact on the iceberg extent. They limit the inflow of Atlantic Water into the Barents Sea and, therefore, its heat content the following year, increasing the mean age of icebergs and thus their potential extension. Finally, the model is able to reproduce the observed extreme iceberg extension southeast of the Barents Sea in May 2003.

  7. A rich Middle Triassic source rock in the Barents Sea Area

    SciTech Connect

    Bjoroy, M.; Hall, P.B.

    1983-05-01

    The scope of the work presented in this paper is an evaluation of the petroleum potential of the source rock which shows most promise for the Barents Sea Area. The evaluation is based on analysis of a large number of samples from a Middle Triassic black shale deposit on the various islands of the Svalbard Archipelago. This investigation has shown that the shale is an oil-prone source rock. Analysis of samples taken from areas in the Barents Sea, indicates that this shale sequence has similar potential as a source rock throughout the area south of Svalbard. Integration of this data with the available geophysical and geological data allows the authors to propose that the rich, oilprone Middle Triassic shale sequence also has a widespread distribution throughout the Norwegian Arctic. The results of the geochemical analysis undertaken on Mesozoic deposits of Svalbard and from subsea outcrops in the Barents Sea area is presented. In addition the significant geological data for the region are included. The geochemical data includes; total organic carbon content, Rock-Eval pyrolysis values, vitrinite reflectance and kerogen analysis in transmitted light. In addition some data on the amount and composition of extractable organic matter in the Triassic shales are mentioned.

  8. The Late Permian - Early Triassic Evolution of the Western Barents Sea

    NASA Astrophysics Data System (ADS)

    Planke, S.; Svensen, H.; Faleide, J.; Myklebust, R.

    2013-12-01

    The Permian-Triassic boundary was temporarily associated with formation of the Siberian Traps Large Igneous Province. Major Late Permian and Early Triassic subsidence is documented by seismic reflection data in the East Barents Basin. Further west, basin subsidence and an abrupt change from carbonate and evaporite deposition to clastic sedimentation is recorded by industry seismic and well data in the south and onshore Svalbard in the north. The Permian-Triassic boundary is commonly not preserved either due to non-deposition or erosion, but could be locally preserved in depocenters. A major northwestward prograding clastic delta sourced from the Uralian hinterland reached the Norwegian (western) part of the Barents Sea in the earliest Triassic (Induan). We suggest that the large-scale changes in paleoenviroment, vertical motions, and sedimentary processes in the Barents Sea region were strongly influenced by large-scale changes in mantle dynamics and paleoclimate caused by the Siberian Traps igneous event. By analogy with other Large Igneous Provinces, such as the North Atlantic Volcanic Province, regional uplift and subsidence associated with a rising mantle plume may precede the arrival of the plume at the base of the lithosphere with 10's of millions of years. In contrast, the paleoenvironmental changes and the associated extinction were mainly caused by rapid intrusion of magma into sedimentary basins and voluminous igneous eruptions.

  9. Effect of the tidal mixing on the average climatic characteristics of the Barents Sea

    NASA Astrophysics Data System (ADS)

    Kagan, B. A.; Sofina, E. V.

    2015-11-01

    The results of two numerical experiments on the determination of the climate of the Barents Sea obtained using the 3D finite element model hydrostatic model QUODDY-4 are presented. One of the experiments is carried out with the wind + thermohaline + tidal forcing, while the second is conducted without taking into account the tidal component. It is shown that the climate in the Barents Sea is experiencing significant changes associated with the tidal forcing. Thus, maximum differences between two solutions are approximately ±1.0°C for the temperature and ±0.4‰ for seawater salinity at the pycnocline depth. The same conclusion follows from the comparison of the diapycnal diffusion coefficient that characterizes the influence of internal tidal waves and the "background" diffusion coefficient determined by total forcing (including tidal forcing). Predicted values of the background diffusion coefficient are of the same order of magnitude as the ones observed by microstructural measurements of shear in velocity, temperature, and electrical conductivity of sea water in the centers of intense mixing in the marginal zone of the sea ice in the Barents Sea.

  10. Benthic macrofauna and productivity regimes in the Barents Sea — Ecological implications in a changing Arctic

    NASA Astrophysics Data System (ADS)

    Cochrane, Sabine K. J.; Denisenko, Stanislav G.; Renaud, Paul E.; Emblow, Christopher S.; Ambrose, William G., Jr.; Ellingsen, Ingrid H.; Skarðhamar, Jofrid

    2009-04-01

    Benthic faunal assemblages were analysed from 47 stations in the central and southern parts of the Barents Sea, together with sedimentary and water column parameters, daily ice records and modelled integrated primary productivity. Sampling spanned areas influenced by Atlantic Water (AW) to those lying under Arctic Water (ArW), and included stations with mixed water masses. Ice cover suppressed water column productivity in the northern areas. Three main faunal groups were identified, based on similarity of numerical faunal composition. The northern and southern faunal groups were separated by the northernmost penetration of AW in the bottom water and the third group, the Hopen group, was influenced by modified bank water. Faunal abundances were significantly higher within the southern faunal group relative to the northern group, but the numbers of taxa present were similar. The particularly rich fauna of the Hopen group reflected sediment heterogeneity and tight pelagic-benthic coupling. These results suggest that a retreat and thinning of the ice cover in the Barents Sea likely will result in the northern parts of the Barents Sea becoming more Atlantic in character, with a higher productivity at the sea floor.

  11. Brucella sp. antibodies in polar bears from Svalbard and the Barents Sea.

    PubMed

    Tryland, M; Derocher, A E; Wiig, Y; Godfroid, J

    2001-07-01

    A prevalence of 5.4% of anti-Brucella sp. antibodies was found in plasma samples from 297 polar bears (Ursus maritimus) from Svalbard and the Barents Sea. Plasma was tested by the classical brucellosis tests Slow Agglutination of Wright (SAW), EDTA modified SAW and Rose Bengal test, as well as by an indirect Protein A ELISA. Only samples classified as positive in all tests were regarded as containing anti-Brucella sp. antibodies. A significant west to east increase in the proportion of bears with anti-Brucella sp. antibodies was found, with 3.6% (n = 253) at Svalbard (Spitsbergen, Nordaustlandet, Edgeøya, Barentsøya and Hopen), and 15.9% (n = 44) in the central Barents Sea. Anti-Brucella sp. antibodies were previously found in ringed seals (Phoca hispida) and harp seals (Phoca groenlandica) from the same geographical areas. The ringed seal is an important prey species for the Svalbard polar bear population, and may thus be a source of brucellosis for the bears. There are no indications of reproductive disorders caused by Brucella sp. or other infectious agents in our study polar bear population. Potential impacts of Brucella sp. exposure on individuals or the population are unknown. PMID:11504225

  12. Respiration and biochemical composition of sedimenting organic matter during summer in the Barents Sea

    NASA Astrophysics Data System (ADS)

    Wassmann, Paul; Martinez, Rosa; Vernet, Maria

    1994-01-01

    Sedimentation of particulate carbon and nitrogen, pigments (fluorometric and HPLC analysis) as well as the activity of the respiratory electron transport system in sedimented matter were studied with unpoisoned, short-term deployed sediment traps during June in the central Barents Sea. The vertical flux of sedimenting material and its biochemical composition in the central Barents Sea was different during summer compared to spring with decreased flux of organic matter and decreased relative supplies of particulate nitrogen, but increased phaeopigment concentrations. The summer situation in the Barents Sea is characterized by recycling of the bulk of the suspended matter in the upper layers, a comparatively small loss of suspended biomass, but high sinking rates of some few, large particles, presumed to be faecal pellets. Respiration calculated as a daily loss rate of carbon in the sedimented material was on average only 1.4% day -1. Loss was strongly temperature dependent. At in situ temperatures 5°C, it is necessary to estimate turnover rates for sedimenting carbon in non-poisoned traps for an accurate elemental budget of a system and for interpretation of estimates from long-term trap deployments.

  13. Tracing Environmental Variation Over The Past 130 Years In The Barents Sea: Mineral Ratio (Mg/Ca, Sr/Ca, Ba/Ca, And Mn/Ca) Evidence In Shells Of The Circumpolar Greenland Cockle, Serripes groenlandicus

    NASA Astrophysics Data System (ADS)

    Henkes, G. A.; Ambrose, W. G.; Johnson, B. J.; Carroll, M. L.; McMahon, K. W.; Denisenko, S. G.; Thorrold, S. R.

    2007-12-01

    In order to quantify the impacts of human induced climate change on Arctic marine ecosystems it is crucial to establish high-resolution proxies to record regional environmental variability. The Barents Sea region is highly influenced by the annual recession and precession of Arctic sea ice and, as an ecosystem is extremely sensitive to seasonal to decadal climatic changes. Long-lived, sessile, marine bivalves have the potential to provide detailed oceanographic and biological proxy information from the Barents Sea in locations where historic, long- term data logging does not exist. Here, we present preliminary mineral ratio evidence (Mg, Sr, Ba, Mn) for Barents Sea environmental variation from shells of the circumpolar Greenland cockle, Serripes groenlandicus, over the past 130 years from 4 different locations in Norwegian and Russian waters. For all mineral ratios there are clear seasonal trends corresponding with dark winter growth checks on the external surface of each individual. The seasonal patterns of Mg and Sr show progressive change. On average for 9 individuals, Mg/Ca was 10.6 percent greater and Sr/Ca was 5.5 percent lower on the winter checks compared to other values, while Ba/Ca and Mn/Ca ratios show peaks during the middle of the summer growth period. Mineral patterns from the Pechora Sea region are particularly pronounced, which may be related to the influence freshwater from summer river discharge. While the mineral data are initially compelling enough to demonstrate clear seasonal periodicity and inter-annual variation, we believe that a multi-proxy approach to interpreting the information obtained from these bivalves is critical. Therefore, parallel to this study, we are examining external, incremental growth and organic carbon isotopes of shell material from the same collection of bivalves.

  14. Gasometric anomalies in bottom sediments of the Barents Sea as instrument of Modern Petroleum System study

    NASA Astrophysics Data System (ADS)

    Fokina, A.; Akhmanov, G.; Andreassen, K.; Yurchenko, A.

    2014-12-01

    In 2011-2013 four research cruises in the Barents Sea were organized by UNESCO-MSU Centre for Marine Geology and Geophysics (Russia) and University of Tromso (Norway) and were carried out onboard the RV "Akademik N. Strakhov" and RV "Helmer Hanssen". The cruises were devoted to finding and studying hydrocarbon seeps (e.g. pockmarks, crater-like structures), evaluating neo-tectonic activity and focusing on some problems in the field of modern geological and geochemical processes in the Arctic region. This topic is focused on identification of the gas anomalies related to the possible cold seep structures, study of the molecular and isotopic composition and origin of the hydrocarbon gases from the bottom sediments. During this research the interpretation of geochemical survey data was carried out within the different structures of the Barents region: 1) The area of distribution of craters, 2) Storfjordrenna and Storfiordbanken, 3) Nordkap and Tiddly basins, Fedynskii high, North-Kildinsk field. 1) In the Central Barents Sea in the area of distribution of craters residual discharge of gas from the Triassic sandstones has occurred and manifested through the activity of gas flares and elevated concentrations of methane. Values of gas coefficients indicate the possible existence of thermogenic gas in the sample. The active unloading of gas and formation of craters associated with the disintegration of gas hydrates. 2) Discovered gas flares, pockmarks and abnormal high concentrations of methane are the first statement about the presence of active gas discharge in the NW Barents Sea. HC gases are formed as a result of microbial processing of thermogenic gas. In the area there is an increased microbial activity resulting in authigenic carbonate formation. Unloading of gas is observed in the edges parts of the large glacial moraine along the base of which the lateral migration of gas occurs. Reservoirs can be Lower-Middle and Lower-Middle Triassic sandstones. 3) In the

  15. Paleoceanographic reconstruction in the western and northern Barents Sea during and after the last deglaciation

    NASA Astrophysics Data System (ADS)

    Aagaard-Sørensen, Steffen; Groot, Diane E.; Husum, Katrine; Hald, Morten

    2013-04-01

    During the last glacial maximum the Barents Sea shelf area was covered by the Svalbard-Barents Sea Ice Sheet (SBIS). After the retreat of the SBIS the Barents Sea gradually became one of the main gate ways for Atlantic Water transport towards the Arctic Ocean. At present, the south-western Barents Sea is influenced by warm and saline Atlantic Water, while the northern part is dominated by cold and less saline Arctic water masses. The sharp temperature and salinity gradients between the two water masses form an oceanic front. The front area is associated with high benthic biological production and approximately defines the winter sea ice extend. Two gravity cores from the western (JM09-KA11, Kveithola Trough, ~74°N, 16°E) and northern (NP05-11-70, Olga Basin, ~78°N, 32°E) Barents Sea were investigated in regards to benthic foraminiferal fauna, stable isotopes and sedimentology. Moreover transfer function reconstructions of bottom water temperature and salinity were performed. The age models set minimum ages of deglaciation at 15.500 and 11.000 cal yr B.P. in the Kveithola Trough and the Olga Basin, respectively. Following the deglaciation of the Kveithola Trough bottom water temperature and salinity fluctuated in response to inputs of melt water and changing influx of Atlantic Water. Sea ice cover and presence of icebergs varied during this period. The area experienced near perennial sea ice cover conditions during the Younger Dryas. Conditions stabilized after ca. 10.000 cal yr B.P. with Atlantic Water dominating the bottom waters until present while sea ice/iceberg presence was reduced to a minimum. In the Olga Basin cold conditions, probably with abundant sea ice, characterized the early Holocene. This period was followed by warmer and more saline bottom water conditions due to an increased input of water of Atlantic origin after ca. 6.000 cal yr B.P. The last 2000 years conditions became colder and more unstable.

  16. The lithosphere-scale density and temperature configuration beneath the Barents Sea and Kara Sea region

    NASA Astrophysics Data System (ADS)

    Klitzke, Peter; Faleide, Jan Inge; Sippel, Judith; Scheck-Wenderoth, Magdalena

    2014-05-01

    The Barents and Kara Sea region on the European Arctic shelf is bounded by the Proterozoic East-European Craton in the south and the young Cenozoic passive margins in the north and the west. Poly-orogenic episodes in late Precambrian to late Paleozoic times have led to amalgamation of the crystalline basement, which subsequently experienced multiple phases of subsidence resulting in the formation of ultra-deep sedimentary basins. These deep basins vary strongly in their configuration across the shelf. In the southwestern Barents Sea numerous narrow and fault-bounded rift basins are defined while the eastern Barents Sea and southern Kara Sea are marked by a wide and bowl-shaped sag basin. A key to understand the evolution and the causative mechanisms behind uplift and subsidence in the Barents Sea and Kara Sea is the present-day lithospheric density configuration. In a first step, a 3D structural model was developed resolving five sedimentary units, the crystalline crust and the lithospheric mantle. To provide best constrained geometries for the resulting 3D-structural model, interpreted seismic refraction and reflection data, geological maps and previously published 3D-models were analysed and integrated. The sedimentary units were assigned lithology-dependent matrix densities and porosities to calculate bulk densities which also consider the effects of erosion, compaction but also in response to published maximum ice sheet thickness. The density configuration of the lithospheric mantle and the asthenosphere down to 250 km depth is derived using an existing velocity-density model. To calculate an initial density configuration of the crystalline crust, the concept of Pratt's isostasy is applied. Finally, the gravitational response of the corresponding 3D-model is calculated and compared with the observed gravity field to further investigate the composition of the crust and the configuration of potential high-density bodies in the deeper lithosphere. To assess the

  17. Drainage divides, Massachusetts; Westfield and Farmington River basins

    USGS Publications Warehouse

    Gadoury, Russell A.; Wandle, S. William, Jr.

    1983-01-01

    Drainage boundaries for selected subbasins in western Hampshire, western Hampden, and southeastern Berkshire Counties, Massachusetts, are delineated on 15 topographic quadrangle maps at a scale of 1:24,000. Drainage basins are shown for all U.S. Geological Survey data-collection sites and for mouths of major rivers. Drainage basins are shown for the outlets of lakes or ponds and for streams where the drainage area is greater than 3 square miles. Successive sites along watercourses are indicated where the intervening area is at least 6 square miles on tributary streams or 10 square miles along the Westfield or Farmington Rivers. (USGS)

  18. Spreading and deposition of drill cuttings in the Barents Sea - Plans of the Barents Sea drill cuttings research initiative (BARCUT) project

    NASA Astrophysics Data System (ADS)

    Junttila, Juho; Aagaard Sørensen, Steffen; Dijkstra, Noortje

    2016-04-01

    The increasing petroleum exploration activity in the Barents Sea will lead to increased release of drill cuttings onto the ocean bottom in the future. Drilling mud consists of both drilling fluid with contaminants and fine sediments. This increasing discharge of drill cuttings provides a need for further knowledge of ocean current transportation of both contaminants and fine sediment particles (clay and silt), their impact on microfauna and the prediction of their accumulation areas. The main object is to study the current status of the sediments and microfauna exposed to different types of drill cuttings in the proximity of drilled exploration wells. Detailed objectives are: 1) To identify the main physical and geochemical characteristics of the sediments near the drilled wells including main areas for drill cutting accumulation and the influence of ocean currents on sediments and drill cuttings; 2) To identify the influence of drill cutting discharge on benthic foraminifera; 3) Monitoring and prediction of future spreading, accumulation and distribution of drill cutting related pollutants. We have conducted two field sampling campaigns, and in total visited seven drilling sites, ranging in age from recently drilled (in 2015) to nearly 30 years since abandonment. In this project, we study mainly push cores taken with a remote operated underwater vehicle (ROV) in the close proximity of exploration wells in the SW Barents Sea. We will determine the modern sedimentation rates based on the ²¹°Pb dating method. We analyze sediment grain-size, heavy metal and polyaromatic hydrocarbon (PAH) contents. Additionally analysis on benthic foraminifera, smectite clay minerals and the total organic carbon (TOC) content will be performed.

  19. Impact assessment of the Fukushima Nuclear Power Plant accidental emission on the Barents Sea ecosystem

    NASA Astrophysics Data System (ADS)

    Matishov, Gennady; Ilyin, Gennady; Kasatkina, Nadezhda; Usiagina, Irina; Pavelskaya, Elena

    2013-04-01

    The traces of emissions from the Fukushima-1 NPP in atmospheric aerosols of the Kola Peninsula near the Barents Sea coast were detected by radiation monitoring stations of the Murmansk Division of the Hydrometeorological Survey MDHMS in the end of March 2011. From the end of March 2011 until April 20, 131I, 134Cs, 132Te, 137Cs radioisotopes were observed in the atmospheric air. The major role was played by 131I isotope; its peak concentrations were (140-220)×10-6 Bq/m3, and it was recorded for several days (March 30-April 1), then radioactivity decreased. 134Cs, 132Te, and 137Cs isotopes were recorded episodically. The supply of radionuclides from accidental emissions into the atmosphere of the Kola Peninsula did not cause significant changes in gamma-radiation dose rates EDR. This value remained within the limits of the average long-term norm, and continued so during the following months 2011. Possible dry and humid precipitation of radionuclides within the water catchment area and in the marine basin did not influence on radioecological state in both coastal and off-shore parts of the Barents Sea. Short-lived isotopes as 131I, 134Cs, and 132Te, which might confidently indicate a trace from the Fukushima-1 NPP, have not been recorded in the samples. In 2011-1012 volumetric activity of 137Cs and 90Sr in water of the Barents Sea (section VI along the meridian 33° 30' N) varied in the range of 1.3-2.5 and 3.4-6.3 Bq/m3, respectively. Radioactive contamination of bottom sediments in the Barents Sea was very low. The specific activity of 137Cs varied from 1 to 8 Bq/kg, the activity of 90Sr did not exceed 4 Bq/kg. Investigations of macrophyte algae showed extremely low concentrations of artificial radionuclides. The specific activity of 137Cs in most samples was at the level of trace concentrations, from 0.2 to 1.5 Bq/kg of dry mass. The content of 90Sr in algae changed in the range of 0.4-4.1 Bq/kg of dry mass. In soft tissues of bivalves Mytilus edulis collected on

  20. Selected anthropogenic and natural radioisotopes in the Barents Sea and off the western coast of Svalbard.

    PubMed

    Leppänen, Ari-Pekka; Kasatkina, Nadezhda; Vaaramaa, Kaisa; Matishov, Gennady G; Solatie, Dina

    2013-12-01

    The Murmansk Marine Biological Institute (MMBI) performed high-latitude expeditions to the Barents Sea during 2007-2009 where a scientist from the Radiation and Nuclear Safety Authority (STUK) participated. The aim of the expeditions was to study and map the current radiological situation throughout the Barents Sea. In the expeditions, samples of seawater, sediment and biota were collected for radioactivity studies. The (90)Sr and (137)Cs isotopes were analysed from the seawater samples and no spatial distribution in the concentrations of (90)Sr and (137)Cs was found. The sediment samples were analysed for γ-emitting isotopes. In the statistical analysis performed only the (90)Sr was found to have no spatial distribution. In the (137)Cs concentrations two areas containing higher concentrations were observed: one in the western part of Svalbard and another in Franz Victoria Trough near the Franz Josef Land archipelago. The increase in the western coast of Svalbard suggests an Atlantic influence while in the Franz Victoria Trough source regions are possibly more complex. Since (137)Cs in marine sediments mainly originates from terrestrial sources, finding higher concentrations in the northern part of the Barents Sea may also suggest a contribution of (137)Cs carried by the ocean currents and by sea ice from the outside Barents Sea. In addition to γ spectrometric measurements, the sediment samples were radiochemically analysed for (210)Pb. It was found that the unsupported fraction of (210)Pb showed significant spatial variation. The fraction of unsupported (210)Pb was reduced to 40-70% near Bear Island, Edge Island and in the Franz Josef Land archipelago. In these regions the sea is typically covered with sea ice during winter. The relatively low fraction of unsupported (210)Pb is possibly caused by blocking of wet and dry deposition of (210)Pb onto the sea by winter sea ice. In biota samples, only small traces, at the level of 0.2 Bq/kg w.w. of (137)Cs, were found

  1. Response of decadal climatic variations to solar signals in the coastal region of the Barents Sea

    NASA Astrophysics Data System (ADS)

    Raspopov, O. M.; Dergachev, V. A.; Shumilov, O. I.; Nevanlinna, H.

    2003-04-01

    Variations in annual temperatures in the coastal region of the Barents sea in Murmansk (69 N, 33 E) for the period of instrumental records since 1878 have been analyzed. Annual temperature variations have been found to exhibit a pronounced decadal periodicity of the order of 1-1.8 degrees Celsius. Comparison of temperature variations with variations in solar activity (Wolf numbers W) point to the synchronism between decadal temperature variations and the 11-year Schwabe solar cycle. Spectral analysis of the tree ring growth (Pinus Sylvestris L.) in Tuloma Valley near Murmansk for the last 350 years has revealed variations in the tree ring growth with a period of 11-12 years. Thus, decadal climatic variations with the period of the Schwabe solar cycle are typical of the coastal region of the Barents sea. The amplitudes of the observed temperature variations (1-1.8 degrees Celsius) cannot be interpreted as resulting from changes in solar irradiation during the 11-year cycle. These changes are of the order of 0.15%, which can lead to the global temperature response of the order of 0.1-0.3 degrees Celsius. Therefore, a 5-6-fold enhancement of the solar signals takes place in the coastal region of the Barents sea. A similar solar signal enhancement was revealed earlier in variations in the Sea Surface Temperature (SST) in the Pacific Ocean. Possible reasons for enhancement of solar signals in variations in SST in the Pacific Ocean were considered by White et al.(2000) on the basis of the model of the delayed action oscillator in the ocean-atmosphere-terrestrial system. It is probable that in the Northern Atlantic region a similar solar signal enhancement occurs in the ocean-atmosphere-terrestrial system. This work was supported by INTAS, Grant 97-31008; PFBR, Grant 00-05-64921 and NorFa.

  2. Benthic foraminiferal responses to operational drill cutting discharge in the SW Barents Sea - a case study.

    NASA Astrophysics Data System (ADS)

    Aagaard-Sørensen, Steffen; Junttila, Juho; Dijkstra, Noortje

    2016-04-01

    Petroleum related exploration activities started in the Barents Sea 1980, reaching 97 exploration wells drilled per January 2013. The biggest operational discharge from drilling operations in the Barents Sea is the release of drill cuttings (crushed seabed and/or bedrock) and water based drilling muds including the commonly used weighing material barite (BaSO4). Barium (Ba), a constituent of barite, does not degrade and can be used to evaluate dispersion and accumulation of drill waste. The environmental impact associated with exploration drilling within the Goliat Field, SW Barents Sea in 2006 was evaluated via a multiproxy investigation of local sediments. The sediments were retrieved in November 2014 at ~350 meters water depth and coring sites were selected at distances of 5, 30, 60, 125 and 250 meters from the drill hole in the eastward downstream direction. The dispersion pattern of drill waste was estimated via measurements of sediment parameters including grain size distribution and water content in addition to heavy metal and total organic carbon contents. The environmental impact was evaluated via micro faunal analysis based on benthic foraminiferal (marine shell bearing protists) fauna composition and concentration changes. Observing the sediment parameters, most notably Ba levels, reveals that dispersion of drill waste was limited to <125 meters from the drill site with drill waste thicknesses decreasing downstream. The abruptness and quantity of drill waste sedimentation initially smothered the foraminiferal fauna at ≤ 30 meters from the drill site, while at a distance of 60 meters, the fauna seemingly survived and bioturbation persisted. Analysis of the live (Nov 2014) foraminiferal fauna reveals a natural species composition at all distances from the drill site within the top sediments (0-5 cm core depth). Furthermore, the fossil foraminiferal fauna composition found within post-impacted top sediment sections, particularly in the cores situated at

  3. Recruitment in the Barents Sea, Icelandic, and eastern Newfoundland/Labrador capelin (Mallotus villosus) stocks

    NASA Astrophysics Data System (ADS)

    Carscadden, James E.; Gjøsæter, Harald; Vilhjálmsson, Hjálmar

    2013-07-01

    Capelin (Mallotus villosus) is a short-lived, coldwater, pelagic species that occurs in large populations in the Barents Sea, around Iceland and in the Newfoundland-Labrador area in the North Atlantic. Most individuals spawn only once at age three or four and die shortly after spawning. The commercial fisheries for capelin in the three areas are prosecuted on the pre-spawning and spawning age groups and knowledge of recruitment to the spawning stock and factors affecting recruitment are important in the management of the fisheries. Herein, we review the state of knowledge regarding recruitment in the three areas and factors that affect recruitment. Year class strength of capelin is fixed fairly early in life; at 0-group stage in the Barents Sea, by age 1 or earlier for Icelandic capelin, and within 2 weeks of hatching for the beach spawners in the Newfoundland area. No obvious single factor, common to the three stocks, has been proven to exert a significant influence on recruitment. In the Barents Sea, juvenile herring prey heavily on capelin larvae and when the estimates of the abundance of these juvenile herring were accounted for in the capelin stock-recruitment analysis, the fit in the stock-recruitment relationship improved. In Iceland, there is no reason to implicate predation as a dominant factor, although detailed studies have not been carried out. In the Newfoundland and Labrador area earlier studies suggested two factors were important for recruitment success: the frequency of onshore winds at a critical period during the residence of newly hatched larvae in the beach gravel and the presence of warm waters during the early larval phase in the pelagic environment. With further testing using more data, the temperature factor was found not to be significant but the frequency of onshore winds still explained a significant portion of the variation in year class strength. There appears to be no significant biological influence, such as predation, that has

  4. Physical-Biogeochemical Interactions that Alter the Uptake of Atmospheric CO2 in the Barents Sea

    NASA Astrophysics Data System (ADS)

    Signorini, S. R.; Hakkinen, S. M.; McClain, C. R.

    2009-04-01

    The Barents Sea is characterized by significant calcification rates during summer promoted by intense coccolithophore blooms that peak during August. Coccolithophores, among which Emiliania huxleyi (E. huxleyi) is the most abundant and widespread species, are considered to be the most productive calcifying organisms on Earth. They inhabit the surface layer (MLD 20m) in highly stratified waters where light intensity is high. E. huxleyi often forms massive blooms in temperate and sub-polar oceans. Coupling of the coccolithophore organic carbon and carbonate pumps interact to consume (photosynthesis) and produce (calcification) CO2. The so-called Rain Ratio, defined as the ratio of particulate inorganic carbon (PIC) to particulate organic carbon (POC) in exported biogenic matter, determines the relative strength of the two biological carbon pumps and influences the flux of CO2 across the surface ocean - atmosphere interface. Here we use a combination of satellite ocean color algorithms, coupled ice-ocean model products, an SST-dependent pCO2 algorithm, and gas exchange parameterization to describe the seasonal and decadal variability of the air-sea CO2 flux in the Barents Sea. Model-derived SST and SSS (1955-2008) are used in conjunction with the pCO2 algorithm and carbonate chemistry to derive decadal trends of sea-air CO2 flux, pH and calcite saturation state. Phytoplankton and calcite production have strong spatial variability. Nutrient supply, biomass and calcite concentrations are modulated by light and MLD seasonal cycle. The size, intensity, and location of coccolithophore blooms vary from year to year, but the peak bloom is always in June in the Central Basin of the sub-polar North Atlantic (45oW - 10oW, 50oN - 65oN) and August in the Barents Sea. Calcification rates range from 5% to 27% of net primary production. The Barents Sea PIC production is about twice that of the Central Basin. Predicted freshening and warming of polar seas may increase stratification

  5. [Dynamics of benthic communities in the central trench of the Barents Sea].

    PubMed

    Liubina, O S; Dikaeva, D R; Frolova, E A; Frolov, A A; Zimina, O L; Akhmetchina, O Iu; Garbul', E A

    2010-01-01

    Based on the data collected in five marine expeditions of the Murmansk Marine Biological Institute from 2002 through 2007, the spatial and temporary variability of benthic communities in the Central Depression of the Barents Sea (licensed plot of the Shtokmanovskoe condensed gas deposit) has been analyzed. The range of quantitative characteristics and the variability of species composition of deep-water zoobenthos have been determined. The influence of an insignificant change in the collecting method on the obtained results has been examined. PMID:21080520

  6. The fate of gas hydrates in the Barents Sea and Kara Sea region

    NASA Astrophysics Data System (ADS)

    Klitzke, Peter; Scheck-Wenderoth, Magdalena; Schicks, Judith; Luzi-Helbing, Manja; Cacace, Mauro; Jacquey, Antoine; Sippel, Judith; Faleide, Jan Inge

    2016-04-01

    The Barents Sea and Kara Sea are located in the European Arctic. Recent seismic lines indicate the presence of gas hydrates in the Barents Sea and Kara Sea region. Natural gas hydrates contain huge amounts of methane. Their stability is mainly sensitive to pressure and temperature conditions which make them susceptible for climate change. When not stable, large volumes of methane will be released in the water column and - depending on the water depth - may also be released into the atmosphere. Therefore, studying the evolution in time and space of the gas hydrates stability zone in the Barents Sea region is of interest for both environmental impact and energy production. In this study, we assess the gas hydrate inventory of the Barents Sea and Kara Sea under the light of increasing ocean bottom temperatures in the next 200 years. Thereby, we make use of an existing 3D structural and thermal model which resolves five sedimentary units, the crystalline crust and the lithospheric mantle. The sedimentary units are characterised by the prevailing lithology and porosity including effects of post-depositional erosion which strongly affect the local geothermal gradient. Governing equations for the conductive 3D thermal field and momentum balance have been integrated in a massively parallel finite-element-method based framework (MOOSE). The MOOSE framework provides a powerful and flexible platform to solve multiphysics problems implicitly on unstructured meshes. First we calculate the present-day steady-state 3D thermal field. Subsequently, we use the latter as initial condition to calculate the transient 3D thermal field for the next 200 years considering an ocean temperature model as upper boundary. Temperature and load distributions are then used to calculate the thickness of the gas hydrate stability zone for each time step. The results show that the gas hydrate stability zone strongly varies in the region due to the local geothermal gradient changes. The latter

  7. The barents sea magmatic province: Geological-geophysical evidence and new 40Ar/39Ar dates

    NASA Astrophysics Data System (ADS)

    Shipilov, E. V.; Karyakin, Yu. V.

    2011-07-01

    Resulting from study of the geological structure of the Franz Josef Land and Svalbard archipelagoes, this work presents new 17 40Ar/39Ar age datings for basalts taken during coastal expeditions in 2006-2010. Radiological age determination for intrusive units (sills) located in the western part of Nordensciold Land (Spitzbergen Island) has been made for the first time. In relation to use of the interpretation results of marine geological-geophysical data, the distribution peculiarities and time ranges for Jurassic-Cretaceous basic magmatism within the studied regions of the Barents Sea continental margin and within the Arctic as a whole are discussed.

  8. Multi-decadal variability of ice extent in the Barents Sea

    NASA Astrophysics Data System (ADS)

    Vinje, T.; Colony, R.

    2003-04-01

    The European Arctic has been explored and commercially exploited for more than 400 years. In 1596, Willem Barentsz sailed the northern Barents Sea reporting on sea-ice extent and on the large number of whales found along the ice edge. By the early 17th century, an extensive and sophisticated whaling industry had developed in northern Spitzbergen. The whale hunters systematically observed and logged sea-ice conditions and ice edge location. These shipboard observations provide sea-ice extent information throughout the Nordic Seas and the western Barents for much of the 17th and 18th centuries. In 1850, Norway began extensive whale/seal hunting along the ice edge, stretching from Iceland to Novaya Zemlya. The records of sea-ice conditions and extent were archived by the Norwegian Polar Research Institute and are now placed in the ACSYS Historical Ice Chart Database. The annual April and August latitude of sea-ice extent in the western Barents is constructed for the period 1730-2000. The early part of the record (1730-1790) suggests April and August ice conditions similar to the modern era. However, just at the end of the 18th century, the sea-ice moved 300 km southward of its previous mean position. For the next 200 years (1800-2000), sea ice cover in the western Barents has steadily receded to its present state. Covariance studies offer insight into the processes controlling sea-ice extent and serve to bound the observational errors. The instrumental temperature record is mostly limited to the past 150-years. During this period, we estimate the correlation between Northern Hemisphere mean temperature and August sea-ice extent at r = 0.80 (using 7-year running means). Temperature records from central England are available from 1700, as are proxy temperature based data boreholes from the Greenland Ice Sheet Project. Again, significant covariance is found. The most provocative data come from sun spot observations and the associated time series of solar total irradiance

  9. A macrodescriptor perspective of ecological attributes for the Bering and Barents Seas

    NASA Astrophysics Data System (ADS)

    Megrey, Bernard A.; Aydin, Kerim Y.

    2009-10-01

    The eastern Bering Sea (EBS) and Barents Sea (BS) are both high-latitude, subarctic ecosystems that share many similar biophysical and trophic characteristics, and support valuable commercial fisheries. In this paper we compare system-level characteristics that make the Bering and Barents Sea ecosystems unique. We use Ecopath models and systems ecology macrodescriptor metrics applied to the two marine ecosystems to identify key areas of differences and similarities. Metrics calculated include number of species, number of interactions or trophic links, connectivity of the system, number of interactions per species, a measure of directed connectance, and an assessment of overall web interaction strength. In addition, number of basal species, number of top predators, total number of intermediate species, number of cannibals, number of cycles, number of omnivores, number of predators for a prey item, number of prey items for a predator, predator to prey ratio, and other indices were enumerated. Calculated food-web metrics for the eastern Bering and Barents Seas are compared between systems as well as with other similar metrics from published sources. We attempt to relate these observations to the questions of the uniqueness of marine food webs, implications for system stability, how climate impacts the physical environment, how the physical environment affects the structure of fish communities in each sea, and how changes in the physical environment affect the production of fish and the ability of the Bering and Barents Seas to support stable fisheries and productive ecosystems. Results show that the average number of trophic steps from primary producers to predators is shorter in the EBS. In the EBS, trophic pathways are shorter and more linear, there are more benthic species (flatfish and crabs) and there are both pelagic and benthic food webs. The BS is mainly a pelagic ecosystem. More production flows to the detritus pool in the BS most likely due to its deeper

  10. Splitting of Atlantic water transport towards the Arctic Ocean into the Fram Strait and Barents Sea Branches - mechanisms and consequences

    NASA Astrophysics Data System (ADS)

    Beszczynska-Möller, Agnieszka; Skagseth, Øystein; von Appen, Wilken-Jon; Walczowski, Waldemar; Lien, Vidar

    2016-04-01

    The heat content in the Arctic Ocean is to a large extent determined by oceanic advection from the south. During the last two decades the extraordinary warm Atlantic water (AW) inflow has been reported to progress through the Nordic Seas into the Arctic Ocean. Warm anomalies can result from higher air temperatures (smaller heat loss) in the Nordic Seas, and/or from an increased oceanic advection. But the ultimate fate of warm anomalies of Atlantic origin depends strongly on their two possible pathways towards the Arctic Ocean. The AW temperature changes from 7-10°C at the entrance to the Nordic Seas, to 6-6.5°C in the Barents Sea opening and 3-3.5°C as the AW leaving Fram Strait enters the Arctic Ocean. When AW passes through the shallow Barents Sea, nearly all its heat is lost due to atmospheric cooling and AW looses its signature. In the deep Fram Strait the upper part of Atlantic water becomes transformed into a less saline and colder surface layer and thus AW preserves its warm core. A significant warming and high variability of AW volume transport was observed in two recent decades in the West Spitsbergen Current, representing the Fram Strait Branch of Atlantic inflow. The AW inflow through Fram Strait carries between 26 and 50 TW of heat into the Arctic Ocean. While the oceanic heat influx to the Barents Sea is of a similar order, the heat leaving it through the northern exit into the Arctic Ocean is negligible. The relative strength of two Atlantic water branches through Fram Strait and the Barents Sea governs the oceanic heat transport into the Arctic Ocean. According to recently proposed mechanism, the Atlantic water flow in the Barents Sea Branch is controlled by the strength of atmospheric low over the northern Barents Sea, acting through a wind-induced Ekman divergence, which intensifies eastward AW flow. The Atlantic water transport in the Fram Strait Branch is mainly forced by the large-scale low-pressure system over the eastern Norwegian and

  11. Influence of regional tectonics on halokinesis in the Nordkapp Basin, Barents Sea

    SciTech Connect

    Nilsen, K.T.; Johansen, J.T.; Vendeville, B.C.

    1996-12-31

    Seismic analysis of salt structures in the Nordkapp Basin, a deep salt basin in the southern Barents Sea, combined with experimental modeling suggests that regional tectonics closely controlled diapiric growth. Diapirs formed in the Early Triassic during basement-involved regional extension. The diapirs then rose rapidly by passive growth and exhausted their source layer. Regional extension in the Middle-Late Triassic triggered down-to-the-basin gravity gliding, which laterally shortened the diapirs. This squeezed salt out of diapir stems, forcing diapirs to rise, extrude, and form diapir overhangs. After burial under more than 1000 m of Upper Triassic-Lower Cretaceous sediments, the diapirs were rejuvenated by a Late Cretaceous episode of regional extension and gravity gliding, which deformed their thick roofs. After extension, diapirs stopped rising and were buried under 1500 m of lower Tertiary sediments. Regional compression of the Barents Sea region in the middle Tertiary caused one more episode of diapiric rise. Diapirs in the Nordkapp Basin are now extinct.

  12. GRACE gravity observations constrain Weichselian ice thickness in the Barents Sea

    NASA Astrophysics Data System (ADS)

    Root, B. C.; Tarasov, L.; Wal, W.

    2015-05-01

    The Barents Sea is subject to ongoing postglacial uplift since the melting of the Weichselian ice sheet that covered it. The regional ice sheet thickness history is not well known because there is only data at the periphery due to the locations of Franz Joseph Land, Svalbard, and Novaya Zemlya surrounding this paleo ice sheet. We show that the linear trend in the gravity rate derived from a decade of observations from the Gravity Recovery and Climate Experiment (GRACE) satellite mission can constrain the volume of the ice sheet after correcting for current ice melt, hydrology, and far-field gravitational effects. Regional ice-loading models based on new geologically inferred ice margin chronologies show a significantly better fit to the GRACE data than that of ICE-5G. The regional ice models contain less ice in the Barents Sea than present in ICE-5G (5-6.3 m equivalent sea level versus 8.5 m), which increases the ongoing difficulty in closing the global sea level budget at the Last Glacial Maximum.

  13. Climatic Consequences of Barents Ice Sheet Collapse During the Last Glaciation: Comparison With Other Release Locations

    NASA Astrophysics Data System (ADS)

    Jones, C. L.; Bigg, G. R.

    2008-12-01

    An intermediate complexity climate model is used to simulate Henirich event-scale freshwater surges and fluxes of icebergs from the collapse of the Barents Ice Sheet during the last glaciation. The impact on convection and deep-water formation in the North Atlantic is compared to similar simulations from three other possible sources of icebergs: Hudson Strait, Gulf of St Lawrence and Norwegian Channel Ice Stream. We show that freshwater forcings and iceberg surges equivalent to 0.1 Sv from all release locations had a significant impact on the meridional overturning circulation, yet differences exist due to the time taken for icebergs to reach the North Atlantic, with the long trajectory of the European Icebergs resulted in a more gradual and delayed influx of meltwater, and a delayed return to previous conditions following the cessation of the influx. Whereas realistic iceberg surges from the Barents ice Sheet and NCIS do not halt the North Atlantic Meridional Overturning, it is halted for fluxes of 0.3 Sv from the Hudson Strait and Gulf of St Lawrence.

  14. Project work across borders in the arctic Barents region: practical challenges for project members.

    PubMed

    Immonen, Ingrid; Anderssen, Norman; Lvova, Maria

    2008-10-01

    The aim of this article was to explore cross-border project cooperation in applied settings in health education as this emerges in the Barents region. Specifically, we wanted to identify the practical challenges for those who participate in the work. This is of direct and indirect relevance to nursing education due to the rapidly increasing student exchange rates, the teachers' increased impetus to take part in international collaboration, and the increased emphasis within nursing education to be culture sensitive and ethnically fair. The considerable differences between countries in the Barents region present clear challenges. Knowledge based on experience from everyday cross-cultural and multinational project work has not been communicated extensively, and each project will have to acquire its own knowledge. Based on participation in various cross-national collaboration projects, we organize the identified practical challenges into five interrelated, everyday challenges: (1) cultural differences: obvious and overlooked, (2) the continuous challenge of language, (3) organizational variations, (4) possibilities and obstacles related to technology, and (5) the important minutiae of project logistics. These exist in all stages of a project. In project applications, these challenges and corresponding realistic consequences for funding are vital. Nursing students and their teachers should be aware that practical cross-national project work poses important challenges that nevertheless might be overcome. PMID:18355948

  15. Low-frequency variability of surface air temperature over the Barents Sea: causes and mechanisms

    NASA Astrophysics Data System (ADS)

    van der Linden, Eveline C.; Bintanja, Richard; Hazeleger, Wilco; Graversen, Rune G.

    2016-08-01

    The predominant decadal to multidecadal variability in the Arctic region is a feature that is not yet well-understood. It is shown that the Barents Sea is a key region for Arctic-wide variability. This is an important topic because low-frequency changes in the ocean might lead to large variations in the sea-ice cover, which then cause massive changes in the ocean-atmosphere heat exchanges. Here we describe the mechanism driving surface temperatures and heat fluxes in the Barents Sea based primarily on analyzes of one global coupled climate model. It is found that the ocean drives the low-frequency changes in surface temperature, whereas the atmosphere compensates the oceanic transport anomalies. The seasonal dependence and the role of individual components of the ocean-atmosphere energy budget are analyzed in detail, showing that seasonally-varying climate mechanisms play an important role. Herein, sea ice is governing the seasonal response, by acting as a lid that opens and closes during warm and cold periods, respectively, thereby modulating the surface heat fluxes.

  16. Drainage divides, Massachusetts; Blackstone and Thames River basins

    USGS Publications Warehouse

    Krejmas, Bruce E.; Wandle, S. William

    1982-01-01

    Drainage boundaries for selected subbasins of the Blackstone and Thames River basins in eastern Hampden, eastern Hampshire, western Norfolk, southern Middlesex, and southern Worcester Counties, Massachusetts, are delineated on 12 topographic quadrangle maps at a scale of 1:24,000. Drainage basins are shown for all U.S. Geological Survey data-collection sites and for mouths of major rivers. Drainage basins are shown for the outlets of lakes or ponds and for streams where the drainage area is greater than 3 square miles. Successive sites along watercourses are indicated where the intervening area is at least 6 miles on tributary streams or 15 square miles along the Blackstone River, French River, or Quinebaug River. (USGS)

  17. Development of the Barents Sea rift and its influence on sedimentation and hydrocarbon formation

    NASA Astrophysics Data System (ADS)

    Balanyuk, Inna; Dmitrievsky, Anatoly; Shapovalov, Sergey; Chaikina, Olga

    2010-05-01

    A special attention is given to the geodynamic active zone of the Barents Sea rift. Its development was accompanied by vigorous tectonic activity, propagation of deep faults, deep fractured zones that played an important role in fluid dynamic and thermobaric regime of the whole region. Geodynamic development of the Barents Sea rift not only played a substantial role in formation of as unique oil and gas fields as Shtokman, Prirazlomnoe and others, but created prerequisites for possible gas outbursts into near-surface sediments that could result, in some cases, in hydrocarbon formation. All the Barents Sea deposits are situated in the epicenter of the rift and, most important, over the zone of listric faults intersection, which set up a knot system over the mantle diapir. It is confirmed by prospecting seismology. Intrusion of hot mantle matter with further cooling down of abnormal lense might be a possible cause of appearance and evolution of ultradeep depressions. A high "seismic stratification" of the lower crust (nearly reaching the basement surface) at time scale about 8 sec. is typical for the deepest part of the depression. Supposing the "seismic stratified" lower crust correspond to "basalt" layer, this area is nearly upper crust ("granitic-gneiss") free. This fact confurmes conception on development of "granite free gaps" in the depression basement. Thick blocks of "seismically transparent" upper crust corresponding to the "granitic-gneiss" layer are marked out within Kolsk-Kanin monocline. An abrupt thickness decrease and appearance of "stratified" areas takes place at the southern edge of the depression. A filling of the over-rift sag with sediments, revival of the faults and their effect on the filtration processes and gas hydrates formation took place in the South Barents Sea depression. Repeating activation of the fault blocks in the basement, especially during late Jurassic - early Cretaceous period contributed to formation of the structures related

  18. The influence of dredging on the biota of the Barents Sea during development of the Stockman condensed gas deposit

    SciTech Connect

    Matishov, G.G.; Shparkovskii, I.A.; Nazimov, V.V.

    1995-11-01

    This article focuses on the nature of the possible dispersion of sediment during the construction of major natural gas pipelines on the shelf of the Barents Sea and its influence on the survival rate of marine organisms. 8 refs., 3 figs.

  19. A three-dimensional geophysical model of the crust in the Barents Sea region: Model construction and basement characterization

    USGS Publications Warehouse

    Ritzmann, O.; Maercklin, N.; Inge, Faleide J.; Bungum, H.; Mooney, W.D.; Detweiler, S.T.

    2007-01-01

    BARENTS50, a new 3-D geophysical model of the crust in the Barents Sea Region has been developed by the University of Oslo, NORSAR and the U.S. Geological Survey. The target region comprises northern Norway and Finland, parts of the Kola Peninsula and the East European lowlands. Novaya Zemlya, the Kara Sea and Franz-Josef Land terminate the region to the east, while the Norwegian-Greenland Sea marks the western boundary. In total, 680 1-D seismic velocity profiles were compiled, mostly by sampling 2-D seismic velocity transects, from seismic refraction profiles. Seismic reflection data in the western Barents Sea were further used for density modelling and subsequent density-to-velocity conversion. Velocities from these profiles were binned into two sedimentary and three crystalline crustal layers. The first step of the compilation comprised the layer-wise interpolation of the velocities and thicknesses. Within the different geological provinces of the study region, linear relationships between the thickness of the sedimentary rocks and the thickness of the remaining crystalline crust are observed. We therefore, used the separately compiled (area-wide) sediment thickness data to adjust the total crystalline crustal thickness according to the total sedimentary thickness where no constraints from 1-D velocity profiles existed. The BARENTS50 model is based on an equidistant hexagonal grid with a node spacing of 50 km. The P-wave velocity model was used for gravity modelling to obtain 3-D density structure. A better fit to the observed gravity was achieved using a grid search algorithm which focussed on the density contrast of the sediment-basement interface. An improvement compared to older geophysical models is the high resolution of 50 km. Velocity transects through the 3-D model illustrate geological features of the European Arctic. The possible petrology of the crystalline basement in western and eastern Barents Sea is discussed on the basis of the observed seismic

  20. The presence of species of Pseudochironomus Malloch 1915 (Diptera: Chironomidae) in watercourses of Chaco Serrano Ecoregion (Argentina, South America).

    PubMed

    Paggi, Analía C; Rodriguez Garay, Gretel N

    2015-01-01

    Male imagos of Pseudochironomus viridis (Kieffer) are redescribed, the immature stages are described and figured for the first time. During this study, larva and pupal exuviae associated to P. richardsoni (Malloch) were recorded for the first time for South America. The specimens were collected from a stream and a river in the Pampasic Hills System in the Chaco Serrano ecoregion of Argentina. PMID:26249080

  1. SW Barents Sea sediment composition in response to Late Glacial-Holocene ice sheet retreat and provenance changes

    NASA Astrophysics Data System (ADS)

    Kaparulina, Ekaterina; Junttila, Juho; Pekka Lunkka, Juha; Strand, Kari

    2015-04-01

    The SW Barents Sea sediments preserve the data of Late Glacial to Holocene development in this area. The marine sediment components are the most reliable recorders for climatic and environmental changes, providing valuable information for reconstructions of past ice sheet dynamics in high latitudes. Detailed investigations of the distribution of clay minerals, geochemical composition of heavy minerals and ice-rafted debris (IRD) of Late Glacial-Holocene sediments from the SW Barents Sea provide important new information about the prominent provenances and retreat of Scandinavian Ice Sheet (SIS). Our particular interest is a study of geochemical composition of Late Glacial-Holocene sediments from the SW Barents Sea via mineralogical proxies and compilation the final results. This may help to advance the knowledge on distribution, pathways and sources of sediment components in these sediments which are currently poorly studied. The mineralogical and geochemical data were generated from the three sediment cores located in Nordkappbanken, SW Barents Sea and display mostly sedimentation cycles from the last deglaciation and Holocene. Sediment analysis will include clay mineral content analysed using X-ray diffraction (XRD), IRD counting and heavy minerals compositions obtained by Electron Probe Microanalyzer (EPMA). It will represent an integrated input function over time which will provide a chronological record of glacial history and paleoclimate. Furthermore, integrated study of these sediment components will elucidate the development of SIS during Late Glacial time. Preliminary results show variations in content of clay minerals. The Barents Sea sources of kaolinite are referred to Franz Josef Land, rock outcroppings on the sea floor, and to a lesser extent the Fennoscandian Shield weathering crust. This can be supported by the lithologies of IRD and heavy mineral contents.

  2. Fragmentation and Flow Regulation of River Systems in the Northern Third the World

    NASA Astrophysics Data System (ADS)

    Dynesius, Mats; Nilsso, Christer

    1994-11-01

    Seventy-seven percent of the total water discharge of the 139 largest river systems in North America north of Mexico, in Europe, and in the republics of the former Soviet Union is strongly or moderately affected by fragmentation of the river channels by dams and by water regulation resulting from reservoir operation, interbasin diversion, and irrigation. The remaining free-flowing large river systems are relatively small and nearly all situated in the far north, as are the 59 medium-sized river systems of Norway, Sweden, Finland, and Denmark. These conditions indicate that many types of river ecosystems have been lost and that the populations of many riverine species have become highly fragmented. To improve the conservation of biodiversity and the sustainable use of biological resources, immediate action is called for to create an international preservation network of free-flowing river systems and to rehabilitate exploited rivers in areas that lack unaffected watercourses.

  3. Anomalous hydrographic conditions in the western Barents Sea observed in March 2014

    NASA Astrophysics Data System (ADS)

    Dobrynin, Mikhail; Pohlmann, Thomas

    2015-12-01

    Observational data have been collected during a cruise to the western Barents Sea in March 2014 covering 33 stations along three west-east sections at 76.34°N, 77.26°N and 78.49°N and along one south-north section at 19.47°E. Our observations suggest a wedge-like water masses structure with colder and fresher Arctic Water moving southward, gliding over warmer and more saline Atlantic Water which below the surface moves to the north. Atlantic Water in the Storfjorden Trench reached farther north than 76.5°N and was present on the eastern and western slopes of the Spitsbergen Bank. Our measurements indicate limited dense water formation in the Storfjorden. A comparison with historical data over the years 1923-2011 reveal an anomalous northern location of the Polar Front for this time of the year in March 2014. A point by point comparison with ten historical stations in 1983 and 1986 shows significantly warmer (by up to 3.8 °C) and saltier (by up to 2.49 psu) conditions in 2014 for nine out of ten stations. Moreover, stations dominated by the Atlantic inflow experienced the largest changes, whereas in stations located in the area of the Arctic outflow the changes were smallest. Furthermore, we used satellite and decadal reanalysis data to estimate the climate variability defined by a range of two standard deviations. We found that in the Storfjorden Trench in March 2014 the water transport was within the range, while the water temperature exceeded the upper limit of climate variability. The sea ice extent in the western Barents Sea was below the lower limit of climate variability from mid-February to mid-March 2014. Combining in situ, satellite and model data, we were able to attribute the warm anomaly observed in March 2014 to two main reasons: (1) an increase of Atlantic water temperature which was evident already in the beginning of 2014 and (2) very little cooling in February and March 2014. From these results we conclude that the north-western Barents Sea

  4. Impact of the Pleistocene Glaciations on Net Erosion Development in the Western Barents Sea

    NASA Astrophysics Data System (ADS)

    Zieba, K. J.; Felix, M.

    2015-12-01

    The Barents Sea shelf was subjected to both tectonic- and glacially-driven erosion during the Cenozoic. It is however unclear which of the erosion mechanisms had the most important role in generating net erosion that indicates a total effect of all erosion events. The literature estimates of glacial to tectonic erosion ratio vary significantly and often do not account for regional variations. The tectonic erosion is often attributed to plate reorganization in the Norwegian-Greenland Sea during the Cenozoic. The literature shows wide diversity of opinions regarding timing and thickness of the tectonic erosion. In contrast, glacial erosion thickness estimates are well constrained and show lower discrepancy in results. The glacial erosion thickness estimates are therefore key information that can be used for constraining the ratio between tectonic and glacial erosion. The glacial contribution to the net erosion is however also controlled by on-shelf deposition that counteracts the process of glacial erosion. However the on-shelf deposition rates have never been calculated. In result, the Pleistocene sediment budget and glacial contribution to the net erosion has never been assessed yet. The Pleistocene contribution to the net erosion was approached by a new Monte-Carlo-type method where the Pleistocene-Holocene sediment budget is calculated and the net erosion thickness is determined as a balance between total deposition and erosion thicknesses. The proposed method requires definite ages of glacial and interglacial periods what is not available in the literature. The timeframe was established by using a new approach based on the regional ice-sheet volume curve. Also, the new glacial/interglacial timeframe enables calculating the erosion rates for glacial duration (103 - 104 yr) timescale what have not been performed before. The results show that the western Barents Sea was glaciated during 4 marine isotope stages for a total duration of 29 kyr. The glacial erosion

  5. A survey of the summer coccolithophore community in the western Barents Sea

    NASA Astrophysics Data System (ADS)

    Giraudeau, Jacques; Hulot, Vivien; Hanquiez, Vincent; Devaux, Ludovic; Howa, Hélène; Garlan, Thierry

    2016-06-01

    The Barents Sea is particularly vulnerable to large-scale hydro-climatic changes associated with the polar amplification of climate change. Key oceanographical variables in this region are the seasonal development of sea-ice and the location and strength of physico-chemical gradients in the surface and subsurface water layers induced by the convergence of Arctic- and Atlantic-derived water masses. Remote sensing imagery have highlighted the increasing success of calcifying haptophytes (coccolithophores) in the summer phytoplankton production of the Barents Sea over the last 20 years, as a response to an overall larger contribution of Atlantic waters to surface and sub-surface waters, as well as to enhanced sea-ice melt-induced summer stratification of the photic layer. The present study provides a first thorough description of coccolithophore standing stocks and diversity over the shelf and slope of the western Barents Sea from two sets of surface and water column samples collected during August-September 2014 from northern Norway to southern Svalbard. The abundance and composition of coccolithophore cells and skeletal remains (coccoliths) are discussed in view of the physical-chemical-biological status of the surface waters and water column based on in-situ (temperature, salinity, fluorescence) and shore-based (microscope enumerations, chemotaxonomy) measurements, as well as satellite-derived data (Chl a and particulate inorganic carbon contents). The coccolithophore population is characterized by a low species diversity and the overwhelming dominance of Emiliania huxleyi. Coccolithophores are abundant both within the well stratified, Norwegian coastal water - influenced shallow mixed layer off northern Norway, as well as within well-mixed cool Atlantic water in close vicinity of the Polar Front. Bloom concentrations with standing stocks larger than 4 million cells/l are recorded in the latter area north of 75°N. Our limited set of chemotaxonomic data suggests

  6. High-Resolution 3D Seismic Imaging of Fluid Flow Anomalies in the Southwest Barents Sea

    NASA Astrophysics Data System (ADS)

    Planke, S.; Eriksen, F. N.; Eriksen, O. K.; Assad, M.; Stokke, H. H.

    2014-12-01

    Fluid flow features imaged as gas flares in the water column, pockmarks and mud volcanoes on the seabed, and high-amplitude cross-cutting reflections and bright spots in the sub-surface are abundant in the SW Barents Sea offshore northern Norway. This region is covered by extensive conventional 2D and 3D deep penetration seismic reflection data and multibeam bathymetry. High-resolution 3D P-Cable seismic data have been acquired in the SW Barents Sea over the past few years to image the uppermost ca. 500 m of the sub-surface. The P-Cable system consist of 12 to 16 short streamers (25 m) that are towed on a cross-cable perpendicular to the vessel's steaming direction. This configuration allows for acquisition of seismic data with high trace density, typically with 6 m in-line separation. The vertical resolution is a good as 1-2 m using conventional site survey air gun configurations. The sedimentary succession in the SW Barents Sea consists of upper Paleozoic evaporites overlaid by Mesozoic and Cenozoic clastic sediments. There are several organic-rich intervals in the sequence, including Paleozoic coals and Triassic and Jurassic marine source rocks that are locally in the oil or gas maturation windows. Glacial erosion has locally removed kilometer thick Cenozoic and Mesozoic successions, leaving the Mesozoic and Paleozoic strata in shallow sub-surface. The new high-resolution 3D surveys have targeted shallow fluid anomalies in the subsurface. These are imaged as high-amplitude reflections in fault blocks and structural highs, locally cross-cutting well-defined Mesozoic reflections. Commonly, disturbed reflections are present in overlying sequences, or high-amplitude reflections are imaged in the glacial overburden sediments. Locally, hundreds of pockmarks are imaged by the seafloor reflection. The deep cross-cutting reflections are interpreted as hydrocarbon accumulations that locally migrate towards the surface. The fluids are stored in shallow gas pockets or

  7. High-resolution 3D seismic data characterize fluid flow systems in the SW Barents Sea

    NASA Astrophysics Data System (ADS)

    Bünz, Stefan; Mienert, Jürgen; Rajan, Anupama

    2010-05-01

    The flow of fluids through marine sediments is one of the most dominant and pervasive processes in continental margins. These processes control the evolution of a sedimentary basin and its seafloor environment, and have implications for hydrocarbon exploration and seabed ecosystems. Many seep sites at the seafloor are associated with large but complex faunal communities that have received significant attention in recent years. However, there is a need for a better understanding of the driving mechanism of fluid flow in various geological settings, the accumulation of fluids in the subsurface and their focused flow through conduits and/or faults to the seabed. The Barents Sea is a large hydrocarbon-prone basin of the Norwegian Arctic region. A significant portion of the hydrocarbons has leaked or migrated into the shallow subsurface and is now trapped in gas-hydrate and shallow-gas reservoirs. Furthermore, there are few places in the Barents Sea, where methane gas is leaking from the seafloor into the oceanosphere. Accumulations of free gas in the shallow subsurface are considered a geohazard. They constitute a risk for safe drilling operations and they may pose a threat to global climate if the seal that is trapping them is breached. P-Cable 3D high-resolution seismic data from the Ringvassøya Fault Complex and the Polheim Sub-Platform provide new and detailed insight into fluid flow controls and accumulation mechanisms. The data shows a wide variety of fluid flow features, mostly in the form of pockmarks, bright spots, wipe-out zones or vertical zones of disturbed reflectivity. Fluids migrate by both diapiric mechanism and channelized along sedimentary layers. Glacigenic sediments generally form a strong boundary for fluid flow in the very shallow section. However, we can recognize pockmarks not only at the seafloor but also at one subsurface layer approximately 50 m below sea floor indicating a former venting period in the SW Barents Sea. At few locations high

  8. Ration of the red king crab on coastal shoals of the Barents Sea.

    PubMed

    Pavlova, L V

    2015-01-01

    In different habitats of the Kola Bay (Western Murman) and Dalnezelenetskaya and Yarnyshnaya bays (Eastern Murman), the size and structure of ecological rations (foraging of benthos) of the red king crab, which is an alien species in the Barents Sea, was established. The material for the study was collected in 2000-2009. In the Kola Bay, significant variability in time of this nutrition was detected for individuals of the same size category, which was associated with the depletion of food resources due to the high abundance of invaders in the area. The stable values of the ration and its structures in Eastern Murman bays indicated the prosperous state of benthic communities and an insignificant impact of crabs on these communities. PMID:26335970

  9. [Interannual Variations in Abundance and Biomass of Planktonic Copepods Oithona in the Barents Sea].

    PubMed

    Dvoretsky, V G; Dvoretsky, A G

    2015-01-01

    The distribution patterns of the common arctic zooplankton species Oithona similis and Oithona atlantica were investigated in the Barents Sea during warm and temperate years. The maximum abundance and biomass of Oithona spp. (159 x 10(3) ind./m2 and 38.8 mgC/m2, respectively) were recorded in the waters of Atlantic origin. O. atlantica occurred in Arctic waters only during anomalously warm years. It has been found that the quantitative characteristics of O. similis were negatively correlated with salinity and the winter NAO index, whereas the abundance of O. atlantica in Atlantic waters was positively correlated with the temperature anomaly. It is found that the abundance and biomass of Oithona pp. were comparable with the values recorded in other Arctic regions. PMID:26638241

  10. Microzooplankton Growth Rates Examined across a Temperature Gradient in the Barents Sea

    PubMed Central

    Franzè, Gayantonia; Lavrentyev, Peter J.

    2014-01-01

    Growth rates (µ) of abundant microzooplankton species were examined in field experiments conducted at ambient sea temperatures (−1.8–9.0°C) in the Barents Sea and adjacent waters (70–78.5°N). The maximum species-specific µ of ciliates and athecate dinoflagellates (0.33–1.67 d−1 and 0.52–1.14 d−1, respectively) occurred at temperatures below 5°C and exceeded the µmax predicted by previously published, laboratory culture-derived equations. The opposite trend was found for thecate dinoflagellates, which grew faster in the warmer Atlantic Ocean water. Mixotrophic ciliates and dinoflagellates grew faster than their heterotrophic counterparts. At sub-zero temperatures, microzooplankton µmax matched those predicted for phytoplankton by temperature-dependent growth equations. These results indicate that microzooplankton protists may be as adapted to extreme Arctic conditions as their algal prey. PMID:24475119

  11. Bacterial abundance, biomass and production during spring blooms in the northern Barents Sea

    NASA Astrophysics Data System (ADS)

    Sturluson, Maria; Gissel Nielsen, Torkel; Wassmann, Paul

    2008-10-01

    To evaluate importance of bacterioplankton in the Barents Sea, we investigated the spatial and temporal distribution of bacterial abundance, biomass and production in relation to spring-bloom stages. During three cruises in 2003-2005, 12 stations were investigated. Average bacterial abundance (±S.D.) in the photic zone was 3.6±3.0×10 5 cells ml -1, corresponding to 7.1±6.1 mg C m -3. Bacterial production in the photic zone was measured using dual labelling technique with 3H-thymidine and 14C-leucine, resulting in average production rates (±S.D.) of 1.5±1.0 and 6.9±4.8 mg C m -3 d -1, respectively. In spite of low water temperature, the bacterial community was well developed and active. Similarity analysis of stations resulted in four distinct spring-bloom stages, covering pre- early-, late- and post-bloom stages. In the photic zone, bacterial biomass on average corresponded to 6±2% of phytoplankton biomass. Highest integrated bacterial biomass was observed at mid- to late-bloom stages. Average bacterial production equalled 32±6% (±S.E., n=24) of particulate primary production. The bacterial production to primary production ratio tended to increase at late-bloom stages. The observed bacterial activity illustrates the importance of the bacterial pathway for channelling carbon from DOC through the microbial food web back into the classical food web, which previously has not been adequately considered in plankton ecosystem models of the Barents Sea.

  12. Spatial and temporal variability of satellite-derived sea surface temperature in the Barents Sea

    NASA Astrophysics Data System (ADS)

    Stramska, Malgorzata; Jakowczyk, Mateusz

    2016-04-01

    The Barents Sea (BS) is an important region for studying climate change. This sea is located on the main pathway of the heat transported from low to high latitudes. Since oceanic conditions in the BS may influence vast areas of the Arctic Ocean, it is important to continue to monitor this region and to analyze the available oceanographic data sets. One of the important quantities that can be used to track climate change is the sea surface temperature (SST). In this study we have analyzed the 32-years (1982-2013) NOAA Optimum Interpolation SST Version 2 data for the BS. Our results indicate that the regionally averaged SST trend in the BS (~0.03 oC/year) is greater than the global trend. This trend varies spatially with the lowest values north from 76°N and the highest values (~0.06oC/year) in proximity of Svalbard and in coastal regions near the White Sea. The SST and 2-m air temperature (AT) trends are high in winter months in the open Barents Sea region located west from Novaya Zemlya. Such trends can be linked to a significant retreat of sea ice in this area in recent years. In this paper we also documented spatial patterns in the annual cycle of SST in the BS. We have shown that the interannual variability of SST is similar in different regions of the BS and well correlated with the interannual patterns in AT variability. This work was funded by the Norway Grants (NCBR contract No. 201985, project NORDFLUX). Partial support for MS comes from the Institute of Oceanology (IO PAN).

  13. Epiplankton in the Barents sea: Summer variations of mesozooplankton biomass, community structure and diversity

    NASA Astrophysics Data System (ADS)

    Dvoretsky, Vladimir G.; Dvoretsky, Alexander G.

    2013-01-01

    Zooplankton link primary producers (phytoplankton) and higher trophic levels (fish, marine mammals, and seabirds) and are considered to be an important component in pelagic marine systems. In this paper we analyze a mesozooplankton data set obtained in the Barents Sea from 2003 to 2009 to test for climatic influences on some important parameters of the epi-zooplankton community in summer. The maxima of both mean water temperature in the upper 100 m layer and averaged chlorophyll a concentration in the surface strata were recorded in 2006, which may be considered as an anomalously-warm year. Total mesozooplankton biomass ranged from 743±106 mg C m-2 in the southern region to 3716±664 mg C m-2 in the northern region. The proportions of herbivores and large zooplankters (animals with total length of 2.7-7.0 mm) were highest in 2006 and tended to increase with temperature. Diversity, evaluated as the Shannon index of the mesozooplankton communities, was weakly correlated in time with environmental variables, and the mean and total number of taxa increased with water temperature in the southern and central Barents Sea. Most of the biological characteristics of the mesozooplankton community were only weakly correlated in time with the NAO and AO indices; however, the proportion of animals in 1.0-2.7 mm and 2.7-7.0 mm size classes tended to increase with increases in the monthly PC-based NAO index for August. Our data suggest that the complex zooplankton parameters (biomass, trophic and size structure, and diversity) can be useful in studying climatic impacts on marine ecosystems.

  14. Life history variation in Barents Sea fish: implications for sensitivity to fishing in a changing environment.

    PubMed

    Wiedmann, Magnus A; Primicerio, Raul; Dolgov, Andrey; Ottesen, Camilla A M; Aschan, Michaela

    2014-09-01

    Under exploitation and environmental change, it is essential to assess the sensitivity and vulnerability of marine ecosystems to such stress. A species' response to stress depends on its life history. Sensitivity to harvesting is related to the life history "fast-slow" continuum, where "slow" species (i.e., large, long lived, and late maturing) are expected to be more sensitive to fishing than "fast" ones. We analyze life history traits variation for all common fish species in the Barents Sea and rank fishes along fast-slow gradients obtained by ordination analyses. In addition, we integrate species' fast-slow ranks with ecosystem survey data for the period 2004-2009, to assess life history variation at the community level in space and time. Arctic fishes were smaller, had shorter life spans, earlier maturation, larger offspring, and lower fecundity than boreal ones. Arctic fishes could thus be considered faster than the boreal species, even when body size was corrected for. Phylogenetically related species possessed similar life histories. Early in the study period, we found a strong spatial gradient, where members of fish assemblages in the southwestern Barents Sea displayed slower life histories than in the northeast. However, in later, warmer years, the gradient weakened caused by a northward movement of boreal species. As a consequence, the northeast experienced increasing proportions of slower fish species. This study is a step toward integrating life history traits in ecosystem-based areal management. On the basis of life history traits, we assess the fish sensitivity to fishing, at the species and community level. We show that climate warming promotes a borealization of fish assemblages in the northeast, associated with slower life histories in that area. The biology of Arctic species is still poorly known, and boreal species that now establish in the Arctic are fishery sensitive, which calls for cautious ecosystem management of these areas. PMID:25478151

  15. Life history variation in Barents Sea fish: implications for sensitivity to fishing in a changing environment

    PubMed Central

    Wiedmann, Magnus A; Primicerio, Raul; Dolgov, Andrey; Ottesen, Camilla A M; Aschan, Michaela

    2014-01-01

    Under exploitation and environmental change, it is essential to assess the sensitivity and vulnerability of marine ecosystems to such stress. A species’ response to stress depends on its life history. Sensitivity to harvesting is related to the life history “fast–slow” continuum, where “slow” species (i.e., large, long lived, and late maturing) are expected to be more sensitive to fishing than “fast” ones. We analyze life history traits variation for all common fish species in the Barents Sea and rank fishes along fast–slow gradients obtained by ordination analyses. In addition, we integrate species’ fast–slow ranks with ecosystem survey data for the period 2004–2009, to assess life history variation at the community level in space and time. Arctic fishes were smaller, had shorter life spans, earlier maturation, larger offspring, and lower fecundity than boreal ones. Arctic fishes could thus be considered faster than the boreal species, even when body size was corrected for. Phylogenetically related species possessed similar life histories. Early in the study period, we found a strong spatial gradient, where members of fish assemblages in the southwestern Barents Sea displayed slower life histories than in the northeast. However, in later, warmer years, the gradient weakened caused by a northward movement of boreal species. As a consequence, the northeast experienced increasing proportions of slower fish species. This study is a step toward integrating life history traits in ecosystem-based areal management. On the basis of life history traits, we assess the fish sensitivity to fishing, at the species and community level. We show that climate warming promotes a borealization of fish assemblages in the northeast, associated with slower life histories in that area. The biology of Arctic species is still poorly known, and boreal species that now establish in the Arctic are fishery sensitive, which calls for cautious ecosystem management of

  16. On model differences and skill in predicting sea surface temperature in the Nordic and Barents Seas

    NASA Astrophysics Data System (ADS)

    Langehaug, H. R.; Matei, D.; Eldevik, T.; Lohmann, K.; Gao, Y.

    2016-04-01

    The Nordic Seas and the Barents Sea is the Atlantic Ocean's gateway to the Arctic Ocean, and the Gulf Stream's northern extension brings large amounts of heat into this region and modulates climate in northwestern Europe. We have investigated the predictive skill of initialized hindcast simulations performed with three state-of-the-art climate prediction models within the CMIP5-framework, focusing on sea surface temperature (SST) in the Nordic Seas and Barents Sea, but also on sea ice extent, and the subpolar North Atlantic upstream. The hindcasts are compared with observation-based SST for the period 1961-2010. All models have significant predictive skill in specific regions at certain lead times. However, among the three models there is little consistency concerning which regions that display predictive skill and at what lead times. For instance, in the eastern Nordic Seas, only one model has significant skill in predicting observed SST variability at longer lead times (7-10 years). This region is of particular promise in terms of predictability, as observed thermohaline anomalies progress from the subpolar North Atlantic to the Fram Strait within the time frame of a couple of years. In the same model, predictive skill appears to move northward along a similar route as forecast time progresses. We attribute this to the northward advection of SST anomalies, contributing to skill at longer lead times in the eastern Nordic Seas. The skill at these lead times in particular beats that of persistence forecast, again indicating the potential role of ocean circulation as a source for skill. Furthermore, we discuss possible explanations for the difference in skill among models, such as different model resolutions, initialization techniques, and model climatologies and variance.

  17. The impact of the hydrodynamic conditions in aquatic areas on the red king crab fouling communities of the Barents Sea

    NASA Astrophysics Data System (ADS)

    Dvoretsky, A. G.; Dvoretsky, V. G.

    2014-03-01

    A comparative analysis of the species composition and indices of associated organisms for the red king crab Paralithodes camtschaticus has been carried out at two aquatic areas of the Barents Sea that differ based on the intensity of their water exchange with the open sea areas. In Dolgaya Bay, a typical fjord of the Barents Sea with low water circulation, such common fouling organisms as the barnacles Balanus crenatus dominated on the crabs, while, in Dalnezelenetskaya Bay, a semiopen coastal area, the most common mobile symbionts on the red king crab were the amphipods Ischyrocerus commensalis and I. anguipes. In Dolgaya Bay, the hydrodynamic conditions promote the settlement of larval foulers, whose colonization leads to a decrease of the crab infestation with the mobile symbionts and changes in their distribution along the host body if compared to the more open coastal areas of Eastern Murman.

  18. Benthic infauna of the seasonally ice-covered western Barents Sea: Patterns and relationships to environmental forcing

    NASA Astrophysics Data System (ADS)

    Carroll, Michael L.; Denisenko, Stanislav G.; Renaud, Paul E.; Ambrose, William G., Jr.

    2008-10-01

    The northwestern Barents Sea and Svalbard archipelago are influenced by both warm Atlantic and cold Arctic water masses. We investigated infaunal benthic community structure in Atlantic- and Arctic-dominated areas, and at the Barents Sea Polar Front in order to assess the patterns of variability and to examine the influence of environmental variables on benthic fauna in this region. As part of the CABANERA program, we sampled 14 stations between 2003 and 2005 for benthic infaunal community composition, density, and biomass. Stations were in offshore shelf locations with soft sediments ranging in depth from 200 to 500 m, and encompassed different water mass characteristics and a wide range of other environmental conditions. Benthic biomass averaged 66 g WW m -2 (range 10-152 g WW m -2), mean density was 4340 ind. m -2 (1970-7896 ind. m -2), and species richness varied from 71-192 taxa stn. -1. Community structure was reflective of large-scale oceanography, as stations clustered in groups related to predominant water masses. Patterns in faunal density and biomass were largely determined by sedimentary characteristics, with water temperature, depth, and annual primary production also influencing some community parameters. Organism density and species richness were 86% and 44% greater at stations located near the Polar Front, compared to stations located in either Atlantic- or Arctic-dominated water masses. This pattern is coincident with elevated primary production at the Polar Front (48% compared to Atlantic- or Arctic-dominated water), suggesting a direct link between food availability in the Barents Sea and the benthic community structure. This leads to the conclusion that benthic communities in northwestern Barents Sea region are food-limited, and strongly dependent on predictable, albeit episodic, delivery of organic matter from the water column. Climatic processes leading to long-term changes in the location of the Polar Front will therefore have impacts on

  19. Assessment of metal exposure, ecological status and required water quality monitoring strategies in small- to medium-size temperate rivers.

    PubMed

    Marijić, Vlatka Filipović; Perić, Mirela Sertić; Kepčija, Renata Matoničkin; Dragun, Zrinka; Kovarik, Ivana; Gulin, Vesna; Erk, Marijana

    2016-01-01

    The present study was undertaken to obtain a better understanding of the seasonal variability of total dissolved metal/metalloid levels and physicochemical parameters within small- to medium-size freshwater ecosystems in temperate climate region. The research was conducted in four seasons in the Sutla River, medium-size polluted, and the Črnomerec Stream, small-size unpolluted watercourse in Croatia. In the Sutla River, characterized by the rural/industrial catchment, physicochemical parameters and total dissolved metal concentrations of 21 trace and 4 macro elements were analysed downstream of the point source of pollution, the glass production facility, indicating for the first time their variability across four seasons. Based on dissolved oxygen, total dissolved solids, nutrient concentrations, conductivity and total chemical oxygen demand, quality status of the Sutla River was good, but moderate to poor during summer, what was additionally confirmed by the highest levels of the most of 25 measured metals/metalloids in summer. Comparison with the reference small-size watercourse, the Črnomerec Stream, indicated significant anthropogenic impact on the Sutla River, most evident for Fe, Mn, Mo, Ni, Pb, Rb and Tl levels (3-70-fold higher in the Sutla River across all seasons). Generally, presented results indicated significant decrease of the water quality in the anthropogenically impacted small- to medium-size watercourses in summer, regarding physicochemical water parameters and total dissolved metal/metalloid concentrations, and pointed to significant seasonality of these parameters. Confirmed seasonality of river ecological status indicates that seasonal assessment represents a prerequisite for proper classification of the water quality in small- to medium-size temperate rivers. PMID:26745644

  20. Spatial features of glacier changes in the Barents-Kara Sector

    NASA Astrophysics Data System (ADS)

    Sharov, A. I.; Schöner, W.; Pail, R.

    2009-04-01

    In the 1950s, the total area of glaciers occupying separate islands and archipelagos of the Barents and Kara seas exceeded 92,300 km² (Atlas of the Arctic 1985). The overall glacier volume reached 20,140 km³ and the average ice thickness was given as 218 m. Our recent remote sensing studies and mass-balance estimates using spaceborne ASTER and LANDSAT imagery, ERS and JERS radar interferometric mosaics, and ICESat altimetry data revealed that, in the 2000s, the areal extent and volume of Barents-Kara glaciation amounted to 86,200±200 km² and 19,330±20 km³, respectively. The annual loss of land ice influenced by severe climate change in longitudinal direction was determined at approx. 8 km³/a in Svalbard, 4 km³/a both in the Franz Josef Land and Novaya Zemlya archipelagos, and less than 0.3 km³/a in Severnaya Zemlya over the past 50 years. The average ice thickness of remaining glaciation increased to 224 m. This fact was explained by rapid disintegration of thinner glacier margins and essential accumulation of snow at higher glacier elevations. Both effects were clearly visible in the series of satellite image maps of glacier elevation changes generated within the framework of the INTEGRAL, SMARAGD and ICEAGE research projects. These maps can be accessed at http://joanneum.dib.at/integral or smaragd (cd results). The largest negative elevation changes were typically detected in the seaward basins of fast-flowing outlet glaciers, both at their fronts and tops. Ablation processes were stronger manifested on southern slopes of ice caps, while the accumulation of snow was generally higher on northern slopes so that main ice divides "shifted" to the north. The largest positive elevation changes (about 100 m) were found in the central part of the study region in the accumulation areas of the biggest ice caps, such as Northern Ice Cap in Novaya Zemlya, Tyndall and Windy ice domes in Franz Josef Land, and Kvitoyjokulen at Kvitøya. The sides of these glaciers

  1. Detection and Origin of Hydrocarbon Seepage Anomalies in the Barents Sea

    NASA Astrophysics Data System (ADS)

    Polteau, Stephane; Planke, Sverre; Stolze, Lina; Kjølhamar, Bent E.; Myklebust, Reidun

    2016-04-01

    We have collected more than 450 gravity cores in the Barents Sea to detect hydrocarbon seepage anomalies and for seismic-stratigraphic tie. The cores are from the Hoop Area (125 samples) and from the Barents Sea SE (293 samples). In addition, we have collected cores near seven exploration wells. The samples were analyzed using three different analytical methods; (1) the standard organic geochemical analyzes of Applied Petroleum Technologies (APT), (2) the Amplified Geochemical Imaging (AGI) method, and (3) the Microbial Prospecting for Oil and Gas (MPOG) method. These analytical approaches can detect trace amounts of thermogenic hydrocarbons in the sediment samples, and may provide additional information about the fluid phases and the depositional environment, maturation, and age of the source rocks. However, hydrocarbon anomalies in seabed sediments may also be related to shallow sources, such as biogenic gas or reworked source rocks in the sediments. To better understand the origin of the hydrocarbon anomalies in the Barents Sea we have studied 35 samples collected approximately 200 m away from seven exploration wells. The wells included three boreholes associated with oil discoveries, two with gas discoveries, one dry well with gas shows, and one dry well. In general, the results of this case study reveal that the oil wells have an oil signature, gas wells show a gas signature, and dry wells have a background signature. However, differences in results from the three methods may occur and have largely been explained in terms of analytical measurement ranges, method sensitivities, and bio-geochemical processes in the seabed sediments. The standard geochemical method applied by APT relies on measuring the abundance of compounds between C1 to C5 in the headspace gas and between C11 to C36 in the sediment extracts. The anomalies detected in the sediment samples from this study were in the C16 to C30 range. Since the organic matter yields were mostly very low, the

  2. On the glacial erosion of the south-western Barents Sea shelf

    NASA Astrophysics Data System (ADS)

    Sverre Laberg, Jan; Andreassen, Karin; Vorren, Tore O.

    2010-05-01

    The Barents Sea has experienced profound glacial erosion during the late Pliocene and Pleistocene which resulted in the development of a characteristic glacial morphology of the continental shelf and deposition of a several km thick sediment wedge/fan along the western margin prograding into the deep sea. During the middle and late Pleistocene, glacial erosion was most severe beneath the paleo-ice streams of the Barents Sea Ice Sheet and affected mainly the trough areas (~200.000 km2). The total erosion is estimated to 435 - 530 m, the average erosion 0.6 - 0.8 mm/yr and the average sedimentation rates on the continental slope were 18 - 22 cm/kyr. The first-order control on the amount of erosion was probably the glaciations duration and velocity of the ice streams. Erosion by paleo-ice streams affected a larger area (~575.000 km2) during the early and middle Pleistocene because they were less topographically stable due to a less pronounced paleo-relief. Also, glaciotectonism was more extensive during this period. The total erosion was estimated to 330 - 420 m and the average erosion 0.4 - 0.5 mm/yr. The average sedimentation rates were 50 - 64 cm/kyr, 2 - 3 times higher than during the succeeding period. In the late Pliocene - early Pleistocene period, proglacial processes including glacifluvial erosion dominated. The total erosion was found to be 170 - 230 m, the average erosion 0.15 - 0.2 mm/yr and the average sedimentation rates were 16 - 22 cm/kyr. In total, the glacial erosion of the troughs has been relatively high throughout the late Pliocene - Pleistocene period, about 1000 - 1100 m. For the banks the erosion is inferred to have increased from late Pliocene to peak in early - middle Pleistocene, later there has been little erosion in these areas which implies a total of 500 - 650 m of erosion. The average glacial erosion during the whole late Pliocene and Pleistocene period is 38 cm/kyr, one order of magnitude higher than the average glacial erosion of the

  3. Radiocaesium (137Cs) in marine mammals from Svalbard, the Barents Sea and the North Greenland Sea.

    PubMed

    Andersen, Magnus; Gwynn, Justin P; Dowdall, Mark; Kovacs, Kit M; Lydersen, Christian

    2006-06-15

    Specific activities of the anthropogenic radionuclide, 137Cs, were determined in marine mammals from Svalbard and the Barents and North Greenland Seas. Muscle samples were collected from 12 polar bears, 15 ringed seals, 10 hooded seals, 7 bearded seals, 14 harp seals, one walrus, one white whale and one blue whale in the period 2000-2003. The mean concentrations (+/-SD) of 137Cs were: 0.72+/-0.62 Bq/kg wet weight (w.w.) for polar bears; 0.49+/-0.07 Bq/kg w.w. for ringed seals; 0.25+/-0.10 Bq/kg w.w. for hooded seals; 0.22+/-0.11 Bq/kg w.w. for bearded seals; 0.36+/-0.13 Bq/kg w.w. for harp seals; 0.67 Bq/kg w.w. for the white whale sample; 0.24 Bq/kg w.w. for the blue whale; and below detection limit for the walrus. Significant differences in 137Cs specific activities between some of the species were found. Ringed seals had higher specific activities than the other seal species in the study. Bearded seals and hooded seals had similar values, which were both significantly lower than the harp seal values. The results in the present study are consistent with previous reported results, indicating low specific activities of 137Cs in Arctic marine mammals in the Barents Sea and Greenland Sea region during the last 20 years. The species specific differences found may be explained by varying diet or movement and distribution patterns between species. No age related patterns were found in specific activities for the two species (polar bears and hooded seals) for which sufficient data was available. Concentration factors (CF) of 137Cs from seawater were determined for polar bears, ringed, bearded, harp and hooded seals. Mean CF values ranged from 79+/-32 (SD) for bearded seals sampled in 2002 to 244+/-36 (SD) for ringed seals sampled in 2003 these CF values are higher than those reported for fish and benthic organisms in the literature, suggesting bioaccumulation of 137Cs in the marine ecosystem. PMID:16154620

  4. Bivalve growth rate and isotopic variability across the Barents Sea Polar Front

    NASA Astrophysics Data System (ADS)

    Carroll, Michael L.; Ambrose, William G.; Locke V, William L.; Ryan, Stuart K.; Johnson, Beverly J.

    2014-02-01

    Analysis of bivalve shell increments provides a means to reconstruct long-term patterns in growth histories and assess factors that regulate marine ecosystems, while tissue stable isotopes are indicators of food sources and trophic dynamics. We examined shell growth patterns and tissue stable isotopic composition (δ13C and δ15N) of the hairy cockle (Ciliatocardium ciliatum) in the northwest Barents Sea to evaluate the influence of different water masses and the Polar Front on growth rates and food sources and to assess the influence of climatic variability on ecological processes over seasonal to decadal scales. Shell growth rates were highest in Atlantic water, intermediate in Arctic water, and lowest at the Polar Front. Temporal patterns of ontogenetically-adjusted growth (SGI) were negatively correlated with the Atlantic Multidecadal Oscillation (AMO), local precipitation and ice-free days. The highest growth occurred during colder periods with more sea ice, while lower growth was associated with warmer periods and less sea ice. Stable isotope values of lipid-extracted tissues from Atlantic water cockles were enriched in δ13C by up to 2.1‰ and δ15N by 1.5‰ compared to animals from Arctic waters. Distinct seasonal and water mass variations in stable isotopic values reflect spatial and temporal variability in food supplies to the bivalves in this region on small spatial scales. Overall, Atlantic waters supported the highest growth rates, the most complex trophic webs, and the greatest sensitivity to interannual variability in environmental conditions. Bivalves from Arctic waters were the most distinct of the three groups in their response to regional climate forcing and local environmental manifestations of those conditions. The Polar Front exhibits growth and isotopic characteristics predominantly of the Atlantic domain. These results demonstrate that integrating results of sclerochronological and stable isotopic analyses of benthic bivalves provide

  5. Tree rings, solar radiation and ice cover of the Barents sea

    NASA Astrophysics Data System (ADS)

    Kasatkina, Elena; Shumilov, Oleg; Timonen, Mauri; Kanatjev, Alexandr

    2015-04-01

    Intercomparisons of the Kola Peninsula tree-ring records, ice cover of the Barents sea and sea and surface temperatures have been made. Tree-ring series over the last 100 years showed a highly significant correlation with the sea surface temperatures and ice cover (r=-0.57, p<0.05). It should be noted that the correlation between the tree-ring widths and local temperatures was not so high. We suppose that a possible reason seems to be the prevailing influence of solar irradiance and their UV components on tree growth in the Kola North. It is known that solar variability and fluctuations of solar irradiance in the UV band of the spectrum has increased over the last decades. In addition, there are frequent cases of total ozone content depletions (or so-called ozone mini-holes) resulting in increased UV-B. The recent studies demonstrate that many boreal and subarctic plants have increased susceptibility to UV-B radiation. An indirect confirmation of the hypothesis proposed is a close relationship between solar total irradiance and global sea surface temperature (Reid, 2000). The results of spectral MTM-analysis also revealed periodicities close to the solar cycles in the ice cover and tree-ring records. These results confirm the above-mentioned interpretation.

  6. Three-Dimensional Model for the Crust and Upper Mantle in the Barents Sea Region

    NASA Astrophysics Data System (ADS)

    Bungum, H.; Ritzmann, O.; Maercklin, N.; Faleide, J.-I.; Mooney, W. D.; Detweiler, S. T.

    2005-04-01

    The Barents Sea and its surroundings is an epicontinental region which previously has been difficult to access, partly because of its remote Arctic location (Figure 1) and partly because the region has been politically sensitive. Now, however, this region, and in particular its western parts, has been very well surveyed with a variety of geophysical studies, motivated in part by exploration for hydrocarbon resources. Since this region is interesting geophysically as well as for seismic verification, a major study [Bungum et al., 2004] was initiated in 2003 to develop a three-dimensional (3-D) seismic velocity model for the crust and upper mantle, using a grid density of 50 km. This study, in cooperation between NORSAR, the University of Oslo (UiO), and the United States Geological Survey (USGS), has led to the construction of a higher-resolution, regional lithospheric model based on a comprehensive compilation of available seismological and geophysical data. Following the methodology employed in making the global crustal model CRUST5.1 [Mooney et al., 1998], the new model consists of five crustal layers: soft and hard sediments, and crystalline upper, middle, and lower crust. Both P- and S-wave velocities and densities are specified in each layer. In addition, the density and seismic velocity structure of the uppermost mantle, essential for Pn and Sn travel time modeling, are included.

  7. Late Triassic (Norian) foraminifera from Hopen Island, Barents Sea, paleoenvironmental significance and sequence stratigraphy implications

    NASA Astrophysics Data System (ADS)

    Cetean, Claudia; Paterson, Niall; Mangerud, Gunn

    2015-04-01

    The dark laminated mudstones of the Flatsalen Formation exposed on Hopen Island, in the Barents Sea record an early Norian transgression. At the base of the Formation, the Slottet Beds are considered to represent a transgressive lag deposit overlaid by the finer sediments which preserve agglutinated foraminifera, radiolaria and ostracod casts in the Lyngefjellet outcrop. During the transgressive phase the maximum abundance of foraminifera was noted, with benthonic assemblages dominated by small size Trochammina and Ammodiscus species. These types of assemblages are indicative of neritic depositional settings in the boreal domain, probably controlled by influxes of fresh water from adjacent land masses (Nagy et al., 2010). An influx of radiolaria, assumed to represent a maximum flooding surface (Mfs), indicating the onset of fully marine conditions was observed higher in the section, with marine microplankton peaking 9m higher. The decoupling between marine benthonic and planktonic microfossils is believed to be a consequence of a stratified water column. The Mfs is coeval with a marked decrease in the abundance and diversity of foraminifera and a change from epifauna to infauna - dominated agglutinated assemblages suggesting bottom waters hypoxia. In the first stage of marine regression, unstable palaeoenvironmental conditions are inferred, based on a gradual increase in dominance of few taxa, including opportunistic species of Glomospira. Nagy, J., Hess, S. and Alve, E., 2010. Environmental significance of foraminiferal assemblages dominated by small-sized Ammodiscus and Trochammina in Triassic and Jurassic delta-influenced deposits. Earth-Science Reviews, 99, 31-49.

  8. Faults in Quaternary cover as a relfection of basement tectonics: Kolguev island, barents sea

    NASA Astrophysics Data System (ADS)

    Krapivner, R. B.; Skorobogat'ko, A. V.

    2012-09-01

    The paper is concerned with the results of the detailed study of dislocations in the Pliocene-Quaternary loose sediments exposed as cliffs extending for ˜30 km along the rectilinear shore of Kolguev Island. According to seismic data, this lineament is related to the Coastal Fault in the lower part of the sedimentary cover. A system of faults longitudinal, diagonal, and transverse relative to the shoreline is established from observations at the cliffs. Their arrangement in plan view corresponds to the geometry of the right-lateral shear zone, the axis of which almost coincides with the shoreline. This has allowed us to identify the faults as secondary disturbances in the region of dynamic effect of the Coastal Fault in the basement. The kinematics of the secondary faults and their dip azimuth are consistent with echeloned geometry in plan view. The low-angle dip of the reverse-strike-slip faults observed at the outcrops is caused by their near-surface flattening toward the subsided block. The shallow-seated dislocations are related to ductile lateral shear in the vertical plane. The lower layers of the sedimentary cover mimic the horizontal movements in the basement more closely than the upper layers. The data obtained indicate high neotectonic activity of the Barents Sea shelf and specify the geodynamic setting of the region in the Pliocene and Quaternary.

  9. On the link between Barents-Kara sea ice variability and European blocking

    NASA Astrophysics Data System (ADS)

    Ruggieri, P.; Buizza, R.; Visconti, G.

    2016-05-01

    This study examines the connection between the variability of sea ice concentration in the Barents and Kara (B-K) seas and winter European weather on an intraseasonal time scale. Low sea ice regimes in autumn and early winter over the B-K seas are shown to affect the strength and position of the polar vortex, and increase the frequency of blocking regimes over the Euro-Atlantic sector in late winter. A hypothesis is presented on the mechanism that links sea ice over the B-K seas and circulation regimes in the North Atlantic, and is investigated considering 34 years of European Centre for Medium-Range Weather Forecasts reanalysis data. Four key steps have been identified, starting from a local response of the near-surface fluxes and modification of the upper tropospheric wave pattern, to the stratospheric adjustment and the tropospheric response in the North Atlantic. The proposed mechanism explains the delayed, late winter response of the North Atlantic Oscillation to the late autumn sea ice reduction, which has been found both in observations and model experiments. It also provides valuable insights on how the reduction of Arctic sea ice can influence the position of the tropospheric jet in the Euro-Atlantic sector.

  10. Characteristics of radionuclide accumulation in benthic organisms and fish of the Barents and Kara Seas

    SciTech Connect

    Matishov, G.G.; Matishov, D.G.; Rissanen, C.

    1995-05-01

    Artificial radionuclides play a specific role in the hydrochemical, geochemical, and hydrobiological processes that are currently occurring in the western Arctic. The existing data on radioactive contamination of different plant and animal species inhabiting the sea shelf are fragmentary. Hence, it was difficult to follow the transformation of radionuclides during their transmission along food chains, from phyto- and zoo-plankton to benthos, fish, birds, and marine mammals. In 1990-1994, the Murmansk Institute of Marine Biology organized expeditions to collect samples of residues on the sea floor and also of benthos, benthic fish, macrophytes, and other organisms inhabiting the shelf of the Barents and Kara Seas. These samples were tested for cesium-137, cesium-134, strontium-90, plutonium-239, plutonium-240, americium-241, and cobalt-60 in Rovaniemi (Finland) by the regional radiation administration of the Finnish Centre for Radiation and Nuclear Safety. Over 1000 tests were made. Their results provided new data on the content and distribution of these radionuclides among different components of marine ecosystems. 7 refs.

  11. Modeling biomagnification and metabolism of contaminants in harp seals of the Barents Sea.

    PubMed

    Fraser, Alison J; Burkow, Ivan C; Wolkers, Hans; Mackay, Don

    2002-01-01

    A simple fugacity-based bioaccumulation model is presented for harp seals (Phoca groenlandica), which feed primarily on polar cod (Boreogadus saida) and a pelagic crustacean (Themisto libellula). Using concentration data reported for 15 polychlorinated biphenyl (PCB) congeners and 27 pesticides in the food and blubber of harp seals from the Barents Sea, the model was used to determine biomagnification factors and metabolic half-lives as well as rates of contaminant uptake and loss processes in seals, including a discussion of uncertainty in biomagnification factors and half-lives. Examination of the model output shows considerable, but highly variable, biomagnification attributable to differences in metabolic rates. It is suggested that two biomagnification factors can be defined and should be used in such assessments, one based on concentration ratios and the other on fugacity ratios or lipid-normalized concentrations. A maximum biomagnification factor specific to the seal is deduced using biomagnification data for the most persistent substances, and from this, metabolic half-lives are estimated for all substances. The approach can be applied to other biomagnification situations, thus quantifying metabolic half-lives as a function of the properties of the bioaccumulating substance and ultimately its molecular structure and the physiological characteristics of the consuming animal. PMID:11804061

  12. Shallow geology of the northern Barents Sea: Implications for petroleum potential

    SciTech Connect

    Gustavsen, F.B.; Solheim, A.; Dypvik, H.

    1997-11-01

    The shallow geology of the northern Barents Sea has been studied through analyses of geophysical data and geological samples from gravity cores. Mesozoic rocks subcrop in the entire study area, with Triassic-Middle Jurassic rocks dominating the shallowest and western part of the area, and Upper Jurassic-Lower Cretaceous rocks dominating the central areas. A palynologically investigated sample, representing in-situ bed rock, gives an Aptian-early Albian age, indicating that Lower Cretaceous units dominate the eastern part of the study area. These beds were deposited during shallow-marine conditions and show a petrograpic composition comparable to the Carolinefjellet Formation of Svalbard. The thickness of the Lower Cretaceous section is almost 1000 m. Organic geochemical analyses of the Aptian-lower Albian rocks suggest a post-Early Cretaceous erosion of a maximum of 2000 m. An important tectonic event in the region was a compressive phase near the Cretaceous-Tertiary boundary. Occurrences of porous, well-sorted Lower Cretaceous sandstones succeeding organic-rich, mature Upper Jurassic and Lower Cretaceous shales, sealed by Lower Cretaceous shales within antiform settings, represent interesting play concepts in the study area. The petroleum potential has been limited by the post-Early Cretaceous uplift and erosion, resulting in the termination of hydrocarbon generation followed by gas expansion.

  13. East Greenland and Barents Sea polar bears (Ursus maritimus): adaptive variation between two populations using skull morphometrics as an indicator of environmental and genetic differences.

    PubMed

    Pertoldi, Cino; Sonne, Christian; Wiig, Øystein; Baagøe, Hans J; Loeschcke, Volker; Bechshøft, Thea Østergaard

    2012-06-01

    A morphometric study was conducted on four skull traits of 37 male and 18 female adult East Greenland polar bears (Ursus maritimus) collected 1892-1968, and on 54 male and 44 female adult Barents Sea polar bears collected 1950-1969. The aim was to compare differences in size and shape of the bear skulls using a multivariate approach, characterizing the variation between the two populations using morphometric traits as an indicator of environmental and genetic differences. Mixture analysis testing for geographic differentiation within each population revealed three clusters for Barents Sea males and three clusters for Barents Sea females. East Greenland consisted of one female and one male cluster. A principal component analysis (PCA) conducted on the clusters defined by the mixture analysis, showed that East Greenland and Barents Sea polar bear populations overlapped to a large degree, especially with regards to females. Multivariate analyses of variance (MANOVA) showed no significant differences in morphometric means between the two populations, but differences were detected between clusters from each respective geographic locality. To estimate the importance of genetics and environment in the morphometric differences between the bears, a PCA was performed on the covariance matrix derived from the skull measurements. Skull trait size (PC1) explained approx. 80% of the morphometric variation, whereas shape (PC2) defined approx. 15%, indicating some genetic differentiation. Hence, both environmental and genetic factors seem to have contributed to the observed skull differences between the two populations. Overall, results indicate that many Barents Sea polar bears are morphometrically similar to the East Greenland ones, suggesting an exchange of individuals between the two populations. Furthermore, a subpopulation structure in the Barents Sea population was also indicated from the present analyses, which should be considered with regards to future management

  14. Stochastic velocity inversion of seismic reflection/refraction traveltime data for rift structure of the southwest Barents Sea

    NASA Astrophysics Data System (ADS)

    Clark, Stephen A.; Faleide, Jan Inge; Hauser, Juerg; Ritzmann, Oliver; Mjelde, Rolf; Ebbing, Jörg; Thybo, Hans; Flüh, Ernst

    2013-05-01

    We present results from an active-source, onshore-offshore seismic reflection/refraction transect acquired as part of the PETROBAR project (Petroleum-related studies of the Barents Sea region). The 700 km-long profile is oriented NW-SE, coincident with previously published multichannel seismic reflection profiles. We utilize layer-based raytracing in a Markov Chain Monte Carlo (MCMC) inversion to determine a probabilistic velocity model constraining the sedimentary rocks, crystalline crust, and uppermost mantle in a complex tectonic regime. The profile images a wide range of crustal types and ages, from Proterozoic craton to Paleozoic to early Cenozoic rift basins; and volcanics related to Eocene continental breakup with Greenland. Our analyses indicate a complex architecture of the crystalline crust along the profile, with crystalline crustal thicknesses ranging from 43 km beneath the Varanger Peninsula to 12 km beneath the Bjørnøya Basin. Assuming an original, post-Caledonide crustal thickness of 35 km in the offshore area, we calculate the cumulative thinning (β) factors along the entire profile. The average β factor along the profile is 1.7 ± 0.1, suggesting 211-243 km of extension, consistent with the amount of overlap derived from published plate reconstructions. Local β factors approach 3, where Bjørnøya Basin reaches a depth of more than 13 km. Volcanics, carbonates, salt, diagenesis and metamorphism make deep sedimentary basin fill difficult to distinguish from original, pre-rift crystalline crust, and thus actual stretching may in places exceed our estimates. Crustal velocity structure reflects multi-stage rifting in the SW Barents Sea. A stochastic inversion is applied to the widely-used RAYINVR raytracing package. β factors peak 200 km landward of the transform margin edge. Maximum β coincides with Caledonian suture. We determine 227 ± 16 km total extension of the Barents Sea rifted margin.

  15. Does active gas seepage and dormant pockmarks indicate multiple episodes of focussed fluid escape along the SW Barents Sea?

    NASA Astrophysics Data System (ADS)

    Chand, S.; Thorsnes, T.; Rise, L.; Brunstad, H.; Stoddart, D.; Bøe, R.; Lågstad, P.; Svolsbru, T.

    2012-12-01

    The SW Barents Sea is versatile in its evolution due to the effect of glaciations that have removed large thicknesses of sediments from the seabed. Unloading due to glacial erosion and deglaciation resulted in opening of pre-existing faults and creation of new ones facilitating fluid escape from the subsurface. The changes in ice load also altered the gas hydrate stability zone (GHSZ) thicknesses causing accumulation of gas as gas hydrates within the GHSZ and free gas below it. Expressions of fluid escape, pockmarks, are widely distributed in the Barents Sea. Several gas flares, some of them 200 metre high, occur along a segment of the Ringvassøy Loppa Fault Complex (RLFC), indicating open fractures and still highly active fluid flow. Observation of gas flares along regional fault complexes outside the pockmark region indicate that the present gas escape activity occurs along these faults mainly. The relatively small thickness of sediments infilling the pockmarks and their penetration of the marine-glaciomarine sediment boundary indicate that they formed after deposition of glaciomarine sediments and were active in the Holocene and possibly some of them to the recent past. Methane hydrate stability zone (MHSZ) modelling shows that by the deglaciation after the Last Glacial Maximum (LGM) ca. 20 000 14C years ago, the MHSZ had thinned from 600 meters to zero in most parts of the SW Barents Sea. The fluid expulsion probably happened after the retreat of the grounded marine ice sheet causing the release of methane from melting methane hydrates through slow fluid escape process which lasted until recent creating pockmarks. Fluids are also leaking from deeper source rocks through formation pathways focussed by stratigraphic boundaries and open faults.

  16. Orthorhombic faults system at the onset of the Late Mesozoic-Cenozoic Barents Sea rifting

    NASA Astrophysics Data System (ADS)

    Collanega, Luca; Breda, Anna; Massironi, Matteo

    2016-04-01

    The structures of the Late Mesozoic/Cenozoic Barents Sea rifting have been investigated with multichannel 3D seismics, covering an area of 7700 sqKm in the Hoop Fault Complex, a transitional area between the platform and the marginal basins. The main structural lineaments have been mapped in a time domain 3D surface and their activity ranges have been constrained through the sin-sedimentary thickness variations detected in time-thickness maps. Two main fault systems have been identified: an orthorhombic fault system consisting of two fault sets trending almost perpendicularly one to the other (WNW-ESE and NNE-SSW) and a graben/half-graben system, elongated approximately N-S in the central part of the study area. While the graben/half-graben system can be explained through the theory of Anderson, this landmark theory fails to explain the simultaneous activity of the two fault sets of the orthorhombic system. So far, the models that can better explain orthorhombic fault arrangements are the slip model by Reches (Reches, 1978; Reches, 1983; Reches and Dieterich, 1983) and the odd-axis model by Krantz (Krantz, 1988). However, these models are not definitive and a strong quest to better understand polymodal faulting is actual (Healy et al., 2015). In the study area, the presence of both a classical Andersonian and an orthorhombic system indicates that these models are not alternative but are both effective and necessary to explain faulting in different circumstances. Indeed, the Andersonian plain strain and the orthorhombic deformation have affected different part of the succession during different phases of the rifting. In particular, the orthorhombic system has affected only the Late Mesozoic-Cenozoic interval of the succession and it was the main active system during the initial phase of the rifting. On the other hand, the graben/half-graben system has affected the whole sedimentary succession, with an increasing activity during the development of the rifting. It has

  17. A link between reduced Barents-Kara sea ice and cold winter extremes over northern continents

    NASA Astrophysics Data System (ADS)

    Petoukhov, Vladimir; Semenov, Vladimir A.

    2010-11-01

    The recent overall Northern Hemisphere warming was accompanied by several severe northern continental winters, as for example, extremely cold winter 2005-2006 in Europe and northern Asia. Here we show that anomalous decrease of wintertime sea ice concentration in the Barents-Kara (B-K) seas could bring about extreme cold events like winter 2005-2006. Our simulations with the ECHAM5 general circulation model demonstrate that lower-troposphere heating over the B-K seas in the Eastern Arctic caused by the sea ice reduction may result in strong anticyclonic anomaly over the Polar Ocean and anomalous easterly advection over northern continents. This causes a continental-scale winter cooling reaching -1.5°C, with more than 3 times increased probability of cold winter extremes over large areas including Europe. Our results imply that several recent severe winters do not conflict the global warming picture but rather supplement it, being in qualitative agreement with the simulated large-scale atmospheric circulation realignment. Furthermore, our results suggest that high-latitude atmospheric circulation response to the B-K sea ice decrease is highly nonlinear and characterized by transition from anomalous cyclonic circulation to anticyclonic one and then back again to cyclonic type of circulation as the B-K sea ice concentration gradually reduces from 100% to ice free conditions. We present a conceptual model that may explain the nonlinear local atmospheric response in the B-K seas region by counter play between convection over the surface heat source and baroclinic effect due to modified temperature gradients in the vicinity of the heating area.

  18. Different temperature adaptation in Arctic and Atlantic heterotrophic bacteria in the Barents Sea Polar Front region

    NASA Astrophysics Data System (ADS)

    Børsheim, Knut Yngve; Drinkwater, Kenneth F.

    2014-02-01

    In the northern Barents Sea, at and around the Polar Front, carbon cycle variables were investigated during 2 weeks in late summer of 2007. Arctic Water primary production in the experimental period averaged 50 mmol C m- 2 day- 1, as estimated from satellite sensed chlorophyll. In Atlantic waters, which appeared to just have passed the culmination of a late summer bloom, primary production was 125 mmol C m- 2 day- 1. Total organic carbon (TOC) averaged 82.4 μM C in the mixed layer, and the values showed a gradient with highest values to the southeast and lowest to the northwest. The distribution of TOC was not related to the distribution of Atlantic and Arctic waters, although the highest values were found in Atlantic Water. Integrated bacterial production in the mixed layer, as estimated from thymidine incorporation rates, averaged 6.3% of primary production. In Atlantic Water, over the depth of the mixed layer, bacterial production rate averaged 0.40 mmol C m- 3 day- 1, which was 6.6 times the average in Arctic Water and 2.3 times the average in the front regions. Below 30 m depth, bacterial production rates were generally higher in the Arctic Water than in the Atlantic Water. Moreover, when production rates of bacteria were compared according to temperature, the rates in Arctic Water were systematically higher than the rates in Atlantic Water. This difference implies that the heterotrophic bacteria from the Arctic have adapted towards higher growth efficiency than the bacteria in Atlantic Water.

  19. A Multi-technique Approach for Provenance Studies of Mesozoic Clastic Rocks in the Barents Sea

    NASA Astrophysics Data System (ADS)

    Matthews, N. E.; Zimmermann, U.; Støle, L.; Ruud, C.; Mostafa, E.; Andò, S.; Borromeo, L.; Magnaghi, M.; Lapen, T. J.

    2015-12-01

    Sediments of Mesozoic age deposited in the Arctic Hammerfest and Tromsø basins (southern Barents Sea) are the focus of a comprehensive provenance study which forms part of ongoing work by the LoCrA consortium (Lower Cretaceous Basin Studies in the Arctic). Jurassic (Stø, Fuglen, Hekkingen) and Cretaceous (Knurr, Kolje, Kolmule) formations were sampled from seven wells. Analytical methods include petrography, whole-rock geochemistry, heavy mineral (HM) analysis and U-Pb on detrital zircons. HM concentration is <1%, with an ultrastable HM assemblage of zircon, rutile, tourmaline, spinel, apatite, garnet, chloritoid and common authigenic heavy minerals and opaques. Cretaceous sedimentary rocks show geochemical variations that reflect an unrecycled Upper Continental Crust signature, whereas Jurassic detritus tends to show more evidence of recycling with a relatively low input of mafic material. Kolmule Formation whole-rock geochemistry indicates sediment recycling from a major Sc-depleted but intermediate to mafic source and hence suggests input of rift detritus from the syn-depositional opening of the Atlantic Ocean. U-Pb ages for detrital zircons for Cretaceous sandstones show age groups of 200-500 Ma, 1200-1800 Ma, and 2100-2800 Ma, indicating potential source regions in the Urals/Novaya Zemlya, the Caledonides, Grenvillian/Sveconorwegian, and Palaeoproterozoic and Archean sources. Provenance data via geochemistry and HM analysis indicate different sources in the same formation basin-wide, with a significant change in provenance and sediment composition from Jurassic to Cretaceous and between the Knurr and Kolmule formations. These differences in composition need to be compared to detailed single grain studies and may only be explained in terms of basin dynamics, or even on a smaller scale, in terms of facies distributions. If so, this case study raises concerns about the use of single samples for provenance models on a larger scale.

  20. Exposure to whole-body vibration in open-cast mines in the Barents region

    PubMed Central

    Burström, Lage; Hyvärinen, Ville; Johnsen, Magnar; Pettersson, Hans

    2016-01-01

    Objectives We aimed to measure and evaluate whole-body vibration (WBV) exposure among drivers of mining vehicles in the Barents region. Study design In the period from November 2012 to August 2014, this cross-sectional study was carried out at 3 mines in Finland, Norway and Sweden as part of the MineHealth project. Methods Measurements of WBV were conducted on the surface of the driver's seat during normal work in accordance with international standards. Personal data on daily exposure times were collected by a questionnaire. Results Measurements were conducted on 95 different mining vehicles both as root mean square (RMS) value and vibration dose value (VDV) representing different manufacturers, models and capacities. Of the 453 miners who answered the questionnaire, 232 indicated that they were exposed to WBV during their working day. The results show that the mean daily exposure time varies between 1.9 and 6.7 h for different vehicles. The calculated mean A(8) could be found in an interval between 0.2 and 1.0 m/s2 and the corresponding 8-h VDV fell between 7 and 17 m/s1.75. Conclusions Exposure to WBV among operators of mining vehicles may be a serious health and safety problem in the mines studied. The employers ought, therefore, take active steps to reduce exposure in accordance with the European vibration directive. Moreover, since some groups of drivers are exposed to vibration that is close to or exceeds the exposure limit values, the employer should take immediate action to reduce exposure below these values. PMID:26864832

  1. Two types of garnet zonation in metajaspilites of Barents sea area (Baltic shield)

    NASA Astrophysics Data System (ADS)

    Larikova, T.

    2003-04-01

    Archean amphibolite and biotite gneisses were studied in Tulomian complex of Murmansk block in Barents sea area. They contain metamorphosed and strongly folded jaspelites. There were reconstructed the metamorphic P-T trend: the prograde stage of metamorphism, peak conditions at 660-680 C and the retrograde amphibolization. A sample of metajaspilite has Grt+Mt+Qtz+Hbl+Act+Chl association. Huge garnet porphiroblastes are cut on small irregular blocks by hornblende veins. Each block is surrounded by Mn-rich (up to 5 wt%) and Fe rich rim of 50 mkm wide. The garnets have two types of the zonation: primary - in the central parts of the small blocks and secondary rims. The primary zonation of a whole porphiroblaste was reconstructed upon the cores of small blocks, and it show more Ca and Mn, and slightly more Mg primary core of the porphiroblaste. There were concluded that this Grt was formed at the peak metamorphic conditions, after that the Grt was amphibolized. Mn enrichment in the rim parts of Grt blocks probably could be explained by secondary Mg-rich amphibole formation upon the Grt and Mn diffusion into rims. The Hbl veins also have some changes in their composition (mainly - in Al) from the core of ex-grain to its rims. Grt-Hbl thermometry show the retrograde trend from 670 to 620 C. Near the chlorite veins the Mn rich rim in Grt is absent or very thin because of more slow diffusion rate at the low temperatures when Chl was formed. The author thanks RFBR for a financial support (00-05-64574)

  2. Crustal and basin evolution of the southwestern Barents Sea: From Caledonian orogeny to continental breakup

    NASA Astrophysics Data System (ADS)

    Gernigon, L.; Brönner, M.; Roberts, D.; Olesen, O.; Nasuti, A.; Yamasaki, T.

    2014-04-01

    A new generation of aeromagnetic data documents the post-Caledonide rift evolution of the southwestern Barents Sea (SWBS) from the Norwegian mainland up to the continent-ocean transition. We propose a geological and tectonic scenario of the SWBS in which the Caledonian nappes and thrust sheets, well-constrained onshore, swing from a NE-SW trend onshore Norway to NW-SE/NNW-SSE across the SWBS platform area. On the Finnmark and Bjarmeland platforms, the dominant inherited magnetic basement pattern may also reflect the regional and post-Caledonian development of the late Paleozoic basins. Farther west, the pre-breakup rift system is characterized by the Loppa and Stappen Highs, which are interpreted as a series of rigid continental blocks (ribbons) poorly thinned as compared to the adjacent grabens and sag basins. As part of the complex western rift system, the Bjørnøya Basin is interpreted as a propagating system of highly thinned crust, which aborted in late Mesozoic time. This thick Cretaceous sag basin is underlain by a deep-seated high-density body, interpreted as exhumed high-grade metamorphic lower crust. The abortion of this propagating basin coincides with a migration and complete reorganization of the crustal extension toward a second necking zone defined at the level of the western volcanic sheared margin and proto-breakup axis. The abortion of the Bjørnøya Basin may be partly explained by its trend oblique to the regional, inherited, structural grain, revealed by the new aeromagnetic compilation, and by the onset of further weakening later sustained by the onset of magmatism to the west.

  3. Optical properties of CDOM across the Polar Front in the Barents Sea: Origin, distribution and significance

    NASA Astrophysics Data System (ADS)

    Hancke, Kasper; Hovland, Erlend K.; Volent, Zsolt; Pettersen, Ragnhild; Johnsen, Geir; Moline, Mark; Sakshaug, Egil

    2014-02-01

    Colored Dissolved Organic Matter (CDOM) is an important optical constituent in seawater, which significantly attenuates the violet to blue portion of visible light. Thus, CDOM reduces the radiation energy available to phytoplankton and affects remote-sensing signals. We present data from two cruises transecting the Polar Front from Atlantic to Arctic waters in the Barents Sea, in 2007 and 2008. The latter took place during the spring bloom of phytoplankton in May (0.2 < [Chl a] < 13 mg m- 3) and the former during August (max. [Chl a] < 2 mg m- 3). Absorption by CDOM at 443 nm ranged from 0.004 to 0.080 m- 1 during May and from 0.006 to 0.162 m- 1 during August. Surprisingly, CDOM absorption differed little across the Polar Front, but was higher during August than during May (P < 0.05). The slope coefficient of the absorption spectra (S) ranged from 0.008 to 0.036 nm- 1 (mean = 0.015 nm-1) including both cruises, and varied little across the Front (P > 0.05). The CDOM remote sensing product from GlobColour correlated well with sampled data (R2 = 0.73) during May. However, during August the satellite product performed poorly (R2 = 0.02) due to extensive scattering caused by coccolithophorids in the Atlantic Water. The CDOM pool was of autochthonous (marine) origin as characterized from its S vs. absorption relationship. Modeling showed that CDOM, on average, contributed equally to the light absorption as did phytoplankton (at 1 mg Chl a m- 3), and thereby reduces the amount of light available for primary production.

  4. Grazing of phytoplankton by microzooplankton in the Barents Sea during early summer

    NASA Astrophysics Data System (ADS)

    Verity, Peter G.; Wassmann, P.; Frischer, M. E.; Howard-Jones, M. H.; Allen, A. E.

    2002-12-01

    Phytoplankton growth rates and grazing losses to microzooplankton were determined in surface waters of the central Barents Sea during a cruise in June/July 1999. Five stations were occupied which had been studied repeatedly over the past 15-20 years. Dilution experiments using chlorophyll a (chl a) as a tracer were used to estimate daily rates in three size fractions; image-analyzed fluorescence microscopy provided quantitative estimates of standing stocks of auto- and heterotrophic nano- and microplankton. Phytoplankton contributed the largest share of protistan biomass, followed by bacteria and microzooplankton. On average, nanophytoplankton (<20 μm) contributed half of the microphytoplankton (<200 μm) biomass. All stocks were low relative to peak spring bloom concentrations reported in previous years. Different taxonomic groups of microzooplankton were relatively more important under the ice, in the marginal ice zone (MIZ), and in open water. Phytoplankton growth and microzooplankton grazing rates were 0.1 to 0.5 day -1, and were closely coupled. Neither growth nor grazing rates alone was closely related to phytoplankton biomass, but the net difference between growth and grazing explained about 2/3 of the variance in chl a standing stocks. Grazing losses ranged from 64% to 97% of daily chl a production, and were greater for smaller size fractions. Growth and grazing coefficients of all size classes exhibited Q 10's of 2-3. These results support the growing body of evidence that small-celled phytoplankton and zooplankton are ubiquitous and important in cold waters as well as temperate and tropical ecosystems.

  5. Simulating the impact of freshwater inputs and deep-draft icebergs formed during a MIS 6 Barents Ice Sheet collapse

    NASA Astrophysics Data System (ADS)

    Green, Clare L.; Green, J. A. Mattias; Bigg, Grant R.

    2011-06-01

    An intermediate complexity climate model is used to simulate the collapse of the Barents Ice Sheet during Marine Isotope Stage 6 (MIS 6; 140 ka B.P) with the purpose of investigating whether a mass input of freshwater from the collapse could have affected the convection and deep water formation in the North Atlantic Ocean. Further experiments used a coupled dynamic and thermodynamic iceberg model to determine the effects of deep-draft icebergs, rather than freshwater alone, on the ocean circulation. The results predict that the collapse of the Barents Ice Sheet had a significant impact on the meridional overturning circulation in both the Atlantic and Pacific oceans. Freshwater fluxes have more of an impact on the Atlantic overturning circulation during the actual release period compared to icebergs, but the bergs induce effects over longer time scales even after the pulse is removed. Freshwater fluxes of 0.15 sverdrup (Sv) and iceberg surges of 0.1 Sv trigger significant changes in the global patterns, particularly in the North Pacific where there is strengthening of the overturning circulation at the expense of that in the North Atlantic, and associated increases in Pacific sea surface temperatures. These results highlight the importance of simulating not only the correct flux but also the form of the freshwater input from ice sheet collapses appropriately.

  6. Annual and seasonal fCO2 and air-sea CO2 fluxes in the Barents Sea

    NASA Astrophysics Data System (ADS)

    Lauvset, S. K.; Chierici, M.; Counillon, F.; Omar, A.; Nondal, G.; Johannessen, T.; Olsen, A.

    2013-03-01

    The Barents Sea is the strongest CO2 sink in the Arctic region, yet estimates of the air-sea CO2 flux in this area show a large span reflecting uncertainty as well as significant variability both seasonally and regionally. Here we use a previously unpublished data set of seawater CO2 fugacity (fCO2), and map these data over the western Barents Sea through multivariable linear regressions with SeaWiFS/MODIS remote sensing and TOPAZ model data fields. We find that two algorithms are necessary in order to cover the full seasonal cycle, mainly because not all proxy variables are available for the entire year, and because variability in fCO2 is driven by different mechanisms in summer and winter. A comprehensive skill assessment indicates that there is a good overall correspondence between observations and predictions. The algorithms are also validated using two independent data sets, with good results. The gridded fCO2 fields reveal tight links between water mass distribution and fCO2 in all months, and particularly in winter. The seasonal cycle show peaks in the total air-sea CO2 influx in May and September, caused by respectively biological drawdown of CO2 and low sea ice concentration leaving a large open water area. For 2007 the annual average air-sea CO2 flux is - 48 ± 5 gC m- 2, which is comparable to previous estimates.

  7. A modelling study of the influence of anomalous wind forcing over the Barents Sea on the Atlantic water flow to the Arctic Ocean in the period 1979-2004

    NASA Astrophysics Data System (ADS)

    Marciniak, Jakub; Schlichtholz, Pawel; Maslowski, Wieslaw

    2016-04-01

    Arctic climate system is influenced by oceanic heat transport with the Atlantic water (AW) streaming towards the Arctic Ocean in two branches, through the deep Fram Strait and the shallow Barents Sea. In Fram Strait, the AW submerges below the Polar surface water and then flows cyclonically along the margin of the Arctic Ocean as a subsurface water mass in the Arctic Slope Current. In contrast to the Fram Strait branch, which is the major source of heat for the Arctic Ocean, most of the heat influx to the Barents Sea through the Barents Sea opening (BSO) is passed to the atmosphere. Only cold remnants of AW outflow to the Arctic Ocean through the northeastern gate of the Barents Sea. Some AW entering the Barents Sea recirculates westward, contributing to an outflow from the Barents Sea through the BSO along the shelf slope south of Bear Island, in the Bear Island Slope Current. Even though the two-branched AW flow toward the Arctic Ocean has been known for more than a century, little is known about co-variability of heat fluxes in the two branches, its mechanisms and climatic implications. Recent studies indicate that the Bear Island Slope Current may play a role in this co-variability. Here, co-variability of the flow through the BSO and Fram Strait is investigated using a pan-Arctic coupled ice-ocean hindcast model run for the period 1979-2004 and forced with daily atmospheric data from the ECMWF. Significant wintertime co-variability between the volume transport in the Bear Island and Arctic slope currents and its link to wind forcing over the Barents Sea is confirmed. It is found that the volume transports in these currents are, however, not correlated in the annual mean and that the wintertime co-variability of these currents has no immediate effect on either the net heat flux through the BSO or the net heat flux divergence in the Barents Sea. It is shown that the main climatic effect of wind forcing over the northern Barents Sea shelf is to induce temperature

  8. Recruitment of shrimp ( Pandalus borealis) in the Barents Sea related to spawning stock and environment

    NASA Astrophysics Data System (ADS)

    Aschan, Michaela; Ingvaldsen, Randi

    2009-10-01

    The shrimp spawn in autumn, and the females carry their eggs as out roe until spring when the larvae hatch. Within a period of 2 months the shrimp larvae settle to the bottom. It has been claimed that the year-class strength probably is determined during the larval phase. Today's assessment and forecast of the shrimp stock productivity and potential fishing yields are weak. This is partly due to poor knowledge on population dynamics from hatching until the shrimp are caught in the fishery at the age of 3 or 4 years. We, therefore, here identify the most important abiotic and biotic factors that affect recruitment in addition to spawning stock biomass. Since 1995, a net attached to the underbelly of the survey trawl used at the annual cruise in the Barents Sea has caught juvenile shrimp. The abundance of settled shrimp larvae varies in time and space. The recruitment to the fishery has been quite stable with the exception of the 1996 year-class, which was observed as 1-year-olds but has not been registered since. The temporal pattern of the three youngest year-classes is studied in relation to abiotic factors such as sea temperature, ice index and North Atlantic Oscillation, as well as biotic factors such as spawning stock biomass and presence of copepods, euphausiids and predating cod. Recruitment indices and factors identified by the Spearmann correlation to be significantly correlated with recruitment were used as input in a principal component analysis (PCA) and a generalized additive model (GAM) was applied. Abundance of 1-year-old shrimp is positively correlated to spawning stock biomass the previous year and to temperature of the previous winter, and negatively correlated with the number of 1-year-old cod. Two-year-old shrimp show significant correlation with temperature, whereas there is a strong negative correlation with euphausiids. Three-year-old shrimp are significantly correlated with the number of 2-year-old shrimp the previous year but negatively

  9. ENVIMINE - developing environmental and geodynamical safety related to mine closure in the Barents region

    NASA Astrophysics Data System (ADS)

    Väisänen, Ulpu; Kupila, Juho; Kozyrev, Anatoly; Konukhin, Vladimir; Alakangas, Lena

    2015-04-01

    A project of mining environmental research in the Barents region was carried out in 2012-2014, in cooperation between Geological Survey of Finland, Mining Institute of Kola Science Centre, Russian Academy of Sciences, Russia, and Luleå University of Technology, Sweden. The study areas were the active chrome mine of Kemi in Northern Finland, and the closed mines of Umbozero in Murmansk region, Northwestern Russia, and Laver in Northern Sweden. Umbozero mine, producing rare earth metals, was in operation 1984-2004. Laver mine with iron sulphide ore, producing copper, was in operation 1936-1946. The objectives of the project were to develop a methodology for environmentally safe mine closure by cross border cooperation, and to produce information of the mining environment for target groups. The aim was also to find out solutions for minimizing environmental impacts and to develop multilateral relations between Finnish, Russian and Swedish organizations, responsible for environmental management. The studies were carried out by sampling and analyzing of groundwater and surface water, surficial deposits and organic sediments of streams in the mine sites and reference areas. Composition of deposits in the tailings was carried out by means of geophysical measurements (GPR, XRF). Research data of Kemi mine indicate diminished emissions, especially after open pit mining was finished in 2006. The results in Laver, Sweden, indicate that the oxidation rate in the tailings has decreased over time, which may be due to the increased distance over which oxygen needs to diffuse to reach unoxidised sulphide grains in the tailings. Problems in Umbozero are seismic instability, high pH values of waters (max. 10.4), fluorine and aluminum concentrations in the mine site, due to the rock type. Concentrations were decreasing downstream, also heavy metal concentrations were low. Results of the project are the basis for updated database of environmental condition of the study areas and for

  10. Bacterial biomass and activity in the marginal ice zone of the northern Barents Sea

    NASA Astrophysics Data System (ADS)

    Tammert, Helen; Olli, Kalle; Sturluson, Maria; Hodal, Helene

    2008-10-01

    Bacteria in the Arctic Waters are well adapted to low temperatures and play a key role in the transformation of organic matter. However, the activity of planktonic bacteria at cellular level remains poorly understood. In this study, we use fluorescent markers (4',6'-diamidino-2-phenylindole (DAPI), 5-cyano-2,3-ditolyl tetrazolium chloride (CTC), Live/Dead BacLight viability kit) to discriminate between bacterial cells with a variety of physiological activities in the 0-200 m water column and sinking particles. During two field studies (July 2003 and 2004), we covered nine stations in the northern Barents Sea. The median bacterial abundance (DAPI staining) in the upper 50 m layer was 0.9×10 6 cells ml -1 (range 0.2-3.2×10 6 cells ml -1) in 2003 and 0.5×10 6 cells ml -1 (range 0.2-1.0×10 6 cells ml -1) in 2004. Bacteria with sufficient electron transport activity to be stained with CTC were on average 10% of the total count and ca. 20% of the total cells had intact cell membranes. In the water column, proxies of substrate availability (POC, PON, chlorophyll a, primary production) and bacterial production (thymidine and leucine uptake) correlated strongly with total bacterial count, CTC-stained cells and cells with 'leaky' membrane (stained with propidium iodine), but not with the concentration of cells with intact cell membrane. Contrary to expectations, the proportion of CTC-stained bacteria was not higher in the sinking particles (captured with sediment traps) compared to the ambient water. However, out of the bacteria with intact cell membranes, a higher proportion scored as CTC positive in the aggregates compared to the ambient water. Bacterial cells with 'leaky' cell membranes formed the largest part of total cell count in all samples, and accumulated in sites with high microbial activity (sinking aggregates, chlorophyll maxima, layers of high primary and bacterial production). We hypothesize that the source of the bacterial cells with 'leaky' cell membranes

  11. Crustal and basin evolution of the southwestern Barents Sea: from the Caledonian orogeny to continental breakup

    NASA Astrophysics Data System (ADS)

    Gernigon, Laurent; Brönner, Marco; Roberts, David; Olesen, Odleiv

    2013-04-01

    A new generation of aeromagnetic data documents the post-Caledonian tectonic evolution of the southwestern Barents Sea (SBS) up to the continent-ocean transition. Clear evidence of reactivation of Caledonian structures controlling both, Late Palaeozoic and Mesozoic basins can be observed at the edge of the Hammerfest and Nordkapp basins where reactivated low-angle detachments are observed on seismics. Our new aeromagnetic surveys confirm most of the previous structural elements, but new features appear and illustrate the complexity of the pre-Permian tectonic and the basement architecture in the SBS. We propose an updated tectonic scenario of the SBS where the Caledonian nappes and thrust sheets, well constrained onshore, swing anticlockwise from a NE-SW trend close to the Varanger Peninsula to NW-SE across the Nordkapp Basin and the Bjarmeland Platform. On the Bjarmeland Platform, the dominant magnetic grain is clearly NNW-SSE. We show that this pattern reflects a regional pre-Permian system involving several Caledonian thrust sheets that possibly collapsed and controlled the post-Caledonian late Palaeozoic rift development of the SBS. We also consider that this model can explain the later development of the SBS. One specific case is the Bjørnøya Basin, located between the Loppa and Stappen highs which are interpreted as a series of rigid and poorly thinned continental blocks (ribbons) flanked by the Hammerfest and Bjørnøya basins and the basins of the Vestbakken volcanic province. As part of this extensive complex system, the Bjørnøya Basin is interpreted as a extensively thinned and propagating system that aborted in Late Mesozoic time. This thick, Cretaceous sag basin is characterised by a deep high-density body, interpreted as a combination of exhumed lower crust and/or potential serpentinised mantle as suggested by potential field modelling. The abortion of this propagating basin may be partly explained by its trend, which is oblique to the inherited

  12. Geomagnetic palaeosecular variation around 15 ka ago from NW Barents Sea cores (south of Svalbard)

    NASA Astrophysics Data System (ADS)

    Sagnotti, Leonardo; Macrì, Patrizia; Lucchi, Renata G.

    2016-02-01

    The sedimentary sequence deposited during the deglaciation phase following the last glacial maximum in the Storfjorden trough, on the northwestern Barents Sea south of Svalbard, was sampled with 10 piston and gravity cores during the SVAIS and EGLACOM cruises. Three cores (SV-02, SV-03 and SV-05) collected on the upper continental slope are characterized by a thin (20-40 cm) Holocene interval and a thick (up to 4.5 m in core SV-03) late Pleistocene sequence of finely laminated fine-grained sediments that have been interpreted as plumites deposited during the Melt Water Pulse 1a (MWP-1a). Radiocarbon ages obtained at the top and bottom of this stratigraphic interval revealed that deposition occurred during less than two centuries at around 15 ka ago, with a very high sedimentary rate exceeding 3 cm a-1. We studied the palaeomagnetic and rock magnetic properties of this interval, by taking magnetic measurements at 1 cm spacing on u-channel samples collected from the three cores. The data show that this sequence is characterized by good palaeomagnetic properties and the palaeomagnetic and rock magnetic trends may be correlated at high resolution from core to core. The obtained palaeomagnetic data therefore offer the unique opportunity to investigate in detail the rate of geomagnetic palaeosecular variation (PSV) in the high northern latitudes at a decadal scale. Notwithstanding the palaeomagnetic trends of the three cores may be closely matched, the amplitude of directional PSV and the consequent virtual geomagnetic pole (VGP) scatter (S) is distinctly higher in one core (SV-05) than in the other two cores (SV-02 and SV-03). This might result from a variable proportion of two distinct populations of magnetic minerals in core SV-05, as suggested by the variable tendency to acquire a gyromagnetic remanent magnetization at high fields during the AF demagnetization treatment. For the plumite interval of cores SV-02 and SV-03, where the magnetic mineralogy is uniform and

  13. High-resolution 3D seismic investigation of giant seafloor craters in the Barents Sea

    NASA Astrophysics Data System (ADS)

    Waage, Malin; Bünz, Stefan; Andreassen, Karin

    2016-04-01

    Multiple giant craters exist on the seafloor in an area of ~ 100 km2 east of Bear Island Trough in the west-central Barents Sea. It has been hypothesized that these craters might have been caused by gas eruptions following the last deglaciation. Gas seepage from the seafloor occurs abundantly in this area. The crater area is still likely to represent one of the largest hot-spots for shallow marine methane release in the arctic. In summer 2015, we acquired high-resolution P-Cable 3D seismic data in this area covering several of the craters and their associated pingo structures. Due to the shallow and hard Triassic bedrock, penetration of the seismic signals is limited to approximately 450 ms bsf. The crater structures are up to 1 km wide and 40 m deep. Pingo structures occur on the rim of some of the craters and are up to 700 m wide and up to 15 m high above the surrounding seafloor. The 3D seismic data reveals faults, fracture networks and weakness zone that resemble pipes or similar vertical, focused fluid-flow structures in the Triassic sedimentary rocks below the craters. The principal orientation of the faults is in a ~ NW-SE direction that coincides with regional faulting from Permo-Triassic extension. The seismic data also show high-amplitude anomalies beneath some of representing shallow gas accumulations that might be the intermediate source of the gas seepage. This might suggest that craters are caused by high pressured gas that migrated from deeper petroleum systems and accumulated in the shallow Triassic rocks during the last glaciation. Previous work indicate that craters of similar size are likely a cause of enormous blow-outs of gas. Our study discusses the formation mechanisms and timing of these potential blow-out craters and whether they formed during the last deglaciation, when this area was likely quite unstable as severe glacial erosion caused localized high isostatic rebound rates here. We also investigate the role of gas hydrates that might

  14. Final deglaciation of the Barents Sea at 12.9 ka and potential trigger of the Arctic atmospheric dipole

    NASA Astrophysics Data System (ADS)

    Hormes, Anne; Briner, Jason

    2016-04-01

    The specific configuration and history of the marine-based Barents Sea ice sheet has been under dispute for decades. Bjørnøya is situated between northern Fennoscandia and the Svalbard archipelago and therefore lies in a key position for understanding the maximum configuration and final retreat of the ice sheet. Bjørnøya also lies between two important trough systems that contributed to the ice sheet drainage: the Bjørnøya and Storfjorden palaeo-ice streams. We obtained 24 cosmogenic 10Be exposure ages from glacial erratics on southern Bjørnøya to 1) investigate the timing of initial deglaciation of the Barents Sea ice sheet, and 2) determine the timing of complete deglaciation of the island. The 10Be ages are from glacially transported sandstone and conglomerate boulders situated in the southern part of the island, calculated using the Arctic 10Be production rate, and presented with analytical uncertainty. 18 10Be ages exhibit a very strong mode from 11.9 to 14.5 ka, averaging 12.9 ± 0.6 ka, a much smaller mode from 24.6 to 26.2 ka (averaging 25.6 ± 1.2 ka), and three samples were excluded as outliers scattering at different times (3.6 ± 0.2 ka, 16.3 ± 0.7 ka and 19.6 ± 1.0 ka). Boulders between 17 and 293 m a.s.l. and the highest samples from Antarcticafjellet (340-351 m a.s.l.) indicate ages averaging 12.9 ± 0.6 ka. These boulders indicate the final deglaciation of restricted local remnants of ice covering the higher Antarctic and Alfred mountains and leaving well-preserved moraine sequences in the lowlands. We will discuss the ice-free Barents Sea as a potential precondition to build up low pressure in this region needed for a strong Arctic atmospheric dipole. In turn a strong Arctic atmospheric dipole causes increase in Meridional winds succeeding in transport of Arctic sea ice into the North Atlantic with the trans-polar drift.

  15. Geochemical monitoring of the bottom sediments of the Barents Sea - exogenous and endogenous sources of polyaromatic hydrocarbons.

    NASA Astrophysics Data System (ADS)

    Petrova, Vera I.; Kursheva, Anna; Litvinenko, Ivan; Morgunova, Inna

    2016-04-01

    Detailed organic geochemical study of the immersed bottom sediments of the Northern and North-Western parts of the Barents Sea region indicated the significant difference in the group and molecular composition of the dispersed organic matter (DOM). Hydrocarbons (HCs) distribution anomalies were identified in the western part of the Svalbard Island shelf, the area around the Shtokman gas condensate field and the Kola-Kanin Monocline shelf zone. The studied sediments (9 cores, up to 2 m length) were collected during scientific research cruises of "VNIIOkeangeology named after I.S. Gramberg" (Saint-Petersburg, Russia) to the Barents Sea between 1992-2006. Analytical procedure included the determination of elementary (TOC, Ccarb), group and molecular composition of DOM soluble part using preparative liquid chromatography and GC-MS analysis with the Agilent Technologies 6850/5973 GC System. The studied samples are generally represented by low carbonate homogeneous pelites and aleuropelites (Ccarb≤0.8% in sed.). The total organic carbon slightly varies through the sediment section and regularly decreases with depth, not exceeding 2% in the upper layer of sediments for the region. The maximum of chloroform bitumoid "a" was detected in the Svalbard shelf area (up to 0.04% in sed.). The molecular composition and ratio of PAHs in the Svalbard samples points to the high level of OM transformation (MPI1≥0.6), that along with the lack of biogenic structures (perylene, cadalene, rethene) and increased concentrations of naphthidogenic PAHs (phenanthrene, alkyl-phenanthrenes), indicates the genetic association with the shore coal deposits. The Shtockman and Kola-Kanin Monocline sediments revealed other general trends in PAHs distribution. They are distinguished by a lower maturity level (MPI1<0.5), halving of naphthidogenic components and the great increase of biogenic structures (mainly perylene) relatively the Svalbard shelf zone. In the case of the Shtokman gas

  16. Application of variable-number tandem-repeat typing to discriminate Ralstonia solanacearum strains associated with English watercourses and disease outbreaks.

    PubMed

    Parkinson, Neil; Bryant, Ruth; Bew, Janice; Conyers, Christine; Stones, Robert; Alcock, Michael; Elphinstone, John

    2013-10-01

    Variable-number tandem-repeat (VNTR) analysis was used for high-resolution discrimination among Ralstonia solanacearum phylotype IIB sequevar 1 (PIIB-1) isolates and further evaluated for use in source tracing. Five tandem-repeat-containing loci (comprising six tandem repeats) discriminated 17 different VNTR profiles among 75 isolates from potato, geranium, bittersweet (Solanum dulcamara), tomato, and the environment. R. solanacearum isolates from crops at three unrelated outbreak sites where river water had been used for irrigation had distinct VNTR profiles that were shared with PIIB-1 isolates from infected bittersweet growing upriver of each site. The VNTR profiling results supported the implication that the source of R. solanacearum at each outbreak was contaminated river water. Analysis of 51 isolates from bittersweet growing in river water at different locations provided a means to evaluate the technique for studying the epidemiology of the pathogen in the environment. Ten different VNTR profiles were identified among bittersweet PIIB-1 isolates from the River Thames. Repeated findings of contiguous river stretches that produced isolates that shared single VNTR profiles supported the hypothesis that the pathogen had disseminated from infected bittersweet plants located upriver. VNTR profiles shared between bittersweet isolates from two widely separated Thames tributaries (River Ray and River Colne) suggested they were independently contaminated with the same clonal type. Some bittersweet isolates had VNTR profiles that were shared with potato isolates collected outside the United Kingdom. It was concluded that VNTR profiling could contribute to further understanding of R. solanacearum epidemiology and assist in control of future disease outbreaks. PMID:23892739

  17. Arctic layer salinity controls heat loss from deep Atlantic layer in seasonally ice-covered areas of the Barents Sea

    NASA Astrophysics Data System (ADS)

    Lind, Sigrid; Ingvaldsen, Randi B.; Furevik, Tore

    2016-05-01

    In the seasonally ice-covered northern Barents Sea an intermediate layer of cold and relatively fresh Arctic Water at ~25-110 m depth isolates the sea surface and ice cover from a layer of warm and saline Atlantic Water below, a situation that resembles the cold halocline layer in the Eurasian Basin. The upward heat flux from the Atlantic layer is of major concern. What causes variations in the heat flux and how is the Arctic layer maintained? Using observations, we found that interannual variability in Arctic layer salinity determines the heat flux from the Atlantic layer through its control of stratification and vertical mixing. A relatively fresh Arctic layer effectively suppresses the upward heat flux, while a more saline Arctic layer enhances the heat flux. The corresponding upward salt flux causes a positive feedback. The Arctic layer salinity and the water column structures have been remarkably stable during 1970-2011.

  18. Integrated interpretation to improve subsalt imaging: a case study from the Nordkapp Basin, Norwegian Barents Sea

    NASA Astrophysics Data System (ADS)

    Olaf Müller, Christian; Brönner, Marco; Götze, Hans-Jürgen

    2015-04-01

    Seismic imaging of subsalt structures is still a difficult task and remaining uncertanties in the salt geometries makes exploration in the vicinity of such complex structures challenging. Gravity and magnetic data have proofed in the past their potential in combination with seismics to better delineate the shape of such salt structures. The current work deals with the improvement of subsalt imaging by combined interpretation of seismic and potential field data examined at a case study from the southern Nordkapp Basin. The Nordkapp Basin is a deep, narrow saliferous basin located in the southwestern Barents Sea. It comprises more than 30 salt diapirs, which are likely to create traps for hydrocarbons at their flanks and overhangs. Consequently exploration of the Nordkapp Basin with seismic methods started already in the 1980s, but until today solely seismics was not sufficient to reveal the nature and geometry for large parts of the basin. Therefore 2D and 3D seismic data were interpreted and used as stratigraphic constraints for the potential field modeling. For this purpose high resolution gravity and full tensor gravity gradient (FTG) data as well as a regional magnetic dataset were available. After processing the potential field data the 3D modeling was conducted by means of the interactive gravity and magnetic modeling software IGMAS+. Furthermore constraints for the rock properties, provided by well logs and susceptibility measurements of adjacent sedimentary well cores, were integrated. The favoured models indicate for both major salt structures a bulky base and a small root. The depth of the base of salt can vary in a range of about ± 300 m. Remaining mother salt is found in the northern part of the survey area and has no connection to the diapiric salt. Due to its higher sensibility to shallower sources the FTG data was used to model the flanks of the salt diapirs. In agreement with adjacent diapirs and encountered sequences a cap rock coverage was

  19. Recording of remote ground explosions in the Barents Region by the Seismic &Infrasound Integrated Array "Apatity"

    NASA Astrophysics Data System (ADS)

    Vinogradov, Y.; Vinogradov, A.

    2003-04-01

    Since 1996, Kola Regional Seismological Centre (KRSC) has been engaged in infrasonic research and development. As part of this effort, a small-aperture microbarographic array was installed in conjunction with the seismic array near lake Imandra in the Kola Peninsula; the digitised data are transmitted in real time to the Processing Centre in Apatity; a data processing includes frequency-wavenumber analysis of the array recordings, estimation of phase velocity and azimuth, and evaluation of group velocity based on travel time calculations. The whole system was named the Seismic and InfraSound Integrated Array (SISIA) "Apatity". We present some examples of coupled recordings for selected events in the Kola Peninsula and adjacent regions. Explosions at large mines in the Barents region are routinely detected by the seismic systems installed in northern Fennoscandia and NW Russia. Seismic and infrasound emission from Khibiny, Pechenga, Kovdor and Olenegorsk mines in the Murmansk County are recording by SISIA "Apatity", and the presented 19 reference records show a high sensitivity of the system and a good accuracy for localisation of events within distance range of 30 to 220 km. A capability of the SISIA for detection of events in a remote zone (more than 220 km) was evaluated in case study performed in September 04 - 09, 2002. A set of explosions caused by ammunition demolition in Northern Finland, at a distance of 300 km from the array, have been successfully recorded in Apatity. Three separate phase arrivals for each of five events were identified as follows: the Tropospheric arrival (Iw), the Stratospheric arrival (Is) and the Thermospheric arrival (It). Was found, that all 15 estimates of azimuth are very consistent, ranging from 278 to 288 degrees (true azimuth is 284 degrees). The observed group velocities (average travel velocities) range between 326-336 m/s for the Iw arrival, 300-305 m/s for the Is arrival and 244-254 m/s for the It arrival. The phase

  20. Climate change and projections for the Barents region: what is expected to change and what will stay the same?

    NASA Astrophysics Data System (ADS)

    Benestad, Rasmus E.; Parding, Kajsa M.; Isaksen, Ketil; Mezghani, Abdelkader

    2016-05-01

    We present an outlook for a number of climate parameters for temperature, precipitation, and storm statistics in the Barents region. Projected temperatures exhibited strongest increase over northern Fennoscandia and the high Arctic, exceeding 7 °C by 2099 for a typical ‘warm winter’ under the RCP4.5 scenario. More extreme temperatures may be expected with the RCP8.5, with an increase exceeding 18 °C in some places. The magnitude of the day-to-day variability in temperature is likely to decrease with higher temperatures. The skill of the downscaling models was moderate for the wet-day frequency for which the projections indicated both increases and decreases within the range of ‑5–+10% by 2099. The downscaled results for the wet-day mean precipitation was poor, but for the warming associated with RCP 4.5, it could result in wet-day mean precipitation being intensified by as much as 70% in 2099. The number of synoptic storms over the Barents Sea was found to increase with a warming in the Arctic, however, other climate parameters may not change much, such as the persistence of the temperature and precipitation. These climate change projections were derived using a new strategy for empirical-statistical downscaling, making use of principal component analysis to represent the local climate parameters and large ensembles of global climate model (GCM) simulations to provide information about the large scales. The method and analysis were validated on three different levels: (a) the representativeness of the GCMs, (b) traditional validation of the downscaling method, and (c) assessment of the ensembles of downscaled results in terms of past trends and interannual variability.

  1. Assessing environmental impact from gas and oil exploration in the SW Barents Sea using benthic foraminiferal assemblages

    NASA Astrophysics Data System (ADS)

    Dijkstra, N.; Junttila, J.; Husum, K.; Carroll, J.; Hald, M.

    2012-04-01

    During the last decades petroleum industry and shipping activities have increased in the SW Barents Sea. Oil exploration wells were drilled in the 1980s with production starting in 2007. These activities are projected to expand in the coming years. As part of the Northern Environmental Waste Management (EWMA) project, a competence cluster for petroleum industry related waste handling, we investigate the impacts of enhanced anthropogenic activities on benthic foraminiferal assemblages in the SW Barents Sea. Sediment cores (0-20 cm) from sites in proximity to two oil- and gas fields are under investigation. These sediment cores, dated with the 210Pb method, represent the last 90 to 150 years. Both dead and living benthic foraminifera (100 µm-1 mm) were counted to elucidate differences in foraminiferal assemblages between pre-impact and recent conditions. In addition, the heavy metal concentrations, persistent organic pollutant (POP) concentrations, grain size and total organic content (TOC) of the sediment cores have been analyzed. Pollution levels of the surface sediments (0-1 cm) are of background to good level (level I-II) according to the definitions of the Water Framework Directorate (WFD). Patterns in living benthic foraminiferal assemblages identified in the sea floor surface sediments, are the result of natural environmental changes such as depth, water mass and sediment composition. Further downcore (1-20 cm) pollution levels are in general of background environmental status (WFD level I). However, at some depth intervals, especially in sediment cores from the near proximity of the oil- and gas- fields, pollution levels are slightly enhanced (WFD level II). Further work will include statistical comparison of dead and living foraminiferal assemblages with sediment pollution levels, sediment properties, and oceanographic conditions. This research contributes to the development of foraminifera as a useful bio-monitoring technique for the Arctic region as

  2. Rock Physical study on an Upper-Palaeozoic Chert and Carbonate Interval in Wells from the Eastern Norwegian Barents Sea.

    NASA Astrophysics Data System (ADS)

    Colpaert, A.; Mienert, J.; Fotland, B.

    2004-12-01

    Due to their general interest as hydrocarbon reservoir, the Upper Palaeozoic chert and carbonate interval in the Norwegian Barents Sea has been investigated from seismic data and well logs. We established a framework for geophysical well log analysis and reservoir characterization for the Finnmark Platform, an area situated in the South-Eastern part of the Norwegian Barents Sea. The interval is composed by approximately 600 m carbonate facies covered by a 60 m interval of spiculitic chert facies. The carbonate facies is characterized by lateral and vertical lithological variations including limestones, dolomites, evaporites and clastic material. The spiculitic interval exists in spiculitic chert and clay alternated with limestones. Data extends over an area with different palaeo environments from inner platform settings to continental slope and even basinal settings. Log curve data from four wells were processed through geophysical well log analysis using Powerlog and Matlab. Multi-well trend analysis was performed for a diagnostic modeling of the rock physical parameters. The examination of the variation of petrophysical properties, and how that variation transfers into the elastic domain is a key to the correlation of rock properties and the seismic attribute information. The final goal is to improve porosity and mineralogy predictions in pseudo-wells from 3D seismic data. The analyses of cross plots allow distinguishing several intervals which in certain cases correspond to individual stratigraphic units. The spiculite interval shows for example different rock types based on rock physics and these parameters can be linked with seismic. For the synthetic seismogram an s-wave velocity log has been modeled. We observed that for several lithological intervals such as the mixed limestone-dolomites and spiculites the Greenberg-Castagna model fitted the best, but for pure dolomite intervals the Krief model is more accurate. Furthermore, for the purest limestone the

  3. Late Quaternary History of River Discharge and Glaciation in the Southern Kara Sea, Arctic Ocean: Preliminary Results

    NASA Astrophysics Data System (ADS)

    Stein, R.; Niessen, F.; Dittmers, K.; Levitan, M.; Levitan, M.; Schoster, F.; Simstich, J.; Steinke, T.; Stepanets, O.

    2001-12-01

    Within the framework of the joint German-Russian project on "The Nature of Continental Run-Off from the Siberian Rivers and its Behavior in the Adjacent Arctic Basin (Siberian River Run-Off-SIRRO)", a multidisciplinary expedition with RV "Akademik Boris Petrov" was carried out in the Ob and Yenisei estuaries and the southern Kara Sea in August-September 2001. From the geological point of view, the variability of river discharge in relationship to climate change and the reconstruction of extent and history of glaciation in the southern Kara Sea during Late Quaternary times are major foci of interest. To reach these goals, an intensive sediment ecosounding (2-12 kHz) survey and sediment coring program has been performed. Based on profiling and sediment core data, the following preliminary statements can be given: (1) The extent of the eastern margin of the Barents Sea LGM Ice Sheet between 74 and 78oN can be mapped in detail. Different types of glacial to nonglacial facies can be distinguished. This ice barrier should have strongly influenced river discharge, diverted towards the NE probably into the Voronin Trough. (2) The local LGM (?) ice sheet on Taymyr Peninsula seems to be not connected with the Barents Sea Ice Sheet. (3) Siberian river discharge reached maximum values during the last deglaciation and displays distinct (cyclic) variability during Holocene times. Further detailed evaluation of the sediment echograph profiles as well as detailed sedimentological studies and AMS 14C datings will follow to support these ideas.

  4. Joint pre-stack depth migration and travel-time tomography applied to a deep seismic profile across the northern Barents Sea igneous province

    NASA Astrophysics Data System (ADS)

    Minakov, Alexander; Faleide, Jan Inge; Sakulina, Tamara; Krupnova, Natalia; Dergunov, Nikolai

    2015-04-01

    The mainly Permo-Triassic North Barents Sea Basin is considered as a superdeep intracratonic basin containing over 20 km of sedimentary material. This basin was strongly affected by magmatism attributed to the formation of the Early Cretaceous High Arctic Large Igneous Province. Dolerite dikes, sills, and lava flows are observed in the northern Barents Sea and on the islands of Svalbard and Franz Josef Land. Some dike swarms can be traced over hundreds of kilometers using high-resolution airborne magnetic data. In the North Barents Sea Basin, the dikes fed giant sill complex emplaced into organic-rich Triassic siliciclastic rocks. The sill complex creates a major challenge for seismic imaging masking the underlying strata. In this contribution, we first perform refraction and reflection travel-time tomography using wide-angle ocean-bottom seismometer data (with receivers deployed every 10 km) along the 4-AR profile (Sakulina et al. 2007, Ivanova et al. 2011). The resulting tomographic model is then used to construct a background velocity model for the pre-stack depth migration. We show that the use of a combined velocity model for the time and depth imaging based on travel-time tomography and RMS velocities constitutes a substantial improvement with respect to a standard processing workflow providing a more coherent seismic structure of this volcanic province. The interpretation of multichannel seismic and high-resolution magnetic data together with P-wave velocity and density anomalies allow to create a model for the system of magmatic feeders in the crystalline basement of the northern Barents Sea region. Sakulina, T.S., Verba, M.L., Ivanova, N.M., Krupnova, N.A., Belyaev I.V., 2007. Deep structure of the north Barents-Kara Region along 4AR transect (Taimyr Peninsula - Franz Joseph Land). In: Models of the Earth's crust and upper mantle after deep seismic profiling. Proceedings of the international scientific-practical seminar. Rosnedra, VSEGEI. St

  5. River Networks As Ecological Corridors for Species, Populations and Pathogens of Water-Borne Disease

    NASA Astrophysics Data System (ADS)

    Rinaldo, A.

    2014-12-01

    River basins are a natural laboratory for the study of the integration of hydrological, ecological and geomorphological processes. Moving from morphological and functional analyses of dendritic geometries observed in Nature over a wide range of scales, this Lecture addresses essential ecological processes that take place along dendritic structures, hydrology-driven and controlled, like e.g.: population migrations and human settlements, that historically proceeded along river networks to follow water supply routes; riparian ecosystems composition that owing to their positioning along streams play crucial roles in their watersheds and in the loss of biodiversity proceeding at unprecedented rates; waterborne disease spreading, like epidemic cholera that exhibits epidemic patterns that mirror those of watercourses and of human mobility and resurgences upon heavy rainfall. Moreover, the regional incidence of Schistosomiasis, a parasitic waterborne disease, and water resources developments prove tightly related, and proliferative kidney disease in fish thrives differently in pristine and engineered watercourses: can we establish quantitatively the critical linkages with hydrologic drivers and controls? How does connectivity within a river network affect community composition or the spreading mechanisms? Does the river basin act as a template for biodiversity or for species' persistence? Are there hydrologic controls on epidemics of water-borne disease? Here, I shall focus on the noteworthy scientific perspectives provided by spatially explicit eco-hydrological studies centered on river networks viewed as ecological corridors for species, populations and pathogens of waterborne disease. A notable methodological coherence is granted by the mathematical description of river networks as the support for reactive transport. The Lecture overviews a number of topics idiosyncratically related to my own research work but ideally aimed at a coherent body of materials and methods. A

  6. The annual invasive plant, Impatiens glandulifera (Himalayan Balsam) as a trigger for high-magnitude soil erosion in temperate river systems

    NASA Astrophysics Data System (ADS)

    Greenwood, Philip; Kuhn, Nikolaus

    2015-04-01

    The invasive plant, Impatiens glandulifera (common English name: Himalayan Balsam), is now found in most temperate European countries, as well as across large parts of North America and on some Australasian islands. As a ruderal species, it favours damp, fertile soils that experience frequent disturbance. Riverbanks and the riparian zone thus represent prime habitat. Its ability to out-compete most perennial vegetation yet tendency to suddenly die during seasonally cold weather has led to claims that it may promote soil erosion, particularly along inland watercourses. Despite the strong implication, this was only recently proven during an investigation conducted over one dieback and regrowth cycle in 2012/13 along a watercourse in northwest Switzerland. Here we reinterpret those initial findings and also present additional data from the same watercourse which now covers three die-off and regrowth cycles, as well as data over two die-off and regrowth cycles from a river system in southwest UK. Results from all monitoring campaigns strongly support the original conclusion that I. glandulifera promotes significant soil erosion along contaminated sections of riverbank and riparian zone. More specifically, however, approximately one third of the total number of contaminated locations monitored (n=41) recorded net ground surface retreat that exceeded, by at least one order of magnitude, equivalent annual erosion rates documented on cultivated hillslopes in temperate regions. Not only does I. glandulifera induce repeat cycles of colonization and die-off, therefore, but collectively, the results generated so far strongly infer that under certain circumstances, this cycle of events can commonly trigger severe or even extreme erosion. Seasonally induced soil loss of this magnitude, particularly along short sections of watercourses, is unsustainable in the long-term and may lead to key fluvial features undergoing profound morphological and structural changes. Such an effect

  7. Predictability of the Barents Sea ice in early winter: Remote effects of oceanic and atmospheric thermal conditions from the North Atlantic

    NASA Astrophysics Data System (ADS)

    Nakanowatari, Takuya; Sato, Kazutoshi; Inoue, Jun

    2015-04-01

    Predictability of sea ice concentrations (SICs) in the Barents Sea in early winter (November-December) is studied using canonical correlation analysis with atmospheric and ocean anomalies from the NCEP Climate Forecast System Reanalysis (NCEP-CFSR) data. We find that the highest prediction skill for a single-predictor model is obtained from the 13-month lead subsurface temperature at 200-m depth (T200) and the in-phase meridional surface wind (Vsfc). T200 skillfully predicts SIC variability in 35% of the Barents Sea, mainly in the eastern side. The T200 for negative sea-ice anomalies exhibits warm anomalies in the subsurface ocean temperature downstream of the Norwegian Atlantic Slope Current (NwASC) on a decadal timescale. The diagnostic analysis of NCEP-CFSR data suggests that the subsurface temperature anomaly stored below the thermocline during summer re-emerges in late autumn by atmospheric cooling and affects the sea-ice. The subsurface temperature anomaly of the NwASC is advected from the North Atlantic subpolar gyre over about 3 years. Vsfc skillfully predicts SIC variability in 32% of the Barents Sea, mainly in the western side. The Vsfc for the negative sea-ice anomalies exhibits southerly wind anomalies. Vsfc is related to the large-scale atmospheric circulation patterns from the subtropical North Atlantic to the Eurasian continent. Our study suggests that both atmospheric and oceanic remote effects have a potential impact on the forecasting accuracy of SIC.

  8. Nearshore half-grabens as analogues for offshore, early Carboniferous rift basins along the SW Barents Sea Margin

    NASA Astrophysics Data System (ADS)

    Koehl, Jean-Baptiste; Bergh, Steffen G.; Indrevær, Kjetil; Lea, Halldis; Bergø, Espen; Henningsen, Tormod; Forthun, Tore; Faleide, Jan-Inge

    2016-04-01

    The present study focuses on the onshore-offshore correlation of brittle faults along the SW Barents Sea Margin, northern Norway. Several studies indicate that the SW Barents Sea Margin experienced a pulse of extensional deformation in the Late Devonian?-early Carboniferous, shortly after the Caledonian contractional deformation ended. The formation of major brittle faults and associated offshore basins that represent targets for hydrocarbon exploration, such as the NE-SW trending Nordkapp Basin, are thought to have initiated during this rifting event. Half-graben structures similar in shape and orientation to the southern segment of the Nordkapp Basin have been identified on the Finnmark Platform and in nearshore areas in coastal Finnmark, northern Norway. Although relatively smaller, these half-graben structures display the same asymmetric, sigma-shaped to triangular architecture in map view as the Nordkapp Basin and also initiated in the earliest Carboniferous, as confirmed by fossiliferous assemblages from shallow cores. The triangular shape of these half-graben structures is related to the presence of possible fault segments of the Trollfjord-Komagelv Fault Zone that trend WNW-ESE and partly truncate the NE-SW trending, sometimes arcuate, extensional brittle faults that bound the half-graben structures. High-resolution bathymetry data show that these half-graben structures internally display minor, NE-SW trending brittle faults and relatively high seafloor relief, thus possible fault displacement, at the intersection between these minor faults and the major, arcuate bounding faults. Microstructural analysis of fault-rocks in nearby onshore fault zones showed multiple generations of cataclasite, suggesting several episodes of faulting in the region. A major goal for future work will be to constrain the exact timing of the faulting event(s) with K/Ar radiometric dating of onshore fault-rocks. This may help estimating the timing of potential fluid migration

  9. Structure and Temperature Configuration of the Barents Sea and Kara Sea region and implications for its lithospheric strength

    NASA Astrophysics Data System (ADS)

    Klitzke, Peter; Scheck-Wenderoth, Magdalena; Gac, Sebastien; Faleide, Jan Inge; Minakov, Alexander; Sippel, Judith

    2016-04-01

    The Arctic Barents Sea and Kara Sea are located between the Proterozoic East-European Craton in the south and Cenozoic passive margins in the north and the west. To investigate the present-day density and temperature structure of the underlying lithosphere, we assess how compositional heterogeneities in the subsedimentary crust control the distribution of thermal properties and consequently temperature anomalies. Considering the derived thermal configuration, we model the lithospheric strength and the effective elastic thickness and implications on the crustal deformation. We make use of a lithosphere-scale 3D structural model that resolves the thicknesses of five sedimentary units, two layers of the subsedimentary crust as well as the lithospheric mantle. The geometries of this 3D structural model are consistent with interpreted seismic refraction and reflection data, geological maps and previously published 3D-models. For the sedimentary units the density distribution is dependent on lithology, porosity and effects of post-depositional erosion. Density anomalies within the continental lithospheric mantle are derived from a recently published velocity-density model. Starting with this initial 3D gravity model, the density distribution is stepwise modified to reproduce the observed gravity field to further investigate the composition of the crystalline crust. The obtained density distribution within the lithosphere provides further constraints on regional variations in thermal properties to calculate the conductive 3D thermal field. The modelled 3D thermal field is validated with measured borehole temperatures to assess the major controlling factors of the latter. Based on the 3D structural and thermal model, we develop a rheological model assuming a brittle and temperature-dependent ductile rheology for the sediments, the crystalline crust and the lithospheric mantle. Our results indicate that the integrated lithospheric strength and the effective elastic

  10. Pelagic and sympagic contribution of organic matter to zooplankton and vertical export in the Barents Sea marginal ice zone

    NASA Astrophysics Data System (ADS)

    Tamelander, Tobias; Reigstad, Marit; Hop, Haakon; Carroll, Michael L.; Wassmann, Paul

    2008-10-01

    The structure and function of the marine food web strongly regulate the cycling of organic matter derived from primary production by phytoplankton and ice algae in Arctic shelf seas. Improved knowledge of trophic relationships and export of organic matter from the surface layer is needed to better understand how the Arctic marine ecosystem may respond to climate-related changes in distribution of sea ice, water masses, and associated primary production regimes. Pelagic and sympagic inputs of organic matter to dominant meso- and macrozooplankton species and vertical export were investigated in the northern Barents Sea by means of stable carbon and nitrogen isotopes (δ 13C and δ 15N). Samples were collected during spring and summer (2003-2005) from a total of 13 stations with different ice conditions, abundances of ice algae, and phytoplankton bloom phases. δ 13C signatures were different in organic matter of phytoplankton (mean -24.3‰) and ice algal origin (mean -20.0‰). Stable carbon isotope compositions showed that most of the energy assimilated by zooplankton originated from pelagic primary production, but at times ice algae also contributed to zooplankton diets. Trophic level (TL) estimates of copepods ( Calanus glacialis and Calanus hyperboreus) and krill ( Thysanoessa inermis and Thysanoessa longicaudata), calculated based on δ 15N values, varied among stations from 1.3 to 2.7 and from 1.5 to 3.1, for respective taxa. TL in C. glacialis was significantly and inversely related to the depth-integrated phytoplankton chlorophyll a concentration. A similar trend, although weaker, also was observed for the other species. This relationship indicates that copepods graze primarily on the abundant autotrophic biomass during the peak bloom phase. At stations with lower chlorophyll a concentration, the TL of Calanus spp. was 1.0 higher, indicating omnivory outside the peak bloom phase in response to changed food availability. The majority of organic matter

  11. Recent trends in nutrient concentrations in Swedish agricultural rivers.

    PubMed

    Ulén, B; Fölster, J

    2007-02-15

    In five out of twelve Swedish agricultural rivers examined during the period 1993-2004, significant trends for decreasing concentrations of reactive inorganic nitrogen (RIN) were indicated after flow normalisation. These decreases were constant (equal to 2-4% per year), most apparent in the Scania region, and weakly correlated to reductions in livestock density (Pearson correlation coefficient -0.825). The number of grazing cattle livestock units per unit area of arable land decreased on average by 14% and that of non-grazing cattle by 17% during 1985-2003. Based on estimates of root-zone leaching, increased area of set-aside and recent EU subsidisation of catch crops (with/without spring tillage) were suggested to be additional substantial causes but these changes were only rapid very recently (years 2000-2001). A significant and constant decrease in reactive phosphorus (RP) (3% per year) was observed in one river, mainly during the season of low flow, with reduced load from point sources suggested to be the main reason. Significant and constant reductions equal to 3-8% per year in concentrations of non-reactive phosphorus (NRP) were calculated for five rivers. These improvements were weakly correlated to the length of grassed buffer zones along the watercourses in arable parts of the river basin (Pearson correlation coefficient -0.845). Establishment of such zones also took place more recently, and together with constructed wetlands represent on average 0.5% of the agricultural area. PMID:17239939

  12. Source quality variations tied to sequence development: Integration of physical and chemical aspects, Lower to Middle Triassic, western Barents Sea

    SciTech Connect

    Bohacs, K.M.; Isaksen, G.H. )

    1991-03-01

    Triassic mudrocks from the Barents Sea area demonstrate to covariance of physical and chemical properties of mudrocks deposited in shelfal environments and the aspect of depositional sequences in distal settings. The tie of physical parameters to chemical character within a detailed sequence-stratigraphic framework enables the construction of depositional-facies models to predict organic-matter content and quality. This allows the explorer to more closely constrain and predict the nature of potential source rocks using seismic and well-log data. Changes in lithology, bedding geometry, sedimentary structures, body and trace-fossil assemblages, and inorganic, bulk-organic, and molecular geochemistry revealed the detailed depositional environments. The depositional environments stack predictably, according to their position in the depositional sequence: from aerobic lower-shoreface--offshore transition environments in lowstand systems tracts to dysaerobic-anaerobic distal open-marine-shelf environment in transgressive and early highstand systems tracts. Quantitative molecular geochemistry also revealed variations within this distal setting and strong covariance with sequence position. Input of organic matter from terrigenous higher plants dominates the lowstands whereas marine-algal organic matter is most prevalent within transgressive and highstand systems tracts. Specifically, the abundance of C{sub 30} steranes, total steranes, and moretane reflected development of the sequences.

  13. Preliminary Results of Marine Electromagnetic Sounding with a Powerful, Remote Source in Kola Bay off the Barents Sea

    NASA Astrophysics Data System (ADS)

    Kruglyakov, M.; Zhdanov, M. S.; Grigor'ev, V.; Korotaev, S.; Orekhova, D.; Scshors, Y.; Tereshchenko, E.; Tereshchenko, P.; Trofimov, I.

    2012-12-01

    The talk is devoted to a natural experiment conducted in Kola Bay off the Barents Sea in which new, six- component electromagnetic seafloor receivers were tested. Signals from a powerful, remote SLW transmitter at several frequencies on the order of tens Hz were recorded at the six sites along a profile across Kola Bay. In spite of the fact that, for technical reasons, not all the components were successfully recorded at every site, the quality of the experimental data was quite satisfactory. The experiment resulted in the successful simulation of an electromagnetic field by the integral equation method. An initial geoelectric model reflecting the main features of the regional geology produced field values that differed greatly from the experimental ones. However, step-by-step modification of the original model considerably improved the fit of the fields. This allowed to correct some features of the regional geology, the fault tectonics in particular. These preliminary results open the possibility of inverse problem solving with more reliable geological conclusions.

  14. Genotoxic evaluation of the River Paranaíba hydrographic basin in Monte Carmelo, MG, Brazil, by the Tradescantia micronucleus

    PubMed Central

    Campos, Carlos F.; Pereira, Boscolli B.; de Campos-Junior, Edimar O.; Sousa, Eduardo F.; Souto, Henrique N.; Morelli, Sandra

    2015-01-01

    Abstract Pollutants have adverse effects on human health and on other organisms that inhabit or use water resources. The aim of the present study was to assess the environmental quality of three watercourses in Monte Carmelo, MG, Brazil, using the micronucleus test on Tradescantia. For each treatment, 15 plants were exposed to water samples for 24 h. The control group was exposed to formaldehyde (0.2%) and the negative control to Hoagland solution. Subsequently the plants were placed in Hoagland solution for 24 h to recover. Cells were stained with 2% acetic carmine and examined by light microscopy. Three hundred tetrads were analyzed per slide. The frequency of genotoxic alterations was expressed as the number of micronuclei per 100 tetrads, and the groups were compared by ANOVA. At all sample sites for each watercourse significant genotoxicity indices were observed. The results suggest that in the Mumbuca creek, the current situation of effluent discharge should be reconsidered by the municipal environmental authorities. The increase in micronucleus frequency denoted for water samples of the Mumbuca creek, Lambari river and Perdizes river emphasizes the need to adopt environmental vigilance strategies, such as biological monitoring. PMID:26692158

  15. The effect of river damming on vegetation: is it always unfavourable? A case study from the River Tiber (Italy).

    PubMed

    Ceschin, Simona; Tombolini, Ilaria; Abati, Silverio; Zuccarello, Vincenzo

    2015-05-01

    River damming leads to strong hydromorphological alterations of the watercourse, consequently affecting river vegetation pattern. A multitemporal and spatial analysis of the dam effect on composition, structure and dynamic of the upstream vegetation was performed on Tiber River at Nazzano-dam (Rome). The main research questions were as follows: How does plant landscape vary over time and along the river? Where does the dam effect on vegetation end? How does naturalistic importance of the vegetation affected by damming change over time? Data collection was performed mapping the vegetation in aerial photos related to the period before (1944), during (1954) and after dam construction (1984, 2000). The plant landscape has significantly changed over time and along the river, particularly as a result of the dam construction (1953). The major vegetation changes have involved riparian forests and macrophytes. Dam effect on vegetation is evident up to 3 km, and gradually decreases along an attenuation zone for about another 3 km. Despite the fact that the damming has caused strong local hydromorphological modification of the river ecosystem transforming it into a sub-lacustrine habitat, it has also led to the formation of wetlands of considerable naturalistic importance. Indeed, in these man-made wetlands, optimal hydrological conditions have been created by favouring both the expansion of pre-existing riparian communities and the rooting of new aquatic communities, albeit typical of lacustrine ecosystems. Some of these plant communities have become an important food resource, refuge or nesting habitats for aquatic fauna, while others fall into category of Natura 2000 habitats. Therefore, river damming seems to have indirectly had a "favourable" effect for habitat conservation and local biodiversity. PMID:25920677

  16. Geophysical constraints on the dynamics and retreat of the Barents Sea ice sheet as a paleobenchmark for models of marine ice sheet deglaciation

    NASA Astrophysics Data System (ADS)

    Patton, Henry; Andreassen, Karin; Bjarnadóttir, Lilja R.; Dowdeswell, Julian A.; Winsborrow, Monica C. M.; Noormets, Riko; Polyak, Leonid; Auriac, Amandine; Hubbard, Alun

    2015-12-01

    Our understanding of processes relating to the retreat of marine-based ice sheets, such as the West Antarctic Ice Sheet and tidewater-terminating glaciers in Greenland today, is still limited. In particular, the role of ice stream instabilities and oceanographic dynamics in driving their collapse are poorly constrained beyond observational timescales. Over numerous glaciations during the Quaternary, a marine-based ice sheet has waxed and waned over the Barents Sea continental shelf, characterized by a number of ice streams that extended to the shelf edge and subsequently collapsed during periods of climate and ocean warming. Increasing availability of offshore and onshore geophysical data over the last decade has significantly enhanced our knowledge of the pattern and timing of retreat of this Barents Sea ice sheet (BSIS), particularly so from its Late Weichselian maximum extent. We present a review of existing geophysical constraints that detail the dynamic evolution of the BSIS through the last glacial cycle, providing numerical modelers and geophysical workers with a benchmark data set with which to tune ice sheet reconstructions and explore ice sheet sensitivities and drivers of dynamic behavior. Although constraining data are generally spatially sporadic across the Barents and Kara Seas, behaviors such as ice sheet thinning, major ice divide migration, asynchronous and rapid flow switching, and ice stream collapses are all evident. Further investigation into the drivers and mechanisms of such dynamics within this unique paleo-analogue is seen as a key priority for advancing our understanding of marine-based ice sheet deglaciations, both in the deep past and in the short-term future.

  17. [A comparative analysis of the helminth fauna of kittiwake Rissa tridactyla (Linnaeus, 1758) and glaucous gull Larus hyperboreus Gunnerus, 1767 from different parts of the Barents Sea].

    PubMed

    Kuklin, V V; Galaktionov, K V; Galkin, A K; Marasaev, S F

    2005-01-01

    The article is based on the results of helminthological observations made on kittiwake Rissa tridactyla and glaucous gull Larus hyperboreus in 1991-2001 in different areas of the Barents Sea (Eastern Murman coast, Franz Josef Land, Novaya Zemlya, Spitzbergen). 18 helminth species (2 trematodes, 11 cestodes, 4 nematodes, and 2 acanthocephalans) were recorded in the kittiwakes and 19 (3 trematodes, 9 cestodes, 5 nematodes and 2 acanthocephalans) species were recorded in the glaucous gulls. Trematodes were absent in the birds collected at the Franz Josef Land and the northern island of Novaya Zemlya. 3 trematode species, namely Gymnophallus sp. (somateria?), Microphallus sp. 1 (M. pseudopygmaeus), and Cryptocotyle lingua were found in the glaucous gulls of western Spitzbergen. It was supposed that the life cycles of these parasites can be completed there. On the other hand, coastal ecosystems of Arctic archipelagoes turn out to be favourable for the transmission of some cestodes. This is closely connected with the regional traits in the marine bird diet, namely the increase of the amphipod (intermediate hosts of hymenolepidids and some dilepidids) and polar cod (supposed second intermediate host for some tetrabothriids) portion in Arctic. As a result, cestodes are the base of the helminth fauna of kittiwakes and glaucous gulls of the Barents Sea, by their species richness, prevalence and abundance. Nematodes and acanthocephalans were represented by a few species with low infection intensity. The main ecological factors affected the regional difference in the species richness and abundance of the helminths parasitising kittiwakes and glaucous gulls in the Barents Sea are proposed. Those are regional climatic features and regional traits in the behaviour and food priorities of birds, and also the distribution of the helminths intermediate hosts, invertebrates and fishes. The phenomenon of host specificity lowering with respect to the definitive host was recorded in some

  18. Trophic relations of capelin Mallotus villosus and polar cod Boreogadus saida in the Barents Sea as a factor of impact on the ecosystem

    NASA Astrophysics Data System (ADS)

    Orlova, Emma L.; Dolgov, Andrey V.; Rudneva, Galina B.; Oganin, Ivan A.; Konstantinova, Ludmila L.

    2009-10-01

    The purpose of the study is to assess the role of trophic relations of the dominant pelagic fishes capelin and polar cod in the Barents Sea with regard to distribution and accessibility as prey for the Atlantic cod in warm years (2004-2005). Unlike in the previous period, during these warm years a dramatic increase of the polar cod population resulted in a northwards expansion of the feeding grounds where overlapping of polar cod and capelin concentrations was observed. This caused an increased competition for copepods, which are the main food item for young fish. In the areas dominated by polar cod the shortage of copepods forced immature capelin to switch to the chaetognath Sagitta, which affected their fatness negatively. During the warm years the feeding grounds of Atlantic cod also expanded, to a large degree caused by the shortage of their main food, the capelin. In 2004-2005 the cod formed feeding concentrations in the north and northeast Barents Sea where they fed on the capelin. In this area the consumption of polar cod by cod increased, and in some local areas the polar cod practically replaced the capelin in the diet of cod. In general polar cod in the diet of Atlantic cod were more important in the northern than in the southern part of the Barents Sea. The fatness of cod was extremely low during the whole spring-summer period (until August), and after the feeding period the fatness index of the Atlantic cod became lower than the average long-term autumn value.

  19. Emerging and priority contaminants with endocrine active potentials in sediments and fish from the River Po (Italy).

    PubMed

    Luigi, Viganò; Giuseppe, Mascolo; Claudio, Roscioli

    2015-09-01

    There is a substantial lack of information on most priority pollutants, related contamination trends, and (eco)toxicological risks for the major Italian watercourse, the River Po. Targeting substances of various uses and origins, this study provides the first systematic data for the River Po on a wide set of priority and emerging chemicals, all characterized by endocrine-active potentials. Flame retardants, natural and synthetic hormones, surfactants, personal care products, legacy pollutants, and other chemicals have been investigated in sediments from the River Po and its tributary, the River Lambro, as well as in four fish species from the final section of the main river. With few exceptions, all chemicals investigated could be tracked in the sediments of the main Italian river for tens or hundreds of kilometres downstream from the Lambro tributary. Nevertheless, the results indicate that most of these contaminants, i.e., TBBPA, TCBPA, TBBPA-bis, DBDPE, HBCD, BPA, OP, TCS, TCC, AHTN, HHCB, and DDT, individually pose a negligible risk to the River Po. In contrast, PBDE, PCB, natural and synthetic estrogens, and to a much lower extent NP, were found at levels of concern either to aquatic life or human health. Adverse biological effects and prohibition of fish consumption deserve research attention and management initiatives, also considering the transport of contaminated sediments to transitional and coastal environments of the Italian river. PMID:25956513

  20. Modelling of glacial isostatic adjustment in the Barents Sea region: Earth rheology inferred from various ice load scenarios for the last glacial cycle

    NASA Astrophysics Data System (ADS)

    Auriac, Amandine; Whitehouse, Pippa L.; Bentley, Michael J.; Patton, Henry; Hubbard, Alun; Lloyd, Jerry M.

    2015-04-01

    The Barents Sea, bordered by Norway to the south, Svalbard to the north and Novaya Zemlya to the east, was covered by ice during the last glacial cycle. The extent and thickness of the marine-based ice sheet as well as timing of glaciation / deglaciation are, however, difficult to constrain, partly due to the few terrestrial areas available. There are various models for the ice load history in this region, but large discrepancies remain between them depending on the dataset used as constraint (e.g. sea-level data, temperature record or geomorphology data). Our aim here is to compare and find the best ice load scenario for this region over the last glacial cycle and solve for the Earth structure in the area. To achieve this, we model the present-day crustal deformation and sea-level variations during the last deglaciation by solving the sea-level equation. We use a wide range of Earth models, where we vary the lithosphere thickness and the upper and lower mantle viscosities, as well as four ice load scenarios. The first three ice load scenarios come from published studies, and include the ICE-5G model as well as models from M. Siegert and J.-O. Näslund, while the last one is currently being developed at the University of Tromsø, Norway. We compare the modelled sea-level predictions to relative sea-level curves at key locations around the Barents Sea using chi square, which enables us to infer the best Earth structure and ice history. We also compare the predicted surface deformation from our best model with GPS observations from stations located around the Barents Sea. The GPS provides a constraint on the present-day evolution of deformation in the area and is complementary to the relative sea-level data, which constrain the long-term deformation. First results show that the published ice load scenarios are not accurate enough to reproduce the sea level curves around the Barents Sea, regardless of the Earth model tried. However, the last model, currently being

  1. Seasonal variation in biomarkers in blue mussel (Mytilus edulis), Icelandic scallop (Chlamys islandica) and Atlantic cod (Gadus morhua): implications for environmental monitoring in the Barents Sea.

    PubMed

    Nahrgang, J; Brooks, S J; Evenset, A; Camus, L; Jonsson, M; Smith, T J; Lukina, J; Frantzen, M; Giarratano, E; Renaud, P E

    2013-02-01

    In the Barents Sea, the limited data on biological relevant indicators and their responses to various anthropogenic stressors have hindered the development of a consistent scientific basis for selecting indicator species and developing practical procedures for environmental monitoring. Accordingly, the main aim of the present study was to develop a common set of baseline values for contaminants and biomarkers in three species, and to identify their strengths and limitations in monitoring of the Barents Sea. Blue mussel (Mytilus edulis), Icelandic scallop (Chlamys islandica) and Atlantic cod (Gadus morhua) were sampled from a north Norwegian fjord in March, June, September and December 2010. Digestive glands from the bivalve species and liver from Atlantic cod were analysed for biomarkers of oxidative stress (catalase [CAT], glutathione peroxidase [GPX], glutathione-S-transferase activities [GST], lipid peroxidation as thiobarbituric reactive substances [TBARS] and total oxyradical scavenging capacity [TOSC]), biotransformation (ethoxyresorufine-O-deethylase activity [EROD]) and general stress (lysosomal membrane stability [LMS]). Concentrations of polycyclic aromatic hydrocarbons (PAHs) and metals in the bivalves and PAH metabolites in fish bile were quantified. Finally, energy reserves (total lipids, proteins and carbohydrates) and electron transport system (ETS) activity in the digestive gland of the bivalves and liver of Atlantic cod provided background information for reproductive cycle and general physiological status of the organisms. Blue mussel and Icelandic scallop showed very similar trends in biological cycle, biomarker expression and seasonality. Biomarker baselines in Atlantic cod showed weaker seasonal variability. However, important biological events may have been undetected due to the large time intervals between sampling occasions. Physiological biomarkers such as energy reserves and ETS activity were recommended as complementary parameters to the

  2. Insights into the activity, formation and origin of seep systems on the seafloor in the SW Barents Sea

    NASA Astrophysics Data System (ADS)

    Mangelsdorf, Kai; Nickel, Julia C.; di Primio, Rolando; Kallmeyer, Jens; Horsfield, Brian; Stoddart, Daniel; Brunstad, Harald

    2014-05-01

    The southwestern Loppa High region, being part of the Barents Sea located in the north of Norway, is a promising area for oil and gas exploration since hydrocarbon discoveries have been made in this area in recent time. Additionally, surface features for hydrocarbon seepage, so called "cold seeps" have been detected on the seafloor, comprising extensive pockmark fields, carbonate crusts bearing areas and fault related gas flares. Leaking hydrocarbons are of specific interest since they are potential indicators for hydrocarbon reservoirs in the subsurface and the emitting hydrocarbons such as the greenhouse gas methane can have significant impact on the evolution of global warming when reaching the atmosphere. In this study cold seep systems like huge pockmark areas and carbonate crust sites from the SW Loppa High region were examined in detail, in order to determine the activity, formation and spatial distribution of the different seepage structures as well as the origin and timing of the seeping hydrocarbon fluids. The sample material comprising sediment cores from pockmarks, reference sites and carbonate crust areas as well as carbonate crust samples have been analyzed applying a combined biogeochemical and microbiological approach. In the carbonate crust area diagnostic biomarkers for the anaerobic oxidation of methane (AOM) were detected in the sediments as well as in the corresponding carbonate crusts. Their depth profiles show a distinct interval of higher concentrations, which points towards a shallow AOM zone in the investigated core. The biomarkers were also characterized by very negative carbon isotope signatures, indicating the involvement of the source microorganisms in the process of AOM. These data and active gas bubbling during sampling indicate the presence of methane at the carbonate crust site. In contrast in the pockmark areas active release of gas from the sediment could not be observed, neither in the gas measurement nor in the biogeochemical

  3. Leeches as Sensor-bioindicators of River Contamination by PCBs

    PubMed Central

    Macova, Stanislava; Harustiakova, Danka; Kolarova, Jitka; Machova, Jana; Zlabek, Vladimir; Vykusova, Blanka; Randak, Tomas; Velisek, Josef; Poleszczuk, Gorzyslaw; Hajslova, Jana; Pulkrabova, Jana; Svobodova, Zdenka

    2009-01-01

    The aim of the study was to evaluate the use of leeches of the genus Erpobdella as a means of assessing polychlorinated biphenyl contamination of watercourses. The River Skalice, heavily contaminated with PCBs, was selected as a model. The source of contamination was a road gravel processing factory in Rožmitál pod Třemšínem from which an estimated 1 metric ton of PCBs leaked in 1986. Levels of PCB were measured in leeches collected between 1992 to 2003 from 11 sites covering about 50 km of the river (the first sampling site upstream to the source of contamination and 10 sites downstream). The PCB indicator congeners IUPA no. 28, 52, 101, 118, 138, 153, and 180 were measured. Levels were highest at the four sampling sites nearest the source of pollution. The highest values of PCB congeners were found in 1992. PCB content decreased from 1992 to 2003 and with distance from the source. The study indicated that leeches of the genus Erpobdella are a suitable bioindicator of contamination in the surface layer of river sediments. PMID:22573988

  4. Delimiting oceanographic provinces to determine drivers of mesoscale patterns in benthic megafauna: A case study in the Barents Sea

    NASA Astrophysics Data System (ADS)

    Lacharité, Myriam; Jørgensen, Lis Lindal; Metaxas, Anna; Lien, Vidar S.; Skjoldal, Hein Rune

    2016-08-01

    Communities of benthic megafauna in the deep waters of continental shelves (> 100 m) are important components of marine ecosystems. In high-latitude ecosystems, this fauna is increasingly impacted by human activities and climate variability. In this study, we provide baseline knowledge on the oceanographic conditions affecting its distribution in the Barents Sea in the vicinity of the Polar Front - an oceanic front occurring at the transition zone between the Atlantic and Arctic water masses. We used fields of temperature and currents from an ocean circulation model (Regional Ocean Modelling System - ROMS) to derive variables divided into 3 groups relevant to bottom fauna (temperature, water column structure and bottom currents) expressing either mean conditions or temporal variability over 10 years (2001-2010). Benthic megafauna was surveyed in summer 2011 at 139 sites. To analyze the relationship between spatial variability in the composition of benthic megafauna (i.e., β-diversity) and oceanographic conditions, we: (1) used generalized dissimilarity modelling (GDM) and (2) delimited oceanographic provinces (i.e., regions of similar conditions) for each group of variables using principal component analysis (PCA) followed by cluster analysis. Turnover in benthic megafauna was explained by 7 oceanographic variables (temperature: 4, water column structure: 2, bottom currents: 1), depth and geographic distance (56.7% of total deviance explained). Concurrently, patterns in oceanographic provinces among the 3 groups of variables coincided with results from the GDM, where provinces derived from temperature were sharply delimited relative to the other groups. We concluded that the spatial structure of the environment is important in the relationship between spatial variability of benthic megafauna and oceanographic conditions in shelf deep waters. Ocean models are powerful tools to study this relationship, but the way in which their inherent uncertainty affects the

  5. Recurrent Mass-wasting in Sørvestsnaget Basin, SW Barents Sea: A test of multiple hypotheses

    NASA Astrophysics Data System (ADS)

    Omosanya, K. O.; Harishidayat, D.; Lolita, M.; Johansen, S. E.; Abrahamson, P.

    2015-12-01

    Mass-wasting on the NE Atlantic margin is commonly attributed to Cenozoic glaciations. Using high-quality and high-resolution seismic dataset, this study investigates the types and mechanisms driving mass-wasting in the Sørvestsnaget Basin, Southwestern Barents. Seven mass-transport deposits (MTDs) ranging in age from Late Miocene to Holocene are interpreted on seismic profiles. The MTDs are vertically stacked from about 1900 ms TWTT to the present seabed. MTD 5 (area ca.1.22 x 103 km2, volume ca.3.4 x 103 km3) is the largest deposit in the study area and is composed largely of debrites and rafted blocks underlain by thin layers of hemipelagic sediments. Miocene and Early Pliocene MTDs in the basin demonstrate tendency for initial translation through canyons and channels. The youngest MTDs in the area are composed of glacigenic sediments remobilized by ice streams during Late Neogene and Quaternary glaciations. In the southern part of the study area, deep-water sediments fed through V-shaped canyons and channels are widespread signifying the Stappen High as the main sediment source area prior to the Late Pliocene. The prevalence of shallow marine successions in the northern part of the study area is linked to the southwesterly propagation of the shelf break from Miocene to Recent times. In this study, the shelf break trajectory is important for reconstructing paleo-sediment routes and dispersal pattern. The older non-glacial MTDs are separated farther from their paleo-shelf break. Mass-wasting is a recurrent process in the Sørvestsnaget Basin. Triggering mechanisms for slope failure in the basin may include increased pore pressure as a result of sea level fall and high sedimentation rate, over-steepened slope, glaciation, volcanism, and gas hydrate dissociation. Mass-wasting in the study area occurred through progressive, retrogressive and whole body or coherent downslope failures.

  6. Submarine landforms and ice-sheet flow in the Kvitøya Trough, northwestern Barents Sea

    NASA Astrophysics Data System (ADS)

    Hogan, K. A.; Dowdeswell, J. A.; Noormets, R.; Evans, J.; Cofaigh, C. Ó.; Jakobsson, M.

    2010-12-01

    High-resolution geophysical and sediment core data are used to investigate the pattern and dynamics of former ice flow in Kvitøya Trough, northwestern Barents Sea. A new swath-bathymetric dataset identifies three types of submarine landform in the study area (streamlined landforms, meltwater channels and cavities, iceberg scours). Subglacially produced streamlined landforms provide a record of ice flow through Kvitøya Trough during the last glaciation. Flow directions are inferred from the orientations of streamlined landforms (drumlins, crag-and-tail features). Ice flowed northward for at least 135 km from an ice divide at the southern end of Kvitøya Trough. A large channel-cavity system incised into bedrock in the southern trough indicates that subglacial meltwater was present at the former ice-sheet base. Modest landform elongation ratios and a lack of mega-scale glacial lineations suggest that, although ice in Kvitøya Trough was melting at the bed and flowed faster than the likely thin and cold-based ice on adjacent banks, a major ice stream probably did not occupy the trough. Retreat was relatively rapid after 14-13.5 14C kyr B.P. and probably progressed via ice sheet-bed decoupling in response to rising sea level. There is little evidence for still stands during ice retreat or of ice-proximal deglacial sediments. Relict iceberg scours in present-day water depths of more than 350 m in the northern trough indicate that calving was an important mass loss mechanism during retreat.

  7. Wintertime response of mid-latitude atmospheric circulation to heat anomalies in the Barents Sea in recent decades

    NASA Astrophysics Data System (ADS)

    Schlichtholz, Pawel

    2015-04-01

    Prospects for seasonal prediction of climate variability depend on the strength of feedbacks between different components of the climate system. Sources for seasonal predictability of surface atmospheric anomalies in middle latitudes have been previously sought in teleconnections to the tropical phenomenon of El-Niño-Southern Oscillation and among various extratropical drivers including sea surface temperature anomalies, Arctic sea ice cover extremes, continental snow variability and tropospheric-stratospheric interactions. However, impacts of extratropical subsurface ocean variability on atmospheric teleconnections are poorly known. Here we use a lagged regression analysis between an index of the observed summertime Atlantic water temperature (AWT) anomalies at the entrance to the Barents Sea in the period 1982-2005 and the corresponding year-round data from the National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalysis to show that subsurface oceanic heat anomalies heading the Arctic Ocean are significant precursors of wintertime atmospheric anomalies over mid-latitude Eurasia and North Pacific. In particular, warm AWT anomalies precede an Arctic warming accompanied by a cooling over Eurasia. The summertime oceanic anomalies explain about 40% of the variance in the surface air temperature averaged over entire Eurasia from 35° to 45° N and 50% of the variance in surface winds over the Far East Asia in the following winter. We find that the remote tropospheric response arises from modification of planetary waves and interaction of mean winds with synoptic eddies leading to a reorganization of the mid-latitude storm tracks. The AWT anomalies explain about 60% of the variance in the upper-tropospheric storm track activity averaged over the Pacific and Eurasia from 35° to 55° N and in the lower-tropospheric poleward transient eddy heat flux over western Eurasia. Finally, we show that the tropospheric response to

  8. Simulation of Non-point Source Pollution in the Songhua River Basin Using GBNP Model

    NASA Astrophysics Data System (ADS)

    Pan, J.; Tang, L.; Chen, Y. D.

    2015-12-01

    China is facing increasingly severe water pollution issue with rapid socio-economic development. Non-point source pollution, which is rarely monitored, has become the main forms of water pollution in China. In this study, the Geomorphology-Based Non-point source Pollution (GBNP) model was used to simulate the processes of rain-runoff, soil erosion, sediment routing and pollutant transport in the Songhua River basin from 2001 to 2010. The spatio-temporal variation of non-point source pollution and river water quality were analyzed based on the simulation outputs. In the entire basin, the annual mean loading of TN, TP and soil erosion are 270,000 ton/a, 42,200 ton/a and 55,900,000 ton/a, respectively. The point and non-point source pollution respectively account for 44.9% and 55.1% in TN loading. For TP loading, the proportions of point and non-point source pollution are 14.4% and 85.6%, respectively. It suggests that the non-point source pollution control and treatments should be paid more attention in the Songhua River basin. The inter-annual and intra-annual variations of non-point source pollution components and potential driving mechanisms are further examined. The annual loading of soil erosion, TN and TP are highly correlated with annual runoff, with the correlation coefficients of 0.75, 0.91 and 0.92, respectively, which implies that rain-runoff could be the main driving force of non-point pollution. The monthly sediment concentration in the watercourse is high in flood season and low in non-flood season, which agrees well with the seasonality of monthly runoff. By contrast, the concentrations of TN and TP in watercourse show the opposite features.

  9. Quality assessment of bed sediments of the Po River (Italy).

    PubMed

    Viganò, Luigi; Arillo, Attilio; Buffagni, Andrea; Camusso, Marina; Ciannarella, Ruggero; Crosa, Giuseppe; Falugi, Carla; Galassi, Silvana; Guzzella, Licia; Lopez, Antonio; Mingazzini, Marina; Pagnotta, Romano; Patrolecco, Luisa; Tartari, Gianni; Valsecchi, Sara

    2003-02-01

    Comprehensive and contemporary evaluations of physical, chemical and toxicological endpoints have been performed on bed sediments of the Po River, the major Italian watercourse. Two extensive sampling campaigns were conducted in summer and winter low-flow conditions. Composite sediment samples were collected from ten reaches of the main river: the first was located in the upper region (ambient control), and the others downstream of the confluences of nine principal tributaries. The two sampling programs were paralleled by contemporary investigations on the macroinvertebrate community. The particle-size composition along the Po River showed a relatively uniform distribution of fine sand, a progressive downstream decrease of coarse sands and a corresponding increase of fine materials. The levels of polychlorinated biphenyls (PCB), polycyclic aromatic hydrocarbons (PAH), extractable organo halides (EOX), Cd, Cr, Cu, Hg, Ni, Pb and Zn were determined in sediment fine particles (< 63 microm), and showed marked changes across the ten river reaches. Their longitudinal trends, as those of organic carbon and total nitrogen, were very similar and largely independent of the survey season. Sediment quality benchmarks were used to evaluate sediment chemistry, and, although the overall level of contamination was from moderate to low, the reaches located downstream of the tributaries Dora Riparia, Dora Baltea, Lambro and Oglio were considered to be at risk. Sediments were tested for toxicity on Oncorhynchus mykiss, Ceriodaphnia dubia, Raphidocelis subcapitata and Vibrio fischeri. The toxicity tests were conducted both with sediment extracts and whole samples. Sediment extracts showed toxic potentials that were consistent with the spatial distribution of contaminants. Whole-sediment toxicity showed moderate/low effects which also included false positives and negatives. Alterations of the macroinvertebrate community were found for many kilometers downstream of Dora Riparia, and

  10. Climate and environmental changes during the last 2000 years on Barentsøya and Edgeøya (E-Svalbard).

    NASA Astrophysics Data System (ADS)

    Hoek, Wim; Woelders, Lineke; Akkerman, Keechy; van Hoof, Tom; Moller Just, Rikke; Wagner-Cremer, Friederike

    2016-04-01

    The Svalbard archipelago is positioned at the northern limb of the Atlantic Gulf Stream and, therefore, highly sensitive to climate changes related to changes in ocean circulation. At present, a strong climate gradient from SW-NE Svalbard illustrates the Atlantic influence. While from Spitsbergen (W-Svalbard) several palaeoclimate records are available, while palaeoclimate records from Barentsøya and Edgeøya (E-Svalbard) are lacking. During the 2015 SEES expedition (http://www.sees.nl/) the first lake sediment records from Barentsøya and Edgeøya (E Svalbard) have been collected. The lakes, formed in isolation basins on dolorite plateaus, were selected based on their elevation. Based on published isostatic rebound values, the lakes became disconnected from the sea around 3000 years ago. Since then the lakes recorded biological production changes which are clearly reflected in the lithology of the cores. The presence of abundant plant macro fossils including Salix polaris leaf remains allows for plant palaeophysiological palaeoclimate estimates, which together with pollen and diatom analysis provides a high detail palaeoenvironmental reconstruction for the last 2000 years. Age assessment of the sediments is based on Pb210 and AMS C14 dating on botanical macrofossils, while we also have indications for the presence of Icelandic tephra.

  11. Modelling multi-species interactions in the Barents Sea ecosystem with special emphasis on minke whales and their interactions with cod, herring and capelin

    NASA Astrophysics Data System (ADS)

    Lindstrøm, Ulf; Smout, Sophie; Howell, Daniel; Bogstad, Bjarte

    2009-10-01

    The Barents Sea ecosystem, one of the most productive and commercially important ecosystems in the world, has experienced major fluctuations in species abundance the past five decades. Likely causes are natural variability, climate change, overfishing and predator-prey interactions. In this study, we use an age-length structured multi-species model (Gadget, Globally applicable Area-Disaggregated General Ecosystem Toolbox) to analyse the historic population dynamics of major fish and marine mammal species in the Barents Sea. The model was used to examine possible effects of a number of plausible biological and fisheries scenarios. The results suggest that changes in cod mortality from fishing or cod cannibalism levels have the largest effect on the ecosystem, while changes to the capelin fishery have had only minor effects. Alternate whale migration scenarios had only a moderate impact on the modelled ecosystem. Indirect effects are seen to be important, with cod fishing pressure, cod cannibalism and whale predation on cod having an indirect impact on capelin, emphasising the importance of multi-species modelling in understanding and managing ecosystems. Models such as the one presented here provide one step towards an ecosystem-based approach to fisheries management.

  12. Amazon River

    Atmospheric Science Data Center

    2013-04-17

    article title:  Mouth of the Amazon River     View Larger Image ... over 6450 kilometers eastward across Brazil, the Amazon River originates in the Peruvian Andes as tiny mountain streams that eventually ...

  13. Nile River

    Atmospheric Science Data Center

    2013-04-15

    article title:  Nile River Fluctuations Near Khartoum, Sudan     ... history, the rising and falling waters of the mighty Nile River have directly impacted the lives of the people who live along its banks. ... the area around Sudan's capital city of Khartoum capture the river's dynamic nature. Acquired by the Multi-angle Imaging SpectroRadiometer ...

  14. Mississippi River

    Atmospheric Science Data Center

    2014-05-15

    article title:  Mississippi River Flooding during Spring 2001     ... South TIFF: 1024 x 724 The Mississippi River, from its source at Lake Itasca Minnesota to the Gulf of Mexico is ... 2348 miles long. Over the course of it's history, the mighty river has flooded many times. The largest flood recorded in the lower valley ...

  15. Niger River

    Atmospheric Science Data Center

    2013-04-15

    article title:  Niger River after the Rainy Season     View larger image The third largest river in Africa, the Niger, forms an inland delta in central Mali. This ... is situated near the top of the image, where the Niger River changes direction to flow more directly eastward. Six hundred years ago, ...

  16. Coastal Storm surge flooding impact under different climate scenarios in Pearl River Delta

    NASA Astrophysics Data System (ADS)

    Li, Li; Boehner, Juergen

    2015-04-01

    The Pearl River Delta is highly vulnerable due to the low altitude and frequent typhoon attack. Flooding poses a severe risk of loss of human life and infrastructural values in this area. This study aims to estimate the inundation area and quantities the economic loss. D-Flow flexible mesh model is employed to simulate the storm surge flooding inundation area under three different typhoon scenarios. D-Flow flexible mesh is the first numerical model combined structure grid and unstructured grid in the world, which is also the first application in the most complicated watercourse in China. The model is calibrated using in-site measured discharge and water level. The inundation area is validated against satellite image. Three typhoon scenarios with different characteristics will be examined. Results of this research will help to relief the flooding loss, also the results would be useful for land use planning and sustainable development in the coastal and delta area.

  17. Relevance of the Paraná River hydrology on the fluvial water quality of the Delta Biosphere Reserve.

    PubMed

    Puig, Alba; Olguín Salinas, Héctor F; Borús, Juan A

    2016-06-01

    The increasing frequency of extreme events in large rivers may affect not only their flow, but also their water quality. In the present study, spatial and temporal changes in fluvial physico-chemical variables were analyzed in a mega-river delta during two extreme hydrological years (La Niña-El Niño) and related to potential explanatory factors. Basic water variables were evaluated in situ at 13 points (distant 2-35 km from each other) in watercourses of the Delta Biosphere Reserve (890 km(2)) in the Lower Paraná River (Argentina) in nine surveys (October 2008-July 2010) without meteorological tides. Samples for laboratory analyses were collected from each main river. Multivariate tests by permutations were applied. The period studied was influenced by a drought, within a long period dominated by low flows combined with dry weather and wildfires, and a large (10 years of recurrence) and prolonged (7 months) flood. The hydrological phase, followed by the season and the hydrological year (according to the ENSO event) were the principal explanatory factors of the main water quality changes, whereas the drainage sub-basin and the fluvial environment (river or stream) were secondary explanatory factors. During the drought period, conductivity, turbidity, and associated variables (e.g., major ions, silicon, and iron concentrations) were maximal, whereas real color was minimal. In the overbanking flood phase, pH and dissolved oxygen concentration were minimal, whereas real color was maximal. Dissolved oxygen saturation was also low in the receding flood phase and total major ion load doubled after the arrival of the overbanking stage. The water quality of these watercourses may be affected by the combination of several influences, such as the Paraná River flow, the pulses with sediments and solutes from the Bermejo River, the export of the Delta floodplain properties mainly by the flood, the season, and the saline tributaries to the Lower Paraná River. The high

  18. Bedrock cores from 89° North: Implications for the geologic framework and Neogene paleoceanography of Lomonosov Ridge and a tie to the Barents shelf

    USGS Publications Warehouse

    Grantz, Arthur; Pease, Victoria L.; Willard, Debra A.; Phillips, R.L.; Clark, David L.

    2001-01-01

    Two piston cores from the Eurasian flank of Lomonosov Ridge near lat 88.9°N, long 140°E provide the first samples of bedrock from this high-standing trans-Arctic ridge. Core 94-PC27 sampled nonmarine siltstone similar in facies and age to uppermost Triassic to lower Lower Jurassic and mid– Lower Cretaceous beds in the 4 to > 5 km Mesozoic section on Franz Josef Land, on the outer Barents shelf. A ca. 250 Ma peak in the cumulative frequency curve of detrital zircons from the siltstone, dated by U- Th-Pb analysis, suggests a source in the post-tectonic syenites of northern Taymyr and nearby islands in the Kara Sea. Textural trends reported in the literature indicate that the Lower Jurassic nonmarine strata of Franz Josef Land coarsen to the southeast; this suggests the existence of a sedimentary system in which detrital zircons could be transported from the northern Taymyr Peninsula to the outer Barents shelf near the position of core 94-PC27 prior to opening of the Eurasia Basin. Correlation of the coaly siltstone in core 94-PC27 with part of the Mesozoic section on Franz Josef Land is compatible with the strong evidence from seafloor magnetic anomalies and bathymetry that Lomonosov Ridge is a continental fragment rifted from the Barents shelf during the Cenozoic. It also suggests that Lomonosov Ridge near the North Pole is underlain by a substantial section of unmetamorphosed Mesozoic marine and nonmarine sedimentary strata. Core 94-PC29 sampled cyclical deposits containing ice-rafted debris (IRD) overlying weakly consolidated laminated olive-black anoxic Neogene siltstone and mudstone with an average total organic carbon (TOC) of 4.1 wt%. The high TOC content of the mudstone indicates that during the Neogene, prior to the introduction of IRD into the Arctic seas about 3.3 Ma (early late Pliocene), the shallow waters of the central Arctic Ocean supported significant primary photosynthetic organic production near the North Pole. These deposits also contain fine

  19. Evolution of a high-latitude sediment drift inside a glacially-carved trough based on high-resolution seismic stratigraphy (Kveithola, NW Barents Sea)

    NASA Astrophysics Data System (ADS)

    Rebesco, Michele; Özmaral, Asli; Urgeles, Roger; Accettella, Daniela; Lucchi, Renata G.; Rüther, Denise; Winsborrow, Monica; Llopart, Jaume; Caburlotto, Andrea; Lantzsch, Hendrik; Hanebuth, Till J. J.

    2016-04-01

    Kveithola is a glacially-carved, E-W trending trough located in the NW Barents Sea, an epicontinental shelf sea of the Arctic Ocean located off northern Norway and Russia. A set of confined sediment drifts (the "Kveithola Drift") is located in the inner part of the trough. In general, drift deposits are commonly characterized by high lateral continuity, restricted occurrence of hiatuses and relatively high accumulation rates, and thus represent excellent repositories of paleo-environmental information. We provide for the first time a detailed morphological and seismostratigraphic insight into this sediment drift, which is further supported by some preliminary lithological and sedimentological analyses. The complex morphology of the drift, imaged by combining all available multibeam data, includes a main and a minor drift body, two drift lenses in the outer part of the trough, more or less connected drift patches in the innermost part and small perched sediment patches in a structurally-controlled channel to the north. The seismic (PARASOUND) data show that the main and minor drift bodies are mainly well-stratified, characterized by sub-parallel reflections of moderate to high amplitude and good lateral continuity. The reflectors show an abrupt pinch-out on the northern edge where a distinct moat is present, and a gradual tapering to the south. Internally we identify the base of the drift and four internal horizons, which we correlate throughout the drift. Facies typical for contourite deposition are found in the sediment cores, with strongly bioturbated sediments and abundant silty/sandy mottles that contain shell fragments. These characteristics, along with the morphological and seismic information, suggest a strong control by a bottom current flowing along the moat on the northern edge of the drift. Though both Atlantic and Arctic waters are known to enter the trough, from the west and the north respectively, brine-enriched shelf water (BSW) produced during

  20. Energy gradient and geomorphological processes along a river influenced by neotectonics (the Saône river, France)

    NASA Astrophysics Data System (ADS)

    Astrade, Laurent; Bravard, Jean-Paul

    1999-01-01

    The purpose of this study is to link the sediment transit and the flood plain storage of the Saône to hydromorphological characteristics of the hydrosystem, which exemplifies a new approach to sediment dynamics. The study of suspended sediment concentration in terms of temporal evolution, together with sediment deposition in terms of spatial variability, is a way to record the longitudinal evolution of the sediment load, which expresses the available energy gradient from upstream to downstream in hydrosystem. The Saône river is a 480-km-long Rhone tributary, with an oceanic pluvial regime, and an average yearly discharge of 440 m s -1 at Lyons. The watercourse is characterised by very gentle slopes controlled by the neotectonics of the Bresse trough and by Holocene fluvial dynamics. Sediments were sampled during the December 1993-January 1994 flood (2 375 m 3 s -1) and the 1995 January-February flood (1 826 m 3 s -1). A fine partition into homogeneous sectors, using stream power as well as shear stress, has been realized on a 400 km reach using longitudinal and cross-sections at one kilometre intervals. This partition, compared with the results of the field sampling, shows that the amount of energy is closely connected to the hydromorphological characteristics of the river.

  1. Population structure and growth rates at biogeographic extremes: a case study of the common cockle, Cerastoderma edule (L.) in the Barents Sea.

    PubMed

    Genelt-Yanovskiy, Evgeny; Poloskin, Alexey; Granovitch, Andrei; Nazarova, Sophia; Strelkov, Petr

    2010-01-01

    A descriptive study of population structure, growth rates and shell morphometry was conducted on nine intertidal populations of the infaunal bivalve Cerastoderma edule in the Murmansk coast of the Barents Sea. Year-to-year population dynamics was analyzed during 2002-2006 on a tidal flat Dalniy Plaj (eastern Murmansk coast). The region constitutes the northern extremes of C. edule range where populations occupied the middle to low intertidal zone and were characterized by low densities. The distribution of age groups and unstable age structure across years in the cockle populations suggest irregular recruitment. Growth rates and shell morphometry showed little variation across the populations studied, and there were no gradient changes from the west to the east parts of Murmansk coast. PMID:20347100

  2. Grounding zone system in outer Bjørnøyrenna, Barents Sea - constraints on its genesis and timing

    NASA Astrophysics Data System (ADS)

    Ruther, Denise; Andreassen, Karin; Forwick, Matthias; Husum, Katrine

    2010-05-01

    A 200 km wide grounding zone system in outer Bjørnøyrenna (Bear Island Trough), south-western Barents Sea, has been investigated using 2D high resolution seismic, sediment gravity cores, regional swath and large scale bathymetry data. Observed sediment facies and three radiocarbon dates from the base of glacimarine units indicate glacier proximal conditions in outermost Bjørnøyrenna between 16,800 and 15,800 cal yrs. The bathymetry data sustain a division into a frontal wedge with a complex morphology of arcuate ridges and depressions, and an upstream part of the wedge characterized by mega scale glacial lineations. A high resolution seismic transect reveals elevation of the sediment deposit of up to 35 m over downstream seafloor and a longitudinal extend of roughly 30 kilometers for the part of the wedge with substantial thicknesses - corresponding to the hummocky frontal wedge. The lobate outline of the sediment wedge together with the arcuate ridge morphologies have earlier led to the hypothesis that the wedge was made of separate lobes which are partly overlapping. The lack of on-lapping strata in a high resolution cross sectional seismic line does however rather suggest the entire wedge to consist of one body of sediment. Based on the distinct morphology and internal structures we infer that the system was deposited during a sudden readvance of the ice front where mega scale glacial lineations have been formed under the grounded ice while pushing and squeezing of soft diluted sediment were the major depositional mechanisms for the hummocky frontal part of the wedge. 10 sediment gravity cores have been recovered from the area. Facies analyses enable the localization of subglacial, glaciproximal, and glacimarine environments in the cores downstream from the wedge, while generally thin non-glacial covers illustrate the Holocene erosive regime on the continental shelf. AMS dates on bulk benthic foraminifera from the bottom of glacimarine units in three of the

  3. Sedimentary response to ice stream advance and retreat on the Storfjorden Trough Mouth Fan (NW Barents Sea), during Late Weichselian

    NASA Astrophysics Data System (ADS)

    Pedrosa, Mayte; Camerlengui, Angelo; de Mol, Ben; Lucchi, Renata. G.; Úrgeles, Roger; Rebesco, Michele; Winsborrow, Monica; Laberg, Jan. S.; Andreassen, Karin; Accettella, Daniela

    2010-05-01

    This seafloor morphological study of the Storfjorden Trough Mouth Fan (TMF) (offshore Svalbard, NW Barents Sea) is based on new multibeam bathymetry and chirp sub-bottom profiler data acquired in 2007 during the BIO Hespérides cruise SVAIS that provides an unprecedented image of the sedimentary processes that accompanied the last advance and retreat of the Storfjorden Ice Stream. Compared to other glacial-marine sedimentary systems (such as the adjacent Bjørnøyrenna TMF), the Storfjorden TMF system is small and associated to a relatively small terrestrial ice sheet, approximately 40.000 km2, with local provenance from Svalbard and the Spitsbergen Bank. Due to this short distance from the ice source to the calving areas and the resulting short residence time of ice in the ice sheet, therefore the glacio -marine system of the Storfjorden reacts rapidly to climatic changes. The Storfjorden continental slope is characterized by three depositional lobes, produced by focused sedimentation at the terminus of ice streams that have changed their location with time. The superficial morphology features associated to the two northernmost lobes are straight gullies in the upper slope, and debris lobes starting from the midslope onwards. The seafloor expression of the southernmost lobe, adjacent to the much smaller Kveithola TMF, demonstrate almost no gully incisions and is dominated by the widespread occurrence of small-scale submarine landslides. The subbottom profiles illustrate that sediment failures occurred throughout the Late Neogene evolution of the southern Storfjorden and Kveithola margin, including large-scale mass transport deposits of up to 200 m thick. Seismic facies of the Neogene sequence shows an alternation of glacigenic debris flows and laminated sediment drape inferred to be plumites. Gullies incising glacigenic debris flows at the surface and subsurface and are filled by an interglacial drape sequence. The gullies are formed during each deglaciation phase

  4. Lophelia pertusa corals from the Ionian and Barents seas share identical nuclear ITS2 and near-identical mitochondrial genome sequences

    PubMed Central

    2013-01-01

    Background Lophelia pertusa is a keystone cold-water coral species with a widespread distribution. Due to the lack of a mitochondrial marker variable enough for intraspecific analyses, the population structure of this species has only been studied using ITS and microsatellites so far. We therefore decided to sequence and compare complete mitochondrial genomes from two distant L. pertusa populations putatively isolated from each other (in the Barents Sea off Norway and in the Mediterranean Sea off Italy) in the hope of finding regions variable enough for population genetic and phylogeographic studies. Results The mitogenomes of two L. pertusa individuals collected in the Mediterranean and Barents seas differed at only one position, which was a non-synonymous substitution, but comparison with another recently published L. pertusa mitochondrial genome sequence from Norway revealed 18 nucleotide differences. These included two synonymous and nine non-synonymous substitutions in protein-coding genes (dN/dS > 1): hence, the mitogenome of L. pertusa may be experiencing positive selection. To test for the presence of cryptic species, the mitochondrial control region and the nuclear ITS2 were sequenced for five individuals from each site: Italian and Norwegian populations turned out to share haplotypes of both markers, indicating that they belonged to the same species. Conclusions L. pertusa corals collected 7,500 km apart shared identical nuclear ITS2 and near-identical mitogenomes, supporting the hypothesis of a recent connection between Lophelia reefs in the Mediterranean and in the Northern Atlantic. Multi-locus or population genomic approaches will be required to shed further light on the genetic connectivity between L. pertusa reefs across Europe; nevertheless, ITS2 and the mitochondrial control region may be useful markers for investigating the phylogeography and species boundaries of the keystone genus Lophelia across its worldwide area of distribution. PMID

  5. Remote Correlation of Paleoceanographic Events in the Northern Parts of Bering and Barents Seas during the Termination I and Early Holocene

    NASA Astrophysics Data System (ADS)

    Ivanova, E. V.; Ovsepyan, E.; Murdmaa, I.; de Vernal, A.; Risebrobakken, B.; Seitkalieva, E.; Radionova, E.; Alekhina, G.

    2014-12-01

    The Barents and Bering seas are closely linked to the High Arctic and to the THC by marine gateways as well as by land-sea and ocean-atmosphere interactions. Our multi-proxy time series demonstrate that these remote seas exhibited dramatic changes during the deglaciation through a succession of global and regional paleoceanographic events including the beginning of Termination I (BT1), Heinrich-1 or Oldest Dryas (OD), Bølling-Allerød (B/A), Younger Dryas (YD) and early Holocene (EH). In the NW Barents Sea, the increased subsurface-to-bottom Atlantic water inflow via the Kvitøya-Erik Eriksen trough (cores S 2519 and S 2528) is inferred at the late OD, late B/A and late YD/EH transition. These events are generally coupled with the strengthened AMOC. A remarkable sea surface warming and sea ice retreat are documented at ~ 13 ka BP. Surface warming and strong Atlantic water inflow were followed by intense iceberg calving in the Erik Eriksen Trough as indicated by the high IRD content of Core S-2519. The rock fragments are unsorted and mainly angular suggesting their ice-rafted (likely iceberg-rafted) origin. Svalbard glaciers apparently derived the material dominated by black schistous mudstones, hard limestones with coral remains, fine-grained sandstones from nearby islands, and icebergs spread it in the Kvitøya-Erik Eriksen Trough during the early deglaciation. The ice rafted coarse terrigenous material supply during the BT1 is also suggested for the NW Bering Sea. In the NW Pacific, NW Bering Sea and Sea of Okhotsk, surface bioproductivity peaked at B/A and EH mainly due to the global warming, enhanced nutrient supply by surface currents from the flooded northeastern shelf, intensified vertical mixing and water exchange through the opened straits. Oxygen-depleted bottom water at intermediate depths characterized several locations including the NW Bering Sea (Core SO201-2-85KL).

  6. Amazon River

    Atmospheric Science Data Center

    2013-04-17

    ... the Rio Solimoes and the Rio Negro converge to form the Amazon River. This image from the Multi-angle Imaging SpectroRadiometer (MISR) ... date:  Jul 23, 2000 Images:  Amazon River location:  South America thumbnail:  ...

  7. Mississippi River

    Atmospheric Science Data Center

    2014-05-15

    ... View Larger Image The mighty Mississippi River, from its source at Lake Itasca, Minnesota to the Gulf of Mexico, is ... heavy rainfall on areas traversed by the upper Mississippi River. Each image in this pair covers an identical 195-kilometer x ...

  8. Landscape Structure Changes in the Slepiotka River Drainage Basin in the Period 1824-1993 (The Silesian Upland, Poland)

    NASA Astrophysics Data System (ADS)

    Mazurek, Kinga

    2014-09-01

    The area of the Upper Silesian Coal Basin is the most important underground mining district in Poland. Coal mines, operating in the area since the eighteenth century, have contributed to massive transformations of the landscape structure. River valleys within range of intensive exploitation activities have been undergoing vast changes. The Slepiotka River drainage basin constitutes an interesting regional example of transformations in the river's watercourse as well as in its adjacent area. It is a left-hand tributary of the Klodnica River with a length of about 8.6 km. Changes in the landscape structure that occurred between 1824-1993 have been analyzed. The starting material consisted of topographical maps that were digitized and calibrated and served as a basis to create colorful compositions. The areas occupied by the different land cover types have been calculated, which allowed to determine their participation in the drainage basin. In about 169 years, significant changes took place in the area of research considering the share of different types of cover and land use. During this time, the river changed its course, both naturally and by human activities. Increasing urbanization and technological development contributed to the diametrical transformation of the landscape structure in the discussed area

  9. The potential influence of the invasive plant, Impatiens glandulifera (Himalayan Balsam), on the ecohydromorphic functioning of inland river systems

    NASA Astrophysics Data System (ADS)

    (Phil) Greenwood, Philip; Fister, Wolfgang; Kuhn, Nikolaus

    2014-05-01

    The invasive plant, Impatiens glandulifera (common English name: Himalayan Balsam), is now found in most temperate European countries, as well as across large parts of North America and on some Australasian islands. As a ruderal species, it favours damp, nutrient-rich soils that experience frequent natural disturbance, such as riparian zones. Its ability to out-compete native vegetation and tendency to suffer rapid dieback during cold weather has led to repeated speculation that it may promote soil erosion, particularly along riverbanks. Despite the strong implication, its ability to promote erosion has only recently been empirically proven during an investigation over one dieback and regrowth cycle along a small watercourse in northwest Switzerland. This presentation now benefits from additional results covering further dieback and regrowth cycles obtained from the same watercourse as above, and from a different river system in southwest UK. These additional results support the original conclusion that I. glandulifera promotes soil erosion along riverbanks and the riparian zone. Importantly, the equivalent ground surface retreat from each group of contaminated locations over the three dieback and regrowth cycles are comparable with erosion in regions where high magnitude events are often recorded. Given these very high erosion rates, albeit over three monitoring phases, it is hypothesised that I. glandulifera may act as a catalyst for repeat cycles of colonisation, dieback and extreme erosion. Aside from the deleterious effect of large quantities of nutrient-rich sediment entering into watercourses, high magnitude soil loss such as this could result in reach-scale sections of riverbank undergoing profound morphological changes and reduced structural stability. Dynamic modifications such as those could ultimately impede the ability of riverbanks to moderate stream flow and offer flood protection, as well as hamper the capacity of riparian zones to buffer and retain

  10. Dispersal of the radionuclide caesium-137 ((137)Cs) from point sources in the Barents and Norwegian Seas and its potential contamination of the Arctic marine food chain: coupling numerical ocean models with geographical fish distribution data.

    PubMed

    Heldal, Hilde Elise; Vikebø, Frode; Johansen, Geir Odd

    2013-09-01

    Dispersal of (137)Cs from the nuclear submarine wrecks Komsomolets and K-159, which are resting on the seabed in the Norwegian and Barents Seas, respectively, is simulated using realistic rates and hypothetical scenarios. Furthermore, spatiotemporal (137)Cs concentrations in Northeast Arctic cod and capelin are estimated based on survey data. The results indicate that neither continuous leakages nor pulse discharges will cause concentrations of (137)Cs in cod muscle or whole body capelin exceeding the intervention level of 600 Bq/kg fw. Continuous leakages from Komsomolets and K-159 and pulse discharges from Komsomolets induced negligible activity concentrations in cod and capelin. A pulse discharge of 100% of the (137)Cs-inventory of K-159 will, however, result in concentrations in muscle of cod of above 100 times the present levels in the eastern Barents Sea. Within three years after the release, (137)Cs levels above 20 Bq/kg fw in cod are no longer occurring in the Barents Sea. PMID:23771062

  11. Towards new Integrated Uses of Potential Fields: Estimating the Heat Generation Potential of the Basement Underlying the Barents Sea Sedimentary Basins, North Norway, and its Importance for Hydrocarbon Maturation.

    NASA Astrophysics Data System (ADS)

    Skilbrei, J.; Barrere, C.; Ebbing, J.; Gernigon, L.; Olesen, O.; Pascal, C.; Wienecke, S.

    2006-12-01

    We estimate the composition of main basement complexes underlying the Barents Sea continental shelf off North Norway, in order to provide input to thermal modelling; radiogenic heat production varies as a function of lithology and constitutes about half of the total heat flow in a typical sedimentary basin. Basement characterization in the coastal areas of Norway will provide ground truth for estimated basement types in the Barents Sea region. Where possible, we also try to project major tectonic units and basement terranes from North Norway and Svalbard into the Barents Sea. The aim is to characterise the basement composition in the offshore areas, to estimate the mean content of radiogenic elements, as well as heat flow estimations. This has been done on land by a series of techniques including heat flow measurements, geochemical analysis and geophysical techniques. In addition thermal measurements have been made in boreholes. Thermal conductivity measurments have been carried out on samples. We use a series of geophysical techniques: Potential field modelling, depth-to-source techniques, isostatic modelling, thermal modelling and interpretation of reflection seismic data, OBS data and velocity data. Integration of the different data sets is a key to the understanding of the deep geology of the area. Moho depths, basement depths, major fault zones and extensional detachments zones, have been interpreted. Preliminary results will be presented from a 5-year research project sponsored by the Norwegian Research Council and Statoil.

  12. Monitoring of metals, organic compounds and coliforms in water catchment points from the Sinos River basin.

    PubMed

    Nascimento, C A; Staggemeier, R; Bianchi, E; Rodrigues, M T; Fabres, R; Soliman, M C; Bortoluzzi, M; Luz, R B; Heinzelmann, L S; Santos, E L; Fleck, J D; Spilki, F R

    2015-05-01

    Unplanned use and occupation of the land without respecting its capacity of assimilation and environmental purification leads to the degradation of the environment and of water used for human consumption. Agricultural areas, industrial plants and urban centres developed without planning and the control of effluent discharges are the main causes of water pollution in river basins that receive all the liquid effluents produced in those places. Over the last decades, environmental management has become part of governmental agendas in search of solutions for the preservation of water quality and the restoration of already degraded resources. This study evaluated the conditions of the main watercourse of the Sinos River basin by monitoring the main physical, chemical and microbiological parameters described in the CONAMA Resolution no. 357/2005.The set of parameters evaluated at five catchment points of water human consumption revealed a river that has different characteristics in each reach, as the upper reach was class 1, whereas the middle and lower reaches of the basin were class 4. Monitoring pointed to households as the main sources of pollutants in those reaches, although metals used in the industrial production of the region were found in the samples analyzed. PMID:26270213

  13. Water resources of the Minnesota River-Hawk Creek watershed, southwestern Minnesota

    USGS Publications Warehouse

    Van Voast, Wayne A.; Broussard, W.L.; Wheat, D.E.

    1972-01-01

    The Minnesota River – Hawk Creek watershed is located in southwestern Minnesota. The watershed has an area of 1,479 square miles and is drained along its southwestern edge by the Minnesota River (Minnesota Division of Waters, 1959). The major watercourse within the watershed is Hawk Creek, having a drainage area of 510 square miles. Other, shorter streams drain into the Minnesota River but are mostly ephemeral. The watershed has a gently undulating land surface formed on glacial deposits. Directly underlying the glacial deposits in most of the area are Cretaceous sedimentary rocks. Paleozoic and Precambrian rocks are also locally in contact with overlying glacial deposits. Beds of sand and gravel buried at various depths within the glacial deposits are generally thin and discomtinuous but are the most accessible and widely used aquifers in the watershed. Beds of poorly consolidated sandstone in the Cretaceous rocks are locally good aquifers, generally yielding softer water, but in lesser quantities, than aquifers in the overlying glacial deposits. In the eastern part of the watershed, aquifers in Paleozoic and Precambrian sedimentary rocks are capable of high yields to wells and contain water of similar quality to water in the overlying Cretaceous and glacial deposits.

  14. Surface water and groundwater characteristics in the wetlands of the Ajó River (Argentina)

    NASA Astrophysics Data System (ADS)

    Carol, E. S.; Dragani, W. C.; Kruse, E. E.; Pousa, J. L.

    2012-10-01

    Intertidal wetlands are complex hydrological environments in which surface water and groundwater interact periodically with tidal flows. This work analyzes how the tidal flow determines the hydrodynamics and salinity of surface water and groundwater at different depths in the intertidal wetland located in the marsh of the Ajó River. Water level and salinity measurements were obtained from the Ajó River, the channels discharging into the river and the phreatic aquifer. The results in the natural marsh indicate the presence of saline stratification and that the surface water-groundwater relationship varies with the tide. At low tide, the water table discharges into the surface watercourses, and when the high tide rises above the regional groundwater discharge level, the tidal flow contributes to the water table, which causes an increase in salinity in surface water and groundwater. When the high tide does not rise above the discharge level, the tidal flow only enters the groundwater at the mouth section and the salinity of the surface water and groundwater decreases from low tide to high tide. In the marsh areas excluded from the tidal cycle due to the presence of floodgates, the water table always discharges into the canals, and in the surface water and groundwater there is no presence of saline stratification. The results obtained make it possible to generate a conceptual model of hydrological behaviour which shows the hydrodynamic and hydrochemical complexity of intertidal wetlands.

  15. River Times.

    ERIC Educational Resources Information Center

    Auldridge, Teresa; And Others

    The James River is one of the most precious resources of Virginia. It was the site of the first permanent English settlement in the New World; the power of the water at the Fall Zone was a major factor in the development of Richmond; and the river served as a primary transportation route to the West via the Kanawha Canal. Both the water itself and…

  16. Geochemical Flows of Heavy Metals in Aquatic Systems of the Volga River Delta

    NASA Astrophysics Data System (ADS)

    Lychagin, Mikhail; Tkachenko, Anna; Kasimov, Nikolay

    2014-05-01

    The paper presents the results of the long-term environmental-geochemical studies of aquatic systems of the Volga River mouth area. It occupies a special place among the world's largest river deltas. The strong interest of researchers from different fields of science in the problems of the Volga River delta is associated with the high rate of periodic fluctuations of the Caspian Sea level, and also many factors of the technogenic geochemical impact on the aquatic systems. They range from the local impact of pollution sources in the delta to the regional impact of pollution sources located upstream. Aquatic systems of the Volga delta are highly diverse in morphology, hydrodynamic regime, lithology, sediments, and biota. This diversity determines the considerable spatial and temporal variability of the conditions of migration of heavy metals (HM) and other chemical elements. The study showed that the present contamination of the aquatic systems is manifested mainly in excess of heavy metals (Cu, Pb, Cd) in suspended matter over the global background values, most notably, in the flood period. In general the content of HM in the water and sediments during the last decades remains low; pollution of the bottom sediments is largely insignificant and of local character. We have identified the significant role of the water plants due to migration and accumulation of heavy metals in the shallow near-shore zones. Higher aquatic plants may serve as biogeochemical indicators of aquatic systems pollution. The metal content in macrophytes varies substantially depending on the ecological and morphological characteristics of species, as well as on conditions of their habitat. The difference between the minimal and maximal HM content may reach two to three orders of magnitude. Thickets of hornweed (Ceratophyllum demersum) and of other macrophytes in the mouths of the watercourses at the near-shore mouth area play the role of the biofilters precipitating a significant part of the

  17. A large thermogenic-methane release event in the SW Barents Sea, during the Last Glacial Maximum. Indications from numerical modelling and seismic reflection data

    NASA Astrophysics Data System (ADS)

    Anka, Z.; Rodrigues, E.; di Primio, R.; Ostanin, I.; Stoddart, D.; Horsfield, B.

    2011-12-01

    The Barents Sea, located in the Norwegian Artic area, has undergone a series of tectonic, paleoceanographic and paleo-climatic events during the Cenozoic, which most likely have caused the redistribution and leakage of hydrocarbons accumulations (Ohm et al., 2008). (Dimakis et al., 1998). Present-day under-filled accumulations are known to have leaked in the past providing a source of hydrocarbons, mostly thermogenic methane. However, the timing, extent and driving factors for this event are largely unconstrained. We built a 3D basin model of the Hammerfest Basin in the SW Barents Sea, in order to quantify the masses of liquid and gaseous hydrocarbons generated, accumulated and eventually leaked from the reservoirs during the evolution of the basin. Particular emphasis was placed on analysing the fate of leaked volumes within the dynamics of Plio-Quaternary glacial cycles and formation or destabilization of gas hydrate deposits. The model was calibrated with maturity and temperature well data and reconstructs, with large degree of accuracy, the composition and volume of the hydrocarbons, particularly the gaseous phase present in the main reservoirs. Our results predict the development of overpressures in the reservoirs due to the ice loading of the basin during the glacial periods. Pressure fluctuations derived from cyclic loading-unloading during the glacial-interglacial periods reached up to 5 MPa. The under-filled nature of the present-day accumulations would result from leakage events during the episodes of glacial retreat, in the transition from glacial to interglacial periods. Considerations of the gas hydrate stability conditions in the basin during the time span between 1.00Ma and ≈11,500 years indicate that the leaking thermogenic methane was probably trapped as gas hydrate deposits during the glacial events and then released at once upon hydrate destabilisation during the Last Glacial Maximun (LGM). These results are supported by the presence of km

  18. Molecular and isotopic composition of gases collected from the bottom sediments in the Western and Central Barents Sea: a preliminary data report

    NASA Astrophysics Data System (ADS)

    Fokina, A.; Akhmanov, G.; Andreassen, K.

    2013-12-01

    Bottom sampling in several areas of the Barents Sea and sub-sampling of gases from collected sediments were carried out as part of various geological marine expeditions. These expeditions were organized by the UNESCO-MSU Training and Research Centre for Marine Geology and Geophysics of the Moscow State University (Russia) and the University of Tromso (Norway) onboard R/V "Akademik Nikolaj Strakhov" and R/V 'Helmer Hanssen' during the period of 2011-2013. A total of 304 gas samples from 51 different stations were analyzed using Gas Chromatography (GC) and Isotope Ratio Mass-Spectrometry (IRMS) techniques. These were combined in a database which was used to investigate the relationship between the type of depositional environment, hydrocarbon gas concentration and sediment composition. Gas samples, collected from shelf deposits, mainly consist of methane (90-99%) with little admixture of ethane and propane. Unsaturated homologues were detected in all samples. Ethylene and propylene predominate over saturated homologues. This, together with the isotopic composition, suggests a biogenic nature of the gases collected in most areas. Gas concentrations were found to be very low for the majority of analyzed sediment samples. This is indicative for their low filtration capacity and low organic matter content. The cause of this is believed to be the pelitic clayey composition of the sediments, their high compaction and the generally frugal bioproductivity in arctic regions. A specific molecular and isotopic composition and high concentrations of gas are characteristic for the zones of focused hydrocarbon seepage on the seafloor that were studied during the cruises. Areas with pockmarks, outcropping salt diapirs and gas flares above the seafloor were classified high petroleum potentials, such as the Hjalmar Johansen High and the North-Kildenskoe gas field, was examined in order to verify characteristics of gas emission from deeply seated accumulations of natural hydrocarbon

  19. Morphometric patterns in Modern carbonate platforms can be applied to the ancient rock record: Similarities between Modern Alacranes Reef and Upper Palaeozoic platforms of the Barents Sea

    NASA Astrophysics Data System (ADS)

    Purkis, Sam; Casini, Giulio; Hunt, Dave; Colpaert, Arnout

    2015-05-01

    In recent years, considerable research has been undertaken in order to gain a better quantitative understanding of morphometric patterns within modern carbonate depositional systems. The industrial application of the scaling/juxtaposition relationships derived from the Modern to subsurface Cenozoic carbonate reservoirs appears relatively straightforward, given that many key biota are common to both. However, the direct application of Modern sedimentary insight further back into the geologic rock record is more controversial, given the enormous changes in the biota, climate, sea level, water chemistry and so on, that have taken place. To justify such an approach, we contend that similar morphometric patterns should be observed in both the Modern and ancient data. In the Norwegian Barents Sea, numerous seismic surveys have imaged Upper Palaeozoic carbonate buildups arranged in polygonal networks, or reticular patterns. These patterns are observed in both warm water photozoan and cool water heterozoan carbonate stratigraphies, and are developed atop platforms founded on stable shelves, in tectonically active settings and platforms developed over basinal evaporites. GIS mapping of multiple seismic horizons allows the Palaeozoic reticulated morphology to be numerically compared to that mapped in Alacranes Reef from QuickBird satellite imagery. QuickBird's metre-scale resolution allows identification of subtle cross-platform trends, such as windward-leeward differences in the packing density of ridge-and-pond complexes, which can be correlated with the kilometre-scale patterning extracted in the Barents subsurface. Despite different controls and architecture, the patterning of reticular networks is statistically inseparable between the two systems, once the metre-scale Modern dataset is down-sampled to seismic resolution. Whilst other controls cannot unequivocally be ruled out, these results suggest that biotic self-organisation is a fundamental driver of sedimentary

  20. Dynamics of the Barents-Kara ice sheet as revealed by quartz sand grain microtextures of the late Pleistocene Arctic Ocean sediments

    NASA Astrophysics Data System (ADS)

    Strand, Kari; Immonen, Ninna

    2010-12-01

    During the entire Quaternary, ice sheets advanced and retreated across the circum-Arctic margins in a series of climate related glacial-interglacial cycles. It is critical to obtain evaluation of the nature of initiated glaciers at the Arctic margins after the pronounced interglacial periods. In this study this will be done by inferring from glacially generated quartz sand grain surface microtextures and related sedimentology extracted from the central Arctic Ocean sediments. These microtextures can be correlated with the generation and fluctuations in the extent of the late Pleistocene Eurasian Ice Sheet i.e. Barents-Kara Ice Sheet. The central Arctic Ocean sediments in the Lomonosov Ridge, having been deposited after the late Pleistocene interglaciations and having had no internal hiatuses, provide an excellent time window for usage of quartz sand grain surface textures for evaluating possible evolving glaciers and continental ice sheets. This is based on the fact that iceberg and sea-ice transported quartz sand grains and their mechanically formed surface textures, created under high cryostatic stress, are diagnostic for glacier thickness and dynamics having been existed in sediment source areas. Sand-sized quartz grains in deep marine sediments favour iceberg or sea-ice transportation with characteristic content of microtextures formed prior this transportation. The sand grain surface microtextures and their frequencies of the selected submarine Lomonosov Ridge sediments during Marine Isotope Stage (MIS) 5 to MIS 3 are analysed using a scanning electron microscope (SEM). Coring during the Arctic Ocean 96 expedition (core 96/12-1pc) provided alternating clay to silty clay sediments which are characterised by prominent silt to sand-size containing intervals. The specific glacial crushing and high cryostatic stress generated features, such as high angularity, conchoidal fractures, steps and sub-parallel linear fractures, were observed from quartz sand grain

  1. Constraints on the timing and duration of methane derived authigenic carbonate formation in the North Sea and the Barents Sea from U-Th dating

    NASA Astrophysics Data System (ADS)

    Condon, D. J.; Sahy, D.; Crémière, A.; Lepland, A.; Noble, S. R.; Chand, S.; Brunstad, H.

    2014-12-01

    Assessment of the tempo of past methane discharges from sub-surface reservoirs, and their relationship to external forcings such as ice-sheet collapse, is in part hindered by the lack of robust age constraints. Methane-derived authigenic carbonate (MDAC) crusts exhibiting characteristic 13C-depleted isotopic signatures were collected from several seepage sites on the Norwegian continental shelf, including sites in the North Sea, the Norwegian Sea and the Barents Sea and a combined petrological, stable isotope and geochronology study has been carried out. MDAC samples exhibited a range of mineralogical compositions and contexts, from carbonate-cemented silt, sand, and gravel, to cavities lined with relatively pure (>90%) late-stage aragonitic infills. The U-Th dating results constrain the main episode of carbonate crust formation in the Barents and Norwegian seas during the time interval between 14 and 5 ka. Based on analyses of matrix-forming CaCO3 and multiple generations of cavity fills individual, up to 15 cm thick crusts may represent at least 3.3 kyr of growth. Cavity fills representing focussed fluid flow post-date the main interval of crust formation by ca. 2 kyr and sub-sampling of these layered cavity fills revealed resolvable growth histories, on the order of 1 kyr. The dating of the main phases of MDAC formation suggest that the methane seepage along the northern Norwegian margin was coincident with the collapse of the Scandinavian ice sheet and deglaciation of the area. The precipitation of studied North Sea carbonate crusts occurred more recently, from 6 to 1 ka, suggesting that their formation is unrelated to the glacial history of the area and gas hydrate stability. These data, combined with published data from other MDAC sites (e.g., Gulf of Mexico, Hydrate Ridge, Sea of Japan) demonstrate the utility of constraining the temporal evolution of hydrate and/or hydrocarbon system related fluid flow from the subsurface to the ocean/atmosphere, and

  2. Unraveling the hydrocarbon charge potential of the Nordkapp Basin, Barents Sea: An integrated approach to reduce exploration risk in complex salt basins

    NASA Astrophysics Data System (ADS)

    Schenk, Oliver; Shtukert, Olga; Bishop, Andrew; Kornpihl, Kristijan; Milne, Graham

    2014-05-01

    The Nordkapp Basin, Barents Sea, is an intra-continental syn-rift basin containing many complex salt structures. The salt is late-Carboniferous to Early Permian in age, with regional extension in the Triassic initiating the salt movement resulting in formation of sub- and mini-basins with significant subsidence (especially in the northeastern part of the basin). Subsequent tectonic phases allowed growth and distortion of salt diapirs that were later affected by uplift and erosion during Tertiary resulting in the formation of salt-related traps in Triassic and Lower Jurassic strata. During Plio-Pleistocene, glacial erosion removed additional Mesozoic and Cenozoic strata. This basin is regarded as a frontier salt province. A small hydrocarbon discovery (Pandora well) in the southwestern part of the basin points to the presence several functioning petroleum systems. The primary play type is related to salt traps below overhangs. Such structures are however, very difficult to image with conventional seismic techniques due to i) generation of multiples from sea floor and top of shallow salt bodies and ii) seismic shadow zones within the salt (possibly resulting from shale and carbonate stringers) which cause severe diffractions so that prospective areas adjacent to the salt remain elusive. Arctic exploration is expensive and the ability to focus on the highest potential targets is essential. A unique solution to this challenging subsurface Arctic environment was developed by integrating petroleum system modeling with full azimuth broadband seismic acquisition and processing. This integrated approach allows intelligent location of seismic surveys over structures which have the maximum chance of success of hydrocarbon charge. Petroleum system modeling was conducted for four seismic sections. Salt was reconstructed according to the diapiric evolution presented in Nilsen et al. (1995) and Koyi et al. (1995). Episodes of major erosion were assigned to Tertiary (tectonic) and

  3. Remediation of PCB-contaminated sediments, in Lake Jaernsjoen, River Emaan, Sweden -- Monitoring and results

    SciTech Connect

    Troedsson, B.; Helgee, A.

    1995-12-31

    Lake Jaernsjoen is a small lake in the Emaan river system which is considered to be one of the most valuable watercourses in Sweden. River Emaan is known for its high diversity of fish species, more than 25 species, e.g. wels (Siluris glanis). The river and its valley are of national interest from the viewpoints of both nature conservation and cultural history. Remediation implies certain hazards for the environment and substantial environmental monitoring is necessary for managing of the work in order to minimize damage to the environment. The content of PCB in the sediments of Jaernsjoen was estimated at about 400 kg and was the most important source for spreading of PCB in River Emaan. Remediation of the contaminated sediments took place during 1993 and 1994. It was carried out using a horizontal auger suction dredger. During dredging, the area with the most contaminated sediments was closed off by a silt curtain in order to protect River Emaan from release of suspended solids and PCB. The environmental monitoring during remediation included measuring of e.g. PCB, turbidity, suspended solids, TOC, nitrogen and phosphorus. Turbidity was measured automatically and registered continuously while samples for analysis of suspended solids and PCB were collected automatically and combined to form daily (suspended solids) and weekly (PCB) average samples. Turbidity, suspended solids and PCB were measured certify that the claims that were laid in the contract for the work and from authorities were fulfilled. Comparisons between monitoring stations upstream and downstream Lake Jaernsjoen show that the remediation have not influenced the River Emaan negatively.

  4. Mechanisms for surface contamination of soils and bottom sediments in the Shagan River zone within former Semipalatinsk Nuclear Test Site.

    PubMed

    Aidarkhanov, A O; Lukashenko, S N; Lyakhova, O N; Subbotin, S B; Yakovenko, Yu Yu; Genova, S V; Aidarkhanova, A K

    2013-10-01

    The Shagan River is the only surface watercourse within the former Semipalatinsk Test Site (STS). Research in the valley of the Shagan River was carried out to study the possible migration of artificial radionuclides with surface waters over considerable distances, with the possibility these radionuclides may have entered the Irtysh River. The investigations revealed that radioactive contamination of soil was primarily caused by the first underground nuclear test with soil outburst conducted at the "Balapan" site in Borehole 1004. The surface nuclear tests carried out at the "Experimental Field" site and global fallout made insignificant contributions to contamination. The most polluted is the area in the immediate vicinity of the "Atomic" Lake crater. Contamination at the site is spatial. The total area of contamination is limited to 10-12 km from the crater piles. The ratio of plutonium isotopes was useful to determine the source of soil contamination. There was virtual absence of artificial radionuclide migration with surface waters, and possible cross-border transfer of radionuclides with the waters of Shagan and Irtysh rivers was not confirmed. PMID:23811126

  5. Effects of bottom water warming and sea level rise on Holocene hydrate dissociation and mass wasting along the Norwegian-Barents Continental Margin

    NASA Astrophysics Data System (ADS)

    Jung, Woo-Yeol; Vogt, Peter R.

    2004-06-01

    Gas hydrate (GH) stability modeling results explain why some major Holocene submarine landslides along the Norwegian-Barents margin could have been triggered by GH dissociation during the early to middle Holocene, not during the lowest sea levels of the Last Glacial Maximum (LGM). Our model results show that subbottom depths of 170-260 m below the pre-slide continental slope (ca. 350-475 m present water depth) must have passed out of gas hydrate stability zone (GHSZ) by 8.15 ka as the effect of warm bottom water inflow at 11 ka penetrated into the subbottom, overcoming the effects of pressure increase due to sea level rise (SLR). The component of local SLR due to the isostatic response to Fennoscandian deglaciation is shown to be relatively insignificant, particularly for the part of the upper continental slope where the slide probably began. The stability relations show that GH could have formed under the ice sheet before deglaciation, and below deeper shelf areas after sea levels began to rise, but before significant warming near the GHSZ base. To the extent water deeper than 800 m has remained cold (-1° to 0°C) since LGM times, the GHSZ continued to thicken in deep water and GH dissociation could not have triggered Holocene failure in that regime. The present distribution of GH stability is limited to water depths greater than about 400 m in the Storegga slide area, and the thickness of the GHSZ increases with water depth.

  6. Pingos, craters and methane-leaking seafloor in the central Barents Sea: signals of decomposing gas hydrate releasing gas from deeper hydrocarbon reservoirs?

    NASA Astrophysics Data System (ADS)

    Andreassen, K.; Plaza-Faverola, A. A.; Winsborrow, M.; Deryabin, A.; Mattingsdal, R.; Vadakkepuliyambatta, S.; Serov, P.; Mienert, J.; Bünz, S.

    2015-12-01

    A cluster of large craters and mounds appear on the gas-leaking sea floor in the central Barents Sea around the upper limit for methane hydrate stability, covering over 360 km2. We use multibeam bathymetry, single-beam echo sounder and high-resolution seismic data to reveal the detailed geomorphology and internal structure of craters and mounds, map the distribution gas in the water and to unravel the subsurface plumbing system and sources of gas leakage. Distinct morphologies and geophysical signatures of mounds and craters are inferred to reflect different development stages of shallow gas hydrate formation and dissociation. Over 600 gas flares extending from the sea floor into the water are mapped, many of these from the seafloor mounds and craters, but most from their flanks and surroundings. Analysis of geophysical data link gas flares in the water, craters and mounds to seismic indications of gas advection from deeper hydrocarbon reservoirs along faults and fractures. We present a conceptual model for formation of mounds, craters and gas leakage of the area.

  7. The results of marine electromagnetic sounding with a high-power remote source in the Kola Bay in the Barents Sea

    NASA Astrophysics Data System (ADS)

    Grigoriev, V. F.; Korotaev, S. M.; Kruglyakov, M. S.; Orekhova, D. A.; Popova, I. V.; Tereshchenko, E. D.; Tereshchenko, P. E.; Schors, Yu. G.

    2013-05-01

    The first Russian six-component seafloor electromagnetic (EM) receivers were tested in an experiment carried out in Kola Bay in the Barents Sea. The signals transmitted by a remote high-power ELF source at several frequencies in the decahertz range were recorded by six receivers deployed on the seafloor along the profile crossing the Kola Bay. Although not all the stations successfully recorded all the six components due to technical failures, the quality of the data overall is quite suitable for interpretation. The interpretation was carried out by the three-dimensional (3D) modeling of an electromagnetic field with neural network inversion. The a priori geoelectrical model of Kola Bay, which was reconstructed by generalizing the previous geological and geophysical data, including the data of the ground magnetotelluric sounding and magnetovariational profiling, provided the EM fields that are far from those measured in the experiment. However, by a step-by-step modification of the initial model, we achieved quite a satisfactory fit. The resulting model provides the basis for introducing the corrections into the previous notions concerning the regional geological and geophysical structure of the region and particularly the features associated with fault tectonics.

  8. Character of seismic motion at a location of a gas hydrate-bearing mud volcano on the SW Barents Sea margin

    NASA Astrophysics Data System (ADS)

    Franek, Peter; Mienert, Jürgen; Buenz, Stefan; Géli, Louis

    2014-08-01

    The Håkon Mosby mud volcano (HMMV) at 1270 m water depth on the SW Barents Sea slope has been intensively studied since its discovery in 1989. A variety of sensors monitored morphological, hydrological, geochemical, and biological parameters in the HMMV area. An ocean bottom seismometer deployment allowed us to register seismic motion for 2 years, from October 2008 to October 2010. The analysis of seismic records documents two types of seismic signals. The first type are harmonic tremors with frequency peaks around 4-5 and 8-10 Hz that occur in swarms. Their origin could be from fluid flow circulation or resonant vibrations of gas bubbles or from delayed movement of fluid-rich sediments in the conduit or in a deeper pseudo-mud chamber of the HMMV. Because swarms occur with a periodicity of ~ 6 h, tide-related effects are suspected to influence the mechanism originating the tremors. The second type of signals are regional earthquakes that were in 15 cases recognized in seismic records. The activity of harmonic tremors was not significantly affected by earthquakes.

  9. Predicting water temperatures using a deterministic model: Application on Miramichi River catchments (New Brunswick, Canada)

    NASA Astrophysics Data System (ADS)

    Caissie, Daniel; Satish, Mysore G.; El-Jabi, Nassir

    2007-04-01

    SummaryWater temperature influences many physical, chemical and biological properties of rivers. It also influences the distribution of fish and many aquatic organisms within the river environment. Hence, a good understanding of the thermal regime of rivers is essential for effective management of fisheries and aquatic resources. This study deals with the modelling of river water temperature using a deterministic model. This model calculates the net heat flux at the water surface using meteorological conditions within the study area. The water temperature model was applied on two watercourses of different size and thermal characteristics, but within a similar meteorological region, i.e. the Little Southwest Miramichi River and Catamaran Brook (New Brunswick, Canada). Data from 1992 to 1994 were used to calibrate the model, while data from 1995 to 1999 were used for the model validation. Results showed equally good agreement between observed and predicted water temperatures during the calibration period for both rivers with a root-mean-square error (RMSE) of 1.49 °C for the Little Southwest Miramichi River compared to 1.51 °C for Catamaran brook. During the validation period, RMSEs were calculated at 1.55 °C for the Little Southwest Miramichi River and 1.61 °C for Catamaran Brook. Poorer model performances were generally observed early in the season (e.g. spring), especially for the Little Southwest Miramichi River due to the influence of snowmelt conditions, while late summer to autumn performances showed among the best results for both rivers. Late autumn performances were more variable in Catamaran Brook and presumably influenced by the groundwater, geothermal conditions and potentially riparian shading. The geothermal aspect was further investigated at Catamaran Brook (using 1998 data) and results revealed that although geothermal fluxes are present, they explained very little of the unexplained variability (<0.1 °C). Similar to previous studies, the net

  10. Nutrient loss and water quality under extensive grazing in the upper Burdekin river catchment, North Queensland.

    PubMed

    O'Reagain, P J; Brodie, J; Fraser, G; Bushell, J J; Holloway, C H; Faithful, J W; Haynes, D

    2005-01-01

    Increased sediment and nutrient losses resulting from unsustainable grazing management in the Burdekin River catchment are major threats to water quality in the Great Barrier Reef Lagoon. To test the effects of grazing management on soil and nutrient loss, five 1 ha mini-catchments were established in 1999 under different grazing strategies on a sedimentary landscape near Charters Towers. Reference samples were also collected from watercourses in the Burdekin catchment during major flow events. Soil and nutrient loss were relatively low across all grazing strategies due to a combination of good cover, low slope and low rainfall intensities. Total soil loss varied from 3 to 20 kg ha(-1) per event while losses of N and P ranged from 10 to 1900 g ha(-1) and from 1 to 71 g ha(-1) per event respectively. Water quality of runoff was considered moderate across all strategies with relatively low levels of total suspended sediment (range: 8-1409 mg l(-1)), total N (range: 101-4000 microg l(-1)) and total P (range: 14-609 microg l(-1)). However, treatment differences are likely to emerge with time as the impacts of the different grazing strategies on land condition become more apparent. Samples collected opportunistically from rivers and creeks during flow events displayed significantly higher levels of total suspended sediment (range: 10-6010 mg l(-1)), total N (range: 650-6350 microg l(-1)) and total P (range: 50-1500 microg l(-1)) than those collected at the grazing trial. These differences can largely be attributed to variation in slope, geology and cover between the grazing trial and different catchments. In particular, watercourses draining hillier, grano-diorite landscapes with low cover had markedly higher sediment and nutrient loads compared to those draining flatter, sedimentary landscapes. These preliminary data suggest that on relatively flat, sedimentary landscapes, extensive cattle grazing is compatible with achieving water quality targets, provided high levels

  11. The hydrology of sand rivers in Zimbabwe and the use of remote sensing to assess their level of saturation

    NASA Astrophysics Data System (ADS)

    Mpala, S. C.; Gagnon, A. S.; Mansell, M. G.; Hussey, S. W.

    2016-06-01

    Sand rivers are ephemeral watercourses containing sand that are occasionally flooded with rainwater runoff during the rainy season. Although the riverbed appears dry for most of the year, there is perennial groundwater flow within the sand. This water flowing beneath the surface is a valuable resource for local communities; nonetheless our understanding of such river systems is limited. Hence, this paper aims to improve our understanding of the hydrology of sand rivers and to examine the potential use of remote sensing to detect the presence of water in the sand. The relationship between rainfall events and changes in the water level of two sand rivers in the Matabeleland South Province of Zimbabwe was investigated. A lagged relationship was observed for the Manzamnyama River but for the Shashani River the relationship was seen only when considering cumulative rainfall events. The comparison of the modelled flow as simulated by a water balance model with observations revealed the important influence of the effective sediment depth on the recharge and recession of the alluvial channels in addition to the length of the channel. The possibility of detecting water in the alluvial sands was investigated using remote sensing. During the wet season, optical images showed that the presence of water on the riverbed was associated with a smooth signal, as it tends to reflect the incident radiation. A chronological analysis of radar images for different months of the year demonstrates that it is possible to detect the presence of water in the sand rivers. These results are a first step towards the development of a methodology that would aim to use remote sensing to help reducing survey costs by guiding exploratory activities to areas showing signs of water abstraction potential.

  12. The potential influence of the annual invasive plant, Impatiens glandulifera (Himalayan Balsam), on the hydro-geomorphic functioning of inland river systems

    NASA Astrophysics Data System (ADS)

    Kuhn, N. J.; Greenwood, P.; Fister, W.

    2014-12-01

    The invasive plant, Impatiens glandulifera (Himalayan Balsam), is now found in most European countries, as well as across large parts of North America and on some Australasian islands. It favours damp, nutrient-rich soils that experience frequent natural disturbance, such as riparian zones. Its ability to out-compete native vegetation and tendency to suffer rapid dieback during cold weather has led to speculation that it may promote soil erosion, particularly along riverbanks. Despite the strong implication, its ability to promote erosion has only recently been shown during an investigation over one dieback and regrowth cycle along a small watercourse in northwest Switzerland. This presentation now benefits from additional results covering further dieback and regrowth cycles obtained from the same watercourse as above, and from a different river system in southwest UK. These additional results support the original conclusion that I. glandulifera promotes soil erosion along riverbanks and the riparian zone. Importantly, the equivalent ground surface retreat from each group of contaminated locations over the three dieback and regrowth cycles are comparable with erosion in regions where high magnitude events are often recorded. Given these very high erosion rates, albeit over three monitoring phases, it is hypothesised that I. glandulifera may act as a catalyst for repeat cycles of colonisation, dieback and extreme erosion. Aside from the deleterious effect of large quantities of nutrient-rich sediment entering into watercourses, high magnitude soil loss such as this could result in reach-scale sections of riverbank undergoing profound morphological changes and reduced structural stability. Dynamic modifications such as those could ultimately impede the ability of riverbanks to moderate stream flow and offer flood protection, as well as hamper the capacity of riparian zones to buffer and retain sediment and associated contaminants during their passage from terrestrial

  13. Total mercury in water, sediment, and selected aquatic organisms, Carson River, Nevada--1972.

    PubMed

    Richins, R T; Risser, A C

    1975-06-01

    A 1971-72 study of the Nevada Carson River drainage system by the Geological Survey, U.S. Department of Interior, revealed substantial amounts of mercury from pre-1900 gold and silver milling operations of the Comstock Lode. A monitoring survey was initiated to determine the extent of mercury uptake from corresponding surface water and sediments for seven aquatic species collected from five sampling stations along the watercourse. Total mercury content in fish ranged from 0.02 to 2.72 ppm; highest concentrations occurred in piscivorous white bass (0.50-2.72 ppm) sampled from Lahontan Reservoir. Residue levels appeared to be related to fish size, as demonstrated by highly significant correlations between wet weight and mercury content of five of the six species. Concentrations also appeared to be directly influenced by the species' position on the aquatic food chain. These results indicate that mercury levels in some fish from the Carson River drainage system may exceed the 0.50 ppm maximum concentration considered by the Food and Drug Administration, U.S. Department of Health, Education, and Welfare, to be safe for human consumption. PMID:1181551

  14. Organic micropollutants on river sediments from Rio de Janeiro State, Southeast Brazil.

    PubMed

    Torres, João Paulo Machado; Malm, Olaf; Vieira, Elisa Diniz Reis; Japenga, Jan; Koopmans, Gerwin Ferdinand

    2002-01-01

    The paper is a contribution for the knowledge upon concentrations and fate of different kinds of organic micropollutants in Tropical River system from a very industrialized region in Brazil. The presented data was obtained during three years of an International Research Project between Brazilian and Dutch institutions. The sediments were sampled at the Paraiba do Sul-Guandu river watershed, the most important watercourse of Rio de Janeiro state, where up 90% of the population depends on its water for domestic uses. After extraction with non-polar solvents in a hot sohxlet device and clean up using chromatographic columns, three classes of organic micropollutants were analyzed: organochlorine insecticides (OCs), polychlorinated biphenyls (PCBs) and polynuclear aromatic hydrocarbons (PAHs). The organochlorines, including the PCBs were scarcely present in the collected samples probably reflecting the restrictions of use of this class of compounds in the Brazilian market. However, the PAHs levels were high at the vicinity of a huge steelworks located in the city of Volta Redonda. This contamination is probably due to the massive use of coal in the above-cited metallurgical plant. PMID:11923889

  15. Bioaccessible heavy metals-sediment particles from Reconquista River induce lung inflammation in mice.

    PubMed

    Ferraro, Sebastián A; Curutchet, Gustavo; Tasat, Deborah R

    2012-09-01

    The Reconquista River (RR), one of the most polluted watercourses in Argentina, receives effluent discharges from heavily industrialized and highly populated settlements. During winter and summer, the floodplain remains dry, producing the oxidation of sulfide and organic matter present in the sediment, making heavy metals more bioaccessible. Dispersion of this sediment occurs, and thus harmful effects on the pulmonary health of residents and workers inhabiting the RR bank may take place. The authors characterized the sediment particles of the RR (RR-PM) morphologically by scanning electron microscopy and its elemental composition by energy dispersive X-ray spectroscopy (EDX) and Community Bureau of Reference (BCR) sequential extraction. Furthermore, the authors evaluated its biological impact on the respiratory system of BALB/c mice, generating four groups: control healthy, sensibilized with ovalbumin, exposed to particles, and sensibilized and exposed to particles. Sediment particles of the Reconquista River contained fine particulate matter, with a high concentration of bioaccessible Cu and Zn. The authors found that animal exposure to RR-PM caused polymorphonuclear cell lung infiltration, augmentation of O2(-), increase of proinflammatory cytokines (tumor necrosis factor alpha [TNFα], interleukin-6 [IL-6]) and apoptosis. This adverse response was more dramatic in the sensibilized and exposed to particles group. Even more, they proved the bioaccessible fraction present in the RR-PM to be responsible for these harmful effects. The authors conclude that RR-PM produces an adverse biological impact on the airways of healthy animals, which is largely aggravated in previously sensibilized animals. PMID:22706987

  16. Estimation of River Pollution Index in a Tidal Stream Using Kriging Analysis

    PubMed Central

    Chen, Yen-Chang; Yeh, Hui-Chung; Wei, Chiang

    2012-01-01

    Tidal streams are complex watercourses that represent a transitional zone between riverine and marine systems; they occur where fresh and marine waters converge. Because tidal circulation processes cause substantial turbulence in these highly dynamic zones, tidal streams are the most productive of water bodies. Their rich biological diversity, combined with the convenience of land and water transports, provide sites for concentrated populations that evolve into large cities. Domestic wastewater is generally discharged directly into tidal streams in Taiwan, necessitating regular evaluation of the water quality of these streams. Given the complex flow dynamics of tidal streams, only a few models can effectively evaluate and identify pollution levels. This study evaluates the river pollution index (RPI) in tidal streams by using kriging analysis. This is a geostatistical method for interpolating random spatial variation to estimate linear grid points in two or three dimensions. A kriging-based method is developed to evaluate RPI in tidal streams, which is typically considered as 1D in hydraulic engineering. The proposed method efficiently evaluates RPI in tidal streams with the minimum amount of water quality data. Data of the Tanshui River downstream reach available from an estuarine area validate the accuracy and reliability of the proposed method. Results of this study demonstrate that this simple yet reliable method can effectively estimate RPI in tidal streams. PMID:23202672

  17. Comparation of Typical Wetlands Classification Accuracy in Yellow River Estuary Using Multi-Angle Proba CHRIS Hyperspectral Remote Sensing Images

    NASA Astrophysics Data System (ADS)

    Wang, Xiaopeng; Zhang, Jie; Ma, Yi; Ren, Guangbo

    2013-01-01

    In this paper, Multi-angle PROBA CHRIS hyperspectral remote sensing images were used to study on their imaging quality and the ability of classification of Typical Wetlands in Yellow River Estuary, by the cooperation of interpretation and automatic classification. Taking 5-angle (0°, ±36°, ±55°) CHRIS hyperspectral remote sensing images of mode 2 obtained in September 2006 as an example, this paper research results indicate that the 0° image has the best imaging quality, with the highest spatial resolution, the ±36° images come second, the ±55° images are last; 5 typical wetlands, such as reservoir, bulrush, watercourse, barren beach and swamp were selected as study objects, then a Support Vector Machine (SVM) algorithm is used to classify different-angle remote sensing images into these 5 typical wetlands using training samples in the same location, the results of classification were analyzed based on field survey data, which shows that (1) The classification accuracy differs along the viewing angle of images, the overall accuracy and Kappa factor of the 0° image is highest, and the -36° image is lowest. (2) The overall accuracy and Kappa factor of the positive-angle images is higher than which of minus-angle images. (3) The producer accuracy and user accuracy of swamp is the lowest among all 5 typical wetlands in all images. (4) The producer accuracy and user accuracy of reservoir, bulrush and barren beach are relatively stable in all 5-angle images, however, the accuracies of Watercourse and swamp are fluctuant in all 5-angle images, and highest in the 0° image.

  18. The seasonal and inter-annual variability of sea-ice, ocean circulation and marine ecosystems in the Barents Sea: model results against satellite data

    NASA Astrophysics Data System (ADS)

    Dvornikov, Anton; Sein, Dmitry; Ryabchenko, Vladimir; Gorchakov, Victor; Pugalova, Svetlana

    2015-04-01

    This study is aimed at modelling the seasonal and inter-annual variability of sea-ice, ocean circulation and marine ecosystems in the Barents Sea in the modern period. Adequate description of marine ecosystems in the ice-covered seas crucially depends on the accuracy in determining of thicknesses of ice and snow on the sea surface which control penetrating photosynthetically active radiation under the ice. One of the few models of ice able to adequately reproduce the dynamics of sea ice is the sea ice model HELMI [1], containing 7 different categories of ice. This model has been imbedded into the Princeton Ocean Model. With this coupled model 2 runs for the period 1998-2007 were performed under different atmospheric forcing prescribed from NCEP/NCAR and ERA-40 archives. For prescribing conditions at the open boundary, all the necessary information about the horizontal velocity, level, temperature and salinity of the water, ice thickness and compactness was taken from the results of the global ocean general circulation model of the Max Planck Institute for Meteorology (Hamburg, Germany) MPIOM [2]. The resulting solution with NCEP forcing with a high accuracy simulates the seasonal and inter-annual variability of sea surface temperature (SST) estimated from MODIS data. The maximum difference between the calculated and satellite-derived SSTs (averaged over 4 selected areas of the Barents Sea) during the period 2000-2007 does not exceed 1.5 °C. Seasonal and inter-annual variations in the area of ice cover are also in good agreement with satellite-derived estimates. Pelagic ecosystem model developed in [3] has been coupled into the above hydrodynamic model and used to calculate the changes in the characteristics of marine ecosystems under NCEP forcing. Preliminarily the ecosystem model has been improved by introducing a parameterization of detritus deposition on the bottom and through the selection of optimal parameters for photosynthesis and zooplankton grazing

  19. Model estimating the effect of marginal ice zone processes on the phytoplankton primary production and air-sea flux of CO2 in the Barents Sea

    NASA Astrophysics Data System (ADS)

    Dvornikov, Anton; Sein, Dmitry; Ryabchenko, Vladimir; Gorchakov, Victor; Martjyanov, Stanislav

    2016-04-01

    This study is aimed to assess the impact of sea ice on the primary production of phytoplankton (PPP) and air-sea CO2 flux in the Barents Sea. To get the estimations, we apply a three-dimensional eco-hydrodynamic model based on the Princeton Ocean Model which includes: 1) a module of sea ice with 7 categories, and 2) the 11-component module of marine pelagic ecosystem developed in the St. Petersburg Branch, Institute of Oceanology. The model is driven by atmospheric forcing, prescribed from the reanalysis NCEP / NCAR, and conditions on the open sea boundary, prescribed from the regional model of the atmosphere-ocean-sea ice-ocean biogeochemistry, developed at Max Planck Institute for Meteorology, Hamburg. Comparison of the model results for the period 1998-2007 with satellite data showed that the model reproduces the main features of the evolution of the sea surface temperature, seasonal changes in the ice extent, surface chlorophyll "a" concentration and PPP in the Barents Sea. Model estimates of the annual PPP for whole sea, APPmod, appeared in 1.5-2.3 times more than similar estimates, APPdata, from satellite data. The main reasons for this discrepancy are: 1) APPdata refers to the open water, while APPmod, to the whole sea area (under the pack ice and marginal ice zone (MIZ) was produced 16 - 38% of PPP); and 2) values of APPdata are underestimated because of the subsurface chlorophyll maximum. During the period 1998-2007, the modelled maximal (in the seasonal cycle) sea ice area has decreased by 15%. This reduction was accompanied by an increase in annual PPP of the sea at 54 and 63%, based, respectively, on satellite data and the model for the open water. According to model calculations for the whole sea area, the increase is only 19%. Using a simple 7-component model of oceanic carbon cycle incorporated into the above hydrodynamic model, the CO2 exchange between the atmosphere and sea has been estimated in different conditions. In the absence of biological

  20. 33 CFR 162.90 - White River, Arkansas Post Canal, Arkansas River, and Verdigris River between Mississippi River...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., Arkansas River, and Verdigris River between Mississippi River, Ark., and Catoosa, Okla.; use... White River, Arkansas Post Canal, Arkansas River, and Verdigris River between Mississippi River, Ark... apply to: (1) Waterways. White River between Mississippi River and Arkansas Post Canal, Ark.;...

  1. Re-examining the roles of surface heat flux and latent heat release in a "hurricane-like" polar low over the Barents Sea

    NASA Astrophysics Data System (ADS)

    Kolstad, Erik W.; Bracegirdle, Thomas J.; Zahn, Matthias

    2016-07-01

    Polar lows are intense mesoscale cyclones that occur at high latitudes in both hemispheres during winter. Their sometimes evidently convective nature, fueled by strong surface fluxes and with cloud-free centers, have led to some polar lows being referred to as "arctic hurricanes." Idealized studies have shown that intensification by hurricane development mechanisms is theoretically possible in polar winter atmospheres, but the lack of observations and realistic simulations of actual polar lows have made it difficult to ascertain if this occurs in reality. Here the roles of surface heat fluxes and latent heat release in the development of a Barents Sea polar low, which in its cloud structures showed some similarities to hurricanes, are studied with an ensemble of sensitivity experiments, where latent heating and/or surface fluxes of sensible and latent heat were switched off before the polar low peaked in intensity. To ensure that the polar lows in the sensitivity runs did not track too far away from the actual environmental conditions, a technique known as spectral nudging was applied. This was shown to be crucial for enabling comparisons between the different model runs. The results presented here show that (1) no intensification occurred during the mature, postbaroclinic stage of the simulated polar low; (2) surface heat fluxes, i.e., air-sea interaction, were crucial processes both in order to attain the polar low's peak intensity during the baroclinic stage and to maintain its strength in the mature stage; and (3) latent heat release played a less important role than surface fluxes in both stages.

  2. Changes of hydrodynamic parameters on mountain stream bed within the block ramp influence and possibility of their use for integrated river management

    NASA Astrophysics Data System (ADS)

    Radecki-Pawlik, Artur; Plesiński, Karol

    2016-04-01

    In modern river management practices and philosophy one can notice coming more into use ecological friendly hydraulic structures. Those, which are especially needed for river training works, as far as expectation of Water Framework Directive is concerned, are block ramps which are hydraulic structures working similar to riffles known very well from fluvial geomorphology studies and are natural features in streams and rivers. What is important well designed block ramps do not stop fish and invertebrates against migrating, provide natural and esthetical view being built within the river channel, still working as hydraulic engineering structures and might be used in river management in different river ecosystems. The main aim of the research was to describe changes of values of hydrodynamics parameters upstream and downstream of the block ramps and to find out their influence on hydrodynamics of the stream. The study was undertaken on the Porębianka River in the Gorce Mountains, Polish Carpathians. Observed hydrodynamic parameters within the reach of the block ramps depend on the location of measuring point and the influence of individual part of the structure. We concluded that: 1. Hydrodynamic parameters close to block ramps depend on the location of the measurement points in relation to particular elements of the structure; 2. The highest value of velocities don't cause the highest force values, which acting on the bed of the watercourse, because they are rather related to the water level of the channel; 3. The values of mean velocities, shear velocities and shear stresses were similar upstream and downstream the block ramps, which means that the structures stabilize the river bed. This study was performed within the scope of the Science Activity money from Ministry of High Education and Young Scientist's Activity Money of Department of Hydraulics Engineering and Geotechnique, University of Agriculture, Cracow, Poland

  3. The Role of Cooperation and Information Exchange in Transnational River Basins: the Zambezi River case

    NASA Astrophysics Data System (ADS)

    Castelletti, A.; Giuliani, M.; Soncini-Sessa, R.

    2012-12-01

    The presence of multiple, institutionally independent but physically interconnected decision-makers is a distinctive features of many water resources systems, especially of transnational river basins. The adoption of a centralized approach to study the optimal operation of these systems, as mostly done in the water resources literature, is conceptually interesting to quantify the best achievable performance, but of little practical impact given the real political and institutional setting. Centralized management indeed assumes a cooperative attitude and full information exchange by the involved parties. However, when decision-makers belong to different countries or institutions, it is very likely that they act considering only their local objectives, producing global externalities that negatively impact on other objectives. In this work we adopt a Multi-Agent Systems framework, which naturally allows to represent a set of self-interested agents (decision-makers and/or stakeholders) acting in a distributed decision-making process. According to this agent-based approach, each agent represents a decision-maker, whose decisions are defined by an explicit optimization problem considering only the agent's local interests. In particular, this work assesses the role of information exchange and increasing level of cooperation among originally non-cooperative agents. The Zambezi River basin is used to illustrate the methodology: the four largest reservoirs in the basin (Ithezhithezhi, Kafue-Gorge, Kariba and Cahora Bassa) are mainly operated for maximizing the economic revenue from hydropower energy production with considerably negative effects on the aquatic ecosystem in the Zambezi delta due to the alteration of the natural flow regime. We comparatively analyse the ideal centralized solution and the current situation where all the decision-makers act independently and non-cooperatively. Indeed, although a new basin-level institution called Zambezi Watercourse Commission

  4. Paleodrainages of the Eastern Sahara - The radar rivers revisited (SIR-A/B implications for a mid-tertiary Trans-African drainage system)

    NASA Technical Reports Server (NTRS)

    Mccauley, J. F.; Breed, C. S.; Schaber, G. G.; Mchugh, W. P.; Haynes, C. C.

    1986-01-01

    The images obtained by the Shuttle Imaging Radar (SIR)-A and -B systems over the southwestern Egypt and northwestern Sudan were coregistered with the Landsat images and the existing maps to aid in extrapolations of the buried paleodrainages ('radar rivers'), first discovered by SIR-A. Field observations explain the radar responses of three types of radar rivers, RR-1 (broad, aggraded valleys filled with alluvium), RR-2 (braided channels inset in the RR-1 valleys), and RR-3 (narrow, long, bedrock-incised channels). A generalized model of the radar rivers, based on field studies and regional geologic relations, shows inferred changes in river regimen since the large valleys were established during the later Paleogene-early Neogene. It is suggested that a former Trans-African master stream system may have flowed from headwaters in the Red Sea Hills southwestward across North Africa, discharging into the Atlantic at the Paleo-Niger delta, prior to the Neogene domal uplifts and building of volcanic edifices across the paths of these ancient watercourses.

  5. Evaluation of the distribution of fecal indicator bacteria in a river system depending on different types of land use in the southern watershed of the Baltic Sea.

    PubMed

    Gotkowska-Płachta, Anna; Gołaś, Iwona; Korzeniewska, Ewa; Koc, Józef; Rochwerger, Andrzej; Solarski, Kamil

    2016-03-01

    The aim of the study was to determine the effects of land use management on changes in the fecal contamination of water in the Łyna River, one of the main lowland watercourses in the southern watershed of the Baltic Sea (northern Poland). A total of 120 water samples were collected in different seasons of 2011 and 2012 at 15 sites where the river intersected forest (FA), agricultural (AA), and urbanized (UA) areas. Fecal indicator bacteria (FIB), the counts of Enterobacteriaceae and Escherichia coli, total bacterial counts (TBCs), and domain Bacteria (EUB338) were determined by culture-dependent and culture-independent methods. Temperature, pH, chemical oxygen demand, dissolved oxygen, total dissolved solids, ammonia nitrogen, nitrite nitrogen, nitrate nitrogen, orthophosphate, and total phosphorus were also determined. The lowest bacterial counts were noted in water samples collected in FA, and the highest in samples collected in UA. Statistically significant differences were determined between bacterial populations across the analyzed land use types and in different sampling seasons. Significant correlations were also observed between the populations of FIB and physicochemical parameters. The results indicate that land use type influenced FIB concentrations in river water. The combined use of conventional and molecular methods improves the accuracy of fecal contamination analyses in river ecosystems. PMID:25869433

  6. YELLOWSTONE RIVER WATCH (YRW)

    EPA Science Inventory

    Yellowstone River Watch seeks to expand its monitoring and education efforts throughout the Yellowstone River Basin by actively recruiting and training new teacher members. Yellowstone River Watch also seeks to advance existing school programs by offering quality assurance/quali...

  7. Change detection of riverbed movements using river cross-sections and LiDAR data

    NASA Astrophysics Data System (ADS)

    Vetter, Michael; Höfle, Bernhard; Mandlburger, Gottfried; Rutzinger, Martin

    2010-05-01

    Today, Airborne LiDAR derived digital terrain models (DTMs) are used for several aspects in different scientific disciplines, such as hydrology, geomorphology or archaeology. In the field of river geomorphology, LiDAR data sets can provide information on the riverine vegetation, the level and boundary of the water body, the elevation of the riparian foreland and their roughness. The LiDAR systems in use for topographic data acquisition mainly operate with wavelengths of at least 1064nm and, thus, are not able to penetrate water. LiDAR sensors with two wavelengths are available (bathymetric LiDAR), but they can only provide elevation information of riverbeds or lakes, if the water is clear and the minimum water depth exceeds 1.5m. In small and shallow rivers it is impossible to collect information of the riverbed, regardless of the used LiDAR sensor. In this article, we present a method to derive a high-resolution DTM of the riverbed and to combine it with the LiDAR DTM resulting in a watercourse DTM (DTM-W) as a basis for calculating the changes in the riverbed during several years. To obtain such a DTM-W we use river cross-sections acquired by terrestrial survey or echo-sounding. First, a differentiation between water and land has to be done. A highly accurate water surface can be derived by using a water surface delineation algorithm, which incorporates the amplitude information of the LiDAR point cloud and additional geometrical features (e.g. local surface roughness). The second step is to calculate a thalweg line, which is the lowest flow path in the riverbed. This is achieved by extracting the lowest point of each river cross section and by fitting a B-spline curve through those points. In the next step, the centerline of the river is calculated by applying a shrinking algorithm of the water boundary polygon. By averaging the thalweg line and the centerline, a main flow path line can be computed. Subsequently, a dense array of 2D-profiles perpendicular to the

  8. Late Weichselian sediment geochemistry of the western Barents Sea margin - an empirical inter-instrumental comparison of core scanning and conventional XRF measurements

    NASA Astrophysics Data System (ADS)

    Klug, Martin; Knies, Jochen; Forwick, Matthias; Haflidason, Haflidi

    2014-05-01

    During the last years an increasing number of studies in geosciences made use of the fast and non-destructive XRF scanning method. To create robust and reproducible data and to interpret geochemical variations across records of different origin and from different instrumentations inter-instrumental comparison becomes a necessary, inevitable and decisive procedure. In this study we present results from an empirical approach of an inter-instrumental XRF comparison including the Avaatech (University of Tromsø), Itrax (University of Bergen) and InnovX-GeoTek (The Geological Survey of Norway) core scanners. In addition single samples were measured with the PANalytical AXIOS XRF spectrometer and the Perkin Elmer 4300 Dual View ICP-AES measurements (both at the Geological Survey of Norway). We analysed the split-surface of a 300 cm long marine sediment core from the continental slope of the western Barents Sea (71°30'N, 16°10' E). The sediment core sections were logged near-continuously with the core scanners along the centre of the core axis, followed by measurements of discrete samples. All devices were standardized and calibrated prior measurements according to the individual, requisite standardisation routines. Results presented here were harmonized to common sampling midpoints. We tested element ratios commonly used in geosciences. Most of the down-core variations of element ratios from the core scans occur in general synchronously and match the variability of single sample measurements from the stand-alone XRF-analyzer indicating a convenient XRF technique implementation in the scanning instruments. However, in certain cases, element ratios appear to show very low variations, likely an indication of detection-limit problems or larger uncertainties associated with the determination of low element concentrations. Apart from good relative fit, absolute variations occur at different levels and instrumental deviation varies for particular element ratios. This likely

  9. Geophysical interpretation of mantle magmatism in the Seiland province and adjacent Barents Sea: Implications for tectonic emplacement of the Kalak Nappe Complex

    NASA Astrophysics Data System (ADS)

    Pastore, Z.; McEnroe, S. A.; Fichler, C.

    2015-12-01

    The Seiland Igneous Province (SIP) has an exposed area of more than 5500 km2 and is the largest complex of mafic and ultramafic intrusions in northern Fennoscandia. The SIP had a massive plumbing system with deep-seated magmatic conduits that generated more than 25000 km3of igneous melts from the mantle through the continental lithosphere to the surface, at ca 560-570 Ma. The SIP is located within the Kalak Nappe Complex, a part of the Middle Allochthon of the North Norwegian Caledonides. The tectonic development, and movement from its original emplacement onto the Baltica craton is a matter of current debate. The SIP exhibits one of the most pronounced positive Bouguer gravity anomalies in northern Fennoscandia (approximately 100 mGal above background) and a clear magnetic signature. We have identified more than 10 distinct magnetic anomalies related to the Seiland Igneous Province. Here, a 3D gravity and magnetic model of the SIP integrating petrophysical data with gravity and aeromagnetic data is presented. The selected densities for the intrusive range from 2800 to 3400 kg m3, with an average density contrast to the host complex of approximately 400 kg m3. Magnetic susceptibility values, ranging from 0.004 SI to 0.2 SI, show a good correlation with the mapped ultramafic intrusions with few exceptions on the Øksfjord peninsula. A multi-profile based 3D model (IGMAS+) shows the deeper structure of the SIP. Our model suggests an irregular shape with its lower boundary varying in depth from North to South from less than 3 km to 10 Km. Two deep roots have been identified located below Seiland and Sørøya islands, the first root slightly dipping southward with two branches in the upper part. The second root is approximately vertical and T- shaped. This model contributes to the understanding of the tectonic, magmatic and the paleogeographic evolution of the SIP and adds new insights to the study of the rich hydrocarbon basins of the Southern Barents Sea.

  10. Radiocarbon content of pre-bomb marine mollusks and variations in the 14C Reservoir age for coastal areas of the Barents and Kara Seas, Russia

    NASA Astrophysics Data System (ADS)

    Forman, Steven L.; Polyak, Leonid

    Fourteen mollusks, collected alive between 1900 and 1945 from the Russian Barents and Kara seas, were analyzed by AMS 14C dating to evaluate variations in the 14C marine reservoir for arctic coastal sites, which is important for correcting ages in paleoenvironmental time-series and advancing understanding of the exchange of carbon. The 14C ages on the mollusks reveal a range of marine reservoir values (R(t)) from 159 14C yr to 764 14C yr. The oldest R(t) values of 764 to 620 14C yr are for the bivalve Portlandia arctica, which often inhabit cold and low salinity waters and muddy substrates. The depleted 14C content for this bivalve reflects possibly the incorporation of old carbon from freshwater inputs and/or the consumption of old organic matter from the underlying sediments and pore waters. Other mollusks with sessile habitats and pelagic food sources gave significantly lower R(t) values between 159 and 344 14C yr. The youngest R(t) values indicate enrichment in 14C and may partially reflect enhanced transfer of 14C-enriched CO2 from the atmosphere to the ocean surface with wind-generated wave agitation. This study underscores that a variety of processes can lead to variable 14C depletion and enrichment of surface waters yielding a ca. 600 year age span for contemporaneous arctic mollusks. There may be added uncertainty in the 14C reservoir correction for deposit-feeder species such as Portlandia sp. and perhaps for certain benthic foraminifera (e.g. Nonion labradoricum) because these taxa often incorporate old organic matter from the substrate. A reservoir correction of ≥700 years may be more appropriate for infaunal, deposit-eater species, particularly in glacier-dominated environments. Mollusks and foraminifera with sessile habits and pelagic food sources should be selected preferentially for 14C dating, because their shells may more closely reflect the 14C content of the global-ocean mixed layer.

  11. Riparian buffer zones on selected rivers in Lower Silesia - an important conservation practice and the management strategy in urban planning

    NASA Astrophysics Data System (ADS)

    Adamska, Maryna

    2013-09-01

    Buffer zones are narrow strips of land lying along the surface water, covered with appropriately selected vegetation. They separate aquatic ecosystems from the direct impact of agricultural land and reduce the movement of nutrients in the environment. In 2008 the European Commission established requirements for the implementation of buffer strips along water courses. Poland committed to the enforcement of these requirements until 1 January 2012. This was one of the reasons of this study. The subject of the analysis included the following rivers in Lower Silesia: Smortawa, Krynka, Czarna Woda and the selected transects of Ślęza and Nysa Łużycka. Detailed studies were designed to estimate the buffer zones occurring on these watercourses and assess these zones’ structure. This will be used to develop clear criteria for the selection of the width of these zones based on land use land management. It can be used in the implementation of executive acts at different levels of space management. Field research consisted of inventory the extent of riparian buffer strips on selected water courses and photographic documentation. Species composition of the vegetation forming a buffer zone was identified by using Braun-Blanquet method. There was lack of continuity of the riparian buffer zones on investigated rivers. Buffer zones should have carefully formulated definition and width because they are element of the significant ecological value, they perform important environmental protective functions and they are also the subject of Community law.

  12. Trace elements in the Fontinalis antipyretica from rivers receiving sewage of lignite and glass sand mining industry.

    PubMed

    Kosior, Grzegorz; Samecka-Cymerman, Aleksandra; Kolon, Krzysztof; Brudzińska-Kosior, Anna; Bena, Waldemar; Kempers, Alexander J

    2015-07-01

    Intensive lignite and glass sand mining and industrial processing release waste which may contain elements hazardous to the aquatic ecosystem and constitute a potential risk to human health. Therefore, their levels must be carefully controlled. As a result, we examined the effects of sewage on the aquatic Fontinalis antipyretica moss in the Nysa Łużycka (lignite industry) and the Kwisa Rivers (glass sand industry). The Nysa Łużycka and the Kwisa Rivers appeared to be heavily polluted with As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, V and Zn, which were reflected in the extremely high concentration of these elements in F. antipyretica along the studied watercourses. In the Nysa Łużycka, trace element composition in the moss species is affected by lignite industry with accumulation in its tissues of the highest concentrations of Cd, Co, Cr, Cu, Mn, Ni, Pb and Zn, while samples from the Kwisa sites influenced by glass sand industry revealed the highest concentrations of As, V and Fe. The principal component and classification analysis classifies the concentration of elements in the aquatic F. antipyretica moss, thus enabling the differentiation of sources of water pollution in areas affected by mining industry. PMID:25647494

  13. Predicting microbial pollution concentrations in UK rivers in response to land use change.

    PubMed

    Hampson, Danyel; Crowther, John; Bateman, Ian; Kay, David; Posen, Paulette; Stapleton, Carl; Wyer, Mark; Fezzi, Carlo; Jones, Philip; Tzanopoulos, Joseph

    2010-09-01

    The Water Framework Directive has caused a paradigm shift towards the integrated management of recreational water quality through the development of drainage basin-wide programmes of measures. This has increased the need for a cost-effective diagnostic tool capable of accurately predicting riverine faecal indicator organism (FIO) concentrations. This paper outlines the application of models developed to fulfil this need, which represent the first transferrable generic FIO models to be developed for the UK to incorporate direct measures of key FIO sources (namely human and livestock population data) as predictor variables. We apply a recently developed transfer methodology, which enables the quantification of geometric mean presumptive faecal coliforms and presumptive intestinal enterococci concentrations for base- and high-flow during the summer bathing season in unmonitored UK watercourses, to predict FIO concentrations in the Humber river basin district. Because the FIO models incorporate explanatory variables which allow the effects of policy measures which influence livestock stocking rates to be assessed, we carry out empirical analysis of the differential effects of seven land use management and policy instruments (fiscal constraint, production constraint, cost intervention, area intervention, demand-side constraint, input constraint, and micro-level land use management) all of which can be used to reduce riverine FIO concentrations. This research provides insights into FIO source apportionment, explores a selection of pollution remediation strategies and the spatial differentiation of land use policies which could be implemented to deliver river quality improvements. All of the policy tools we model reduce FIO concentrations in rivers but our research suggests that the installation of streamside fencing in intensive milk producing areas may be the single most effective land management strategy to reduce riverine microbial pollution. PMID:20708770

  14. Modeling the Water - Quality Effects of Changes to the Klamath River Upstream of Keno Dam, Oregon

    USGS Publications Warehouse

    Sullivan, Annett B.; Sogutlugil, I. Ertugrul; Rounds, Stewart A.; Deas, Michael L.

    2013-01-01

    The Link River to Keno Dam (Link-Keno) reach of the Klamath River, Oregon, generally has periods of water-quality impairment during summer, including low dissolved oxygen, elevated concentrations of ammonia and algae, and high pH. Efforts are underway to improve water quality in this reach through a Total Maximum Daily Load (TMDL) program and other management and operational actions. To assist in planning, a hydrodynamic and water-quality model was used in this study to provide insight about how various actions could affect water quality in the reach. These model scenarios used a previously developed and calibrated CE-QUAL-W2 model of the Link-Keno reach developed by the U.S. Geological Survey (USGS), Watercourse Engineering Inc., and the Bureau of Reclamation for calendar years 2006-09 (referred to as the "USGS model" in this report). Another model of the same river reach was previously developed by Tetra Tech, Inc. and the Oregon Department of Environmental Quality for years 2000 and 2002 and was used in the TMDL process; that model is referred to as the "TMDL model" in this report. This report includes scenarios that (1) assess the effect of TMDL allocations on water quality, (2) provide insight on certain aspects of the TMDL model, (3) assess various methods to improve water quality in this reach, and (4) examine possible water-quality effects of a future warmer climate. Results presented in this report for the first 5 scenarios supersede or augment those that were previously published (scenarios 1 and 2 in Sullivan and others [2011], 3 through 5 in Sullivan and others [2012]); those previous results are still valid, but the results for those scenarios in this report are more current.

  15. Aquatic habitat modifications in La Plata River basin, Patagonia and associated marine areas.

    PubMed

    Mugetti, Ana Cristina; Calcagno, Alberto Tomás; Brieva, Carlos Alberto; Giangiobbe, María Silvia; Pagani, Andrea; Gonzalez, Silvia

    2004-02-01

    This paper describes the environmental characteristics and situation of aquatic habitats and communities in southern continental and maritime areas of southeastern South America (Patagonian Shelf GIWA Subregion), resulting from an overall assessment carried out within the framework of a GIWA project, mostly on the basis of publicly available data. The main focus of the analysis was on the current situation of transboundary water resources and anthropogenic impacts. In the inland waters, habitat and community modifications result, principally, from dams and reservoirs built in the main watercourses for hydroelectric power generation and other uses. The transformation of lotic environments into lentic ones have affected habitats and altered biotic communities. In the La Plata River basin, invasive exotic species have displaced native ones. Habitats in the ocean have been degraded, as their biodiversity becomes affected by overfishing and pollution. This article includes a discussion on the causal chain and the policy options elaborated for the Coastal Ecosystem of Buenos Aires province and the Argentinean-Uruguayan Common Fishing Zone, where fishing resources are shared by both countries. PMID:15083653

  16. In-situ inventory of gas and gas hydrates in deposits of the Hâkon Mosby mud volcano, SW Barents Sea

    NASA Astrophysics Data System (ADS)

    Pape, T.; Feseker, T.; Kasten, S.; Fischer, D.; Abegg, F.; Hohnberg, H.-J.; Bohrmann, G.

    2009-04-01

    Submarine mud volcanoes are an important source and reservoir of methane and other low-molecular weight hydrocarbons (LMWHC). Consequently, mud volcanoes located within the gas hydrate stability zone (GHSZ) are known to host shallow buried gas hydrates in high density. However, gas hydrate inventories in shallow mud volcano deposits are strongly affected by changes in local physico-chemical conditions due to episodic volcanic activity and response by fixation or release of abundant portions of LMWHC. We determined the in situ gas inventories in shallow deposits of the Håkon Mosby mud volcano (HMMV, SW Barents Sea) in approx. 1,250 m water depth by quantitative degassing of pressure cores recovered with our Dynamic Autoclave Piston Corer. As recognized during previous studies of the HMMV, a concentric arrangement of geochemical parameters and topographic features allow for the distinction of three geomorphological units (I, II, III). During our cruise in summer 2008 we recovered pressure cores (up to 2.65 m below seafloor, b.s.f.) from all the three units and volumetric gas-sediment (wet) ratios ranged between 2.6 in a core taken at the northwestern outer rim (Unit III), and 25.2 obtained for a core in the northeastern section (Unit II). Gas sub-samples collected during degassing of pressure cores belonging to the three units showed C1/C2+ ratios >1,000 suggestive of a predominantly microbial LMWHC origin. Hydrate stability calculations based on LMWHC distributions, pore water salinities and bottom water temperatures suggest that structure I hydrates are the most stable crystallographic hydrate structure at the HMMV. Pore water chloride and sulfate profiles combined with in situ temperature data were used to delineate local boundaries of hydrate accumulations in each of the three geomorphologic units. Subsequently, gas volumes in pressure cores were referred to core segments comprising gas hydrates, and hydrate concentrations were calculated. Low gas hydrate

  17. Time-lapse ERT and DTS for seasonal and short-term monitoring of an alpine river hyporheic zone

    NASA Astrophysics Data System (ADS)

    Boaga, Jacopo; Laura, Busato; Mariateresa, Perri; Giorgio, Cassiani

    2016-04-01

    The hyporheic zone (HZ) is the area located beneath and adjacent to rivers and streams, where the interactions between surface water and groundwater take place. This complex physical domain allows the transport of several substances from a stream to the unconfined aquifer below, and vice versa, thus playing a fundamental role in the river ecosystem. The importance of the hyporheic zone makes its characterization a goal shared by several disciplines, which range from applied geophysics to biogeochemistry, from hydraulics to ecology. The frontier field of HZ characterization stays in applied non-invasive methodologies as Electrical Resistivity Tomography - ERT - and Distributed Temperature Sensing - DTS. ERT is commonly applied in cross-well configuration or with a superficial electrodes deployment while DTS is used in hydro-geophysics in the last decade, revealing a wide applicability to the typical issues of this field of study. DTS for hydro-geophysics studies is based on Raman scattering and employs heat as tracer and uses a fiber-optic cable to acquire temperature values. We applied both techniques for an alpine river case studies located in Val di Sole, TN, Italy. The collected measurements allow high-resolution characterization of the hyporheic zone, overcoming the critical problem of invasive measurements under riverbeds. In this work, we present the preliminary results regarding the characterization of the hyporheic zone of the alpine river obtained combining ERT and DTS time-lapse measurements. The data collection benefits from an innovative instrumentation deployment, which consists of both an ERT multicore cable and a DTS fiber-optic located in two separated boreholes drilled 5m under the watercourse and perpendicular to it. In particular we present the first year monitoring results and a short time-lapse monitoring experiment conducted during summer 2015. The site and the results here described are part of the EU FP7 CLIMB (Climate Induced Changes on the

  18. Regional and inter-annual variability in Atlantic zooplankton en route to the Arctic Ocean: potential effects of multi-path Atlantic water advection through Fram Strait and the Barents Sea

    NASA Astrophysics Data System (ADS)

    Kwasniewski, Slawomir; Gluchowska, Marta; Trudnowska, Emilia; Ormanczyk, Mateusz; Walczowski, Waldemar; Beszczynska-Moeller, Agnieszka

    2016-04-01

    The Arctic is among the regions where the climate change effects on ecosystem will be the most rapid and consequential, with Arctic amplification recognized as an integral part of the process. Great part of the changes are forced by advection of warm waters from the North Atlantic and the expected modifications of Arctic marine ecosystem will be induced not only by changing environmental conditions but also as a result of introducing Atlantic biota. Thus, the knowledge of physical and biological heterogeneity of Atlantic inflow is requisite for understanding the effects of climate change on biological diversity and ecosystem functioning in the Arctic. The complex and variable two-branched structure of the Atlantic Water flow via Fram Strait and the Barents Sea most likely has a strong influence on the ocean biology in these regions, especially in the pelagic realm. Zooplankton are key components of marine ecosystems which form essential links between primary producers and grazer/predator consumers, thus they are important for functioning of the biological carbon pump. Changes in zooplankton distribution and abundance may have cascading effects on ecosystem functioning, with regulatory effects on climate. Based on data collected in summers of 2012-2014, within the scope of the Polish-Norwegian PAVE research project, we investigate zooplankton distribution, abundance and selected structural characteristics of communities, in relation to water mass properties in the Atlantic Water complex flow to the Arctic Ocean. The main questions addressed here are: what are the differences in zooplankton patterns between the Fram Strait and Barents Sea branches, and how does the inter-annual variability of Atlantic Water advection relate to changes in zooplankton? The results of the investigation are precondition for foreseeing changes in the pelagic realm in the Arctic Ocean and are necessary for constructing and tuning plankton components of ecosystem models.

  19. Geomorphic impacts of active tectonics on a river course, the case of Klissoura gorge, central Greece.

    NASA Astrophysics Data System (ADS)

    Tsanakas, Konstantinos; Fubelli, Giandomenico; Karymbalis, Efthimios

    2014-05-01

    The delicate balance of the natural processes within the river systems can be easily tipped making them very sensitive to changes occurring on the earth surface. Fluvial systems are therefore profoundly influenced by endogenic processes such as active tectonics as well as global sea level fluctuations following the climatic variations during the Quaternary. This study deals with the geomorphological evolution of the broader area of the abandoned gorge of Klissoura which is located in central Greece. This 130 m deep and roughly 3 km long gorge is a characteristic example of an old drainage course preserved on the footwall blocks of two normal faults which confine both outlets of the deeply incised valley. The gorge has formed by a river that once had a N-S flow direction discharging into the Gulf of Patras. Acheloos River and the much smaller Ermitza Remma Stream are the two recent primary watercourses which drain the area close to the abandoned gorge. Both the dimensions and morphological characteristics of the abandoned deep valley indicate that the gorge has formed by a large river with high discharge in order to incise into the limestone bedrock. In order to investigate the tectonic constrains and determine the geomorphic and climatic processes that compelled the lower reaches of Acheloos River to abandon the gorge and find an outlet following its present course a GIS based analysis at a scale of 1:50.000 was applied in the drainage basin of Acheloos River. Additionally, to reconstruct the palaeolandscape and the earth surface processes, a detailed morphometric and geomorphic analysis of the abandoned gorge was also performed at a scale of 1:5.000 coupled with field observations and stratigraphic analysis of the deposits outcropping on the valley sides within the gorge as well as on both outlets. The geomorphic analysis led to the conclusion that the primary course of the gorge abandonment and diversion and reverse of the drainage is the uplift of the footwall

  20. Brazil: Xingu River

    Atmospheric Science Data Center

    2013-04-18

    ... title:  Fire and Deforestation near the Xingu River     View Larger Image Numerous fires occurred near the headwaters of the Xingu River and the Xingu Indigenous Peoples' Reserve in Mato Grosso, Brazil, during ...

  1. Measuring River Pollution

    ERIC Educational Resources Information Center

    Ayyavoo, Gabriel

    2004-01-01

    The Don River watershed is located within Canada's most highly urbanized area--metropolitan Toronto. Many residential and commercial uses, including alterations to the river's course with bridges, have had a significant impact on the Don's fauna and flora. Pollutants have degraded the river's water quality, a situation exacerbated by the…

  2. Mathematics. Rivers Curriculum Guide.

    ERIC Educational Resources Information Center

    Brueggeman, Gail; Clendenin, Donna

    The Rivers Project at Southern Illinois University began in February, 1990 as a pilot program involving eight high schools along the Mississippi and lower Illinois River. The Rivers Project network has grown through the training of teachers from across the United States and Canada. With scientific literacy as the ultimate goal, students collect…

  3. Rethinking the River.

    ERIC Educational Resources Information Center

    Tenenbaum, David

    1994-01-01

    Examines the ecological impacts of the Mississippi River flood of 1993 and the rethinking of river management practices that has resulted. Provides a map of the flood area which shows the occurrence of rare wildlife found in or near the region's rivers. (LZ)

  4. Flowing with Rivers

    ERIC Educational Resources Information Center

    Anderson, Heather

    2004-01-01

    This article describes a lesson in which students compare how artists have depicted rivers in paintings, using different styles, compositions, subject matter, colors, and techniques. They create a watercolor landscape that includes a river. Students can learn about rivers by studying them on site, through environmental study, and through works of…

  5. Amu Darya River

    Atmospheric Science Data Center

    2013-04-16

    article title:  Amu Darya River     View Larger Image This false-color image of the Amu Darya River was acquired by the Multi-angle Imaging SpectroRadiometer (MISR) in late ... highly vegetated areas to appear red. The Amu Darya river forms a wide delta in the western deserts of Uzbekistan and northeastern ...

  6. Spatial and temporal trends of physicochemical parameters in the water of the Reconquista river (Buenos Aires, Argentina).

    PubMed

    Castañé, Patricia M; Rovedatti, María G; Topalián, Mirta L; Salibián, Alfredo

    2006-06-01

    The Reconquista river is one of the most polluted watercourses in Argentina. More than 3 million people and over 10,000 industries are settled on its basin. The available data show that pollution is mainly related to the discharge of domestic and industrial liquid wastes that are poured into the river almost untreated. At present no site of the river can be characterized as free of pollutants. Samples were taken monthly from 5 sites of the river; some 18-20 physicochemical parameters were determined in each sample. Analyses revealed significant differences in the degree of deterioration between sites. Two of them, close to the source of the river (Cascallares-S(1) and Paso del Rey-S(2)) resulted less polluted than the two points located close to the mouth of the river (San Martin-S(4) and Bancalari-S(5)). The worsening of the water quality in S(4)-S(5) was attributed to the discharges of the Moron stream, a tributary that flows into the main course of the river a complex mixture of non treated waste waters. PCA was used in the ordination of samples (sites, season and physicochemical parameters). In the PCA performed using all variables, the first principal component showed positive correlation with N-NH(4) (+), conductivity, orthophosphate, BOD(5), COD and alkalinity, and negative correlation with DO. The second principal component was positively correlated with pH, temperature and chlorophyll a and negatively with phenols and hardness. In respect to the spatial distribution, the plot of the scores for the first two components of samples taken in each sampling station showed S(1) and S(2) values displayed farthest at the left side of the X axis with high DO. In contrast, S(4) and S(5) values stayed at the right side of this axis with high N-NH(4) (+), conductivity, orthophosphate, BOD(5), COD and alkalinity; data of S(3) were "intermediate". In order to identify seasonal trends in the concentration of contaminants scores of cases labeled by season were plotted. The

  7. Decabromodiphenyl ether (BDE-209) enters the food web of the River Po and is metabolically debrominated in resident cyprinid fishes.

    PubMed

    Viganò, Luigi; Roscioli, Claudio; Guzzella, Licia

    2011-11-01

    Decabromodiphenyl ether (BDE-209), the primary constituent of a widely used flame retardant formulation, is present at relatively high levels in sediments and macroinvertebrates of the River Po. Since it was demonstrated that BDE-209 can be biotransformed to smaller and more toxic polybrominated dipheyl ethers (PBDEs), the main objective of this study was to assess whether the large quantities of BDE-209 present in the River Po are bioavailable to the higher levels of the food web and are biotransformed in feral fishes. To this aim, 23 cyprinids, mainly common carp, were analysed for the hepatic contents of PBDEs. Contrary to sediments and invertebrates of the same area, no fish sample contained detectable levels of BDE-209. All fishes contained typical PBDE representatives, e.g. BDE-47, BDE-99, BDE-100, BDE-153 and BDE-154, but more importantly they contained three congeners, i.e. BDE-179, BDE-188 and BDE-202, which are not present in any technical formulations and are known products of BDE-209 debromination in fish. The age of carps had no effects on the bioaccumulation of PBDEs. Conversely, the contents of PCBs, which also were determined in the same fish samples, showed a positive correlation with age. Both groups of chemicals displayed a tendency to a higher contamination in male fish. This study shows that BDE-209 enters the food web of the River Po contributing to the load of lower brominated PBDEs and thus to the load of chemical stressors threatening the aquatic life of the major Italian watercourse. PMID:21925710

  8. 76 FR 51887 - Safety Zone; Patuxent River, Patuxent River, MD

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-19

    ...) entitled ``Safety Zone; Patuxent River, Patuxent River, MD'' in the Federal Register (76 FR 36447). We... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Patuxent River, Patuxent River, MD AGENCY... safety zone during the ``NAS Patuxent River Air Expo '11,'' which consists of aerial...

  9. A review of the contributions of fisheries and climate variability to contrasting dynamics in two Arcto-boreal Atlantic cod (Gadus morhua) stocks: Persistent high productivity in the Barents Sea and collapse on the Newfoundland and Labrador Shelf

    NASA Astrophysics Data System (ADS)

    Lilly, George R.; Nakken, Odd; Brattey, John

    2013-07-01

    Stocks of Atlantic cod (Gadus morhua) across the North Atlantic and adjacent seas have been fished intensively for years, and many are now severely depleted. In order to promote recovery and sustainable harvesting, it is essential to understand factors that have contributed to the declines and to variability in rates of recovery. Considerable insight may be gleaned by comparing and contrasting the histories of the Northeast Arctic (NEA) cod in the Barents Sea - Svalbard area of the northeast Atlantic and the “northern cod” on the Newfoundland and Labrador (NL) shelf in the northwest Atlantic. These two stocks, which were among the 3 largest cod stocks during the middle of the 20th century, are Arcto-boreal, and have many species of prey and predators in common. The biomass of NEA cod has varied considerably over time, and in 2009 was a little above 60% of its maximum observed level, which occurred in the late 1940s and early 1950s. In contrast, the biomass of NL cod decreased steadily from the early 1960s to the late 1970s, increased somewhat during the 1980s, and crashed during the early 1990s to an extremely low level, at which it remained for a decade before showing recent indications of improvement. Although both stocks were influenced by similar changes in harvesting strategies and environmental circumstances, both biotic and abiotic, there are two events which stand out as being particularly influential. First, crises developed in the management of both stocks in the late 1980s. For NEA cod, the crisis was environmental, caused by the collapse of capelin (Mallotus villosus), the main food for adult cod, whereas for NL cod the crisis was caused by a sudden large reduction in scientific perception of stock size. The difference in response to these crises strongly influenced subsequent stock dynamics. Catches of NEA cod were reduced considerably, preventing severe overharvesting of the cod that at that time experienced low productivity, whereas catches of NL

  10. Reconsidering Himalayan river anticlines

    NASA Astrophysics Data System (ADS)

    Montgomery, David R.; Stolar, Drew B.

    2006-12-01

    The observation that major Himalayan rivers flow parallel to and down the axis of anticlines oriented transverse to the primary structural grain of the range has puzzled geomorphologists for decades. Although there is a general consensus that the courses of trans-Himalayan rivers predate the Himalayan orogeny, the close association of rivers and structural highs would not be expected to result from the superposition of rivers onto pre-existing structures. Moreover, in the past several decades structural studies have shown that the development of river anticlines represents the most recent phase of deformation in the range. It is proposed that Himalayan river anticlines are the consequence of focused rock uplift in response to significant differences between net erosion along major rivers and surrounding regions. This hypothesis is supported by large gradients in observed and predicted erosion rates across major Himalayan rivers and by results from an isostasy-driven model, which requires relatively low flexural rigidities to match the wavelength of Himalayan river anticlines. Whether the amplitude of these structures is due to isostasy or also reflects active crustal channeling is not well-constrained, but given the uncertainty in the flexural rigidity and in the local and far-field erosion rates, both possibilities remain viable explanations. Given the observed correlation between the Arun River anticline and local rainfall maxima, it is proposed that Himalayan river anticlines are the expression of a relatively fine-scale linkage between tectonics, erosion and climate superimposed on the broader and older canvas of the Himalayan orogeny. Finally, it is suggested that the development of river anticlines represents one example along a continuum of features arising from different degrees of erosion-structure coupling in active orogens.

  11. Rivers: Nature's Wondrous Waterways.

    ERIC Educational Resources Information Center

    Harrison, David L.

    Rivers play a vital role in the life of the planet. They provide water for wildlife, plant life, and people, and they help to fertilize fields where corn and other crops grow. But how were these rivers made? This children's book takes readers/students on a journey down a river from its source at the top of a mountain to its mouth where it meets…

  12. Student-Designed River Study.

    ERIC Educational Resources Information Center

    Turkall, Sheila Florian

    1996-01-01

    Describes an integrated student-designed investigation in which students explore different aspects of the Chagrin River including the river ecosystem, velocity and average depth, river flooding, water quality, and economic and political factors. (JRH)

  13. Remediation of Uranium Impacted Sediments in a Watercourse - 12486

    SciTech Connect

    Shephard, E.; Walter, N.; Downey, H.; Collopy, P.; Conant, J.

    2012-07-01

    In 2009, remediation was initiated for a non-operational fuel cycle facility previously used for government contract work. Between 2009 and the spring of 2011, remediation efforts were focused on demolition of contaminated buildings and removal of contaminated soil. In the late spring of 2011, the last phase of remediation commenced involving the removal of contaminated sediments from portions of a 1,200 meter long gaining stream. Planning and preparation for remediation of the stream began in 2009 with submittal of permit applications to undertake construction activities in a wetland area. The permitting process was lengthy and involved securing permits from multiple agencies. However, early and frequent communication with stakeholders played an integral role in efficiently obtaining the permit approvals. Frequent communication with stakeholders throughout the planning and remediation process also proved to be a key factor in timely completion of the project. The remediation of the stream involved the use of temporary bladder berms to divert surface water flow, water diversion piping, a sediment vacuum removal system, excavation of sediments using small front-end loaders, sediment dewatering, and waste packaging, transportation and disposal. Many safeguards were employed to protect several species of concern in the work area, water management during project activities, challenges encountered during the project, methods of Final Status Survey, and stream restoration. The planning and permitting effort for the Site Brook remediation began in May 2009 and permits were approved and in place by February 2011. The remediation and restoration of the Site Brook began in April 2011 and was completed in November 2011. The remediation of the Site Brook involved the use of temporary bladder berms to divert surface water flow, water diversion piping, a sediment vacuum removal system, excavation of sediments using small front-end loaders, sediment dewatering, and waste packaging, transportation, disposal, FSS, and restoration. Early and frequent communications with stakeholders proved to be a key factor in timely completion of the project. Challenges encountered during the remediation effort were overcome by proper planning and having preparedness procedures in place prior to executing the work. With the remediation and restoration successfully completed, the only remaining task is to monitor/maintain the restoration for 10 years. (authors)

  14. River and Stream Pollution

    MedlinePlus

    ... Pollution Dirt Dirt is a big cause of pollution in our rivers and streams. Rain washes dirt into streams and rivers. Dirt can smother fish and other animals that live in the water. If plants can't get enough sunlight because ...

  15. Hudson River School

    ERIC Educational Resources Information Center

    McCloskey, Patrick J.

    2004-01-01

    In this article, the author features the "Clearwater," a full-size working replica of a 19th century Hudson River cargo sloop. The "Clearwater" has been serving New York state students as a link to both local history and the environment, helping them to learn lessons about the history of the Hudson River and the environment, thereby supplementing…

  16. Mississippi River. [Lesson Plan].

    ERIC Educational Resources Information Center

    Buchberg, Wendy

    Based on novels and books about the Mississippi River, this lesson plan presents activities designed to help students understand that the Mississippi River has made its mark on America's geography, commerce, and literature; and that booktalks provide a summary, explains what kind of reader the book will appeal to, and may also contain a oral…

  17. Alaska Glaciers and Rivers

    NASA Technical Reports Server (NTRS)

    2007-01-01

    The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Terra satellite captured this image on October 7, 2007, showing the Alaska Mountains of south-central Alaska already coated with snow. Purple shadows hang in the lee of the peaks, giving the snow-clad land a crumpled appearance. White gives way to brown on the right side of the image where the mountains yield to the lower-elevation Susitna River Valley. The river itself cuts a silver, winding path through deep green forests and brown wetlands and tundra. Extending from the river valley, are smaller rivers that originated in the Alaska Mountains. The source of these rivers is evident in the image. Smooth white tongues of ice extend into the river valleys, the remnants of the glaciers that carved the valleys into the land. Most of the water flowing into the Gulf of Alaska from the Susitna River comes from these mountain glaciers. Glacier melt also feeds glacier lakes, only one of which is large enough to be visible in this image. Immediately left of the Kahiltna River, the aquamarine waters of Chelatna Lake stand out starkly against the brown and white landscape.

  18. One river, many stories

    EPA Science Inventory

    Interactive exhibition elements include opportunity to add stories, drawings, and place names to maps of the river; record & share your vision for the river with public television. The Duluth Art Institute will present the kick-off event for the month-long media focus around ...

  19. The Illinois Rivers Project.

    ERIC Educational Resources Information Center

    Williams, Robert A.; And Others

    The Illinois Rivers Project was developed as an integrated, multidimensional science/technology/society pilot project designed to introduce water quality dimensions into Illinois high schools. The project involved high school science, social science, and English teachers in an integrated study of their local river and community. Science students…

  20. Synoptical situations and meteorological conditions associated to floods in the mouth of rivers in the European part of Russia

    NASA Astrophysics Data System (ADS)

    Matveeva, Tatiana; Gushchina, Daria

    2013-04-01

    The synoptical situations associated to the various type of floods in the mouth of rivers in European part of Russia are described. The storm surges, water flows and ice-jams are considered for Baltic, Barents sea, White sea, Azov sea, Black sea and Caspian sea regions. It is shown that the specific types of flood may be associated to various synoptical situations. Therefore it is unlikely to introduce the classification of synoptical regimes resulting in specific type of floods. However for each zone under consideration and for each specific flood type it is possible to determine the potential predictors of inundation: i.e. meteorological parameters which are characteristics of all cases of specific flood. There are: • for storm surges - long term wind forcing resulting in seiches in the sea, strong wind speed (the threshold varies in dependence on region), the wind direction orthogonal to the flow of river and strong baric gradient; • for water flows - the abundant precipitation, usually associate with the intensive frontal zone, the sudden change of air temperature resulting in snow melting in spring time; • for ice-jams - the strong temperature gradient extended in north-south direction resulting in negative temperature in the river mouth and positive temperature in the other basin. The probability of occurrence of predictors mentioned above was estimated for modern climate and global warming conditions using the outputs of ECHAM5/MPI-OM model. It is shown that the occurrence of intensive frontal zone and rainfall in the South of Russia will increase (decrease) in summer (winter) under warmer climate conditions which may contribute to the increase of water flows in this region. Maximum of floods occurs during the warm period, we can conclude that global warming increases the risk of floods in Black Sea coast.

  1. The impact of hydrograph variability and frequency on the morphodynamics of gravel-bed rivers

    NASA Astrophysics Data System (ADS)

    Plumb, Ben; Franca, Mário; Juez, Carmelo; Schleiss, Anton; Annable, William

    2016-04-01

    Hydromodification is the alteration of natural watershed hydrologic processes, which is known to change the way that water naturally enters watercourses. In the case of urbanization, this change has manifested through individual hydrograph characteristics (resulting in a decrease in duration and in the time-to-peak), as well as through the increase of the frequency of morphologically significant flood events. These hydrologic changes have been documented to impact the morphology of gravel-bed rivers, often resulting in channel degradation. However, the actual extent that urbanization changes bedload transport characteristics, which is known to be the most important driver of channel morphology, are not yet known. A laboratory experiment was undertaken in a 0.5m gravel-bed flume with sediment feed using a single poorly sorted bimodal sediment mixture in order to evaluate the impacts of changing hydrograph characteristics and frequencies on bedload transport and bed morphology. The hydrograph characteristics and frequencies were derived from long term stream-gauge records of urbanizing gravel-bed watercourses. These records are long enough to therefore be representative of the actual relative changes of the hydrologic regime; from an unaltered to a highly hydromodified system. A series of four hydrologic scenarios were established, representing 10 years of morphologically significant discharge events for four different stages of urban land-use, and corresponding hydrologic regimes. Each scenario begins with the same initial conditions and is allowed to evolve naturally with each successive hydrograph. For each scenario, the hydrograph duration and unsteadiness were varied, while peak discharge remained constant for all scenarios. In addition, the number of hydrographs ranged from nine to 33 for the unaltered to the most hydromodified scenarios, respectively. Discharge was measured constantly with a v-notch weir, and varied with a calibrated valve relationship

  2. 2. View of Tombigbee River Bridge facing southeast. River flow ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. View of Tombigbee River Bridge facing southeast. River flow is to left. South Pony span in background is not clearly shown. North pony span is shown on the left of main span. - Tombigbee River Bridge, Spanning Tombigbee River at State Highway 182, Columbus, Lowndes County, MS

  3. 36 CFR 7.89 - New River Gorge National River.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... River Gorge National River? (i) In addition to the applicable provisions in 36 CFR part 4, all... 36 Parks, Forests, and Public Property 1 2014-07-01 2014-07-01 false New River Gorge National River. 7.89 Section 7.89 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF...

  4. 33 CFR 117.734 - Navesink River (Swimming River).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Navesink River (Swimming River... BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New Jersey § 117.734 Navesink River (Swimming River). The Oceanic Bridge, mile 4.5, shall open on signal; except that, from December 1...

  5. 33 CFR 117.734 - Navesink River (Swimming River).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Navesink River (Swimming River... BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New Jersey § 117.734 Navesink River (Swimming River). The Oceanic Bridge, mile 4.5, shall open on signal; except that, from December 1...

  6. 33 CFR 117.734 - Navesink River (Swimming River).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Navesink River (Swimming River... BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New Jersey § 117.734 Navesink River (Swimming River). The Oceanic Bridge, mile 4.5, shall open on signal; except that, from December 1...

  7. 33 CFR 117.734 - Navesink River (Swimming River).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Navesink River (Swimming River... BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New Jersey § 117.734 Navesink River (Swimming River). The Oceanic Bridge, mile 4.5, shall open on signal; except that, from December 1...

  8. 33 CFR 117.734 - Navesink River (Swimming River).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Navesink River (Swimming River... BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New Jersey § 117.734 Navesink River (Swimming River). The Oceanic Bridge, mile 4.5, shall open on signal; except that, from December 1...

  9. 36 CFR 7.89 - New River Gorge National River.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 36 Parks, Forests, and Public Property 1 2011-07-01 2011-07-01 false New River Gorge National River. 7.89 Section 7.89 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.89 New River Gorge National River....

  10. Status of riverine soils of a Mediterranean river catchment (the Turia river, Spain) regarding potential contamination of heavy metals and pesticides

    NASA Astrophysics Data System (ADS)

    Andreu, Vicente; Gimeno-García, Eugenia; Pascual, Juan Antonio; Picó, Yolanda

    2016-04-01

    Rivers are sink structures receiving diffuse contamination mainly from agricultural practices. Hydrological dynamics of these watercourses favour, by one hand, the transport of contaminants (dissolved, complexed or adsorbed to suspended particles) and, by the other, their accumulation in sediments. These circumstances affect at different scales the quality of soils, waters, and the entire riverine ecosystems. In this work, 7 heavy metals and 50 pesticides were monitored in riverine soils of the Turia River catchment. From the source to the mounth, along the entiere river, 22 sampling points were selected for sampling according different lithologies, land uses, population size and the proximity to waste waters treatment plants (WWTPs). Cd, Co, Cr, Cu, Pb, Ni and Zn were analysed to determine its total and extractable contents in soils. Total content of metals was established by microwave acid digestion and the extractable fraction in soils and sediments by treatment with EDTA. Atomic Absorption Spectrometry, using graphite furnace when necessary, was used for the determination of the selected metals. Pesticide residues were extracted from the soil samples using the QuEchERS method and determined by Liquid Chromatograph-tandem Mass Spectrometry (LC-MS/MS). Recoveries ranged from 40 to 105 %. The limits of quantification ranged from 0.1 to 5.0 ng g-1. The higest levels of total and extractable Cd, Co, Cr and Ni were determined near the Benageber reservoir, located in the middle course of the river, where an important forest fires occurred a year ago. High levels of metals, mainly Cr and Zn, appeared headwaters in the Alfambra tributary. This deserves special mention because it was selected as a little impacted area that could serve as non-contaminated reference for the river. From the 50 pesticides condsidered, 26 were detected, with the highest levels for acetochlor (290.00 ng g-1) and a degradation product of terbutyazine - terbuthylazine deethyl - (234.75 ng g-1

  11. BPA and phthalate fate in a sewage network and an elementary river of France. Influence of hydroclimatic conditions.

    PubMed

    Tran, Bich Chau; Teil, Marie Jeanne; Blanchard, Martine; Alliot, Fabrice; Chevreuil, Marc

    2015-01-01

    Our purpose was to characterize the fate of bisphenol A (BPA) and phthalate contamination simultaneously in a sewage network and a watercourse, in relation with hydrological and climatic conditions. An elementary catchment of the Seine basin, receiving effluents from a wastewater treatment plant (WWTP), was chosen because of its basic hydrological features. BPA and DEHP concentrations in the WWTP inputs were 4 and 33 μg L(-1) whereas in the outputs, they were only 0.4 and 2 μg L(-1), respectively. Contaminant ratios in the suspended sediment phase of the WWTP inputs ranged from 0.5% to 88%, related to their molecular properties. BPA and phthalates were effectively removed in the WWTP (>90% for both compounds), by degradation and decantation. Upstream of the discharge, river concentrations ranged from 0.002 to 0.175 μg L(-1) for BPA and from 0.16 to 0.90 μg L(-1) for DEHP. Downstream from the WWTP outputs, concentrations ranged from 0.11 to 0.79 μg L(-1) for BPA and from 0.31 μg L(-1) to 1.7 μg L(-1) for DEHP: the WWTP discharge led to contaminant increases of 3.8 and 2 times, respectively. Far downstream, concentrations were lower ranging from 0.11 to 0.19 μg L(-1) for BPA and from 0.36 μg L(-1) to 1.1 μg L(-1) for DEHP. BPA and phthalates displayed opposite seasonal variations with a decrease for the first one and an increase for the second one during summer. BPA contamination in the Charmoise river derived mainly from the WWTP, while phthalate contamination was attributed to both WWTP discharges and diffuse sources such as atmospheric bulk deposition. PMID:24964009

  12. Uranium in river water

    SciTech Connect

    Palmer, M.R. ); Edmond, J.M. )

    1993-10-01

    The concentration of dissolved uranium has been determined in over 250 river waters from the Orinoco, Amazon, and Ganges basins. Uranium concentrations are largely determined by dissolution of limestones, although weathering of black shales represents an important additional source in some basins. In shield terrains the level of dissolved U is transport limited. Data from the Amazon indicate that floodplains do not represent a significant source of U in river waters. In addition, the authors have determined dissolved U levels in forty rivers from around the world and coupled these data with previous measurements to obtain an estimate for the global flux of dissolved U to the oceans. The average concentration of U in river waters is 1.3 nmol/kg, but this value is biased by very high levels observed in the Ganges-Brahmaputra and Yellow rivers. When these river systems are excluded from the budget, the global average falls to 0.78 nmol/kg. The global riverine U flux lies in the range of 3-6 [times] 10[sup 7] mol/yr. The major uncertainty that restricts the accuracy of this estimate (and that of all other dissolved riverine fluxes) is the difficulty in obtaining representative samples from rivers which show large seasonal and annual variations in runoff and dissolved load.

  13. A combined linear optimisation methodology for water resources allocation in Alfeios River Basin (Greece) under uncertain and vague system conditions

    NASA Astrophysics Data System (ADS)

    Bekri, Eleni; Yannopoulos, Panayotis; Disse, Markus

    2013-04-01

    In the present study, a combined linear programming methodology, based on Li et al. (2010) and Bekri et al. (2012), is employed for optimizing water allocation under uncertain system conditions in the Alfeios River Basin, in Greece. The Alfeios River is a water resources system of great natural, ecological, social and economic importance for Western Greece, since it has the longest and highest flow rate watercourse in the Peloponnisos region. Moreover, the river basin was exposed in the last decades to a plethora of environmental stresses (e.g. hydrogeological alterations, intensively irrigated agriculture, surface and groundwater overexploitation and infrastructure developments), resulting in the degradation of its quantitative and qualitative characteristics. As in most Mediterranean countries, water resource management in Alfeios River Basin has been focused up to now on an essentially supply-driven approach. It is still characterized by a lack of effective operational strategies. Authority responsibility relationships are fragmented, and law enforcement and policy implementation are weak. The present regulated water allocation puzzle entails a mixture of hydropower generation, irrigation, drinking water supply and recreational activities. Under these conditions its water resources management is characterised by high uncertainty and by vague and imprecise data. The considered methodology has been developed in order to deal with uncertainties expressed as either probability distributions, or/and fuzzy boundary intervals, derived by associated α-cut levels. In this framework a set of deterministic submodels is studied through linear programming. The ad hoc water resources management and alternative management patterns in an Alfeios subbasin are analyzed and evaluated under various scenarios, using the above mentioned methodology, aiming to promote a sustainable and equitable water management. Li, Y.P., Huang, G.H. and S.L., Nie, (2010), Planning water resources

  14. Modeling river delta formation.

    PubMed

    Seybold, Hansjörg; Andrade, José S; Herrmann, Hans J

    2007-10-23

    A model to simulate the time evolution of river delta formation process is presented. It is based on the continuity equation for water and sediment flow and a phenomenological sedimentation/erosion law. Different delta types are reproduced by using different parameters and erosion rules. The structures of the calculated patterns are analyzed in space and time and compared with real data patterns. Furthermore, our model is capable of simulating the rich dynamics related to the switching of the mouth of the river delta. The simulation results are then compared with geological records for the Mississippi River. PMID:17940031

  15. Nile River Delta, Egypt

    NASA Technical Reports Server (NTRS)

    1984-01-01

    The Nile River Delta of Egypt (30.0N, 31.0E) irrigated by the Nile River and its many distributaries, is some of the richest farm land in the world and home to some 45 million people, over half of Egypt's population. The capital city of Cairo is at the apex of the delta. Just across the river from Cairo can be seen the ancient three big pyramids and sphinx at Giza and the Suez Canal is just to the right of the delta.

  16. Modeling river delta formation

    PubMed Central

    Seybold, Hansjörg; Andrade, José S.; Herrmann, Hans J.

    2007-01-01

    A model to simulate the time evolution of river delta formation process is presented. It is based on the continuity equation for water and sediment flow and a phenomenological sedimentation/erosion law. Different delta types are reproduced by using different parameters and erosion rules. The structures of the calculated patterns are analyzed in space and time and compared with real data patterns. Furthermore, our model is capable of simulating the rich dynamics related to the switching of the mouth of the river delta. The simulation results are then compared with geological records for the Mississippi River. PMID:17940031

  17. BELLE FOURCHE RIVER WATERSHED ASSESSMENT

    EPA Science Inventory

    The Belle Fourche River is a natural stream that drains portions of Butte, Lawrence, and Meade Counties in South Dakota and flows to the Cheyenne River in Meade County. The river receives runoff from agricultural operations and both the river and its tributaries have experienced...

  18. Klamath River Water Quality and Acoustic Doppler Current Profiler Data from Link River Dam to Keno Dam, 2007

    USGS Publications Warehouse

    Sullivan, Annett B.; Deas, Michael L.; Asbill, Jessica; Kirshtein, Julie D.; Butler, Kenna; Stewart, Marc A.; Wellman, Roy W.; Vaughn, Jennifer

    2008-01-01

    In 2007, the U.S. Geological Survey, Watercourse Engineering, and the Bureau of Reclamation began a project to construct and calibrate a water quality and hydrodynamic model of the 21-mile reach of the Klamath River from Link River Dam to Keno Dam. To provide a basis for this work, data collection and experimental work were planned for 2007 and 2008. This report documents sampling and analytical methods and presents data from the first year of work. To determine water velocities and discharge, a series of cross-sectional acoustic Doppler current profiler (ADCP) measurements were made on the mainstem and four canals on May 30 and September 19, 2007. Water quality was sampled weekly at five mainstem sites and five tributaries from early April through early November, 2007. Constituents reported here include field parameters (water temperature, pH, dissolved oxygen concentration, specific conductance); total nitrogen and phosphorus; particulate carbon and nitrogen; filtered orthophosphate, nitrite, nitrite plus nitrate, ammonia, organic carbon, iron, silica, and alkalinity; specific UV absorbance at 254 nm; phytoplankton and zooplankton enumeration and species identification; and bacterial abundance and morphological subgroups. The ADCP measurements conducted in good weather conditions in May showed that four major canals accounted for most changes in discharge along the mainstem on that day. Direction of velocity at measured locations was fairly homogeneous across the channel, while velocities were generally lowest near the bottom, and highest near surface, ranging from 0.0 to 0.8 ft/s. Measurements in September, made in windy conditions, raised questions about the effect of wind on flow. Most nutrient and carbon concentrations were lowest in spring, increased and remained elevated in summer, and decreased in fall. Dissolved nitrite plus nitrate and nitrite had a different seasonal cycle and were below detection or at low concentration in summer. Many nutrient and

  19. River basin management

    SciTech Connect

    Newsome, D.H.; Edwards, A.M.C.

    1984-01-01

    The quality of water is of paramount importance in the management of water resources - including marine waters. A quantitative knowledge of water quality and the factors governing it is required to formulate and implement strategies requiring an inter-disciplinary approach. The overall purpose of this conference was to bring together the latest work on water quality aspects of river basin management. These proceedings are structured on the basis of five themes: problems in international river basins; the contribution of river systems to estuarial and marine pollution; the setting of standards; monitoring; and practical water quality management including use of mathematical models. They are followed by papers from the workshop on advances in the application of mathematical modelling to water quality management, which represent some of the current thinking on the problems and concepts of river basin management.

  20. Santa Cruz River Options

    EPA Science Inventory

    This presentation summarizes qualitative research insights gained during development of a nonmarket valuation survey for changes to the Santa Cruz River in Southern Arizona. Qualitative research provides an important avenue for understanding how the public interprets valuation s...

  1. Colorado River Delta

    NASA Technical Reports Server (NTRS)

    2008-01-01

    The Colorado River ends its 2330 km journey in the Gulf of Mexico in Baja California. The heavy use of the river as an irrigation source for the Imperial Valley has dessicated the lower course of the river in Mexico such that it no longer consistently reaches the sea. Prior to the mid 20th century, the Colorado River Delta provided a rich estuarine marshland that is now essentially desiccated, but nonetheless is an important ecological resource.

    The image was acquired May 29, 2006, covers an area of 44.3 x 57.5 km, and is located at 32.1 degrees north latitude, 115.1 degrees west longitude.

    The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

  2. River Meander Studies

    NASA Technical Reports Server (NTRS)

    Lingenfelter, R. E.

    1972-01-01

    The meander patterns of the Feather and Colorado rivers were studied in an attempt to correlate pattern changes and flood probability. Attempts were also made to correlate stream meander power spectrum and stream discharge frequency distribution.

  3. Mackenzie River Delta, Canada

    NASA Technical Reports Server (NTRS)

    2007-01-01

    The Mackenzie River in the Northwest Territories, Canada, with its headstreams the Peace and Finley, is the longest river in North America at 4241 km, and drains an area of 1,805,000 square km. The large marshy delta provides habitat for migrating Snow Geese, Tundra Swans, Brant, and other waterfowl. The estuary is a calving area for Beluga whales. The Mackenzie (previously the Disappointment River) was named after Alexander Mackenzie who travelled the river while trying to reach the Pacific in 1789.

    The image was acquired on August 4, 2005, covers an area of 55.8 x 55.8 km, and is located at 68.6 degrees north latitude, 134.7 degrees west longitude.

    The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

  4. Laminar laboratory rivers

    NASA Astrophysics Data System (ADS)

    Seizilles, Grégoire; Devauchelle, Olivier; Lajeunesse, Éric; Métivier, François

    2014-05-01

    A viscous fluid flowing over fine plastic grains spontaneously channelizes into a few centimeters-wide river. After reaching its equilibrium shape, this stable laboratory flume is able to carry a steady load of sediments, like many alluvial rivers. When the sediment discharge vanishes, the river size, shape and slope fit the threshold theory proposed by Glover and Florey (1951), which assumes that the Shields parameter is critical on the channel bed. As the sediment discharge is increased, the river widens and flattens. Surprisingly, the aspect ratio of its cross section depends on the sediment discharge only, regardless of the water discharge. We propose a theoretical interpretation of these findings based on the balance between gravity, which pulls particles towards the center of the channel, and the diffusion of bedload particles, which pushes them away from areas of intense bedload.

  5. THE GREAT RIVERS NEWSLETTER

    EPA Science Inventory

    The Great Rivers Newsletter is a periodic publication of the EPA's Mid-Continent Ecology Division. It is designed to disseminate timely information about the EMAP-GRE project among EPA investigators; state, federal, and tribal collaborators; and other stakeholders.

  6. Hood River Production Master Plan.

    SciTech Connect

    O'Toole, Patty

    1991-07-01

    The Northwest Power Planning Council's 1987 Columbia River Fish and Wildlife Program authorizes the development of artificial production facilities to raise chinook salmon and steelhead for enhancement in the Hood, Umatilla, Walla Walla, Grande Ronde and Imnaha rivers and elsewhere. On February 26, 1991 the Council agreed to disaggregate Hood River from the Northeast Oregon Hatchery Project, and instead, link the Hood River Master Plan (now the Hood River Production Plan) to the Pelton Ladder Project (Pelton Ladder Master Plan 1991).

  7. Connecticut River Hydrologic Observatory

    NASA Astrophysics Data System (ADS)

    Ballestero, T. P.

    2004-12-01

    The Connecticut River basin possesses some characteristics that make it unique for studying hydrologic issues that transcend scale. The watershed was first dramatically altered through natural processes (glaciation) and then heavily impacted by human stresses (dams, deforestation, acid precipitation/deposition), only to exhibit recent decades of return to a more natural state (reforestation, land conservation, stream restoration, pollution abatement, and dam removal). The watershed is sufficiently north to be classified as a cold region. More specifically to hydrology, the watershed exhibits the spectrum of flooding problems: ice dams, convective storms, hurricanes, rain on melting snow, and low pressure systems. The 28,000 square kilometer Connecticut River Watershed covers one third of the states of New Hampshire, Vermont, Massachusetts, and Connecticut. The >640-km long rivers' headwaters start on the Canadian border at the Fourth Connecticut Lake, and flows southward to discharge in Long Island sound. The lower 100 km of river are tidally influenced. The Connecticut River is responsible for 70 % of the freshwater inflow to Long Island Sound. The Connecticut River is a sixth order stream that exhibits a dendritic pattern in an elongated scheme. This setting therefore affords many first and second order streams in almost parallel fashion, flowing west or east towards the central Connecticut River spine. There are 38 major tributaries to the mainstem Connecticut River, and 26 of these tributaries drain greater than 250 square kilometers. There is in excess of 30,000 km of perennially flowing stream length in the watershed. For more information, see: http://www.unh.edu/erg/connho/

  8. The rivers of civilization

    NASA Astrophysics Data System (ADS)

    Macklin, Mark G.; Lewin, John

    2015-04-01

    The hydromorphic regimes that underpinned Old World river-based civilizations are reviewed in light of recent research. Notable Holocene climatic changes varied from region to region, whilst the dynamics of floodplain environments were equally diverse, with river channel changes significantly affecting human settlement. There were longer-term trends in Holocene hydroclimate and multi-centennial length 'flood-rich' and 'flood-poor' episodes. These impacted on five identified flooding and settlement scenarios: (i) alluvial fans and aprons; (ii) laterally mobile rivers; (iii) rivers with well-developed levees and flood basins; (iv) river systems characterised by avulsions and floodouts; and (v) large river-fed wetlands. This gave a range of changes that were either more or less regular or incremental from year-to-year (and thus potentially manageable) or catastrophic. The latter might be sudden during a flood event or a few seasons (acute), or over longer periods extending over many decades or even centuries (chronic). The geomorphic and environmental impacts of these events on riparian societies were very often irreversible. Contrasts are made between allogenic and autogenic mechanism for imposing environmental stress on riverine communities and a distinction is made between channel avulsion and contraction responses. Floods, droughts and river channel changes can precondition as well as trigger environmental crises and societal collapse. The Nile system currently offers the best set of independently dated Holocene fluvial and archaeological records, and the contrasted effects of changing hydromorphological regimes on floodwater farming are examined. The persistence of civilizations depended essentially on the societies that maintained them, but they were also understandably resilient in some environments (Pharaonic Egypt in the Egyptian Nile), appear to have had more limited windows of opportunity in others (the Kerma Kingdom in the Nubian Nile), or required

  9. Synthetic River Valleys

    NASA Astrophysics Data System (ADS)

    Brown, R.; Pasternack, G. B.

    2011-12-01

    The description of fluvial form has evolved from anecdotal descriptions to artistic renderings to 2D plots of cross section or longitudinal profiles and more recently 3D digital models. Synthetic river valleys, artificial 3D topographic models of river topography, have a plethora of potential applications in fluvial geomorphology, and the earth sciences in general, as well as in computer science and ecology. Synthetic river channels have existed implicitly since approximately the 1970s and can be simulated from a variety of approaches spanning the artistic and numerical. An objective method of synthesizing 3D stream topography based on reach scale attributes would be valuable for sizing 3D flumes in the physical and numerical realms, as initial input topography for morphodynamic models, stream restoration design, historical reconstruction, and mechanistic testing of interactions of channel geometric elements. Quite simply - simulation of synthetic channel geometry of prescribed conditions can allow systematic evaluation of the dominant relationships between river flow and geometry. A new model, the control curve method, is presented that uses hierarchically scaled parametric curves in over-lapping 2D planes to create synthetic river valleys. The approach is able to simulate 3D stream geometry from paired 2D descriptions and can allow experimental insight into form-process relationships in addition to visualizing past measurements of channel form that are limited to two dimension descriptions. Results are presented that illustrate the models ability to simulate fluvial topography representative of real world rivers as well as how channel geometric elements can be adjusted. The testing of synthetic river valleys would open up a wealth of knowledge as to why some 3D attributes of river channels are more prevalent than others as well as bridging the gap between the 2D descriptions that have dominated fluvial geomorphology the past century and modern, more complete, 3D

  10. Assessment of the water self-purification capacity on a river affected by organic pollution: application of chemometrics in spatial and temporal variations.

    PubMed

    González, S Oliva; Almeida, C A; Calderón, M; Mallea, M A; González, P

    2014-09-01

    Water pollution caused by organic matter is a major global problem which requires continuous evaluation. Multivariate statistical analysis was applied to assess spatial and temporal changes caused by natural and anthropogenic phenomena along Potrero de los Funes River. Cluster analysis (CA), principal component analysis (PCA) and analysis of variance (ANOVA) were applied to a data set collected throughout a period of 3 years (2010-2012), which monitored 22 physical, chemical and biological parameters. Content of dissolved oxygen in water and biochemical oxygen demand in a watercourse are indicators of pollution caused by organic matter. For this reason, the Streeter-Phelps model was used to evaluate the water self-purification capacity. Hierarchical cluster analysis grouped the sampling sites based on the similarity of water quality characteristics. PCA resulted in two latent factors explaining 75.2 and 17.6 % of the total variance in water quality data sets. Multidimensional ANOVA suggested that organic pollution is mainly due to domestic wastewater run-offs and anthropogenic influence as a consequence of increasing urbanization and tourist influx over the last years. Besides, Streeter-Phelps parameters showed a low reaeration capacity before dam with low concentration of dissolved oxygen. Furthermore, self-purification capacity loss was correlated with the decrease of the Benthic Index. This measurement suggested that biological samplings complement the physical-chemical analysis of water quality. PMID:24888622

  11. Reduction in the estrogenic activity of a treated sewage effluent discharge to an English river as a result of a decrease in the concentration of industrially derived surfactants.

    PubMed

    Sheahan, David A; Brighty, Geoff C; Daniel, Mic; Jobling, Susan; Harries, Jule E; Hurst, Mark R; Kennedy, Joe; Kirby, Sonia J; Morris, Steven; Routledge, Edwin J; Sumpter, John P; Waldock, Michael J

    2002-03-01

    As a result of the introduction of tighter discharge limits and effluent treatment processes at source, the concentration of alkylphenol ethoxylates and nonylphenol present in the final effluent discharge from a sewage treatment works that treats trade effluent from the textiles industry was reduced. The estrogenic effects of the final effluent discharge to the Aire River were compared over a four-year period during which various treatment measures were introduced. Male rainbow trout exposed to the effluent on four occasions in consecutive years (1994-1997) showed a reduction in the level of induced vitellogenesis between 1994 and 1997. A marked decrease in gonadosomatic index (GSI) and increase in heptaosomatic index (HSI) was measured in fish exposed to the effluent in 1994. In successive years, these differences diminished, and in the case of the GSI no measurable difference was observed between fish exposed to the final effluent or those in the control group in 1997. However, an increase in HSI was still measurable in 1997 in fish exposed to the final effluent and at sites farther downstream. The reduction in the effects of the effluent paralleled the reduction in the concentration of nonylphenol as well as its mono- and diethoxylates, which have been demonstrated to produce estrogenic effects in trout exposed to these compounds in the laboratory. This study demonstrates that the setting of more restricted discharge limits for known estrogenic chemicals of industrial origin can lead to significant reductions in the estrogenic activity of the watercourses into which the effluents are discharged. PMID:11878464

  12. Investigation and incorporation of water inflow uncertainties through stochastic modelling in a combined optimisation methodology for water allocation in Alfeios River (Greece)

    NASA Astrophysics Data System (ADS)

    Bekri, Eleni; Yannopoulos, Panayotis; Disse, Markus

    2014-05-01

    The Alfeios River plays a vital role for Western Peloponnisos in Greece from natural, ecological, social and economic aspect. The main river and its six tributaries, forming the longest watercourse and the highest streamflow rate of Peloponnisose, represent a significant source of water supply for the region, aiming at delivering and satisfying the expected demands from a variety of water users, including irrigation, drinking water supply, hydropower production and recreation. In the previous EGU General Assembly, a fuzzy-boundary-interval linear programming methodology, based on Li et al. (2010) and Bekri et al. (2012), has been presented for optimal water allocation under uncertain and vague system conditions in the Alfeios River Basin. Uncertainties associated with the benefit and cost coefficient in the objective function of the main water uses (hydropower production and irrigation) were expressed as probability distributions and fuzzy boundary intervals derived by associated α-cut levels. The uncertainty of the monthly water inflows was not incorporated in the previous initial application and the analysis of all other sources of uncertainty has been applied to two extreme hydrologic years represented by a selected wet and dry year. To manage and operate the river system, decision makers should be able to analyze and evaluate the impact of various hydrologic scenarios. In the present work, the critical uncertain parameter of water inflows is analyzed and its incorporation as an additional type of uncertainty in the suggested methodology is investigated, in order to enable the assessment of optimal water allocation for hydrologic and socio-economic scenarios based both on historical data and projected climate change conditions. For this purpose, stochastic simulation analysis for a part of the Alfeios river system is undertaken, testing various stochastic models from simple stationary ones (AR and ARMA), Thomas-Fiering, ARIMA as well as more sophisticated and

  13. The Nile River

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This image of the northern portion of the Nile River was captured by MISR's nadir camera on January 30, 2001 (Terra orbit 5956). The Nile is the longest river in the world, extending for about 6700 kilometers from its headwaters in the highlands of eastern Africa. At the apex of the fertile Nile River Delta is the Egyptian capital city of Cairo. To the west are the Great Pyramids of Giza. North of here the Nile branches into two distributaries, the Rosetta to the west and the Damietta to the east. Also visible in this image is the Suez Canal, a shipping waterway connecting Port Said on the Mediterranean Sea with the Gulf of Suez. The Gulf is an arm of the Red Sea, and is located on the righthand side of the picture. Image credit: NASA/GSFC/LaRC/JPL, MISR Team.

  14. Alaskan river environmental acoustics

    NASA Astrophysics Data System (ADS)

    Dahl, Peter H.; Pfisterer, Carl; Geiger, Harold J.

    2005-04-01

    Sonars are used by the Alaska Department of Fish and Game (ADF&G) to obtain daily and hourly estimates of at least four species of migratory salmon during their seasonal migration which lasts from June to beginning of September. Suspended sediments associated with a river's sediment load is an important issue for ADF&G's sonar operations. Acoustically, the suspended sediments are a source of both volume reverberation and excess attenuation beyond that expected in fresh water. Each can impact daily protocols for fish enumeration via sonar. In this talk, results from an environmental acoustic study conducted in the Kenai River (June 1999) using 420 kHz and 200 kHz side looking sonars, and in the Yukon River (July 2001) using a 120 kHz side looking sonar, are discussed. Estimates of the volume scattering coefficient and attenuation are related to total suspended sediments. The relative impact of bubble scattering and sediment scattering is also discussed.

  15. Rivers of Evidence

    PubMed Central

    Adams, Clive E

    2013-01-01

    There has been too much of a one-way flow drift down a river of evidence. Researchers from rich countries have produced the primary evidence which they proceed to summarise within reviews. These summaries have directed care worldwide. However, things are changing and the river of evidence can flow in the other direction. The care of women with eclampsia has been changed or refined throughout the world because of a large low and middle income country trial. The global care of people with heart disease has been greatly modified by studies originating in China. The care of people who are acutely aggressive because of psychosis has to be reconsidered in the light of the evidence coming from Brazil and India. Healthcare is an issue everywhere and evaluation of care is not the premise of any one culture—the evidence—river must run both ways. PMID:24596880

  16. 33 CFR 207.380 - Red Lake River, Minn.; logging regulations for portion of river above Thief River Falls.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Red Lake River, Minn.; logging... Red Lake River, Minn.; logging regulations for portion of river above Thief River Falls. (a) Parties wishing to run logs on Red Lake River must provide storage booms near the head of the river to take...

  17. 33 CFR 207.380 - Red Lake River, Minn.; logging regulations for portion of river above Thief River Falls.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false Red Lake River, Minn.; logging... Red Lake River, Minn.; logging regulations for portion of river above Thief River Falls. (a) Parties wishing to run logs on Red Lake River must provide storage booms near the head of the river to take...

  18. 76 FR 36447 - Safety Zone; Patuxent River, Patuxent River, MD

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-22

    ..., 2008, issue of the Federal Register (73 FR 3316). Public meeting We do not now plan to hold a public... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Patuxent River, Patuxent River, MD AGENCY... a temporary safety zone during the ``NAS Patuxent River Air Expo '11'', which consists of...

  19. Regional river sulfur runoff

    SciTech Connect

    Husar, R.B.; Husar, J.D.

    1985-01-20

    The water and sulfur runoff data for 54 large river basins were assembled, covering 65% of the nondesert land area of the world. The sulfur concentration ranges from 0.5 mg S/L for the West African rivers Niger and Volta to 100 mg S/L in the Colorado River; the world average is 3.2 mg S/L. The concentrations in central and eastern Europe as well as central and eastern North America exceed 8 mg S/L. The sulfur runoff density is also highest in the river basins over these industrialized regions, exceeding 2 g S/m/sup 2//yr. However, high sulfur runoff density in excess of 3 g S/m/sup 2//yr is also measured over the Pacific islands New Zealand and New Guinea and the archipelagos of Indonesia and the Philippines. The natural background sulfur runoff was estimated by assuming that South America, Africa, Australia, and the Pacific Islands are unperturbed by man and that the average river sulfur concentration is in the range 1--3 mg S/L. Taking these background concentration values, the man-induced sulfur runoff for Europe ranges between 2 and 8 times the natural flow, and over North America, man's contribution ranges between 1 and 5 times the natural runoff. The global sulfur flow from nondesert land to the oceans and the Caspian Sea is estimated as 131 Tg S/yr, of which 46--85 Tg S/yr is attributed to natural causes. The regional river sulfur runoff pattern discussed in this paper does not have enough spatial resolution to be directly applicable to studies of the environmental effects of man-induced sulfur flows. However, it points to the continental-size regions where those perturbations are most evident and to the magnitude of the perturbations as expressed in units of the natural flows.

  20. Regional river sulfur runoff

    NASA Astrophysics Data System (ADS)

    Husar, Rudolf B.; Husar, Janja Djukic

    1985-01-01

    The water and sulfur runoff data for 54 large river basins were assembled, covering 65% of the nondesert land area of the world. The sulfur concentration ranges from 0.5 mg S/L for the West African rivers Niger and Volta to 100 mg S/L in the Colorado River; the world average is 3.2 mg S/L. The concentrations in central and eastern Europe as well as central and eastern North America exceed 8 mg S/L. The sulfur runoff density is also highest in the river basins over these industrialized regions, exceeding 2 g S/m2/yr. However, high sulfur runoff density in excess of 3 g S/m2/yr is also measured over the Pacific islands New Zealand and New Guinea and the archipelagos of Indonesia and the Philippines. The natural background sulfur runoff was estimated by assuming that South America, Africa, Australia, and the Pacific Islands are unperturbed by man and that the average river sulfur concentration is in the range 1-3 mg S/L. Taking these background concentration values, the man-induced sulfur runoff for Europe ranges between 2 and 8 times the natural flow, and over North America, man's contribution ranges between 1 and 5 times the natural runoff. The global sulfur flow from nondesert land to the oceans and the Caspian Sea is estimated as 131 Tg S/yr, of which 46-85 Tg S/yr is attributed to natural causes. The regional river sulfur runoff pattern discussed in this paper does not have enough spatial resolution to be directly applicable to studies of the environmental effects of man-induced sulfur flows. However, it points to the continental-size regions where those perturbations are most evident and to the magnitude of the perturbations as expressed in units of the natural flows.

  1. Osmium in the rivers

    SciTech Connect

    Sharma, M. |; Wasserburg, G.J.

    1997-12-01

    There is a large uncertainty in our understanding of the behavior of osmium during weathering and transport into deep oceans and the osmium budget of the oceans. The problem stems chiefly from the lack of osmium data on the dissolved load in the rivers and in the estuaries. In this study, the concentration and isotopic composition of osmium have been determined in three North American rivers (the Mississippi, the Columbia, and the Connecticut) and one river draining central Europe and flowing into the Baltic Sea (the Vistula). Osmium concentration in the Mississippi and the Vistula is about 45 femto mol kg{sup -1}; it is about 14 and 15 femto mol kg{sup -1} for the Connecticut and the Columbia, respectively. The {sup 187}Os/{sup 186}Os ratios estimated for the Mississippi and the Vistula are 10.4 and 10.7, respectively. For the Connecticut and the Columbia {sup 187}Os/{sup 186}Os = 8.8 and 14.4, respectively. Of all the rivers examined, the Mississippi is by far the largest, supplying {approximately}1.6% of the total annual world river flow. Its osmium isotopic composition is identical to the upper Mississippi valley loesses indicating (1) congruent dissolution of the bedrock and (2) little or no impact of anthropogenic sources on the osmium isotopic composition of the dissolved load. The latter observation indicates that the upper limit of the anthropogenic input in the dissolved osmium load of the Mississippi outflow is about 250 g yr{sup -1}. While the osmium concentration of the Vistula is high the isotopic composition does not appear to have been affected by substantial pollution. The river data can be used to put limits on the mean residence time of osmium in the oceans ({bar {tau}}{sub Os}) and on the osmium budget of the oceans. 17 refs., 1 fig., 1 tab.

  2. River Pollution: Part I.

    ERIC Educational Resources Information Center

    Openshaw, Peter

    1983-01-01

    Describes a unit on river pollution and analytical methods to use in assessing temperature, pH, flow, calcium, chloride, dissolved oxygen, biochemical oxygen demand, dissolved nitrogen, detergents, heavy metals, sewage pollution, conductivity, and sediment cores. Suggests tests to be carried out and discusses significance of results. (JM)

  3. Savannah River Site Robotics

    ScienceCinema

    None

    2012-06-14

    Meet Sandmantis and Frankie, two advanced robotic devices that are key to cleanup at Savannah River Site. Sandmantis cleans hard, residual waste off huge underground storage tanks. Frankie is equipped with unique satellite capabilities and sensing abilties that can determine what chemicals still reside in the tanks in a cost effective manner.

  4. Ecological River Basin Management.

    ERIC Educational Resources Information Center

    Smith, Anthony Wayne

    Addressing the Seventh American Water Resources Conference, Washington, D. C., October, 1971, Anthony Wayne Smith, President, National Parks and Conservation Association, presents an expose on how rivers should be managed by methods which restores and preserve the natural life balances of the localities and regions through which they flow. The…

  5. Nissitissit River Investigation.

    ERIC Educational Resources Information Center

    Sweatman, Jon

    Prepared for the student participant, this manual guides a day's exploration of the Nissitissit River. The unit, one of several developed in conjunction with Project Exploration, has the broad goals of promoting--through experiential learning in a variety of environments outside the classroom--the student's self-confidence and ability to work…

  6. Colwater fish in rivers

    EPA Science Inventory

    A standard sampling protocol to assess the fish assemblages and abundances in large, coldwater rivers is most accurate and precise if consistent gears and levels of effort are used at each site. This requires thorough crew training, quality control audits, and replicate sampling...

  7. Discover the Nile River

    ERIC Educational Resources Information Center

    Project WET Foundation, 2009

    2009-01-01

    Bordering on the Fantastic. As the longest river on earth, the Nile passes through 10 countries. Presented through a wide range of activities and a winning array of games, it's also unsurpassed at taking young minds into exploring the world of water, as well as natural and man made wonders.

  8. River on Trial

    ERIC Educational Resources Information Center

    Carney, Thomas R.

    1972-01-01

    Presents controversy over damming of Wyoming's Upper Green River to supply water to the arid basins of eastern Wyoming. Possibilities of wildlife destruction, flooding of valley lands, and opposition to the construction of the Kendall Dam itself are enumerated together with legislative action to date. (BL)

  9. The River Rock School.

    ERIC Educational Resources Information Center

    Gereaux, Teresa Thomas

    1999-01-01

    In the early 1920s, the small Appalachian community of Damascus, Virginia, used private subscriptions and volunteer labor to build a 15-classroom school made of rocks from a nearby river and chestnut wood from nearby forests. The school building's history, uses for various community activities, and current condition are described. (SV)

  10. The Nation's Rivers

    ERIC Educational Resources Information Center

    Wolman, M. Gordon

    1971-01-01

    Illustrates difficulties in measuring long term changes in water temperature and content of dissolved oxygen, inorganic ions, radiation, pesticides, and trash and debris by reference to selected U. S. river systems. Concludes that observations to detect polluters may not provide data for assessing trends and trend reversals. (AL)

  11. Savannah River Site Robotics

    SciTech Connect

    2010-01-01

    Meet Sandmantis and Frankie, two advanced robotic devices that are key to cleanup at Savannah River Site. Sandmantis cleans hard, residual waste off huge underground storage tanks. Frankie is equipped with unique satellite capabilities and sensing abilties that can determine what chemicals still reside in the tanks in a cost effective manner.

  12. The Svalbard Barents Sea Ice Sheet deglaciation and its contribution to meltwater pulse 1a: Constraining ice sheet history with geomorphological mapping and 10Be exposure dating on Svalbard's southern cape

    NASA Astrophysics Data System (ADS)

    Nothaft, D. B.; Koffman, T.; Schaefer, J. M.; Young, N. E.; Hormes, A.; Briner, J. P.

    2014-12-01

    Pinpointing the sources of meltwater pulse (MWP) 1a—the most abrupt period of sea level rise during the last glacial termination—remains one of paleoclimatology's greatest challenges, with implications for the understanding of rapid climate change, isostatic rebound, and past ocean circulation. Here, we present an annotated geomorphological map of a southern region of Svalbard, Norway, that we will use in the interpretation of a soon-to-be published 10Be chronology of this study area where no cosmogenic nuclide exposure data has yet been produced. From this map, we infer historic ice sheet thickness, flow rate, and erosivity. Together, this data will enable us to constrain ice sheet volume change over time in southern Svalbard. The map identifies raised beaches at an altitude of 40 m, indicating an ice sheet thickness of 400-800 m during the Last Glacial Maximum (LGM) when compared to other shoreline data from the region and ice sheet models. We also observed an abundance of glacially smoothed features in valleys, despite an absence of such features at higher elevations. This could suggest a transition from warm-based, erosive ice to cold-based, non-destructive ice with increasing elevation. It is also possible that mountain peaks in this region were not glaciated at LGM. It is important to assess the historic erosivity of an ice sheet because cosmogenic nuclides may be inherited from prior interstadials when the bedrock was deglaciated, if not "reset" by erosion. This can result in erroneously old exposure dates. If this portion of the Svalbard Barents Sea Ice Sheet (SBSIS) did contribute largely to MWP-1a, then we would expect exposure dates from sites differing in elevation by 100 m or more to fall within a 500-year range, centered around 14 ka. Expeditions to collect samples for exposure dating at other field sites in southern Svalbard, scheduled for the coming field season, will help to further inform our understanding of the SBSIS deglaciation and the MWP

  13. Distribution of phthalates, pesticides and drug residues in the dissolved, particulate and sedimentary phases from transboundary rivers (France-Belgium).

    PubMed

    Net, Sopheak; Rabodonirina, Suzanah; Sghaier, Rafika Ben; Dumoulin, David; Chbib, Chaza; Tlili, Ines; Ouddane, Baghdad

    2015-07-15

    Various drug residues, pesticides and phthalates are ubiquitous in the environment. Their presence in the environment has attracted considerable attention due to their potential impacts on ecosystem functioning and on public health. In this work, 14 drug residues, 24 pesticides and 6 phthalates have been quantified in three matrices (in the dissolved phase, associated to suspended solid matter (SSM), and in sediment) collected from fifteen watercourses and rivers located in a highly industrialized zone at the cross-border area of Northern France and Belgium. The extractions have been carried out using accelerated solvent extraction (ASE) for solid matrices (SSM and sediment) and using solid phase extraction (SPE) for liquid matrix. The final extract was analyzed using GC-MS technique. Among the three classes of compounds, phthalates have been found at highest level compared to pesticides and drug residues. The Σ6PAE concentrations were ranging from 17.2±2.58 to 179.1±26.9μgL(-1) in dissolved phase, from 2.9±0.4 to 21.1±3.2μgL(-1) in SSM and from 1.1±0.2 to 11.9±1.8μgg(-1)dw in sediment. The Σ14drug residue concentrations were lower than 1.3μgL(-1) in the dissolved phases, lower than 30ngL(-1) associated to SSM and from nondetectable levels to 60.7±9.1ngg(-1)dw in sediment. For pesticides, all compounds were below the LOQ values in dissolved phase and in sediment, and only EPTC could be quantified in SSM. PMID:25829293

  14. Variation of dissolved organic carbon transported by two Chinese rivers: The Changjiang River and Yellow River.

    PubMed

    Liu, Dong; Pan, Delu; Bai, Yan; He, Xianqiang; Wang, Difeng; Zhang, Lin

    2015-11-15

    Real-time monitoring of riverine dissolved organic carbon (DOC) and the associated controlling factors is essential to coastal ocean management. This study was the first to simulate the monthly DOC concentrations at the Datong Hydrometric Station for the Changjiang River and at the Lijin Hydrometric Station for the Yellow River from 2000 to 2013 using a multilayer back-propagation neural network (MBPNN), along with basin remote-sensing products and river in situ data. The average absolute error between the modeled values and in situ values was 9.98% for the Changjiang River and 10.84% for the Yellow River. As an effect of water dilution, the variations of DOC concentrations in the two rivers were significantly negatively affected by discharge, with lower values reported during the wet season. Moreover, vegetation growth status and agricultural activities, represented by the gross primary product (GPP) and cropland area percent (CropPer) in the river basin, respectively, also significantly affected the DOC concentration in the Changjiang River, but not the Yellow River. The monthly riverine DOC flux was calculated using modeled DOC concentrations. In particular, the riverine DOC fluxes were affected by discharge, with 71.06% being reported for the Changjiang River and 90.71% for the Yellow River. Over the past decade, both DOC concentration and flux in the two rivers have not shown significant changes. PMID:26404069

  15. 3. ENVIRONMENT, FROM SOUTH, SHOWING RIVER ROAD RIDGE CARRYING CASSELMAN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. ENVIRONMENT, FROM SOUTH, SHOWING RIVER ROAD RIDGE CARRYING CASSELMAN RIVER ROAD OVER CASSELMAN RIVER - River Road Bridge, Crossing Casselman River on Casselman River Road, Grantsville, Garrett County, MD

  16. Hood River Passive House

    SciTech Connect

    Hales, D.

    2013-03-01

    The Hood River Passive Project was developed by Root Design Build of Hood River Oregon using the Passive House Planning Package (PHPP) to meet all of the requirements for certification under the European Passive House standards. The Passive House design approach has been gaining momentum among residential designers for custom homes and BEopt modeling indicates that these designs may actually exceed the goal of the U.S. Department of Energy's (DOE) Building America program to reduce home energy use by 30%-50% (compared to 2009 energy codes for new homes). This report documents the short term test results of the Shift House and compares the results of PHPP and BEopt modeling of the project.

  17. Chesapeake Bay, Potomac River

    NASA Technical Reports Server (NTRS)

    1973-01-01

    The nation's capital lies astride the Potomac River (38.5N, 77.5W) at the head of the Potomac Estuary. Baltimore, MD, also in the scene, is connected to Washington by the Baltimore-Washington Parkway. The suburbs of both cities tend to cluster around the Washington and Baltimore Beltways. Most of the countryside in the eastern two-thirds of this scene is either heavily forested or is in farming, dairy operations or poultry production.

  18. Onilahy River, Madagascar

    NASA Technical Reports Server (NTRS)

    1982-01-01

    Near the southern tip of Madagascar, the Onilahy River (23.5S, 44E) drains a near barren landscape, the result of rapid deforestation for quick profits from the lumber industry with no regard to the environmental impact. At the turn of the century, the island was a lush tropical paradise with about 90 percent of the surface forested. Now, at the close of the century, only about 10 percent of the forests remain in inaccessible rugged terrain.

  19. River networks as biodiversity hotlines.

    PubMed

    Décamps, Henri

    2011-05-01

    For several years, measures to insure healthy river functions and to protect biodiversity have focused on management at the scale of drainage basins. Indeed, rivers bear witness to the health of their drainage basins, which justifies integrated basin management. However, this vision should not mask two other aspects of the protection of aquatic and riparian biodiversity as well as services provided by rivers. First, although largely depending on the ecological properties of the surrounding terrestrial environment, rivers are ecological systems by themselves, characterized by their linearity: they are organized in connected networks, complex and ever changing, open to the sea. Second, the structure and functions of river networks respond to manipulations of their hydrology, and are particularly vulnerable to climatic variations. Whatever the scale considered, river networks represent "hotlines" for sharing water between ecological and societal systems, as well as for preserving both systems in the face of global change. River hotlines are characterized by spatial as well as temporal legacies: every human impact to a river network may be transmitted far downstream from its point of origin, and may produce effects only after a more or less prolonged latency period. Here, I review some of the current issues of river ecology in light of the linear character of river networks. PMID:21640951

  20. 77 FR 30589 - SteelRiver Infrastructure Partners LP, SteelRiver Infrastructure Associates LLC, SteelRiver...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-23

    ... Surface Transportation Board SteelRiver Infrastructure Partners LP, SteelRiver Infrastructure Associates LLC, SteelRiver Infrastructure Fund North America LP, and Patriot Funding LLC--Control Exemption--Patriot Rail Corp., et al. SteelRiver Infrastructure Partners LP (SRIP LP), SteelRiver...

  1. 50 CFR 226.205 - Critical habitat for Snake River sockeye salmon, Snake River fall chinook salmon, and Snake River...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies of the USGS publication and maps may be... salmon, Snake River fall chinook salmon, and Snake River spring/summer chinook salmon. 226.205 Section... Snake River sockeye salmon, Snake River fall chinook salmon, and Snake River spring/summer...

  2. 50 CFR 226.205 - Critical habitat for Snake River sockeye salmon, Snake River fall chinook salmon, and Snake River...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies of the USGS publication and maps may be... salmon, Snake River fall chinook salmon, and Snake River spring/summer chinook salmon. 226.205 Section... Snake River sockeye salmon, Snake River fall chinook salmon, and Snake River spring/summer...

  3. Flooding on Elbe River

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Heavy rains in Central Europe over the past few weeks have led to some of the worst flooding the region has witnessed in more than a century. The floods have killed more than 100 people in Germany, Russia, Austria, Hungary, and the Czech Republic and have led to as much as $20 billion in damage. This false-color image of the Elbe River and its tributaries was taken on August 20, 2002, by the Moderate Resolution Imaging Spectroradiometer (MODIS), flying aboard NASA's Terra satellite. The floodwaters that inundated Dresden, Germany, earlier this week have moved north. As can be seen, the river resembles a fairly large lake in the center of the image just south of the town of Wittenberg. Flooding was also bad further downriver in the towns of Maqgdeburge and Hitzacker. Roughly 20,000 people were evacuated from their homes in northern Germany. Fifty thousand troops, border police, and technical assistance workers were called in to combat the floods along with 100,000 volunteers. The floodwaters are not expected to badly affect Hamburg, which sits on the mouth of the river on the North Sea. Credit:Image courtesy Jacques Descloitres, MODIS Land Rapid Response Team at NASA GSFC

  4. Flooding along Danube River

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Heavy rains in Central and Eastern Europe over the past few weeks have led to some of the worst flooding the region has witnessed in over a century. The floods have killed more than 100 people in Germany, Russia, Austria, Hungary and the Czech Republic and have led to as much as $20 billion in damage. This false-color image of the Danube River and its tributaries was taken on August 19, 2002, by the Moderate Resolution Imaging Spectroradiometer (MODIS), flying aboard NASA's Terra satellite. Budapest, the capital of Hungary, sits just south of the large bend in the river at the top of the image. Here the water reached levels not seen since 1965. Fortunately, the riverbanks are lined with 33-foot retainer walls throughout the city, so it did not face the same fate as Dresden or Prague along the Elbe River. But as one can see, the floodwaters hit many rural areas farther south. As last reported, the water was receding along the Danube. Credit: Image courtesy Jacques Descloitres, MODIS Land Rapid Response Team at NASA GSFC.

  5. Tsunami Impacts in River Environments

    NASA Astrophysics Data System (ADS)

    Tolkova, E.; Tanaka, H.; Roh, M.

    2014-12-01

    The 2010 Chilean and the 2011 Tohoku tsunami events demonstrated the tsunami's ability to penetrate much farther along rivers than the ground inundation. At the same time, while tsunami impacts to the coastal areas have been subject to countless studies, little is known about tsunami propagation in rivers. Here we examine the field data and conduct numerical simulations to gain better understanding of the tsunami impacts in rivers.The evidence which motivated our study is comprised of water level measurements of the aforementioned tsunamis in multiple rivers in Japan, and the 2011 Tohoku and some other tsunamis in the Columbia River in the US. When the available tsunami observations in these very different rivers are brought together, they display remarkably similar patterns not observed on the open coast. Two phenomena were discovered in the field data. First, the phase of the river tide determines the tsunami penetration distance in a very specific way common to all rivers. Tsunami wave progressively disappears on receding tide, whereas high tide greatly facilitates the tsunami intrusion, as seen in the Figure. Second, a strong near-field tsunami causes substantial and prolonged water accumulation in lower river reaches. As the 2011 tsunami intruded rivers in Japan, the water level along rivers rose 1-2 m and stayed high for many hours, with the maximum rise occurring several km from the river mouth. The rise in the water level at some upstream gaging stations even exceeded the tsunami amplitude there.Using the numerical experiments, we attempt to identify the physics behind these effects. We will demonstrate that the nonlinear interactions among the flow components (tsunami, tide, and riverine flow) are an essential condition governing wave dynamics in tidal rivers. Understanding these interactions might explain some previous surprising observations of waves in river environments. Figure: Measurements of the 2010/02/27 tsunami along Naruse and Yoshida rivers

  6. Fluoride in UK rivers.

    PubMed

    Neal, Colin; Neal, Margaret; Davies, Helen; Smith, Jennifer

    2003-10-01

    Fluoride concentrations in eastern UK rivers (the Humber, Tweed, Wear, Great Ouse and Thames) are described based on information collected within the Land-Ocean Interaction Study (LOIS) and by the Environment Agency (EA) of England and Wales. The results show varied fluoride concentrations across the region, with a range from <0.01 to >10 mg l(-1); and mean, median and range in mean concentrations of 0.30, 0.21 and 0.05-3.38 mg l(-1) (excluding one outlier point), respectively. Within the main rivers and tributaries, the mean fluoride concentration varied from approximately 0.5 to over 2 mg l(-1) and the highest values occurred within the Don basin (Don, Dearne and Rother) and parts of the Trent basin (upper Tame and mid-upper Derbyshire Derwent) in highly industrialised and urbanised areas (Sheffield and Rotherham in the Don basin; Birmingham and Derby on the Trent). For localised inputs to the rivers, fluoride concentrations were slightly higher, and considerably higher in one outlier case. Correspondingly, the other rivers examined typically had mean fluoride concentrations between approximately 0.2 and 0.5 mg l(-1), but fluoride concentrations were lower in the headwater areas. As there is much less information on fluoride levels in upland areas, extensive data collected as part of an acid waters survey are used to show that fluoride concentrations are generally less than 0.1 mg l(-1) for the upland UK. The data are summarised in terms of both fluoride concentrations and flux, and the values are cross-referenced to other determinands collected within LOIS. The high positive correlation with boron and negative correlation with flow show the importance of point source (sewage) inputs of fluoride, while strong positive correlations between fluoride and barium indicate the relative importance of vein mineralisation in the bedrock in supplying fluoride to the waters of the Yorkshire Ouse and its tributaries. There seems to be some process that limits the fluoride

  7. 33 CFR 125.06 - Western rivers.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Western rivers. 125.06 Section... VESSELS § 125.06 Western rivers. The term western rivers as used in the regulations in this subchapter shall include only the Red River of the North, the Mississippi River and its tributaries above the...

  8. 33 CFR 125.06 - Western rivers.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Western rivers. 125.06 Section... VESSELS § 125.06 Western rivers. The term western rivers as used in the regulations in this subchapter shall include only the Red River of the North, the Mississippi River and its tributaries above the...

  9. 33 CFR 125.06 - Western rivers.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Western rivers. 125.06 Section... VESSELS § 125.06 Western rivers. The term western rivers as used in the regulations in this subchapter shall include only the Red River of the North, the Mississippi River and its tributaries above the...

  10. 33 CFR 125.06 - Western rivers.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Western rivers. 125.06 Section... VESSELS § 125.06 Western rivers. The term western rivers as used in the regulations in this subchapter shall include only the Red River of the North, the Mississippi River and its tributaries above the...

  11. Rehabilitating China's largest inland river.

    PubMed

    Li, Yiqing; Chen, Yaning; Zhang, Yaoqi; Xia, Yang

    2009-06-01

    Wetlands are particularly important for conserving China's biodiversity but riparian wetlands in the Tarim River basin in western China have been reduced by 46% during the last 3 decades. The world's largest habitat for Populus euphratica, which is in the Tarim River basin, significantly shrank. To protect and restore the deteriorated ecosystems along the Tarim River and its associated wetlands, China's government initiated a multimillion dollar river restoration project to release water from upper dams to the dried-up lower reaches of the Tarim River starting in 2000. We monitored the responses of groundwater and vegetation to water recharge in the lower reaches of the river from 2000 to 2006 by establishing nine 1000-m-long transects perpendicular to the river at intervals of 20-45 km along the 320-km river course below the Daxihaizi Reservoir, the source of water conveyance, to Lake Taitema, the terminus of the Tarim River. Water recharges from the Daxihaizi Reservoir to the lower reaches of the Tarim River significantly increased groundwater levels and vegetation coverage at all monitoring sites along the river. The mean canopy size of the endangered plant species P. euphratica doubled after 6 years of water recharge. Some rare migrating birds returned to rest on the restored wetlands in summer along the lower reaches of the Tarim River. The biggest challenge facing decision makers, however, is to balance water allocation and water rights between agricultural and natural ecosystems in a sustainable way. A large number of inhabitants in the Tarim Basin depend on these limited water resources for a living. At the same time, the endangered ecosystems need to be protected. Given the ecological, socioeconomic, and sociopolitical realities in the Tarim Basin, adaptive water policies and strategies are needed for water allocation in these areas of limited water resources. PMID:22748091

  12. Trinity river basin, Texas

    USGS Publications Warehouse

    Ulery, Randy L.; Van Metre, Peter C.; Crossfield, Allison S.

    1993-01-01

    In 1991 the Trinity River Basin National Water-Quality Assessment (NAWQA) will include assessments of surface-water and ground-water quality. Initial efforts have focused on identifying water-quality issues in the basin and on the environmental factors underlying those issues. Physical characteristics described include climate, geology, soils, vegetation, physiography, and hydrology. Cultural characteristics discussed include population distribution, land use and land cover, agricultural practices, water use, an reservoir operations. Major water-quality categories are identified and some of the implications of the environmental factors for water quality are presented.

  13. Methane Emission from Tropical Rivers

    NASA Astrophysics Data System (ADS)

    Sawakuchi, H. O.; Rasera, M. F. F. L.; Krusche, A. V.; Ballester, M. V. R.

    2012-04-01

    Inland water is already known as an important source of methane to atmosphere. Methane is produced in anaerobic environments usually find in lakes and floodplain bottom sediment. It is the main reason that almost all information regarding methane flux come from this environments. However, while floodplain dries during low water season reducing methanogenesis, rivers keep the capacity to emit methane throughout the year. Here we present preliminary results of CH4 flux measurements done in 6 large tropical rivers within the Amazon basin. We measured 17 areas using floating chamber during dry (low water) season, between September and November of 2011, in Amazon river mainstem, Araguaia, Xingu, Tapajós, Madeira, and Negro Rivers. Measured fluxes of all rivers ranged from 59.3 to 2974.4 mmol m-2 yr-1. Geomorphologic structure of channels is one important factor that contributes to this high heterogeneity due to development of low flow velocity depositional settings allowing formation of anoxic zones in rivers. Hydraulic and sediment barriers in the confluence of river channels promote the generation of natural dams which function as a trap for the suspension load favoring the deposition of organic rich muds. This kind of environment is very different from common river channels and has a stronger potential of methane emission. Average values of our flux measurements for this two river environments show that depositional areas can have much higher fluxes than the main channel, 1089.6 and 163.1 mmol m-2 yr-1, respectively. Hence, CH4 flux from these depositional zones is similar to some tropical floodplain lakes and reservoirs. Although the low flux from channel, the area covered by water is very large resulting in a significant contribution to the regional methane emission to the atmosphere. Moreover, mapping the area of these depositional river zones will give us a better idea of the magnitude of methane flux from tropical rivers.

  14. River Capture in Disequilibrium Landscapes

    NASA Astrophysics Data System (ADS)

    McCoy, S. W.; Perron, J.; Willett, S.; Goren, L.

    2013-12-01

    The process of river piracy or river capture has long drawn interest as a potential mechanism by which drainage basins large and small evolve towards an equilibrium state. River capture transfers both drainage area and drainage lines from one river basin to another, which can cause large, abrupt shifts in network topology, drainage divide positions, and river incision rates. Despite numerous case studies in which river capture has been proposed to have occurred, there is no general, mechanistic framework for understanding the controls on river capture, nor are there quantitative criteria for determining if capture has occurred. Here we use new metrics of landscape disequilibrium to first identify landscapes in which drainage reorganization is occurring. These metrics are based on a balance between an integral of the contributing drainage area and elevation. In an analysis of rivers in the Eastern United States we find that many rivers are in a state of disequilibrium and are experiencing recent or ongoing area exchange between basins. In these disequilibrium basins we find widespread evidence for network rearrangement via river capture at multiple scales. We then conduct numerical experiments with a 2-D landscape evolution model to explore the conditions in which area exchange among drainage basins is likely to occur as discrete capture events as opposed to continuous divide migration. These experiments indicate that: (1) capture activity increases with the degree of disequilibrium induced by persistent spatial gradients in tectonic forcing or by temporal changes in climate or tectonic forcing; (2) capture activity is strongly controlled by the initial planform drainage network geometry; and (3) capture activity scales with the fluvial incision rate constant in the river power erosion law.

  15. 33 CFR 117.865 - Clatskanie River.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... after each day's authorized commercial fishing period established by the Columbia River Compact (Washington State Department of Fisheries and the Fish Commission of Oregon) for the Columbia River...

  16. 33 CFR 117.865 - Clatskanie River.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... after each day's authorized commercial fishing period established by the Columbia River Compact (Washington State Department of Fisheries and the Fish Commission of Oregon) for the Columbia River...

  17. 33 CFR 117.865 - Clatskanie River.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... after each day's authorized commercial fishing period established by the Columbia River Compact (Washington State Department of Fisheries and the Fish Commission of Oregon) for the Columbia River...

  18. 33 CFR 117.865 - Clatskanie River.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... after each day's authorized commercial fishing period established by the Columbia River Compact (Washington State Department of Fisheries and the Fish Commission of Oregon) for the Columbia River...

  19. Always a River. Activity Booklet.

    ERIC Educational Resources Information Center

    Environmental Protection Agency, Cincinnati, OH.

    This activity booklet was designed to accompany a floating barge exhibition entitled "Always a River" that brought together the experiences of the past, the opportunities of the present, and the hopes of the future afforded by the Ohio River. The interdisciplinary activities in this booklet aim at enriching the lives of young people and making…

  20. INDIAN RIVER LAGOON IR, 2004

    EPA Science Inventory

    Since the Indian River Lagoon Program's last implementation review, the NEP through the local sponsorship of the St. Johns River Water Management District, has seen a three-fold increase in implementation funding from $6.7 million in 1999, to $21.3 million in FY 2003. This fundin...

  1. Treasure Along the Parker River.

    ERIC Educational Resources Information Center

    Fitzpatrick, Ann-Marie; And Others

    Designed so that 100 to 125 heterogeneously grouped 7th and 8th grade students and a team of 5 core teachers might experience and discover the natural and historical "treasure" in the Parker River area of Massachusetts, this interdisciplinary unit centers on a hike to Parker River (6.7 miles) and visits to a cemetery, a monument, and Old Town…

  2. Flooding on Russia's Lena River

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Nearly every year in the late spring, ice blocks the flow of water at the mouth of the Lena River in northeastern Russia and gives rise to floods across the Siberian plains. This year's floods can be seen in this image taken on June 2, 2002, by the MODIS (Moderate Resolution Imaging Spectroradiometer) instrument aboard the Terra satellite. The river runs down the left side of the image, and its delta is shrouded in ice (red) at the top of the image. Normally, the river would resemble a thin black line in MODIS imagery. The river, which is Russia's longest, flows 2,641 miles (4,250 kilometers) south to north through Siberia and into the Laptev Sea. In the winter, the river becomes nearly frozen. In the spring, however, water upstream thaws earlier than water at the mouth of the river. As the southern end of the river begins to melt, blocks of ice travel downstream to the still frozen delta, pile up, and often obstruct the flow of water. Flooding doesn't always occur on the same parts of the river. The floods hit further south last year. If the flooding grows severe enough, explosive charges are typically used to break up the ice jams. In these false-color images land areas are a dull, light green or tan, and water is black. Clouds appear pink, and ice comes across as bright red. Image courtesy Jacques Descloitres, MODIS Land Rapid Response Team at NASA GSFC

  3. Hood River Passive House

    SciTech Connect

    Hales, D.

    2014-01-01

    The Hood River Passive Project was developed by Root Design Build of Hood River Oregon using the Passive House Planning Package (PHPP) to meet all of the requirements for certification under the European Passive House standards. The Passive House design approach has been gaining momentum among residential designers for custom homes and BEopt modeling indicates that these designs may actually exceed the goal of the U.S. Department of Energy's (DOE) Building America program to reduce home energy use by 30%-50% (compared to 2009 energy codes for new homes). This report documents the short term test results of the Shift House and compares the results of PHPP and BEopt modeling of the project. The design includes high R-Value assemblies, extremely tight construction, high performance doors and windows, solar thermal DHW, heat recovery ventilation, moveable external shutters and a high performance ductless mini-split heat pump. Cost analysis indicates that many of the measures implemented in this project did not meet the BA standard for cost neutrality. The ductless mini-split heat pump, lighting and advanced air leakage control were the most cost effective measures. The future challenge will be to value engineer the performance levels indicated here in modeling using production based practices at a significantly lower cost.

  4. Hood River Passive House

    SciTech Connect

    Hales, David

    2014-01-01

    The Hood River Passive Project was developed by Root Design Build of Hood River Oregon using the Passive House Planning Package (PHPP) to meet all of the requirements for certification under the European Passive House standards. The Passive House design approach has been gaining momentum among residential designers for custom homes and BEopt modeling indicates that these designs may actually exceed the goal of the U.S. Department of Energy's (DOE) Building America program to "reduce home energy use by 30%-50% (compared to 2009 energy codes for new homes). This report documents the short term test results of the Shift House and compares the results of PHPP and BEopt modeling of the project. The design includes high R-Value assemblies, extremely tight construction, high performance doors and windows, solar thermal DHW, heat recovery ventilation, moveable external shutters and a high performance ductless mini-split heat pump. Cost analysis indicates that many of the measures implemented in this project did not meet the BA standard for cost neutrality. The ductless mini-split heat pump, lighting and advanced air leakage control were the most cost effective measures. The future challenge will be to value engineer the performance levels indicated here in modeling using production based practices at a significantly lower cost.

  5. Geomorphology and River Dynamics of the Lower Copper River, Alaska

    USGS Publications Warehouse

    Brabets, Timothy P.; Conaway, Jeffrey S.

    2009-01-01

    Located in south-central Alaska, the Copper River drains an area of more than 24,000 square miles. The average annual flow of the river near its mouth is 63,600 cubic feet per second, but is highly variable between winter and summer. In the winter, flow averages approximately 11,700 cubic feet per second, and in the summer, due to snowmelt, rainfall, and glacial melt, flow averages approximately 113,000 cubic feet per second, an order of magnitude higher. About 15 miles upstream of its mouth, the Copper River flows past the face of Childs Glacier and enters a large, broad, delta. The Copper River Highway traverses this flood plain, and in 2008, 11 bridges were located along this section of the highway. The bridges cross several parts of the Copper River and in recent years, the changing course of the river has seriously damaged some of the bridges. Analysis of aerial photography from 1991, 1996, 2002, 2006, and 2007 indicates the eastward migration of a channel of the Copper River that has resulted in damage to the Copper River Highway near Mile 43.5. Migration of another channel in the flood plain has resulted in damage to the approach of Bridge 339. As a verification of channel change, flow measurements were made at bridges along the Copper River Highway in 2005-07. Analysis of the flow measurements indicate that the total flow of the Copper River has shifted from approximately 50 percent passing through the bridges at Mile 27, near the western edge of the flood plain, and 50 percent passing through the bridges at Mile 36-37 to approximately 5 percent passing through the bridges at Mile 27 and 95 percent through the bridges at Mile 36-37 during average flow periods. The U.S. Geological Survey's Multi-Dimensional Surface-Water Modeling System was used to simulate water-surface elevation and velocity, and to compute bed shear stress at two areas where the Copper River is affecting the Copper River Highway. After calibration, the model was used to examine the

  6. Pollution from urban development and setback outfalls as a catchment management measure for river water quality improvement

    NASA Astrophysics Data System (ADS)

    Allen, Deonie; Haynes, Heather; Arthur, Scott

    2016-04-01

    Urban development causes an increase in fine sediment and heavy metal stormwater pollution. Pollution load estimation theorises that stormwater pollutant load and type are strongly, directly influenced by contributing catchment land use. The research presented investigates the validity of these assumptions using an extensive novel field data set of 53 catchments. This research has investigated the relationships between land use and pollutant concentrations (Cu, Zn, Pb, Ni, Ca, Ba, Sn, Mn) in urban stormwater outfall sediments. Cartographic and aerial photography data have been utilised to delineate the surface and subsurface contributing catchment land use. A zoned sub-catchment approach to catchment characterisation of stormwater pollutant concentration has been defined and tested. This method effectively describes the specific land use influence on pollutant concentrations at the stormwater outfall, showing strong dependency with road length, brake points, impervious area and open space. Road networks and open space are found to influence land use, and thus stormwater pollution, closer to stormwater outfall/receiving waterbody suggesting storage, treatment, assimilation, loss or dilution of the land use influence further away from stormwater outfall. An empirical description has been proposed with which to predict outfall pollutant contributions to the receiving urban waterbody based on catchment land use information. With the definition and quantification of contributing catchment specific fine sediment and urban heavy metal pollutants, the influence of urban stormwater outfall management on the receiving watercourse has been considered. The locations of stormwater outfalls, and their proximity to the receiving waterway, are known as key water quality and river health influences. Water quality benefits from the implementation of stormwater outfalls set back from the receiving waterway banks have been investigated using the catchment case study. Setback outfalls

  7. Numerical modelling of fine-grained sediments remobilization in heavily polluted streams. Case study: Elbe and Bílina River, Czech Republic.

    NASA Astrophysics Data System (ADS)

    Kaiglová, Jana; Langhammer, Jakub; Jiřinec, Petr; Janský, Bohumír; Chalupová, Dagmar

    2014-05-01

    The study aimed to estimate remobilization of channel and riparian cohesive sediment of streams, heavily polluted by industrial emmissions. There were analyzed four stream stretches in Czech Republic: (1) Elbe River from Usti nad Labem to the boundary with Germany; (2) Bílina river, draining industrial and mining areas of Northwest Bohemia; (3) Midstream reach of Czech Elbe by the confluence with Vltava river, affected by chemical industry and (4) fluvial lakes in the riparian zone of Czech Elbe river downstream of Pardubice burdened by old loads from heavy chemical industry. Sediments of clay and silt character bedded in the riparian water-courses are regarded heavily polluted by wide range of toxic matters. In the sediment samples, there were found elevated concentrations of persistent organic matters (DDT, PCB, HCH, Fluoranthen), Heavy metals (Hg, As, Cd), and others. The pollution in sediment is resulting from the unregulated heavy industrial production in the area in the second half of 20th century during the socialistic regime in Czech republic that still play an important role in Elbe river water quality. The main goal of the study was to evaluate the risk of remobilization of polluted sediments by the assessment of discharge (values and return periods), initiating remobilization of sediment from the river bed. The modeling stems on basic assumption, that once the sediment is elevated from the bed, it could be transported far downstream in the form of suspended load. The evaluation was made on the basis of numerical hydrodynamic calculation coupled with sediment transport model. The MIKE by DHI modelling software with different levels of schematization was used according the flow conditions and available data sources. For 50 km stretch of Bílina river the 1D schematization (MIKE 11) was selected as the discharges driving remobilization were expected within the extent of channel capacity due to the stream regulation. For the lower and middle course of Elbe

  8. Indicators for transboundary river management.

    PubMed

    Lorenz, C M; Gilbert, A J; Cofino, W P

    2001-07-01

    The aim of this paper is to analyze the potential of indicators for integrated river basin management and to develop a set of indicators for the management of transboundary river basins. An indicator, comprising a variable or some aggregation of variables, describes a system or process such that it has significance beyond the face value of its components. Integrated river basin management takes into account policies and measures for the multifunctional use of rivers on a catchment scale and associated institutional changes. Indicators are useful instruments for this process for two reasons. Firstly, they meet the information need of policy- and decision-makers. Secondly, indicators can be used to structure the definition and description of information needs and collection of information between the different international, institutional, and sectoral management levels. The development of indicators involves a number of steps: definition of aim, construction of conceptual model, selection of variables, comparison with selection criteria, database assessment, and indicator selection. In this paper these steps are discussed and specified for integrated river basin management. This results in a set of indicators describing the pressure to the river, the state of the river ecosystem, the impact to goods and services provided by the river, and the societal response. The proposed set of indicators measured at a river basin scale provides integrated information on the use and supply of goods and services, underlying cause-effect relationships and possible trade-offs and their spatial distribution (e.g., upstream versus downstream). Furthermore, we propose a division of tasks and responsibilities for river basin management with regard to the development of indicators, data collection, and their application in decision-making. PMID:11436995

  9. 6. SANDY RIVER BRIDGE AT TROUTDALE, EAST ELEVATION, LOOKING 306 ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. SANDY RIVER BRIDGE AT TROUTDALE, EAST ELEVATION, LOOKING 306 DEGREES NORTHWEST. - Historic Columbia River Highway, Sandy River Bridge at Troutdale, Historic Columbia River Highway spanning Sandy River, Troutdale, Multnomah County, OR

  10. 3. SANDY RIVER BRIDGE AT TROUTDALE, NORTH END, LOOKING 184 ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. SANDY RIVER BRIDGE AT TROUTDALE, NORTH END, LOOKING 184 DEGREES SOUTH. SAME PHOTO AS OR-36-2. - Historic Columbia River Highway, Sandy River Bridge at Troutdale, Historic Columbia River Highway spanning Sandy River, Troutdale, Multnomah County, OR

  11. 7. SANDY RIVER BRIDGE AT TROUTDALE, PERSPECTIVE LOOKING EAST. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. SANDY RIVER BRIDGE AT TROUTDALE, PERSPECTIVE LOOKING EAST. - Historic Columbia River Highway, Sandy River Bridge at Troutdale, Historic Columbia River Highway spanning Sandy River, Troutdale, Multnomah County, OR

  12. 1. SANDY RIVER BRIDGE AT TROUTDALE, SOUTH END, LOOKING 18 ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. SANDY RIVER BRIDGE AT TROUTDALE, SOUTH END, LOOKING 18 DEGREES NORTH. SAME PHOTO AS OR-36-1. - Historic Columbia River Highway, Sandy River Bridge at Troutdale, Historic Columbia River Highway spanning Sandy River, Troutdale, Multnomah County, OR

  13. 2. SANDY RIVER BRIDGE AT TROUTDALE, SOUTH END, LOOKING 20 ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. SANDY RIVER BRIDGE AT TROUTDALE, SOUTH END, LOOKING 20 DEGREES NORTH. - Historic Columbia River Highway, Sandy River Bridge at Troutdale, Historic Columbia River Highway spanning Sandy River, Troutdale, Multnomah County, OR

  14. 5. SANDY RIVER BRIDGE AT TROUTDALE, EAST ELEVATION DETAIL, LOOKING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. SANDY RIVER BRIDGE AT TROUTDALE, EAST ELEVATION DETAIL, LOOKING 6 DEGREES NORTH. - Historic Columbia River Highway, Sandy River Bridge at Troutdale, Historic Columbia River Highway spanning Sandy River, Troutdale, Multnomah County, OR

  15. 4. SANDY RIVER BRIDGE AT TROUTDALE, NORTH END, LOOKING 224 ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. SANDY RIVER BRIDGE AT TROUTDALE, NORTH END, LOOKING 224 DEGREES SOUTHWEST. - Historic Columbia River Highway, Sandy River Bridge at Troutdale, Historic Columbia River Highway spanning Sandy River, Troutdale, Multnomah County, OR

  16. River network routing in all rivers of the Texas Gulf

    NASA Astrophysics Data System (ADS)

    David, C. H.; Maidment, D. R.; Hong, S.; Niu, G.; Yang, Z.

    2009-12-01

    The mapped rivers and streams of the contiguous United States are available in a high resolution geographic information system (GIS) dataset called NHDPlus. This hydrographic dataset has about 3 million river and water body reaches along with information on how they are connected into networks. A river network model called RAPID is developed for the NHDPlus river network and applied to the 68,143 river reaches of the entire Texas Gulf, whose lateral inflow to the river network is calculated by a land surface model. RAPID allows for a matrix-based calculation of flow and volume of water in all reaches of a river network, with many thousands of reaches. Gages from the USGS National Water Information System are used to assess the quality of model calculations and to automatically determine optimal model parameters with about 1 gage available for each 160 reaches simulated. RAPID is adapted for parallel computing and has been tested on the Lonestar supercomputer (http://www.tacc.utexas.edu/resources/hpcsystems/) although challenges related to parallel computing are significant. The first author was awarded the 2008 Horton (Hydrology) Research Grant for this work.

  17. River-Based Experiential Learning: the Bear River Fellows Program

    NASA Astrophysics Data System (ADS)

    Rosenberg, D. E.; Shirley, B.; Roark, M. F.

    2012-12-01

    The Department of Civil and Environmental Engineering, Outdoor Recreation, and Parks and Recreation programs at Utah State University (USU) have partnered to offer a new, unique river-based experiential learning opportunity for undergraduates called the Bear River Fellows Program. The program allows incoming freshmen Fellows to experience a river first hand during a 5-day/4-night river trip on the nearby Bear River two weeks before the start of their first Fall semester. As part of the program, Fellows will navigate the Bear River in canoes, camp along the banks, interact with local water and environmental managers, collect channel cross section, stream flow, vegetation cover, and topological complexity data, meet other incoming freshmen, interact with faculty and graduate students, develop boating and leadership skills, problem solve, and participate as full members of the trip team. Subsequently, Fellows will get paid as undergraduate researchers during their Fall and Spring Freshman semesters to analyze, synthesize, and present the field data they collect. The program is a collaborative effort between two USU academic units and the (non-academic) division of Student Services and supports a larger National Science Foundation funded environmental modelling and management project for the lower Bear River, Utah watershed. We have advertised the program via Facebook and emails to incoming USU freshmen, received 35 applications (60% women), and accepted 5 Fellows into the program (3 female and 2 male). The river trip departs August 14, 2012. The poster will overview the Bear River Fellows Program and present qualitative and preliminary outcomes emerging from the trip and Fellows' work through the Fall semester with the field data they collect. We will also undertake more rigorous and longer longitudinal quantitative evaluation of Program outcomes (for example, in problem-solving and leadership) both in Spring 2013 and in subsequent 2013 and 2014 offerings of the

  18. Will the Atchafalaya River Capture the Lower Mississippi River?

    NASA Astrophysics Data System (ADS)

    Edmonds, D.

    2011-12-01

    The Old River Control Structure (ORCS) was built in the 1960s to prevent the Atchafalaya River from capturing the lower Mississippi River. The 2011 flood on the Mississippi River tested ORCS and renewed concerns about what would happen to the rivers if ORCS failed. Most consider capture a foregone conclusion if ORCS failed, but this hypothesis has never been tested. A viable alternative hypothesis is that the discharge distribution between the Atchafalaya and Mississippi would stabilize at the relative proportions predicted by recent theory such that both channels transmit water. To test these hypotheses I conducted numerical experiments of the Mississippi-Atchafalaya rivers in the absence of ORCS using Delft3D. All model runs have evolving beds and are depth-integrated. The grid is 2D in planform and follows the banks of each river. The channel walls are fixed, tributaries are not included, and there are no floodplains. At the upstream boundary I specify the water discharge and sediment fluxes. The incoming discharge carries two grain sizes, one noncohesive (200 microns) and one cohesive (15 microns). At the downstream boundaries water surface elevations are set to zero. The initial bed topography in each river comes from 2004 and 2006 hydrographic surveys of the Mississippi and Atchafalaya, respectively. I conducted 7 experiments where the discharge upstream of ORCS (Qup) is steady, but varies among experiments from 5000 m3 s-1 to 50000 m3 s-1. Results show that the response of the rivers depends strongly on Qup. When Qup > 15000 m3 s-1 there is net flow capture by the Atchafalaya, and the capture rate increases with increasing Qup. But when Qup < 15000 m3 s-1 there is net flow capture by the Mississippi. The rates of capture for different values of Qup can be used to calculate if capture would occur for a realistic, unsteady hydrograph.

  19. Dissolved oxygen analysis, TMDL model comparison, and particulate matter shunting—Preliminary results from three model scenarios for the Klamath River upstream of Keno Dam, Oregon

    USGS Publications Warehouse

    Sullivan, Annett B.; Rounds, Stewart A.; Deas, Michael L.; Sogutlugil, I. Ertugrul

    2012-01-01

    Efforts are underway to identify actions that would improve water quality in the Link River to Keno Dam reach of the Upper Klamath River in south-central Oregon. To provide further insight into water-quality improvement options, three scenarios were developed, run, and analyzed using previously calibrated CE-QUAL-W2 hydrodynamic and water-quality models. Additional scenarios are under development as part of this ongoing study. Most of these scenarios evaluate changes relative to a "current conditions" model, but in some cases a "natural conditions" model was used that simulated the reach without the effect of point and nonpoint sources and set Upper Klamath Lake at its Total Maximum Daily Load (TMDL) targets. These scenarios were simulated using a model developed by the U.S. Geological Survey (USGS) and Watercourse Engineering, Inc. for the years 2006–09, referred to here as the "USGS model." Another model of the reach was developed by Tetra Tech, Inc. for years 2000 and 2002 to support the Klamath River TMDL process; that model is referred to here as the "TMDL model." The three scenarios described in this report included (1) an analysis of whether this reach of the Upper Klamath River would be in compliance with dissolved oxygen standards if sources met TMDL allocations, (2) an application of more recent datasets to the TMDL model with comparison to results from the USGS model, and (3) an examination of the effect on dissolved oxygen in the Klamath River if particulate material were stopped from entering Klamath Project diversion canals. Updates and modifications to the USGS model are in progress, so in the future these scenarios will be reanalyzed with the updated model and the interim results presented here will be superseded. Significant findings from this phase of the investigation include: * The TMDL analysis used depth-averaged dissolved oxygen concentrations from model output for comparison with dissolved oxygen standards. The Oregon dissolved oxygen

  20. 33 CFR 207.380 - Red Lake River, Minn.; logging regulations for portion of river above Thief River Falls.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Red Lake River, Minn.; logging regulations for portion of river above Thief River Falls. 207.380 Section 207.380 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE NAVIGATION REGULATIONS § 207.380 Red Lake River, Minn.;...

  1. 33 CFR 207.380 - Red Lake River, Minn.; logging regulations for portion of river above Thief River Falls.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Red Lake River, Minn.; logging regulations for portion of river above Thief River Falls. 207.380 Section 207.380 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE NAVIGATION REGULATIONS § 207.380 Red Lake River, Minn.;...

  2. River history and tectonics.

    PubMed

    Vita-Finzi, C

    2012-05-13

    The analysis of crustal deformation by tectonic processes has gained much from the clues offered by drainage geometry and river behaviour, while the interpretation of channel patterns and sequences benefits from information on Earth movements before or during their development. The interplay between the two strands operates at many scales: themes which have already benefited from it include the possible role of mantle plumes in the breakup of Gondwana, the Cenozoic development of drainage systems in Africa and Australia, Himalayan uplift in response to erosion, alternating episodes of uplift and subsidence in the Mississippi delta, buckling of the Indian lithospheric plate, and changes in stream pattern and sinuosity along individual alluvial channels subject to localized deformation. Developments in remote sensing, isotopic dating and numerical modelling are starting to yield quantitative analyses of such effects, to the benefit of geodymamics as well as fluvial hydrology. PMID:22474680

  3. Lena River, Russia

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This pair of true- and false-color images from the Moderate Resolution Imaging Spectroradiometer (MODIS) from June 28, 2002, shows numerous burn scars dotting the northern Siberian landscape along the Lena River. In the true-color image, the burn scars appear dark grayish-brown, while in the false-color image they appear red, as does the bare exposed soil of the Verkhoyansk Mountain Range to the east of the north-flowing Lena. A tinge of blue along the mountains in the false-color image means there is some lingering snow or ice, and that the bare soil is due to spring's late arrival there, and not to burn scars. At the top, sea ice still fills the Laptev Sea. Credit: Jacques Descloitres, MODIS Land Rapid Response Team, NASA/GSFC

  4. Uplift histories from river profiles

    NASA Astrophysics Data System (ADS)

    Pritchard, D.; Roberts, G. G.; White, N. J.; Richardson, C. N.

    2009-12-01

    Longitudinal river profiles, where elevation of a river bed is plotted as a function of distance along the river bed, contain information about uplift rate. When a region adjacent to a reference level (e.g., sea level) is uplifted, a rapid change in gradient occurs near the river mouth. The erosional process causes this change in gradient to migrate upstream. Thus a river profile is effectively a ‘tape recording’ of the uplift rate history, provided that the erosional process can be adequately parameterized. Here, we use a non-linear equation to relate the shape of a river profile, z(x), to uplift rate history, U(t). If erosion is assumed to be dominated by knickpoint retreat, an inverse model can be formulated and used to calculate uplift rate histories. Our model builds upon standard stream profile analysis, which focuses on the relationship between profile slope and drainage area. We have applied this analytical approach to river profiles from the Bié Dome, Angola. Calculated uplift rate histories agree with independent geologic estimates.

  5. Ice Jams the Ob River

    NASA Technical Reports Server (NTRS)

    2007-01-01

    Russia's Ob River flows from south to north, and each summer, it thaws in the same direction. The result is that an ice jam sits downstream from thawed portions of the river, which is laden with heavy runoff from melted snow. On June 29, 2007, the Moderate Resolution Imaging Spectroradiometer (MODIS) flying on NASA's Terra satellite captured this image of the almost completely thawed Ob River. The scene is typical for early summer. South of the ice jam, the Gulf of Ob is swollen with pent-up run-off, and upstream from that, the river is widened as well. Unable to carve through frozen land, the river has little choice but to overflow its banks. For a comparison of early summer and autumn conditions, see Flooding on the Ob River in the Earth Observatory's Natural Hazards section. Besides the annual overflow, this image captures other circumstances of early summer. Sea ice is retreating from the Kara Sea. A lingering line of snow cover snakes its way along the Ob River, to the west. And while the land is lush and green in the south, it appears barren and brown in the north. Near the mouth of the river and the Kara Sea, the land is cold-adapted tundra, with diminutive plants and a short growing season. Just as the ice plugging the river had yet to thaw in the Far North's short summer, the tundra had not yet to greened up either. In this image it still appears lifeless beige. NASA image courtesy Jeff Schmaltz, MODIS Rapid Response Team, Goddard Space Flight Center

  6. PCBs in the Harlem River

    NASA Astrophysics Data System (ADS)

    Wang, J.

    2012-12-01

    Polychlorinated biphenyls (PCBs) are persistent, toxic and bioaccumulated contaminants of great environmental concern. PCB is a tracer of wastewater, stormwater and CSOs inputs; PCBs contamination of fish is a main environmental concern for the Harlem River. PCBs in the Harlem River are from combined sewer overflows (CSOs), stormwater runoff, wastewater, as well as upper Hudson GE (General Electric at Fort Edward)'s release. PCBs affect human health mostly from contaminated fish consumption. Many research focused on PCBs in the Hudson River and New York/New Jersey Harbor. However, PCBs source, transport and environmental impact in the Harlem River-a natural straight that connects the Hudson River and the East River, had not been well studied. In this research, water sample were collected from the Harlem River and analyzed PCBs by HR GC/MS (High resolution gas chromatography mass spectrophotometer). Preliminary results showed that certain PCBs congeners in the water column. Results also indicated that nutrients (phosphorus and ammonia) as well as bacteria levels exceeded EPA standards: Total phosphorus-10μg/L, total nitrogen-0.38mg/L; E.Coli-126 MPN/100ml, Enterococcus- 104MPN/100ml, Fecal Coliform-200 MPN/100ml. This research is under process, and more results could give further detail in near future. This research will help improve water quality of the Harlem River, improve environmental health and raise environmental awareness.SO tank Nutrient and bacterial levels of selected sites in the Harlem RiverCSO: Combined Sewer OverflowWWTP: Waste Water Treatment Plant

  7. Status of river herring stocks in large rivers

    USGS Publications Warehouse

    Schmidt, R.E.; Jessop, B.M.; Hightower, J.E.

    2003-01-01

    We examined long-term data sets from large rivers in the northern, central, and southern parts of the ranges of anadromous river herring (alewife Alosa pseudoharengus and blueback herring A. aestivalis) to assess the current status of these species and for evidence of fishery-induced effects on their demographic characteristics. Both species show signs of overexploitation in all rivers examined, such as reductions in mean age, decreases in percentage of returning spawners, and decreases in abundance. These two species should be managed separately since exploitation within a given river is often biased toward one or the other and there are enough differences in their biology so that a single management option will affect them differently. These species are not distinguished in commercial catches, which hinders understanding of their exploitation. ?? 2003 by the American Fisheries Society.

  8. Arctic River organic matter transport

    NASA Astrophysics Data System (ADS)

    Raymond, Peter; Gustafsson, Orjan; Vonk, Jorien; Spencer, Robert; McClelland, Jim

    2016-04-01

    Arctic Rivers have unique hydrology and biogeochemistry. They also have a large impact on the Arctic Ocean due to the large amount of riverine inflow and small ocean volume. With respect to organic matter, their influence is magnified by the large stores of soil carbon and distinct soil hydrology. Here we present a recap of what is known of Arctic River organic matter transport. We will present a summary of what is known of the ages and sources of Arctic River dissolved and particulate organic matter. We will also discuss the current status of what is known about changes in riverine organic matter export due to global change.

  9. Where rivers and oceans collide

    NASA Astrophysics Data System (ADS)

    Crockett, J. S.; Nittrouer, C. A.; Ogston, A. S.; Sternberg, R. W.; Driscoll, N. W.; Babcock, J.; Milliman, J. D.; Slingerland, R.; Naar, D. F.; Donahue, B.; Walsh, J. P.; Dietrich, W.; Parker, G.; Bera, M.; Davies, H.; Harris, P.; Goni, M.; Aller, R.; Aller, J.

    Fluvial sediment fills the coastal ocean, and sea level rise floods river valleys. This epic battle of terrestrial and marine processes occurs along all shorelines, and the complexities are especially well revealed in the Gulf of Papua, a foreland basin on the southern coast of New Guinea. Two hundred to four hundred million tons of sediment are supplied each year by the Fly and other rivers to a continental shelf that has been dissected by ancestors of these same rivers. The new sediment builds a large depositional feature known as a clinoform, which grows seaward and buries the record of earlier environments.

  10. [Characteristics of absorption and fluorescence spectra of dissolved organic matter from confluence of rivers: case study of Qujiang River-Jialing River and Fujiang River-Jialing River].

    PubMed

    Yan, Jin-Long; Jiang, Tao; Gao, Jie; Wei, Shi-Qiang; Lu, Song; Liu, Jiang

    2015-03-01

    Three-dimensional fluorescence spectroscopy combined with ultraviolet-visible (UV-Vis) absorption spectra was used to investigate the change characteristics of dissolved organic matter (DOM) in confluences water of Qujiang River-Jialing River and Fujiang River-Jialing River, respectively. The results suggested that DOM showed a significant terrestrial input signal in all the sampling sites, FI < 1.4, HIX > 0.8, possibly representing remarkable signals of humus resulted from humic-like component. Moreover, the mixing zone of this study showed a non-conservative mixed behavior, which had a limited contribution, and was not the dominant factor to interpret the change characteristics of DOM in confluences zones. Different land-use types along all the rivers had an obvious impact on DOM inputs. Results of cluster analysis showed that a higher degree of aromaticity and humification components was observed as the predominant contributor to DOM when the land-use type was forest and farmland ecosystem, for example the confluences of Qujiang River-Jialing River. On the other hand, high concentrations of DOM with relative simple structures were found in the water when the urban land-use type was predominant, for example the confluences of Fujiang River-Jialing River. Meanwhile, a new fluorescent signal of protein-like components (peak T) appeared, which manifested a significant effect on the water quality resulted from anthropogenic activities. PMID:25929053

  11. Useful characteristics of the Savannah River

    SciTech Connect

    Watts, J R

    1982-05-19

    The following information about the Savannah River is tabulated: significant activities and discharges along the Savannah River, river water temperature data near Jackson st Savannah River Plant, flow informatiom, and reservoir parameters for Clarks Hill, Richard B. Russell and Hartwell reservoirs.

  12. 29 CFR 1917.126 - River banks.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 7 2012-07-01 2012-07-01 false River banks. 1917.126 Section 1917.126 Labor Regulations...) MARINE TERMINALS Terminal Facilities § 1917.126 River banks. (a) This section applies to temporary installations or temporary operations near a river bank. (b) Where working surfaces at river banks slope...

  13. 29 CFR 1917.126 - River banks.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false River banks. 1917.126 Section 1917.126 Labor Regulations...) MARINE TERMINALS Terminal Facilities § 1917.126 River banks. (a) This section applies to temporary installations or temporary operations near a river bank. (b) Where working surfaces at river banks slope...

  14. 27 CFR 9.164 - River Junction.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false River Junction. 9.164... River Junction. (a) Name. The name of the viticultural area described in this section is “River Junction.” (b) Approved maps. The appropriate maps for determining the boundaries of the River...

  15. 76 FR 23485 - Safety Zone; Red River

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-27

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Red River AGENCY: Coast Guard, DHS. ACTION... Red River in the State of North Dakota, including those portions of the river bordered by Richland... across latitude 46 20'00'' N, extending the entire width of the river. This safety zone is needed...

  16. 29 CFR 1917.126 - River banks.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 7 2011-07-01 2011-07-01 false River banks. 1917.126 Section 1917.126 Labor Regulations...) MARINE TERMINALS Terminal Facilities § 1917.126 River banks. (a) This section applies to temporary installations or temporary operations near a river bank. (b) Where working surfaces at river banks slope...

  17. 33 CFR 117.237 - Christina River.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Christina River. 117.237 Section... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Delaware § 117.237 Christina River. (a) The owners of... Bridge over Christina River at milepost 1.4 will be closing to river traffic.” Five short blasts of...

  18. 33 CFR 117.237 - Christina River.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Christina River. 117.237 Section... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Delaware § 117.237 Christina River. (a) The owners of... Bridge over Christina River at milepost 1.4 will be closing to river traffic.” Five short blasts of...

  19. 27 CFR 9.164 - River Junction.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false River Junction. 9.164... River Junction. (a) Name. The name of the viticultural area described in this section is “River Junction.” (b) Approved maps. The appropriate maps for determining the boundaries of the River...

  20. 29 CFR 1917.126 - River banks.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 7 2014-07-01 2014-07-01 false River banks. 1917.126 Section 1917.126 Labor Regulations...) MARINE TERMINALS Terminal Facilities § 1917.126 River banks. (a) This section applies to temporary installations or temporary operations near a river bank. (b) Where working surfaces at river banks slope...

  1. 29 CFR 1917.126 - River banks.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 7 2013-07-01 2013-07-01 false River banks. 1917.126 Section 1917.126 Labor Regulations...) MARINE TERMINALS Terminal Facilities § 1917.126 River banks. (a) This section applies to temporary installations or temporary operations near a river bank. (b) Where working surfaces at river banks slope...

  2. 33 CFR 117.237 - Christina River.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Christina River. 117.237 Section... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Delaware § 117.237 Christina River. (a) The owners of... Bridge over Christina River at milepost 1.4 will be closing to river traffic.” Five short blasts of...

  3. 33 CFR 117.237 - Christina River.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Christina River. 117.237 Section... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Delaware § 117.237 Christina River. (a) The owners of... Bridge over Christina River at milepost 1.4 will be closing to river traffic.” Five short blasts of...

  4. 33 CFR 117.237 - Christina River.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Christina River. 117.237 Section... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Delaware § 117.237 Christina River. (a) The owners of... Bridge over Christina River at milepost 1.4 will be closing to river traffic.” Five short blasts of...

  5. 78 FR 22423 - Drawbridge Operation Regulations; Taunton River, Fall River and Somerset, MA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-16

    ... SECURITY Coast Guard 33 CFR Part 117 Drawbridge Operation Regulations; Taunton River, Fall River and... Brightman Street Bridge across the Taunton River, mile 1.8, between Fall River and Somerset, Massachusetts.... The Taunton River is a recreational waterway. The bridge rarely opens during the time period...

  6. Elwha River dam removal-Rebirth of a river

    USGS Publications Warehouse

    Duda, Jeffrey J.; Warrick, Jonathan A.; Magirl, Christopher S.

    2011-01-01

    After years of planning for the largest project of its kind, the Department of the Interior will begin removal of two dams on the Elwha River, Washington, in September 2011. For nearly 100 years, the Elwha and Glines Canyon Dams have disrupted natural processes, trapping sediment in the reservoirs and blocking fish migrations, which changed the ecology of the river downstream of the dams. All five Pacific salmon species and steelhead-historically present in large numbers-are locally extirpated or persist in critically low numbers. Upstream of the dams, more than 145 kilometers of pristine habitat, protected inside Olympic National Park, awaits the return of salmon populations. As the dams are removed during a 2-3 year project, some of the 19 million cubic meters of entrapped sediment will be carried downstream by the river in the largest controlled release of sediment into a river and marine waters in history. Understanding the changes to the river and coastal habitats, the fate of sediments, and the salmon recolonization of the Elwha River wilderness will provide useful information for society as future dam removals are considered.

  7. Flooding on California's Russian River: Role of atmospheric rivers

    USGS Publications Warehouse

    Ralph, F.M.; Neiman, P.J.; Wick, G.A.; Gutman, S.I.; Dettinger, M.D.; Cayan, D.R.; White, A.B.

    2006-01-01

    Experimental observations collected during meteorological field studies conducted by the National Oceanic and Atmospheric Administration near the Russian River of coastal northern California are combined with SSM/I satellite observations offshore to examine the role of landfalling atmospheric rivers in the creation of flooding. While recent studies have documented the characteristics and importance of narrow regions of strong meridional water vapor transport over the eastern Pacific Ocean (recently referred to as atmospheric rivers), this study describes their impact when they strike the U.S. West Coast. A detailed case study is presented, along with an assessment of all 7 floods on the Russian River since the experimental data were first available in October 1997. In all 7 floods, atmospheric river conditions were present and caused heavy rainfall through orographic precipitation. Not only do atmospheric rivers play a crucial role in the global water budget, they can also lead to heavy coastal rainfall and flooding, and thus represent a key phenomenon linkingweather and climate. Copyright 2006 by the American Geophysical Union.

  8. Quaternary Morphodynamics for two large rivers: the Fly River, PNG, and the Mekong River, Cambodia.

    NASA Astrophysics Data System (ADS)

    Aalto, R. E.; Lauer, J. W.; Darby, S. E.; Goni, M. A.; Dietrich, W. E.

    2014-12-01

    During glacial marine transgressions, sediment & carbon are deposited due to the infilling of lowland fluvial systems, material that is then largely removed during ensuing regressions. Measuring & modelling these processes would help quantify the amount, timing, & preservation of these materials, providing insight into the morphodynamics of lowland fluvial systems in response to sea level change. We investigated the infilling dynamics of the Fly and Strickland Rivers, Papua New Guinea. Field data include: 14C dated deep cores recording base level evolution over the Holocene, sonar imaging of floodbasin stratigraphy, and the observations of blocked valley lakes and weathered erosional remnants from LGM conditions. Similar research was conducted on the Mekong River, Cambodia, where we have imaged basin fill stratigraphy and recorded the extent of blocked valley lakes. Such field data provide tantalizing empirical glimpses into the landscapes & flux buffering exhibited by large tropical rivers during glacial-interglacial transitions. We upscale our observations by modelling river system evolution, employing a GpU Lowland Landscape Evolution Model (GULLEM) to predict the evolution of the entire basin. A novel & powerful (>10 Tflops on an inexpensive computer) simulator, GULLEM models morphodynamics and estimates the accommodation space subsequently infilled during marine transgressions by representing a range of geomorphic processes, including: river & tributary incision, non-linear diffusion, sea level and isostatic change, hydraulic geometry, tectonic deformation, sediment production, transport & deposition, & tracking of the resulting stratigraphy. GULLEM's vectorized approach allows for massively parallel operation on GPUs (Graphics Processing Unit), making it practical to model coupled fluvial-landscape evolution for complex lowland river systems over large temporal and spatial scales. Our combined approach affords estimates for the timing and budgets of sediment

  9. Remote sensing at Savannah River

    SciTech Connect

    Corey, J.C.

    1986-01-01

    The paper discusses remote sensing systems used at the Savannah River Plant. They include three ground-based systems: ground penetrating radar, sniffers, and lasers; and four airborne systems: multispectral photography, lasers, thermal imaging, and radar systems. (ACR)

  10. NEUSE RIVER WATER QUALITY DATABASE

    EPA Science Inventory

    The Neuse River water quality database is a Microsoft Access application that includes multiple data tables and some associated queries. The database was developed by Prof. Jim Bowen's research group.

  11. Manganese oxidation model for rivers

    USGS Publications Warehouse

    Hess, Glen W.; Kim, Byung R.; Roberts, Philip J.W.

    1989-01-01

    The presence of manganese in natural waters (>0.05 mg/L) degrades water-supply quality. A model was devised to predict the variation of manganese concentrations in river water released from an impoundment with the distance downstream. The model is one-dimensional and was calibrated using dissolved oxygen, biochemical oxygen demand, pH, manganese, and hydraulic data collected in the Duck River, Tennessee. The results indicated that the model can predict manganese levels under various conditions. The model was then applied to the Chattahoochee River, Georgia. Discrepancies between observed and predicted may be due to inadequate pH data, precipitation of sediment particles, unsteady flow conditions in the Chattahoochee River, inaccurate rate expressions for the low pH conditions, or their combinations.

  12. Humboldt River main stem, Nevada

    USGS Publications Warehouse

    Warmath, Eric; Medina, Rose L.

    2001-01-01

    This data set contains the main stem of the Humboldt River as defined by Humboldt Project personnel of the U.S. Geological Survey Nevada District, 2001. The data set was digitized on screen using digital orthophoto quadrangles from 1994.

  13. Mississippi River Delta

    NASA Technical Reports Server (NTRS)

    2002-01-01

    As the Mississippi River enters the Gulf of Mexico, it loses energy and dumps its load of sediment that it has carried on its journey through the mid continent. This pile of sediment, or mud, accumulates over the years building up the delta front. As one part of the delta becomes clogged with sediment, the delta front will migrate in search of new areas to grow. The area shown on this image is the currently active delta front of the Mississippi. The migratory nature of the delta forms natural traps for oil. Most of the land in the image consists of mud flats and marsh lands. There is little human settlement in this area due to the instability of the sediments. The main shipping channel of the Mississippi River is the broad stripe running northwest to southeast.

    This image was acquired on May 24, 2001 by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite. With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER will image Earth for the next 6 years to map and monitor the changing surface of our planet.

    ASTER is one of five Earth-observing instruments launched December 18,1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. Dr. Anne Kahle at NASA's Jet Propulsion Laboratory, Pasadena, California, is the U.S. Science team leader; Bjorn Eng of JPL is the project manager. The Terra mission is part of NASA's Earth Science Enterprise, a long-term research and technology program designed to examine Earth's land, oceans, atmosphere, ice and life as a total integrated system.

    The broad spectral coverage and high spectral resolution of ASTER will provide scientists in numerous disciplines with critical information for surface mapping

  14. River patterns and their meaning

    NASA Astrophysics Data System (ADS)

    Twidale, C. R.

    2004-10-01

    Rivers are largely responsible for shaping the Earth's continental landscapes. River patterns, the spatial arrangements of channels in the landscape, are determined by slope and structure. At site and sector scale, channel morphology varies spatially and in time, but river patterns and drainage texture, or the frequency of stream lines per unit area, together determine the intricacy, or otherwise, of topography. Most river patterns evolve through natural selection. Slope induces the formation of such patterns as parallel, radial and distributary, while structure produces straight, angular, trellis and annular arrangements. Once established, patterns tend to persist. Nevertheless, at many sites the usual patterns have been disturbed and patterns that are anomalous in terms of slope and structure have been produced by diversion, tectonism, volcanism, glaciation, mass movements, and human activities; by antecedence, superimposition, inheritance or underprinting; by the persistence of deeply eroding rivers which encounter alien structures; and by climatic change. River patterns provide clues to underlying structure and to the chronology of events. They have also proved significant in the search for minerals.

  15. 76 FR 75543 - Missisquoi River Technologies; Missisquoi River Hydro LLC; Notice of Transfer of Exemption

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-02

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Missisquoi River Technologies; Missisquoi River Hydro LLC; Notice of Transfer of Exemption 1. By letter filed November 16, 2011, Missisquoi River Technologies informed...

  16. 77 FR 45653 - Yakima River Basin Conservation Advisory Group; Yakima River Basin Water Enhancement Project...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-01

    ... Bureau of Reclamation Yakima River Basin Conservation Advisory Group; Yakima River Basin Water... on the structure, implementation, and oversight of the Yakima River Basin Water Conservation Program... of the Water Conservation Program, including the applicable water conservation guidelines of...

  17. 76 FR 71342 - Proposed CERCLA Administrative Cost Recovery Settlement; River Forest Dry Cleaners Site, River...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-17

    ... AGENCY Proposed CERCLA Administrative Cost Recovery Settlement; River Forest Dry Cleaners Site, River Forest, Cook County, IL AGENCY: Environmental Protection Agency (EPA). ACTION: Notice; request for public... proposed administrative settlement for recovery of past response costs concerning the River Forest...

  18. Impacts of urbanization on river system structure: a case study on Qinhuai River Basin, Yangtze River Delta.

    PubMed

    Ji, Xiaomin; Xu, Youpeng; Han, Longfei; Yang, Liu

    2014-01-01

    Stream structure is usually dominated by various human activities over a short term. An analysis of variation in stream structure from 1979 to 2009 in the Qinhuai River Basin, China, was performed based on remote sensing images and topographic maps by using ArcGIS. A series of river parameters derived from river geomorphology are listed to describe the status of river structure in the past and present. Results showed that urbanization caused a huge increase in the impervious area. The number of rivers in the study area has decreased and length of rivers has shortened. Over the 30 years, there was a 41.03% decrease in river length. Complexity and stability of streams have also changed and consequently the storage capacities of river channels in intensively urbanized areas are much lower than in moderately urbanized areas, indicating a greater risk of floods. Therefore, more attention should be paid to the urban disturbance to rivers. PMID:25116497

  19. Ecosystem Services of Rivers: The Don River (Russian Federation) and the Roanoke River (USA)

    EPA Science Inventory

    The concept of ecosystem services recognizes the services, and benefits, provided to people by ecosystems. River systems provide many services to people, including freshwater provisioning, carbon storage, fisheries, recreation, transportation, and biodiversity. Here, we review th...

  20. Valley evolution by meandering rivers

    NASA Astrophysics Data System (ADS)

    Limaye, Ajay Brian Sanjay

    Fluvial systems form landscapes and sedimentary deposits with a rich hierarchy of structures that extend from grain- to valley scale. Large-scale pattern formation in fluvial systems is commonly attributed to forcing by external factors, including climate change, tectonic uplift, and sea-level change. Yet over geologic timescales, rivers may also develop large-scale erosional and depositional patterns that do not bear on environmental history. This dissertation uses a combination of numerical modeling and topographic analysis to identify and quantify patterns in river valleys that form as a consequence of river meandering alone, under constant external forcing. Chapter 2 identifies a numerical artifact in existing, grid-based models that represent the co-evolution of river channel migration and bank strength over geologic timescales. A new, vector-based technique for bank-material tracking is shown to improve predictions for the evolution of meander belts, floodplains, sedimentary deposits formed by aggrading channels, and bedrock river valleys, particularly when spatial contrasts in bank strength are strong. Chapters 3 and 4 apply this numerical technique to establishing valley topography formed by a vertically incising, meandering river subject to constant external forcing---which should serve as the null hypothesis for valley evolution. In Chapter 3, this scenario is shown to explain a variety of common bedrock river valley types and smaller-scale features within them---including entrenched channels, long-wavelength, arcuate scars in valley walls, and bedrock-cored river terraces. Chapter 4 describes the age and geometric statistics of river terraces formed by meandering with constant external forcing, and compares them to terraces in natural river valleys. The frequency of intrinsic terrace formation by meandering is shown to reflect a characteristic relief-generation timescale, and terrace length is identified as a key criterion for distinguishing these

  1. 11. OVERVIEW FROM WEST BANK OF SCHUYLKILL RIVER, LOOKING EAST. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    11. OVERVIEW FROM WEST BANK OF SCHUYLKILL RIVER, LOOKING EAST. - Philadelphia & Reading Railroad, Schuylkill River Viaduct, Spanning Schuylkill River, southeast of Roosevelt Boulevard Bridge, Philadelphia, Philadelphia County, PA

  2. 17. OVERVIEW FROM WEST BANK OF SCHUYLKILL RIVER, LOOKING EAST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    17. OVERVIEW FROM WEST BANK OF SCHUYLKILL RIVER, LOOKING EAST - Philadelphia & Reading Railroad, Schuylkill River Viaduct, Spanning Schuylkill River, southeast of Roosevelt Boulevard Bridge, Philadelphia, Philadelphia County, PA

  3. 9. LOOKING NW FROM EAST BANK OF SCHUYLKILL RIVER. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    9. LOOKING NW FROM EAST BANK OF SCHUYLKILL RIVER. - Philadelphia & Reading Railroad, Schuylkill River Viaduct, Spanning Schuylkill River, southeast of Roosevelt Boulevard Bridge, Philadelphia, Philadelphia County, PA

  4. VIEW OF APALACHICOLA RIVER BRIDGE WEST APPROACH (CALHOUN COUNTY SIDE), ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF APALACHICOLA RIVER BRIDGE WEST APPROACH (CALHOUN COUNTY SIDE), SOUTH SIDE, FACING NORTHEAST - Apalachicola River Bridge, State Route 20 spanning the Apalachicola River, Blountstown, Calhoun County, FL

  5. Yazoo River Basin (Lower Mississippi River) Hydrologic Observatory

    NASA Astrophysics Data System (ADS)

    Cheng, A.; Davidson, G.; Altinakar, M.; Holt, R.

    2004-12-01

    The proposed Yazoo River Basin Hydrologic Observatory consists of the 34,000 square km Yazoo River watershed in northwestern Mississippi and a 320 km segment of the Mississippi River separated from the watershed by a manmade levee. Discharge from the basin flows from the Yazoo River into the Mississippi River north of Vicksburg, MS. Major streams within the basin include the Yazoo, Tallahatchie, Yalobusha, Coldwater, Yocona, and Big Sunflower Rivers. Four large flood control reservoirs (Arkabutla, Enid, Sardis, and Grenada) and two national forests (Delta and Holly Springs) are also located within the basin. The watershed is divided between upland forested hills and intensively cultivated lowlands. The lowland area, locally known as the "Delta", lies on the ancestral floodplain of the Mississippi River. Flooding by the Mississippi River was once a common event, but is now limited by the levee system. Abundant wetlands occupy abandoned stream channels throughout the Delta. The Yazoo River Basin has many unique features that make it an attractive site for an Hydrologic Observatory. Example features and issues of scientific interest include: 1) Extensive system of levees which have altered recharge to the regional aquifer, shifted population centers, and created backwater flooding areas. 2) Abundant wetlands with a century-long history of response to agricultural sediment and chemical fluxes. 3) Erosion of upland streams, and stream sediment loads that are the highest in the nation. 4) Groundwater mining in spite of abundant precipitation due to a regional surface clay layer that limits infiltration. 5) A history of agricultural Best Management Practices enabling evaluation of the effectiveness of such measures. 6) Large scale catfish farming with heavy reliance on groundwater. 7) Near enough to the Gulf coast to be impacted by hurricane events. 8) Already existing network of monitoring stations for stream flow, sediment-load, and weather, including complete coverage

  6. Dispersal scaling from the world's rivers

    USGS Publications Warehouse

    Warrick, J.A.; Fong, D.A.

    2004-01-01

    Although rivers provide important biogeochemical inputs to oceans, there are currently no descriptive or predictive relationships of the spatial scales of these river influences. Our combined satellite, laboratory, field and modeling results show that the coastal dispersal areas of small, mountainous rivers exhibit remarkable self-similar scaling relationships over many orders of magnitude. River plume areas scale with source drainage area to a power significantly less than one (average = 0.65), and this power relationship decreases significantly with distance offshore of the river mouth. Observations of plumes from large rivers reveal that this scaling continues over six orders of magnitude of river drainage basin areas. This suggests that the cumulative area of coastal influence for many of the smallest rivers of the world is greater than that of single rivers of equal watershed size. Copyright 2004 by the American Geophysical Union.

  7. Pecos River Water Management Project

    NASA Astrophysics Data System (ADS)

    Roberts, J. D.; James, S. C.

    2003-12-01

    Sandia National Laboratories is providing technical assistance to farmer members of the Carlsbad Irrigation District (CID) to better plan the storage, delivery, and application of water to the Carlsbad Project. The surface waters along the Pecos River are allocated by the State of New Mexico to three major entities: 1) The State of Texas - each year a percentage of water from the natural river flow must be delivered to Texas as governed by the Interstate Streams Commission; 2) CID farmer members - a fixed portion of water must be delivered to the farming members of the CID; and 3) wildlife - an amount of water must be allocated to support the wildlife habitat in the Pecos River, most notably, the endangered Pecos Bluntnose Shiner Minnow. The Pecos Bluntnose Shiner Minnow habitat preference is under investigation by other state and national agencies and preliminary work has established that water depth, water velocity, and sediment activity (dunes, ripples, etc.) are the key parameters influencing minnow habitat preference. The amount of water (river flow rate) necessary to maintain a preferable habitat to support this species has yet to be determined. With a limited amount of water in the Pecos River and its reservoirs, it is critical to allocate water efficiently such that habitat is maintained, the farmers of the CID are supported, and New Mexico meets its commitments to the State of Texas. This study investigates the relationship between flow rate in the river and water depth, water velocity, and sediment activity. The goal is to establish a predictive tool that supports informed decisions about water management practices along the Pecos River that will maximize water available for agriculture and the State of Texas while maintaining the aquatic habitat.

  8. Flood trends and river engineering on the Mississippi River system

    USGS Publications Warehouse

    Pinter, N.; Jemberie, A.A.; Remo, J.W.F.; Heine, R.A.; Ickes, B.S.

    2008-01-01

    Along >4000 km of the Mississippi River system, we document that climate, land-use change, and river engineering have contributed to statistically significant increases in flooding over the past 100-150 years. Trends were tested using a database of >8 million hydrological measurements. A geospatial database of historical engineering construction was used to quantify the response of flood levels to each unit of engineering infrastructure. Significant climate- and/or land use-driven increases in flow were detected, but the largest and most pervasive contributors to increased flooding on the Mississippi River system were wing dikes and related navigational structures, followed by progressive levee construction. In the area of the 2008 Upper Mississippi flood, for example, about 2 m of the flood crest is linked to navigational and flood-control engineering. Systemwide, large increases in flood levels were documented at locations and at times of wing-dike and levee construction. Copyright 2008 by the American Geophysical Union.

  9. Intermittent ephemeral river-breaching

    NASA Astrophysics Data System (ADS)

    Reniers, A. J.; MacMahan, J. H.; Gallagher, E. L.; Shanks, A.; Morgan, S.; Jarvis, M.; Thornton, E. B.; Brown, J.; Fujimura, A.

    2012-12-01

    In the summer of 2011 we performed a field experiment in Carmel River State Beach, CA, at a time when the intermittent natural breaching of the ephemeral Carmel River occurred due to an unusually rainy period prior to the experiment associated with El Nino. At this time the river would fill the lagoon over the period of a number of days after which a breach would occur. This allowed us to document a number of breaches with unique pre- and post-breach topographic surveys, accompanying ocean and lagoon water elevations as well as extremely high flow (4m/s) velocities in the river mouth during the breaching event. The topographic surveys were obtained with a GPS-equipped backpack mounted on a walking human and show the evolution of the river breaching with a gradually widening and deepening river channel that cuts through the pre-existing beach and berm. The beach face is qualified as a steep with an average beach slope of 1:10 with significant reflection of the incident waves (MacMahan et al., 2012). The wave directions are generally shore normal as the waves refract over the deep canyon that is located offshore of the beach. The tide is mixed semi-diurnal with a range on the order of one meter. Breaching typically occurred during the low-low tide. Grain size is highly variable along the beach with layers of alternating fine and coarse material that could clearly be observed as the river exit channel was cutting through the beach. Large rocky outcroppings buried under the beach sand are also present along certain stretches of the beach controlling the depth of the breaching channel. The changes in the water level measured within the lagoon and the ocean side allows for an estimate of the volume flux associated with the breach as function of morphology, tidal elevation and wave conditions as well as an assessment of the conditions and mechanisms of breach closure, which occurred on the time scale of O(0.5 days). Exploratory model simulations will be presented at the

  10. Tsunami Bores in Kitakami River

    NASA Astrophysics Data System (ADS)

    Tolkova, Elena; Tanaka, Hitoshi

    2016-07-01

    The 2011 Tohoku tsunami entered the Kitakami river and propagated there as a train of shock waves, recorded with a 1-min interval at water level stations at Fukuchi, Iino, and the weir 17.2 km from the mouth, where the bulk of the wave was reflected back. The records showed that each bore kept its shape and identity as it traveled a 10.9-km-path Fukuchi-Iino-weir-Iino. Shock handling based on the cross-river integrated classical shock conditions was applied to reconstruct the flow velocity time histories at the measurement sites, to estimate inflow into the river at each site, to evaluate the wave heights of incident and reflected tsunami bores near the weir, and to estimate propagation speed of the individual bores. Theoretical predictions are verified against the measurements. We discuss experiences of exercising the shock conditions with actual tsunami measurements in the Kitakami river, and test applicability of the shallow-water approximation for describing tsunami bores with heights ranging from 0.3 to 4 m in a river segment with a depth of 3-4 m.

  11. Morphodynamics: Rivers beyond steady state

    NASA Astrophysics Data System (ADS)

    Church, M.; Ferguson, R. I.

    2015-04-01

    The morphology of an alluvial river channel affects the movement of water and sediment along it, but in the longer run is shaped by those processes. This interplay has mostly been investigated empirically within the paradigm of Newtonian mechanics. In rivers, this has created an emphasis on equilibrium configurations with simple morphology and uniform steady flow. But transient adjustment, whether between equilibrium states or indefinitely, is to be expected in a world in which hydrology, sediment supply, and base level are not fixed. More fundamentally, water flows and all the phenomena that accompany them are inherently unsteady, and flows in natural channels are characteristically nonuniform. The morphodynamics of alluvial river channels is the striking consequence. In this paper, we develop the essential connection between the episodic nature of bed material transport and the production of river morphology, emphasizing the fundamental problems of sediment transport, the role of bar evolution in determining channel form, the role of riparian vegetation, and the wide range of time scales for change. As the key integrative exercise, we emphasize the importance of physics-based modeling of morphodynamics. We note consequences that can be of benefit to society if properly understood. These include the possibility to better be able to model how varying flows drive morphodynamic change, to understand the influence of the sediments themselves on morphodynamics, and to recognize the inherent necessity for rivers that transport bed material to deform laterally. We acknowledge pioneering contributions in WRR and elsewhere that have introduced some of these themes.

  12. Towards a sociogeomorphology of rivers

    NASA Astrophysics Data System (ADS)

    Ashmore, Peter

    2015-12-01

    While human impacts on rivers and other landforms have long been a component of geomorphic research, little of this work explicitly includes insights into human agency from social science or recognises that in many cases rivers can be considered to be hybrid co-productions or 'socio-natures'. A socio-geomorphic approach proposed here has parallels with some aspects of sociohydrology and can extend and enrich existing geomorphic explanations of the morphology of, for example, urban rivers by explicitly recognising and working with the co-evolution of the human and natural systems. Examples from recent literature illustrate ways in which these relationships can be understood and analyzed, showing a range of socio-natural influences in particular contexts that have material consequences for river morphology and recognising that events in the system have many forms. The approach recognises the importance of contingency in time and place together with the role and nature of both local and global knowledge. An important element of this approach is that it provides ways for understanding the nature, position and intention of geomorphic and other scientific interventions as part of the system, for example in the case of river restoration. This also leads to the need for reflexivity by geomorphologists and reconsideration of the nature of geomorphological knowledge by those involved in such work and with respect to sociogeomorphology as a whole.

  13. Colloids in the River Inn

    NASA Astrophysics Data System (ADS)

    Ueckert, Martina; Baumann, Thomas

    2014-05-01

    In the light of an increasing number of technical applications using nanoparticles and reports of adverse effects of engineered nanoparticles, research on the occurrence and stability of particles in all compartments has to be intensified. Colloids in river water represent the geologic setting, environmental conditions, and the anthropogenic use in its catchment. The river not only acts as a sink for nanoparticles but also as the source term due to exchange in the hyporheic zone and in bank filtration setups. The concentration, size distribution and elemental composition of particles in the River Inn were studied from the source in the Swiss Alps to the river mouth at Passau. Samples were collected after each tributary from a sub-catchment and filtered on-site. The elemental composition was determined after acid digestion with ICP/MS. SEM/EDX analyses provided morphological and elemental information for single particles. A complementary chemical analysis of the river water was performed to assess the geochemical stability of indvidual particles. Particles in the upper, rural parts mainly reveal changes in the geological setting of the tributary catchments. Not unexpectedly, particles originating from crystalline rocks, were more stable than particles originating from calcareous rocks. Anthropogenic and industrial influences increase in the lower parts. This went together with a change of the size distribution, an increase of the number of organic particles, and a decrease of the microfauna. Interestingly, specific leisure activities in a sub-catchment, like extensive downhill skiing, manifest itself in the particle composition.

  14. The economic value of Trinity River water

    USGS Publications Warehouse

    Douglas, A.J.; Taylor, J.G.

    1999-01-01

    The Trinity River, largest tributary of the Klamath River, has its head-waters in the Trinity Alps of north-central California. After the construction of Trinity Dam in 1963, 90% of the Trinity River flow at Lewiston was moved to the Sacramento River via the Clear Creek Tunnel, a manmade conduit. Hydropower is produced at four installations along the route of Trinity River water that is diverted to the Sacramento River, and power production at three of these installations would diminish if no Trinity River water were diverted to the Sacramento River. After Trinity River water reaches the Sacramento River, it flows toward the Sacramento-San Joaquin Delta and San Francisco Bay. Trinity River water is pumped via Bureau of Reclamation canals and pumps to the northern San Joaquin Valley, where it is used for irrigated agriculture. The social cost of putting more water down the Trinity River is the sum of the value of the foregone consumer surplus from hydropower production as well as the value of the foregone irrigation water. Sharply diminished instream flows have also severely affected the size and robustness of Trinity River salmon, steelhead, shad and sturgeon runs. Survey data were used to estimate the non-market benefits of augmenting Trinity River instream flows by letting more water flow down the Trinity and moving less water to the Sacramento River. Preservation benefits for Trinity River instream flows and fish runs are $803 million per annum for the scenario that returns the most water down the Trinity River, a value that greatly exceeds the social cost estimate.The Trinity River, largest tributary of the Klamath River, has its headwaters in the Trinity Alps of north-central California. After the construction of Trinity Dam in 1963, 90% of the Trinity River flow at Lewiston was moved to the Sacramento River via the Clear Creek Tunnel, a manmade conduit. Hydropower is produced at four installations along the route of Trinity River water that is diverted to the

  15. The River Danube: An Examination of Navigation on the River

    NASA Astrophysics Data System (ADS)

    Cooper, R. W.

    One of the definitions of Navigation that gets little attention in this Institute is (Oxford English Dictionary), and which our French friends call La Navigation. I have always found this subject fascinating, and have previously navigated the Rivers Mekong, Irrawaddy, Hooghly, Indus, Shatt-al-Arab, Savannah and RhMainKanal (RMDK) and the River Danube, a distance of approximately 4000 km. This voyage has only recently become possible with the opening of the connecting RMDK at the end of 1992, but has been made little use of because of the civil war in the former Yugoslavia.

  16. On the use of airborne LiDAR for braided river monitoring and water surface delineation

    NASA Astrophysics Data System (ADS)

    Vetter, M.; Höfle, B.; Pfeifer, N.; Rutzinger, M.; Stötter, J.

    2009-04-01

    density for all shots. The amplitude density ratio is the relation between the number of laser echoes having an amplitude within a specific interval (i.e. very low amplitudes) plus the dropouts (i.e. with amplitude of zero) divided by the number of all laser shots in a fixed search distance of a point. (e) We classify each point in water or a non-water by using the attributes of (i) the standard deviation of the height and (ii) the amplitude density ratio. For validation, a terrestrial orthophoto is used, which was taken at the same time as the laser campaign. A major advantage of this new approach is the ability of a point cloud based delineation of water and non-water areas. We demonstrate the results at the glacier forefield of the Hintereisferner (Ötztal, Tyrol, Austria) with multitemporal data sets. The multitemporal analysis demonstrates the strength of the delineation method for mapping the watercourse and monitoring the changes in the flow path of the braided river between the different epochs.

  17. Adaptation Challenges in Complex River Basins: Lessons Learned and Unlearned for the Colorado

    NASA Astrophysics Data System (ADS)

    Pulwarty, R. S.

    2008-12-01

    management (e.g. through metering and pricing), and institutional changes that improve the tradability of water rights. The co-evolution of climate history and adaptation did not start with the release of IPCC scenarios. The development of the Colorado River Basin was itself influenced by water resources planners from around the world (including the Middle East) in the late 1800s. As such lessons identified, but not always learned, abound. These hold considerable promise for water savings and the reallocation of water to highly valued uses. Supply-side strategies generally involve increases in storage capacity, abstraction from watercourses, and water transfers. Integrated water resources management provides an important governance framework to achieve adaptation measures across socio-economic, environmental and administrative systems. However, several paradoxes in water management and governance mitigate against the effectiveness of scientific information for meeting short term needs in the context of reducing longer-term vulnerabilities and for providing water to meet environmental needs. Consequently a complete analysis of the effects of climate change on human water uses would consider cross-sector interactions, including the impacts of changes in water use efficiency and intentional transfers of the use of water from one sector to another.

  18. The Challenges and Opportunities of Hydrologic Remote Sensing in Data-Poor Regions: Case Study of Nile River Basin

    NASA Astrophysics Data System (ADS)

    Hasan, E.; Kirstetter, P.; Zhang, K.; Hong, Y.

    2015-12-01

    The Nile River Basin (NRB) is one of the largest trans-boundary watercourses; it is the lifeline for more than 300 million people belonging to 11 African nations sharing the NRB. The riparian countries are challenged by their infirm relationships, lack of information sharing and insufficient monitoring stations. Thus, to understand the water future along the NRB under the changing climate, reliable, and sufficient information are needed. This to assess and understand: whether will be more rainfall and induced flooding events, or the drought conditions with less surface runoff will be dominant over the Nile Basin? In addition, to what extent the available remote sensing and model reanalysis data can substitute the lack of detailed ground information, and help to determine the size and risk associated to the climatic impact on the Nile Basin? In the current study, we utilizing multi-scale remote sensing, and model reanalysis datasets for hydrologic monitoring along the NRB in Africa. The list of remote sensing, and model reanalysis datasets that implemented: several MODIS satellite products such as the NDVI, LAI, LST, and LULC datasets. Three GRACE satellite derivative products: TWS, EWT, and DTWS, and TRMM satellite precipitation product. In addition to number of model reanalysis datasets including Global Precipitation Climatological Center (GPCC) datasets, Global Land Data Assimilation System (GLDAS) products, Climate Research Unit (CRU) datasets, Physical Science Division (PSD) gridded climate dataset, and in situ Global Runoff Data Centre (GRDC) datasets. The main objective of our research is to monitor the hydrological changes and the variation in water balance along the NRB. The study approach accomplished through: (1) developing a distributed storage changes based grid, (2) trend analysis and inter-annual variability shift detections using regime shift analysis, (3) define the water stress and water deficit periods along the Nile Basins, (4) applying multi

  19. Behavior of dissolved aluminum in the Huanghe (Yellow River) and its estuary: Impact of human activities and sorption processes

    NASA Astrophysics Data System (ADS)

    Wang, Zhao-Wei; Ren, Jing-Ling; Zhang, Gui-Ling; Liu, Su-Mei; Zhang, Xiang-Zhao; Liu, Zhe; Zhang, Jing

    2015-02-01

    Dissolved aluminum (Al) is a sensitive tracer for biogeochemical cycles in the ocean. There has been a dramatic decline in water and sediment fluxes into the sea from the Huanghe because of climate change and human activities. Water-Sediment Regulation Schemes (WSRSs) have been implemented annually to flush trapped sediments from the upstream watercourse and reservoirs of the river. Monthly observations to investigate the behavior of dissolved Al in the lower reach of the Huanghe were carried out from November 2008 to December 2010. During 2009, daily observations were made to assess the impact of the ninth WSRS on the lower reach of the Huanghe and three cruises were carried out in the Huanghe Estuary in 2009 (prior to, during and following the WSRS). The monthly concentrations of dissolved Al ranged from 25 nM to 362 nM (average 90 nM) in the lower reach of the Huanghe. Assessment of the seasonal variation of dissolved Al showed that the highest concentrations occurred in summer and the lowest in winter: these corresponded to the variations in water discharge and sediment loads, which were controlled by WSRS events. During the ninth WSRS events in 2009 the daily runoff and sediment load increased from 200 m3/s to 3600 m3/s and from 0.1 g/L to 5 g/L, respectively. The concentration of dissolved Al increased from 180 nM to 600 nM (average 380 nM) in less than 20 days, which were equivalent to 43% of the annual Al flux into the Bohai. Exchange between dissolved and particulate Al, investigated using a simple sorption model based on the distribution coefficient (Kd), was approximately 106 mL/g in the Huanghe. The average concentrations of dissolved Al in the Huanghe Estuary prior to, during and following the WSRS were 243 nM, 238 nM and 186 nM, respectively. The comparable concentrations of dissolved Al in the Huanghe Estuary prior to and during the WSRS indicate that removal processes occurred in the initial stages of mixing in the estuary. The Al

  20. 1. SNAKE RIVER VALLEY IRRIGATION DISTRICT DAM, VIEW OF NORTH ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. SNAKE RIVER VALLEY IRRIGATION DISTRICT DAM, VIEW OF NORTH ELEVATION OF INTAKE ON EAST SIDE OF DAM - Snake River Valley Irrigation District, East Side of Snake River (River Mile 796), Shelley, Bingham County, ID

  1. Sacramento River Water Treatment Plant Intake Pier & Access Bridge, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Sacramento River Water Treatment Plant Intake Pier & Access Bridge, Spanning Sacramento River approximately 175 feet west of eastern levee on river; roughly .5 mile downstream from confluence of Sacramento & American Rivers, Sacramento, Sacramento County, CA

  2. 3. SANDY RIVER (STARK ST.) BRIDGE, SOUTH END, LOOKING 295 ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. SANDY RIVER (STARK ST.) BRIDGE, SOUTH END, LOOKING 295 DEGREES WEST-SOUTHWEST. - Historic Columbia River Highway, Stark Street Bridge, Spanning Sandy River on Stark Street at Historic Columbia River Highway, Troutdale, Multnomah County, OR

  3. 1. SANDY RIVER (STARK ST.) BRIDGE, NORTH END, LOOKING 135 ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. SANDY RIVER (STARK ST.) BRIDGE, NORTH END, LOOKING 135 DEGREES SOUTHEAST. - Historic Columbia River Highway, Stark Street Bridge, Spanning Sandy River on Stark Street at Historic Columbia River Highway, Troutdale, Multnomah County, OR

  4. 5. SANDY RIVER (STARK ST.) BRIDGE, EAST ELEVATION, LOOKING 194 ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. SANDY RIVER (STARK ST.) BRIDGE, EAST ELEVATION, LOOKING 194 DEGREES SOUTH. - Historic Columbia River Highway, Stark Street Bridge, Spanning Sandy River on Stark Street at Historic Columbia River Highway, Troutdale, Multnomah County, OR

  5. 4. SANDY RIVER (STARK ST.) BRIDGE, WEST ELEVATION, LOOKING 118 ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. SANDY RIVER (STARK ST.) BRIDGE, WEST ELEVATION, LOOKING 118 DEGREES EAST-SOUTHEAST. - Historic Columbia River Highway, Stark Street Bridge, Spanning Sandy River on Stark Street at Historic Columbia River Highway, Troutdale, Multnomah County, OR

  6. 2. SANDY RIVER (STARK ST.) BRIDGE, NORTH END, LOOKING 163 ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. SANDY RIVER (STARK ST.) BRIDGE, NORTH END, LOOKING 163 DEGREES SOUTH. - Historic Columbia River Highway, Stark Street Bridge, Spanning Sandy River on Stark Street at Historic Columbia River Highway, Troutdale, Multnomah County, OR

  7. Past, present, and future concepts in large river ecology

    USGS Publications Warehouse

    Johnson, B.L.; Richardson, W.B.; Naimo, T.J.

    1995-01-01

    How rivers function and how human activities influence river processes. Many important questions are likely to require natural experiments or large-scale manipulations that compare rivers or river reaches.

  8. VIEW OF APALACHICOLA RIVER BRIDGE SPANS 2, 3, AND 4, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF APALACHICOLA RIVER BRIDGE SPANS 2, 3, AND 4, EAST SIDE, FROM CENTER OF RIVER, FACING WEST - Apalachicola River Bridge, State Route 20 spanning the Apalachicola River, Blountstown, Calhoun County, FL

  9. VIEW OF APALACHICOLA RIVER BRIDGE SPANS 2, 3, 4, AND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF APALACHICOLA RIVER BRIDGE SPANS 2, 3, 4, AND 5, EAST SIDE, FROM NORTH SHORE OF RIVER (CALHOUN COUNTY SIDE), FACING SOUTH - Apalachicola River Bridge, State Route 20 spanning the Apalachicola River, Blountstown, Calhoun County, FL

  10. VIEW OF APALACHICOLA RIVER BRIDGE SPANS 1, 2, 3, 4, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF APALACHICOLA RIVER BRIDGE SPANS 1, 2, 3, 4, AND 5, EAST SIDE, FROM SOUTH SHORE OF RIVER (LIBERTY COUNTY SIDE), FACING WEST - Apalachicola River Bridge, State Route 20 spanning the Apalachicola River, Blountstown, Calhoun County, FL

  11. VIEW OF APALACHICOLA RIVER BRIDGE PIER 3 SHOWING LOWER PEDESTAL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF APALACHICOLA RIVER BRIDGE PIER 3 SHOWING LOWER PEDESTAL AND FRAMING OF STEEL BRIDGE TRUSS, EAST SIDE, FROM RIVER, FACING WEST - Apalachicola River Bridge, State Route 20 spanning the Apalachicola River, Blountstown, Calhoun County, FL

  12. VIEW OF APALACHICOLA RIVER BRIDGE SPAN 3, SHOWING EAST SIDE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF APALACHICOLA RIVER BRIDGE SPAN 3, SHOWING EAST SIDE AND SUBSTRUCTURE, FROM CENTER OF RIVER, FACING SOUTHWEST - Apalachicola River Bridge, State Route 20 spanning the Apalachicola River, Blountstown, Calhoun County, FL

  13. VIEW OF APALACHICOLA RIVER BRIDGE SPANS 3, 4, AND 5, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF APALACHICOLA RIVER BRIDGE SPANS 3, 4, AND 5, WEST SIDE, FROM NORTH SHORE OF RIVER (CALHOUN COUNTY SIDE), FACING SOUTHEAST - Apalachicola River Bridge, State Route 20 spanning the Apalachicola River, Blountstown, Calhoun County, FL

  14. VIEW OF APALACHICOLA RIVER BRIDGE SPANS 2, 3, AND 4, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF APALACHICOLA RIVER BRIDGE SPANS 2, 3, AND 4, WEST SIDE, FROM CENTER OF RIVER, FACING EAST - Apalachicola River Bridge, State Route 20 spanning the Apalachicola River, Blountstown, Calhoun County, FL

  15. VIEW OF APALACHICOLA RIVER BRIDGE STEEL BRIDGE TRUSS AND ROADWAY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF APALACHICOLA RIVER BRIDGE STEEL BRIDGE TRUSS AND ROADWAY AT PIER 3, EAST SIDE, FROM RIVER, FACING WEST - Apalachicola River Bridge, State Route 20 spanning the Apalachicola River, Blountstown, Calhoun County, FL

  16. VIEW OF APALACHICOLA RIVER BRIDGE SPANS 1, 2, AND 3, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF APALACHICOLA RIVER BRIDGE SPANS 1, 2, AND 3, WEST SIDE, FROM SOUTH SHORE OF RIVER (LIBERTY COUNTY SIDE), FACING NORTH - Apalachicola River Bridge, State Route 20 spanning the Apalachicola River, Blountstown, Calhoun County, FL

  17. Radioactive effluents in Savannah River

    SciTech Connect

    Winn, W.G.

    1991-11-27

    During 1990, low-level radiometric studies of the Savannah River continued to distinguish between effluent contributions from Plant Vogtle and the Savannah River Site. Measurements of these radioactive effluents are of mutual interest to both institutions, as they can address disturbing trends before they become health and legal concerns. The Environmental Technology Section (ETS) has conducted radiometric studies of Plant Vogtle since late 1986, prior to its startup. The plant has two 1100 MWe pressurized water reactors developed by Westinghouse. Unit 1 started commercial operations in June 1987, and Unit 2 began in May 1989. During powered operations, ETS has routinely detected neutron-activated isotopes in controlled releases but all activities have been several orders of magnitude below the DOE guide values. In 1990, processing improvements for Vogtle effluents have yielded even lower activities in the river. The Vogtle release data and the ETS measurements have tracked well over the past four years.

  18. Nelson River and Hudson Bay

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Rivers that empty into large bodies of water can have a significant impact on the thawing of nearshore winter ice. This true-color Moderate Resolution Imaging Spectroradiometer (MODIS) image from May 18, 2001, shows the Nelson River emptying spring runoff from the Manitoba province to the south into the southwestern corner of Canada's Hudson Bay. The warmer waters from more southern latitudes hasten melting of ice near the shore, though some still remained, perhaps because in shallow coastal waters, the ice could have been anchored to the bottom. High volumes of sediment in the runoff turned the inflow brown, and the rim of the retreating ice has taken on a dirty appearance even far to the east of the river's entrance into the Bay. The sediment would have further hastened the melting of the ice because its darker color would have absorbed more solar radiation than cleaner, whiter ice. Image courtesy Jacques Descloitres, MODIS Land Rapid Response Team at NASA GSFC

  19. Grays River Watershed Geomorphic Analysis

    SciTech Connect

    Geist, David R

    2005-04-30

    This investigation, completed for the Pacific Northwest National Laboratory (PNNL), is part of the Grays River Watershed and Biological Assessment commissioned by Bonneville Power Administration under project number 2003-013-00 to assess impacts on salmon habitat in the upper Grays River watershed and present recommendations for habitat improvement. This report presents the findings of the geomorphic assessment and is intended to support the overall PNNL project by evaluating the following: The effects of historical and current land use practices on erosion and sedimentation within the channel network The ways in which these effects have influenced the sediment budget of the upper watershed The resulting responses in the main stem Grays River upstream of State Highway 4 The past and future implications for salmon habitat.

  20. Harlem River water quality improvement

    NASA Astrophysics Data System (ADS)

    Wang, J.

    2011-12-01

    Harlem River is a navigable tidal strait, which flows 8 miles connecting the Hudson River and the East River. In wet weather condition, there is untreated sewage mixed rainfall discharged to the river directly at CSO's discharge point. These raw sewer contain bacteria such as Fecal Coliform, E. Coli, Entercocci those can cause illness. There are total 37 CSOs dicharge point along the Harlem River. Water samples were collected from five sites and analyzed on a weekly basis in spring from March to May 2011, and on a monthly basis in July and August. Results showed that ammonia concentrations were ranged from 0.25 to 2.2 mg/L, and there was an increased pattern in summer when temperature increases; soluble reactive phosphorus (SRP) ranged from 0.04 to 0.2 mg/L; total P (TP) ranged from 0.03 to 0.7 mg/L; organic P (OP) ranged from 0.006 to 0.5 mg/L. In rain storm (wet weather condition), untreated sewer discharged into the river with distinguished higher nutrient concentrations (ammonia=2.9 mg/L, TP=3.1 mg/L, OP=2.9 mg/L) and extremely high bacteria levels (fecal coliform-millions, countless colonies; E. Coli-thousands). Results showed spatial variations among the five sites, seasonal variations from spring to summer, and variations under different weather conditions (temperature, storms). The raw sewer discharge during heavy rainstorms resulted in higher nutrients and bacteria levels, and the water quality was degraded.

  1. River Sinuosity Classification - The method

    NASA Astrophysics Data System (ADS)

    Petrovszki, J.; Székely, B.; Timár, G.

    2012-04-01

    We introduced a new evaluation method, the classification of multiple window-size based sinuosity spectrum. If the river is long enough for the analysis, the classification could be as useful, as the sinuosity spectrum, but sometimes it is more straightforward. Furthermore, for the classification, we did not need the main parameters of the river, e.g. the bankfull discharge. Each sinuosity calculation that was performed for a given window size, has been considered as one band (one channel) of a multichannel "image". Then, the sinuosity spectrums became multichannel images are of size 1 X N where N represents the length of the actual river in pixels. Using this multichannel input unsupervised ISOCLASS classification was carried out on these data, using ER Mapper software. The requested number of classes was set to 5. The results of the sinuosity calculations are scalars. Earlier, it was a subjective decision to divide the sinuosity values into the categories (low, medium-low, medium, medium-high, and high), while the new method provides integer numbers (1 to 5) itself. These numbers are calculated from the sinuosity values, but are not equal to them. Analysing the results of the classification, it is important to note that the method typically splits the river course into contiguous sections that belong to the same class. Boundaries of these classes can be considered as points of considerable change in the river course, because the method uses statistically relevant amount of data of the river course in a robust way to detect changes. Some specific classes or their boundaries seem to be correlated to tectonically active zones. The research is made in the frame of project OTKA-NK83400 (SourceSink Hungary). The European Union and the European Social Fund also have provided financial support to the project under the grant agreement no. TÁMOP 4.2.1./B-09/1/KMR-2010-0003.

  2. Substructure Main Bridge, River Piers A & V ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Substructure - Main Bridge, River Piers A & V - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  3. Columbia River Impact Evaluation Plan

    SciTech Connect

    Weiss, S.G.

    1994-03-01

    A preliminary impact evaluation was conducted to assess the adequacy of existing data and proposed data collection programs for evaluating cumulative health and environmental impacts to the Columbia River due to past practices at the Hanford Site. The results of this evaluation were used to develop this plan to ensure collection of sufficient data for adequate characterization of the Columbia River along the 100 Area for CERCLA purposes. The evaluation used to develop the plan is not a risk assessment; the plan presented here is only a mechanism to collect additional data to support a future risk assessment.

  4. Arctic River Mobility: A Baseline Assessment

    NASA Astrophysics Data System (ADS)

    Rowland, J. C.; Wilson, C. J.; Brumby, S. P.; Pope, P. A.

    2009-12-01

    In many arctic river systems, permafrost and the presence of frozen floodplain materials provides a significant source of bank cohesion. Due to this cohesion, permafrost may play an important control of arctic river mobility and meandering dynamics. Whether changes in the rates of permafrost thawing has had or will have as significant a geomorphic impact on arctic river meandering as has already been observed for arctic coastline retreat, lake size and distribution, and hillslope stability is at present an unanswered question. The potential impact of climate driven changes in arctic river meandering has important implications for river planform morphology, floodplain dynamics, river ecology, and the export of carbon and nutrients to coastal oceans. We present results of remote sensing analysis of river mobility for the Yukon River in Alaska and sections of the Siberian Rivers including the Lena, the Kolyma and the Indigirka Rivers. Comparisons of river location at successive intervals in time were conducted using Landsat imagery archives and higher resolution aerial photographs and satellite imagery. Extraction of river channel locations was accomplished using the GeniePro automated feature extraction software. Over the period of Landsat coverage (mid-1980s to present) arctic rivers show limited to no movement at the resolution of the Landsat data (30 m per pixel). On the Yukon Flats regions of the Yukon River, the most mobile sections of the river have migration rates comparable to reach-average values reported for temperate rivers; given that large portions of the Yukon display no detectable movement, reach-averaged values are far less than observed in temperate systems. Field inspection of areas of high erosion along the Yukon River indicate that erosional processes associated with the thermal degradation of permafrost play a dominant role in many of these areas. Thermal niching and large scale bank collapse due to undercutting play a large role in bank erosion

  5. 33 CFR 117.911 - Atlantic Intracoastal Waterway, Little River to Savannah River.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., Little River to Savannah River. 117.911 Section 117.911 Navigation and Navigable Waters COAST GUARD... § 117.911 Atlantic Intracoastal Waterway, Little River to Savannah River. (a) General. Public vessels of... List of CFR Sections Affected, which appears in the Finding Aids section of the printed volume and...

  6. 33 CFR 117.911 - Atlantic Intracoastal Waterway, Little River to Savannah River.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., Little River to Savannah River. 117.911 Section 117.911 Navigation and Navigable Waters COAST GUARD... § 117.911 Atlantic Intracoastal Waterway, Little River to Savannah River. (a) General. Public vessels of... Register citations affecting § 117.911, see the List of CFR Sections Affected, which appears in the...

  7. 33 CFR 117.911 - Atlantic Intracoastal Waterway, Little River to Savannah River.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., Little River to Savannah River. 117.911 Section 117.911 Navigation and Navigable Waters COAST GUARD... § 117.911 Atlantic Intracoastal Waterway, Little River to Savannah River. (a) General. Public vessels of... Register citations affecting § 117.911, see the List of CFR Sections Affected, which appears in the...

  8. ALWAYS A RIVER - SUPPLEMENTAL ENVIRONMENTAL EDUCATION CURRICULUM ON THE OHIO RIVER AND WATER GRADES K - 12

    EPA Science Inventory

    This curriculum was developed as a significant component of the project, Always a River: The Ohio River and the American Experience, a six-state collaboration devoted to exploring the historical and cultural development of the Ohio River. The Always a River project is being joint...

  9. 76 FR 22033 - Safety Zone; Red River Safety Zone, Red River, MN

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-20

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AAOO Safety Zone; Red River Safety Zone, Red River, MN AGENCY... Safety Unit Duluth, MN is establishing a temporary safety zone on the Red River, MN. This safety zone is... entering all navigable waters of the Red River in the State of Minnesota north of a line drawn...

  10. 33 CFR 117.353 - Atlantic Intracoastal Waterway, Savannah River to St. Marys River.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., Savannah River to St. Marys River. 117.353 Section 117.353 Navigation and Navigable Waters COAST GUARD....353 Atlantic Intracoastal Waterway, Savannah River to St. Marys River. (a) General. Public vessels of... Friday, except Federal holidays the draw need open only at 7 a.m., 8 a.m. and 5:30 p.m. (c)...

  11. 33 CFR 117.353 - Atlantic Intracoastal Waterway, Savannah River to St. Marys River.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., Savannah River to St. Marys River. 117.353 Section 117.353 Navigation and Navigable Waters COAST GUARD....353 Atlantic Intracoastal Waterway, Savannah River to St. Marys River. (a) General. Public vessels of... Friday, except Federal holidays the draw need open only at 7 a.m., 8 a.m. and 5:30 p.m. (c)...

  12. Rivers Run Through It: Discovering the Interior Columbia River Basin.

    ERIC Educational Resources Information Center

    Davis, Shelley; Wojtanik, Brenda Lincoln; Rieben, Elizabeth

    1998-01-01

    Explores the Columbia River Basin, its ecosystems, and challenges faced by natural resource managers. By studying the basin's complexity, students can learn about common scientific concepts such as the power of water and effects of rain shadows. Students can also explore social-scientific issues such as conflicts between protecting salmon runs and…

  13. Home on the Big River: Great River Habitat Quality Indices

    EPA Science Inventory

    EPA’s Environmental Monitoring and Assessment Program sampled the Upper Mississippi, Missouri and Ohio Rivers from 2004 through 2006 as part of an integrated assessment of ecological condition. We developed fish habitat indices by dividing the components of habitat into four ca...

  14. Development of a stream-aquifer numerical flow model to assess river water management under water scarcity in a Mediterranean basin.

    PubMed

    Mas-Pla, Josep; Font, Eva; Astui, Oihane; Menció, Anna; Rodríguez-Florit, Agustí; Folch, Albert; Brusi, David; Pérez-Paricio, Alfredo

    2012-12-01

    Stream flow, as a part of a basin hydrological cycle, will be sensible to water scarcity as a result of climate change. Stream vulnerability should then be evaluated as a key component of the basin water budget. Numerical flow modeling has been applied to an alluvial formation in a small mountain basin to evaluate the stream-aquifer relationship under these future scenarios. The Arbúcies River basin (116 km(2)) is located in the Catalan Inner Basins (NE Spain) and its lower reach, which is related to an alluvial aquifer, usually becomes dry during the summer period. This study seeks to determine the origin of such discharge losses whether from natural stream leakage and/or induced capture due to groundwater withdrawal. Our goal is also investigating how discharge variations from the basin headwaters, representing potential effects of climate change, may affect stream flow, aquifer recharge, and finally environmental preservation and human supply. A numerical flow model of the alluvial aquifer, based on MODFLOW and especially in the STREAM routine, reproduced the flow system after the usual calibration. Results indicate that, in the average, stream flow provides more than 50% of the water inputs to the alluvial aquifer, being responsible for the amount of stored water resources and for satisfying groundwater exploitation for human needs. Detailed simulations using daily time-steps permit setting threshold values for the stream flow entering at the beginning of the studied area so surface discharge is maintained along the whole watercourse and ecological flow requirements are satisfied as well. The effects of predicted rainfall and temperature variations on the Arbúcies River alluvial aquifer water balance are also discussed from the outcomes of the simulations. Finally, model results indicate the relevance of headwater discharge management under future climate scenarios to preserve downstream hydrological processes. They also point out that small mountain basins

  15. Columbia River Component Data Evaluation Summary Report

    SciTech Connect

    C.S. Cearlock

    2006-08-02

    The purpose of the Columbia River Component Data Compilation and Evaluation task was to compile, review, and evaluate existing information for constituents that may have been released to the Columbia River due to Hanford Site operations. Through this effort an extensive compilation of information pertaining to Hanford Site-related contaminants released to the Columbia River has been completed for almost 965 km of the river.

  16. Nile River, Lake Nasser, Aswan Dam, Egypt

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Egypt's High Aswan Dam on the Nile River at the first cataracts, Nile River, (24.0N, 33.0E) was completed in 1971 to provide cheap hydroelectric power and to regulate the historically uneven flow of the Nile River. The contrast between the largely base rock desert east of the Nile versus the sand covered desert west of the river and the ancient irrigated floodplain downstream from the damsite is clearly shown.

  17. Floods in the Raccoon River basin, Iowa

    USGS Publications Warehouse

    Heinitz, Albert J.

    1980-01-01

    Evaluation of flood hazards, and the planning, design, and operation of various facilities on flood plains requires information on floods. This report provides information on flood stages and discharges, flood magnitude and frequency, bench mark data, and flood profiles for the Raccoon River and some of its tributaries. Ir covers the Raccoon River, the North Raccoon River to the northern boundary of Sac County and the lower reaches of the Middle and South Raccoon Rivers.

  18. RiverCare: towards self-sustaining multifunctional rivers

    NASA Astrophysics Data System (ADS)

    Augustijn, Denie; Schielen, Ralph; Hulscher, Suzanne

    2014-05-01

    Rivers are inherently dynamic water systems involving complex interactions among hydrodynamics, morphology and ecology. In many deltas around the world lowland rivers are intensively managed to meet objectives like safety, navigation, hydropower and water supply. With the increasing pressure of growing population and climate change it will become even more challenging to reach or maintain these objectives and probably also more demanding from a management point of view. In the meantime there is a growing awareness that rivers are natural systems and that, rather than further regulation works, the dynamic natural processes should be better utilized (or restored) to reach the multifunctional objectives. Currently many integrated river management projects are initiated all over the world, in large rivers as well as streams. Examples of large scale projects in the Netherlands are 'Room for the River' (Rhine), the 'Maaswerken' (Meuse), the Deltaprogramme and projects originating from the European Water Framework Directive (WFD). These projects include innovative measures executed never before on this scale and include for example longitudinal training dams, side channels, removal of bank protection, remeandering of streams, dredging/nourishment and floodplain rehabilitation. Although estimates have been made on the effects of these measures for many of the individual projects, the overall effects on the various management objectives remains uncertain, especially if all projects are considered in connection. For all stakeholders with vested interests in the river system it is important to know how that system evolves at intermediate and longer time scales (10 to 100 years) and what the consequences will be for the various river functions. If the total, integrated response of the system can be predicted, the system may be managed in a more effective way, making optimum use of natural processes. In this way, maintenance costs may be reduced, the system remains more natural

  19. Flood inundation maps and water-surface profiles for tropical storm Irene and selected annual exceedance probability floods for Flint Brook and the Third Branch White River in Roxbury, Vermont

    USGS Publications Warehouse

    Ahearn, Elizabeth A.; Lombard, Pamela J.

    2014-01-01

    Flint Brook, a tributary to the Third Branch White River in Roxbury, Vermont, has a history of flooding the Vermont Fish and Wildlife Department’s Roxbury Fish Culture Station (the hatchery) and surrounding infrastructure. Flooding resulting from tropical storm Irene on August 28–29, 2011, caused widespread destruction in the region, including extensive and costly damages to the State-owned hatchery and the transportation infrastructure in the Town of Roxbury, Vermont. Sections of State Route 12A were washed out, and several bridges and culverts on Oxbow Road, Thurston Hill Road, and the New England Central Railroad in Roxbury were heavily damaged. Record high peak-discharge estimates of 2,140 cubic feet per second (ft3/s) and 4,320 ft3/s were calculated for Flint Brook at its confluence with the Third Branch White River and for the Third Branch White River at about 350 feet (ft) downstream from the hatchery, respectively. The annual exceedance probabilities (AEPs) of the peak discharges for Flint Brook and the Third Branch White River were less than 0.2 percent (less than a one in 500 chance of occurring in a given year). Hydrologic and hydraulic analyses of Flint Brook and the Third Branch White River were done to investigate flooding at the hatchery in Roxbury and support efforts by the Federal Emergency Management Agency to assist State and local mitigation and reconstruction efforts. During the August 2011 flood, the majority of flow from Flint Brook (97 percent or 2,070 ft3/s) diverged from its primary watercourse due to a retaining wall failure immediately upstream of Oxbow Road and inundated the hatchery. Although a minor amount of flow from the Third Branch White River could have overtopped State Route 12A and spilled into the hatchery, the Third Branch White River did not cause flood damages or exacerbate flooding at the hatchery during the August 2011 flood. The Third Branch White River which flows adjacent to the hatchery does not flood the hatchery

  20. 4. ENVIRONMENT, FROM NORTH, SHOWING RIVER ROAD BRIDGE CARRYING CASSELMAN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. ENVIRONMENT, FROM NORTH, SHOWING RIVER ROAD BRIDGE CARRYING CASSELMAN RIVER ROAD OVER CASSELMAN RIVER, WITH MARYLAND GEOLOGICAL SURVEY STREAM-GAUGING STATION AT NORTHEAST CORNER OF BRIDGE - River Road Bridge, Crossing Casselman River on Casselman River Road, Grantsville, Garrett County, MD