WorldWideScience

Sample records for seine seamounts part

  1. RRS "Discovery" Cruise 282, 30 Jun - 01 Aug 2003. The environment and ecology of Seine and Sedlo Seamounts, NE Atlantic

    OpenAIRE

    Bett, B.J.

    2004-01-01

    The general aim of the cruise is to undertake a range of physical, chemical and biological investigations on and around Seine and Sedlo Seamounts. Specific objectives for the cruise included: a) the recovery of two current meter moorings from Seine Seamount (originally deployed from FS Poseidon in March 2004); b) to make underway observations of upper water column currents and zooplankton migrations (using ADCPs and 10 kHz echosounder); c) to assess water column hydrography, primary productio...

  2. Seamount ecology and dynamics: A multidisciplinary data set from repeated surveys at different seamounts in the Northeast Atlantic and Mediterranean (2003 - 2013).

    Science.gov (United States)

    Mohn, C.; Christiansen, B.; Denda, A.; George, K. H.; Kaufmann, M.; Maranhão, M.; Martin, B.; Metzger, T.; Peine, F.; Schuster, A.; Springer, B.; Stefanowitsch, B.; Turnewitsch, R.; Wehrmann, H.

    2016-02-01

    Seamounts are amongst the most common physiographic open ocean systems, but remoteness and geographic complexity have limited the number of integrated and multidisciplinary seamount surveys in the past. As a consequence, important aspects of seamount ecology and dynamics remain poorly studied. Here we present a multi-parameter data set from individual and repeated seamount surveys conducted at different sites in the Northeast Atlantic and Eastern Mediterranean between 2003 and 2013. The main objective of these surveys was to establish a collection of ecosystem relevant descriptors and to develop a better understanding of seamount ecosystem composition and variability in different dynamical and bio-geographic environments. Measurements were conducted at four seamounts in the Northeast Atlantic (Ampère, Sedlo, Seine, Senghor) and two seamounts in the Eastern Mediterranean (Anaximenes, Eratosthenes). The data set comprises records from a total number of 11 cruises including physical oceanography (temperature, salinity, pressure, currents), biology (phytoplankton, zooplankton, fish, benthos) and biogeochemistry (sedimentary particle dynamics, carbon flux). The resulting multi-disciplinary data collection provides a unique opportunity for comparative studies of seamount ecosystem structure and dynamics between different physical, biological and biogeochemical regimes

  3. New 40Ar/39Ar age and geochemical data from seamounts in the Canary and Madeira volcanic provinces: support for the mantle plume hypothesis

    OpenAIRE

    Geldmacher, Jörg; Hoernle, Kaj; van den Bogaard, Paul; Duggen, Svend; Werner, Reinhard

    2005-01-01

    The role of mantleplumes in the formation of intraplate volcanic islands and seamount chains is being increasingly questioned. Particular examples are the abundant and somewhat irregularly distributed island and seamount volcanoes off the coast of northwest Africa. New40Ar / 39Ar ages and Sr–Nd–Pb isotope geochemistry of volcanic rocks from seamounts northeast of the Madeira Islands (Seine and Unicorn) and northeast of the Canary Islands (Dacia and Anika), however, provide support for the plu...

  4. Ocean currents and acoustic backscatter data from shipboard ADCP measurements at three North Atlantic seamounts between 2004 and 2015.

    Science.gov (United States)

    Mohn, Christian; Denda, Anneke; Christiansen, Svenja; Kaufmann, Manfred; Peine, Florian; Springer, Barbara; Turnewitsch, Robert; Christiansen, Bernd

    2018-04-01

    Seamounts are amongst the most common physiographic structures of the deep-ocean landscape, but remoteness and geographic complexity have limited the systematic collection of integrated and multidisciplinary data in the past. Consequently, important aspects of seamount ecology and dynamics remain poorly studied. We present a data collection of ocean currents and raw acoustic backscatter from shipboard Acoustic Doppler Current Profiler (ADCP) measurements during six cruises between 2004 and 2015 in the tropical and subtropical Northeast Atlantic to narrow this gap. Measurements were conducted at seamount locations between the island of Madeira and the Portuguese mainland (Ampère, Seine Seamount), as well as east of the Cape Verde archipelago (Senghor Seamount). The dataset includes two-minute ensemble averaged continuous velocity and backscatter profiles, supplemented by spatially gridded maps for each velocity component, error velocity and local bathymetry. The dataset is freely available from the digital data library PANGAEA at https://doi.pangaea.de/10.1594/PANGAEA.883193.

  5. Ocean currents and acoustic backscatter data from shipboard ADCP measurements at three North Atlantic seamounts between 2004 and 2015

    Directory of Open Access Journals (Sweden)

    Christian Mohn

    2018-04-01

    Full Text Available Seamounts are amongst the most common physiographic structures of the deep-ocean landscape, but remoteness and geographic complexity have limited the systematic collection of integrated and multidisciplinary data in the past. Consequently, important aspects of seamount ecology and dynamics remain poorly studied. We present a data collection of ocean currents and raw acoustic backscatter from shipboard Acoustic Doppler Current Profiler (ADCP measurements during six cruises between 2004 and 2015 in the tropical and subtropical Northeast Atlantic to narrow this gap. Measurements were conducted at seamount locations between the island of Madeira and the Portuguese mainland (Ampère, Seine Seamount, as well as east of the Cape Verde archipelago (Senghor Seamount. The dataset includes two-minute ensemble averaged continuous velocity and backscatter profiles, supplemented by spatially gridded maps for each velocity component, error velocity and local bathymetry. The dataset is freely available from the digital data library PANGAEA at https://doi.pangaea.de/10.1594/PANGAEA.883193. Keywords: Seamounts, Northeast Atlantic, Shipboard ADCP, CODAS processing, DIVA gridding

  6. Morphology and distribution of seamounts surrounding Easter Island

    Science.gov (United States)

    Rappaport, Y.; Naar, D.F.; Barton, C.C.; Liu, Z.-J.; Hey, R.N.

    1997-01-01

    We investigate the morphology and distribution of a seamount population on a section of seafloor influenced by both superfast seafloor spreading and hotspot volcanism. The population under investigation is part of a broad chain of seamounts extending eastward from the East Pacific Rise, near Easter Island. In order to define the morphological variability of the seamounts, basal shape, cross-sectional area, volume, flatness, and flank slope are plotted against height for 383 seamounts with heights greater than 200 m, based on bathymetry data collected by GLORI-B and SeaBeam 2000, during three cruises onboard the R/V Melville in the spring of 1993. Nearly complete swath mapping coverage of the seamounts is available for the analysis of size and shape distribution. We quantitatively describe the seamount population of this active region, in which seamounts cover ???27% of the seafloor, and account for ???4.2% of the total crustal volume. Over 50% of the total volume (61,000 km3) of seamounts used in this study is made up by the 14 largest seamounts, and the remaining volume is made up by the 369 smaller seamounts (>200 m in height). Our analysis indicates there are at least two seamount populations in the Easter Island-Salas y Gomez Island (25??-29??S, 113??-104??W) study area. One population of seamounts is composed of short seamounts (1200 m), shield-like, pointy cones (flatness ???1200 m) originate exclusively from a hotspot source, but only a portion of the smaller volcanoes (

  7. Science priorities for seamounts: research links to conservation and management.

    Directory of Open Access Journals (Sweden)

    Malcolm R Clark

    Full Text Available Seamounts shape the topography of all ocean basins and can be hotspots of biological activity in the deep sea. The Census of Marine Life on Seamounts (CenSeam was a field program that examined seamounts as part of the global Census of Marine Life (CoML initiative from 2005 to 2010. CenSeam progressed seamount science by collating historical data, collecting new data, undertaking regional and global analyses of seamount biodiversity, mapping species and habitat distributions, challenging established paradigms of seamount ecology, developing new hypotheses, and documenting the impacts of human activities on seamounts. However, because of the large number of seamounts globally, much about the structure, function and connectivity of seamount ecosystems remains unexplored and unknown. Continual, and potentially increasing, threats to seamount resources from fishing and seabed mining are creating a pressing demand for research to inform conservation and management strategies. To meet this need, intensive science effort in the following areas will be needed: 1 Improved physical and biological data; of particular importance is information on seamount location, physical characteristics (e.g. habitat heterogeneity and complexity, more complete and intensive biodiversity inventories, and increased understanding of seamount connectivity and faunal dispersal; 2 New human impact data; these shall encompass better studies on the effects of human activities on seamount ecosystems, as well as monitoring long-term changes in seamount assemblages following impacts (e.g. recovery; 3 Global data repositories; there is a pressing need for more comprehensive fisheries catch and effort data, especially on the high seas, and compilation or maintenance of geological and biodiversity databases that underpin regional and global analyses; 4 Application of support tools in a data-poor environment; conservation and management will have to increasingly rely on predictive

  8. Science priorities for seamounts: research links to conservation and management.

    Science.gov (United States)

    Clark, Malcolm R; Schlacher, Thomas A; Rowden, Ashley A; Stocks, Karen I; Consalvey, Mireille

    2012-01-01

    Seamounts shape the topography of all ocean basins and can be hotspots of biological activity in the deep sea. The Census of Marine Life on Seamounts (CenSeam) was a field program that examined seamounts as part of the global Census of Marine Life (CoML) initiative from 2005 to 2010. CenSeam progressed seamount science by collating historical data, collecting new data, undertaking regional and global analyses of seamount biodiversity, mapping species and habitat distributions, challenging established paradigms of seamount ecology, developing new hypotheses, and documenting the impacts of human activities on seamounts. However, because of the large number of seamounts globally, much about the structure, function and connectivity of seamount ecosystems remains unexplored and unknown. Continual, and potentially increasing, threats to seamount resources from fishing and seabed mining are creating a pressing demand for research to inform conservation and management strategies. To meet this need, intensive science effort in the following areas will be needed: 1) Improved physical and biological data; of particular importance is information on seamount location, physical characteristics (e.g. habitat heterogeneity and complexity), more complete and intensive biodiversity inventories, and increased understanding of seamount connectivity and faunal dispersal; 2) New human impact data; these shall encompass better studies on the effects of human activities on seamount ecosystems, as well as monitoring long-term changes in seamount assemblages following impacts (e.g. recovery); 3) Global data repositories; there is a pressing need for more comprehensive fisheries catch and effort data, especially on the high seas, and compilation or maintenance of geological and biodiversity databases that underpin regional and global analyses; 4) Application of support tools in a data-poor environment; conservation and management will have to increasingly rely on predictive modelling

  9. Science Priorities for Seamounts: Research Links to Conservation and Management

    Science.gov (United States)

    Clark, Malcolm R.; Schlacher, Thomas A.; Rowden, Ashley A.; Stocks, Karen I.; Consalvey, Mireille

    2012-01-01

    Seamounts shape the topography of all ocean basins and can be hotspots of biological activity in the deep sea. The Census of Marine Life on Seamounts (CenSeam) was a field program that examined seamounts as part of the global Census of Marine Life (CoML) initiative from 2005 to 2010. CenSeam progressed seamount science by collating historical data, collecting new data, undertaking regional and global analyses of seamount biodiversity, mapping species and habitat distributions, challenging established paradigms of seamount ecology, developing new hypotheses, and documenting the impacts of human activities on seamounts. However, because of the large number of seamounts globally, much about the structure, function and connectivity of seamount ecosystems remains unexplored and unknown. Continual, and potentially increasing, threats to seamount resources from fishing and seabed mining are creating a pressing demand for research to inform conservation and management strategies. To meet this need, intensive science effort in the following areas will be needed: 1) Improved physical and biological data; of particular importance is information on seamount location, physical characteristics (e.g. habitat heterogeneity and complexity), more complete and intensive biodiversity inventories, and increased understanding of seamount connectivity and faunal dispersal; 2) New human impact data; these shall encompass better studies on the effects of human activities on seamount ecosystems, as well as monitoring long-term changes in seamount assemblages following impacts (e.g. recovery); 3) Global data repositories; there is a pressing need for more comprehensive fisheries catch and effort data, especially on the high seas, and compilation or maintenance of geological and biodiversity databases that underpin regional and global analyses; 4) Application of support tools in a data-poor environment; conservation and management will have to increasingly rely on predictive modelling

  10. The Seamount Catalog in EarthRef.org

    Science.gov (United States)

    Gotberg, N. K.; Koppers, A. A.; Staudigel, H.; Perez, J.

    2004-12-01

    Seamounts are important to research and education in many scientific fields, providing a wide range of data on physical, chemical, biological and geological processes. In order to make a diverse set of seamount data accessible we have developed the Seamount Catalog in EarthRef.org, available through the http://earthref.org/databases/SC/. The primary goal of the Seamount Catalog is to provide access to digital data files on a large assortment of interdisciplinary seamount research. The catalog can be searched at a variety of ability or expert levels allowing it to be used from basic education to advanced research. Each seamount is described in terms of its location, height, volume, elongation, azimuth, irregularity, rifts, morphological classification and relation to other features. GEBCO (General Bathymetric Chart of the Ocean) gazetteer data (2002; 2003) is included in the database in order to provide information on the history, discovery and names of the seamounts. Screen-optimized bathymetry maps, grid files and the original multibeam data files are available for online viewing with higher resolution downloadable versions (AI, PS, PDF) also offered. The data files for each seamount include a map made from the multibeam data only, a map made from Smith and Sandwell's (1996) predicted bathymetry, a merged map incorporating both data sets, and a map showing the differences between the two data sets. We are working towards expanding the Seamount Catalog by integrating bathymetry data from various sources, developing and linking disciplinary reference models, and integrating information from multiple disciplines and from the literature. We hope to create a data integrative environment that provides access to seamount data and the tools needed for working with that data.

  11. The Ecology of Seamounts: Structure, Function, and Human Impacts

    Science.gov (United States)

    Clark, Malcolm R.; Rowden, Ashley A.; Schlacher, Thomas; Williams, Alan; Consalvey, Mireille; Stocks, Karen I.; Rogers, Alex D.; O'Hara, Timothy D.; White, Martin; Shank, Timothy M.; Hall-Spencer, Jason M.

    2010-01-01

    In this review of seamount ecology, we address a number of key scientific issues concerning the structure and function of benthic communities, human impacts, and seamount management and conservation. We consider whether community composition and diversity differ between seamounts and continental slopes, how important dispersal capabilities are in seamount connectivity, what environmental factors drive species composition and diversity, whether seamounts are centers of enhanced biological productivity, and whether they have unique trophic architecture. We discuss how vulnerable seamount communities are to fishing and mining, and how we can balance exploitation of resources and conservation of habitat. Despite considerable advances in recent years, there remain many questions about seamount ecosystems that need closer integration of molecular, oceanographic, and ecological research.

  12. The ecology of seamounts: structure, function, and human impacts.

    OpenAIRE

    Clark, MR; Rowden, AA; Schlacher, T; Williams, A; Consalvey, M; Stocks, KI; Rogers, AD; O'Hara, TD; White, M; Shank, TM; Hall-Spencer, JM

    2010-01-01

    In this review of seamount ecology, we address a number of key scientific issues concerning the structure and function of benthic communities, human impacts, and seamount management and conservation. We consider whether community composition and diversity differ between seamounts and continental slopes, how important dispersal capabilities are in seamount connectivity, what environmental factors drive species composition and diversity, whether seamounts are centers of enhanced biological prod...

  13. Predicting the effect of seine rope layout pattern and haul-in procedure on the effectiveness of demersal seine fishing: A Computer simulation-based approach.

    Science.gov (United States)

    Madsen, Nina A H; Aarsæther, Karl G; Herrmann, Bent

    2017-01-01

    Demersal Seining is an active fishing method applying two long seine ropes and a seine net. Demersal seining relies on fish responding to the seine rope as it moves during the fishing process. The seine ropes and net are deployed in a specific pattern encircling an area on the seabed. In some variants of demersal seining the haul-in procedure includes a towing phase where the fishing vessel moves forward before starting to winch in the seine ropes. The initial seine rope encircled area, the gradual change in it during the haul-in process and the fish's reaction to the moving seine ropes play an important role in the catch performance of demersal seine fishing. The current study investigates this subject by applying computer simulation models for demersal seine fishing. The demersal seine fishing is dynamic in nature and therefore a dynamic model, SeineSolver is applied for simulating the physical behaviour of the seine ropes during the fishing process. Information about the seine rope behaviour is used as input to another simulation tool, SeineFish that predicts the catch performance of the demersal seine fishing process. SeineFish implements a simple model for how fish at the seabed reacts to an approaching seine rope. Here, the SeineSolver and SeineFish tools are applied to investigate catching performance for a Norwegian demersal seine fishery targeting cod (Gadus morhua) in the coastal zone. The effect of seine rope layout pattern and the duration of the towing phase are investigated. Among the four different layout patterns investigated, the square layout pattern was predicted to perform best; catching 69%-86% more fish than would be obtained with the rectangular layout pattern. Inclusion of a towing phase in the fishing process was found to increase the catch performance for all layout patterns. For the square layout pattern, inclusion of a towing phase of 15 or 35 minutes increased the catch performance by respectively 37% and 48% compared to fishing without

  14. New 40Ar / 39Ar age and geochemical data from seamounts in the Canary and Madeira volcanic provinces: Support for the mantle plume hypothesis

    Science.gov (United States)

    Geldmacher, J.; Hoernle, K.; Bogaard, P. v. d.; Duggen, S.; Werner, R.

    2005-08-01

    The role of mantle plumes in the formation of intraplate volcanic islands and seamount chains is being increasingly questioned. Particular examples are the abundant and somewhat irregularly distributed island and seamount volcanoes off the coast of northwest Africa. New 40Ar / 39Ar ages and Sr-Nd-Pb isotope geochemistry of volcanic rocks from seamounts northeast of the Madeira Islands (Seine and Unicorn) and northeast of the Canary Islands (Dacia and Anika), however, provide support for the plume hypothesis. The oldest ages of shield stage volcanism from Canary and Madeira volcanic provinces confirm progressions of increasing age to the northeast. Average volcanic age progression of ∼1.2 cm/a is consistent with rotation of the African plate at an angular velocity of ∼0.20° ± 0.05 /Ma around a common Euler pole at approximately 56° N, 45° W computed for the period of 0-35 Ma. A Euler pole at 35° N, 45° W is calculated for the time interval of 35-64 Ma. The isotope geochemistry further confirms that the Madeira and Canary provinces are derived from different sources, consistent with distinct plumes having formed each volcanic group. Conventional hotspot models, however, cannot easily explain the up to 40 m.y. long volcanic history at single volcanic centers, long gaps in volcanic activity, and the irregular distribution of islands and seamounts in the Canary province. A possible explanation could involve interaction of the Canary mantle plume with small-scale upper mantle processes such as edge-driven convection. Juxtaposition of plume and non-plume volcanism could also account for observed inconsistencies of the classical hotspot concept in other volcanic areas.

  15. Endemicity, biogeograhy, composition, and community structure on a northeast pacific seamount.

    Directory of Open Access Journals (Sweden)

    Craig R McClain

    Full Text Available The deep ocean greater than 1 km covers the majority of the earth's surface. Interspersed on the abyssal plains and continental slope are an estimated 14000 seamounts, topographic features extending 1000 m off the seafloor. A variety of hypotheses are posited that suggest the ecological, evolutionary, and oceanographic processes on seamounts differ from those governing the surrounding deep sea. The most prominent and oldest of these hypotheses, the seamount endemicity hypothesis (SMEH, states that seamounts possess a set of isolating mechanisms that produce highly endemic faunas. Here, we constructed a faunal inventory for Davidson Seamount, the first bathymetric feature to be characterized as a 'seamount', residing 120 km off the central California coast in approximately 3600 m of water (Fig 1. We find little support for the SMEH among megafauna of a Northeast Pacific seamount; instead, finding an assemblage of species that also occurs on adjacent continental margins. A large percentage of these species are also cosmopolitan with ranges extending over much of the Pacific Ocean Basin. Despite the similarity in composition between the seamount and non-seamount communities, we provide preliminary evidence that seamount communities may be structured differently and potentially serve as source of larvae for suboptimal, non-seamount habitats.

  16. Modeling internal wave generation by seamounts in oceans

    Science.gov (United States)

    Zhang, L.; Buijsman, M. C.; Comino, E. L.; Swinney, H.

    2017-12-01

    Recent global bathymetric data at 30 arc-sec resolution has revealed that there are 33,452 seamounts and 138,412 knolls in the oceans. To develop an estimate for the energy converted from tidal flow to internal gravity waves, we have conducted numerical simulations using the Massachusetts Institute of Technology circulation model (MITgcm) to compute the energy conversion by randomly distributed Gaussian-shaped seamounts. We find that for an isolated axisymmetric seamount of height 1100 m and radius 1600 m, which corresponds to the Wessel height-to-radius ratio 0.69, the conversion rate is 100 kW, assuming a tidal speed amplitude 1 cm/s, buoyancy frequency 1e-3 rad/s, and circularly polarized tidal motion, and taking into account the earth's rotation. The 100 kW estimate is about 60% less than the 3-D linear theory prediction because fluid goes around a seamount instead of over it. Our estimate accounts the suppression of energy conversion due to wave interference at the generation site of closely spaced seamounts. We conclude that for randomly distributed Gaussian seamounts of varying widths and separations, separated on average by 18 km as in the oceans, wave interference reduces the energy conversion by seamounts by only about 16%. This result complements previous studies of wave interference for 2-D ridges.

  17. Basinal seamounts and seamount chains of the Central Indian Ocean: Probable near-axis origin from a fast-spreading ridge

    Digital Repository Service at National Institute of Oceanography (India)

    Mukhopadhyay, R.; Batiza, R.

    Hydrosweep mapping of crust in the Central Indian Ocean Basin reveals abundant volcanoes occurring both as isolated seamounts and linear seamount chains parallel to flow lines. Their shapes, sizes and overall style of occurrence...

  18. Seamount physiography and biology in the north-east Atlantic and Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    T. Morato

    2013-05-01

    Full Text Available This work aims at characterising the seamount physiography and biology in the OSPAR Convention limits (north-east Atlantic Ocean and Mediterranean Sea. We first inferred potential abundance, location and morphological characteristics of seamounts, and secondly, summarized the existing biological, geological and oceanographic in situ research, identifying examples of well-studied seamounts. Our study showed that the seamount population in the OSPAR area (north-east Atlantic and in the Mediterranean Sea is large with around 557 and 101 seamount-like features, respectively. Similarly, seamounts occupy large areas of about 616 000 km2 in the OSPAR region and of about 89 500 km2 in the Mediterranean Sea. The presence of seamounts in the north-east Atlantic has been known since the late 19th century, but overall knowledge regarding seamount ecology and geology is still relatively poor. Only 37 seamounts in the OSPAR area (3.5% of all seamounts in the region, 22 in the Mediterranean Sea (9.2% of all seamounts in the region and 25 in the north-east Atlantic south of the OSPAR area have in situ information. Seamounts mapped in both areas are in general very heterogeneous, showing diverse geophysical characteristics. These differences will likely affect the biological diversity and production of resident and associated organisms.

  19. Growth constraints of the Indian Ocean seamounts

    Digital Repository Service at National Institute of Oceanography (India)

    Mukhopadhyay, R.; Khadge, N.H.

    lineaments and is infested with about 800 seamounts of various height ranging from 50 m to 1250 m. Statistical analysis suggests that summit height, flatness and volume primarily control shape of seamounts. The remarkable similarity in distribution, flow line...

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

    Science.gov (United States)

    Denda, Anneke; Stefanowitsch, Benjamin; Christiansen, Bernd

    2017-12-01

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

  1. Seamounts are hotspots of pelagic biodiversity in the open ocean.

    Science.gov (United States)

    Morato, Telmo; Hoyle, Simon D; Allain, Valerie; Nicol, Simon J

    2010-05-25

    The identification of biodiversity hotspots and their management for conservation have been hypothesized as effective ways to protect many species. There has been a significant effort to identify and map these areas at a global scale, but the coarse resolution of most datasets masks the small-scale patterns associated with coastal habitats or seamounts. Here we used tuna longline observer data to investigate the role of seamounts in aggregating large pelagic biodiversity and to identify which pelagic species are associated with seamounts. Our analysis indicates that seamounts are hotspots of pelagic biodiversity. Higher species richness was detected in association with seamounts than with coastal or oceanic areas. Seamounts were found to have higher species diversity within 30-40 km of the summit, whereas for sets close to coastal habitat the diversity was lower and fairly constant with distance. Higher probability of capture and higher number of fish caught were detected for some shark, billfish, tuna, and other by-catch species. The study supports hypotheses that seamounts may be areas of special interest for management for marine pelagic predators.

  2. Pacific seamount volcanism in space and time

    Science.gov (United States)

    Hillier, J. K.

    2007-02-01

    Seamounts constitute some of the most direct evidence about intraplate volcanism. As such, when seamounts formed and into which tectonic setting they erupted (i.e. on-ridge or off-ridge) are a useful reflection of how the properties of the lithosphere interact with magma generation in the fluid mantle beneath. Proportionately few seamounts are radiometrically dated however, and these tend to be recently active. In order to more representatively sample and better understand Pacific seamount volcanism this paper estimates the eruption ages (tvolc) of 2706 volcanoes via automated estimates of lithospheric strength. Lithospheric strength (GTRrel) is deduced from the ratio of gravity to topography above the summits of volcanoes, and is shown to correlate with seafloor age at the time of volcanic loading (Δt) at 61 sites where radiometric constraints upon Δt exist. A trend of fits data for these 61, and with seafloor age (tsf) known, can date the 2706 volcanoes; tvolc = tsf - Δt. Widespread recurrences of volcanism proximal to older features (e.g. the Cook-Austral alignment in French Polynesia) suggest that the lithosphere exerts a significant element of control upon the location of volcanism, and that magmatic throughput leaves the lithosphere more susceptible to the passage of future melts. Observations also prompt speculation that: the Tavara seamounts share morphological characteristics and isostatic compensation state with the Musicians, and probably formed similarly; the Easter Island chain may be a modern analogy to the Cross-Lines; a Musicians - South Hawaiian seamounts alignment may be deflecting the Hawaiian hotspot trace.

  3. The Census of Marine Life on Seamounts: results from a global science program

    Science.gov (United States)

    Stocks, K.; Clark, M.; Rowden, A.; Consalvey, M.

    2010-12-01

    CenSeam (a Global Census of Marine Life on Seamounts) is a network of more than 500 scientists, policy makers and conservationists around the world. These participants are collaborating to increase our understanding of the factors driving seamount community composition and diversity, such that we can better understand and manage the effects of human activities. The major scientific outcomes of the CenSeam community include the findings that 1) Seamount community composition is often similar to surrounding habitats; however, community structure can be different. 2) Contrary to conventional wisdom, few seamounts follow island biogeography predictions. 3) Seamounts can support a higher benthic biomass than surrounding habitats. 4) Seamounts can support species and communities new to science, and represent range extensions for known species, which are being described from CenSeam voyages. 5) For the first time, the extent of the vulnerability and risk to seamount benthic communities from fishing has been quantified. 6) Whilst long assumed, CenSeam researchers have demonstrated that seamount communities are disturbed by fishing and are slow to recover. And 7) Seamounts might act as repositories of biodiversity during future periods of extreme environmental change, as they have likely done in the past. The major products of Censeam include 1) a book synthesizing seamount knowledge: Seamounts: Ecology, Fisheries and Conservation (from Blackwell Publishing); 2) a recent review of the structure and function of seamount benthic communities, human impacts, and seamount management and conservation (Ann Rev Mar Sci); 3) hundreds of scientific publications, including Special Issues in Marine Ecology and Oceanography (in collaboration with the Seamount Biogeogsciences Network), and a Special Collection in PLoSONE; 4) guidance documents and formal advising for seamount management communities, including the United Nations Environment Program, International Seabed Authority

  4. Diversity, ecological distribution and biotechnological potential of Actinobacteria inhabiting seamounts and non-seamounts in the Tyrrhenian Sea

    KAUST Repository

    Ettoumi, Besma; Chouchane, Habib; Guesmi, Amel; Mahjoubi, Mouna; Brusetti, Lorenzo; Neifar, Mohamed; Borin, Sara; Daffonchio, Daniele; Cherif, Ameur

    2016-01-01

    In the present study, the ecological distribution of marine Actinobacteria isolated from seamount and non-seamount stations in the Tyrrhenian Sea was investigated. A collection of 110 isolates was analyzed by Automated Ribosomal Intergenic Spacer Analysis (ARISA) and 16S rRNA gene sequencing of representatives for each ARISA haplotype (n = 49). Phylogenetic analysis of 16S rRNA sequences showed a wide diversity of marine isolates and clustered the strains into 11 different genera, Janibacter, Rhodococcus, Arthrobacter, Kocuria, Dietzia, Curtobacterium, Micrococcus, Citricoccus, Brevibacterium, Brachybacterium and Nocardioides. Interestingly, Janibacter limosus was the most encountered species particularly in seamounts stations, suggesting that it represents an endemic species of this particular ecosystem. The application of BOX-PCR fingerprinting on J. limosus sub-collection (n = 22), allowed their separation into seven distinct BOX-genotypes suggesting a high intraspecific microdiversity among the collection. Furthermore, by screening the biotechnological potential of selected actinobacterial strains, J. limosus was shown to exhibit the most important biosurfactant activity. Our overall data indicates that Janibacter is a major and active component of seamounts in the Tyrrhenian Sea adapted to low nutrient ecological niche.

  5. Diversity, ecological distribution and biotechnological potential of Actinobacteria inhabiting seamounts and non-seamounts in the Tyrrhenian Sea

    KAUST Repository

    Ettoumi, Besma

    2016-04-01

    In the present study, the ecological distribution of marine Actinobacteria isolated from seamount and non-seamount stations in the Tyrrhenian Sea was investigated. A collection of 110 isolates was analyzed by Automated Ribosomal Intergenic Spacer Analysis (ARISA) and 16S rRNA gene sequencing of representatives for each ARISA haplotype (n = 49). Phylogenetic analysis of 16S rRNA sequences showed a wide diversity of marine isolates and clustered the strains into 11 different genera, Janibacter, Rhodococcus, Arthrobacter, Kocuria, Dietzia, Curtobacterium, Micrococcus, Citricoccus, Brevibacterium, Brachybacterium and Nocardioides. Interestingly, Janibacter limosus was the most encountered species particularly in seamounts stations, suggesting that it represents an endemic species of this particular ecosystem. The application of BOX-PCR fingerprinting on J. limosus sub-collection (n = 22), allowed their separation into seven distinct BOX-genotypes suggesting a high intraspecific microdiversity among the collection. Furthermore, by screening the biotechnological potential of selected actinobacterial strains, J. limosus was shown to exhibit the most important biosurfactant activity. Our overall data indicates that Janibacter is a major and active component of seamounts in the Tyrrhenian Sea adapted to low nutrient ecological niche.

  6. Diversity, ecological distribution and biotechnological potential of Actinobacteria inhabiting seamounts and non-seamounts in the Tyrrhenian Sea.

    Science.gov (United States)

    Ettoumi, Besma; Chouchane, Habib; Guesmi, Amel; Mahjoubi, Mouna; Brusetti, Lorenzo; Neifar, Mohamed; Borin, Sara; Daffonchio, Daniele; Cherif, Ameur

    2016-01-01

    In the present study, the ecological distribution of marine Actinobacteria isolated from seamount and non-seamount stations in the Tyrrhenian Sea was investigated. A collection of 110 isolates was analyzed by Automated Ribosomal Intergenic Spacer Analysis (ARISA) and 16S rRNA gene sequencing of representatives for each ARISA haplotype (n=49). Phylogenetic analysis of 16S rRNA sequences showed a wide diversity of marine isolates and clustered the strains into 11 different genera, Janibacter, Rhodococcus, Arthrobacter, Kocuria, Dietzia, Curtobacterium, Micrococcus, Citricoccus, Brevibacterium, Brachybacterium and Nocardioides. Interestingly, Janibacter limosus was the most encountered species particularly in seamounts stations, suggesting that it represents an endemic species of this particular ecosystem. The application of BOX-PCR fingerprinting on J. limosus sub-collection (n=22), allowed their separation into seven distinct BOX-genotypes suggesting a high intraspecific microdiversity among the collection. Furthermore, by screening the biotechnological potential of selected actinobacterial strains, J. limosus was shown to exhibit the most important biosurfactant activity. Our overall data indicates that Janibacter is a major and active component of seamounts in the Tyrrhenian Sea adapted to low nutrient ecological niche. Copyright © 2016 Elsevier GmbH. All rights reserved.

  7. Seamounts - windows of opportunities and the Indian scenario

    Digital Repository Service at National Institute of Oceanography (India)

    Iyer, S.D.; Das, P.; Kalangutkar, N.G.; Mehta, C.M.

    , flow rate, gravity pull) of the magma. Commonly, seamounts have steep outer slopes, flat or nearly flat, circular, summit areas, calderas and craters 4,7,23 . Morphologically, seamounts of variable sizes resemble sub-aerial volcanoes. Small, young...

  8. Seamount physiography and biology in North-East Atlantic and Mediterranean Sea

    OpenAIRE

    T. Morato; K. Ø. Kvile; G. H. Taranto; F. Tempera; B. E. Narayanaswamy; D. Hebbeln; G. Menezes; C. Wienberg; R. S. Santos; T. J. Pitcher

    2012-01-01

    This work aims at characterising the seamount physiography and biology in the OSPAR Convention limits (North-East Atlantic Ocean) and Mediterranean Sea. We first inferred potential abundance, location and morphological characteristics of seamounts, and secondly, summarized the existing biological, geological and oceanographic in-situ research, identifying examples of well-studied seamounts. Our study showed that the seamount population in the OSPAR area (North-East Atlantic) and in Mediterran...

  9. Otolith chemistry reveals seamount fidelity in a deepwater fish

    Science.gov (United States)

    Régnier, Thomas; Augley, Julian; Devalla, Sandhya; Robinson, Craig D.; Wright, Peter J.; Neat, Francis C.

    2017-03-01

    There are thousands of seamounts (underwater mountains) throughout the world's deep oceans, many of which support diverse faunal communities and valuable fish stocks. Although seamounts are often geographically and bathymetrically isolated from one another, it is not clear how biologically isolated they are from one another. We analysed the chemical signature of the otoliths of a deepwater fish, the roundnose grenadier (Coryphaenoides rupestris) to test the null hypothesis that there is random exchange between individuals from a seamount and other adjacent areas. The fish were sampled on the Scottish west coast, from the Rosemary Bank seamount and two adjacent locations of similar depth, in the same year at roughly the same time of year. We used flow-injection inductively coupled plasma mass spectrometry to measure trace element concentrations from micro-milled portions of the otolith corresponding to adult and juvenile life history stages. The elemental signatures of the fish from the seamount were distinguishable from the fish from the two other areas during both the juvenile and adult life-history phase. We infer that once juveniles settle on the seamount they remain there for the rest of their lives. Evidence for population structure should be factored into exploitation strategies to prevent local depletion and is an important consideration with respect to Rosemary bank being included in a network of Marine Protected Areas around Scotland.

  10. Danish seine – Ecosystem effects of fishing

    DEFF Research Database (Denmark)

    Noack, Thomas

    In 2014, the project “Danish seine – Ecosystem effects of fishing” got initiated in order to establish a better scientific understanding around Danish anchor seining and its effects on the environment. By comparing catch profiles of Danish seiners and demersal otter trawlers, we could show...

  11. Morphometry of Concepcion Bank: Evidence of Geological and Biological Processes on a Large Volcanic Seamount of the Canary Islands Seamount Province.

    Directory of Open Access Journals (Sweden)

    Jesus Rivera

    Full Text Available Concepcion Bank is the largest seamount in the Canary Islands Seamount Province (CISP, an oceanic area off NW Africa including 16 main seamounts, the Canaries archipelago and the Selvagens subarchipelago. The Bank is located 90 km northeast of Lanzarote Island and has been identified as a candidate Marine Protected Area (MPA to be included in the Natura 2000 network. A compilation of complementary datasets consisting of multibeam bathymetry, TOPAS seismic reflection profiles, side scan sonar sonographs, Remotely Operated Vehicle video records and seafloor samples allowed describing in detail and ground truthing the submarine landforms and bioconstructions exhibited by the bank. The Concepcion Bank presently rises up to 2,433 m above the adjacent seafloor and exhibits two main domains: an extensive summit plateau and steep flanks. The sub-round summit plateau is 50km by 45 km and ranges from 158 to 1,485 m depth. The steep flanks that bound it descend to depths ranging between 1,700 and 2,500 m and define a seamount base that is 66km by 53 km. This morphology is the result of constructive and erosive processes involving different time scales, volumes of material and rates of change. The volcanic emplacement phase probably lasted 25-30 million years and was likely responsible for most of the 2,730 km3 of material that presently form the seamount. Subsequently, marine abrasion and, possibly, subaerial erosion modulated by global sea level oscillations, levelled the formerly emerging seamount summit plateau, in particular its shallower (<400 m, flatter (<0.5° eastern half. Subsidence associated to the crustal cooling that followed the emplacement phase further contributed the current depth range of the seamount. The deeper and steeper (2.3° western half of Concepcion Bank may result from tectonic tilting normal to a NNE-SSW fracture line. This fracture may still be expressed on the seafloor surface at some scarps detected on the seamount's summit

  12. Morphometry of Concepcion Bank: Evidence of Geological and Biological Processes on a Large Volcanic Seamount of the Canary Islands Seamount Province.

    Science.gov (United States)

    Rivera, Jesus; Canals, Miquel; Lastras, Galderic; Hermida, Nuria; Amblas, David; Arrese, Beatriz; Martín-Sosa, Pablo; Acosta, Juan

    2016-01-01

    Concepcion Bank is the largest seamount in the Canary Islands Seamount Province (CISP), an oceanic area off NW Africa including 16 main seamounts, the Canaries archipelago and the Selvagens subarchipelago. The Bank is located 90 km northeast of Lanzarote Island and has been identified as a candidate Marine Protected Area (MPA) to be included in the Natura 2000 network. A compilation of complementary datasets consisting of multibeam bathymetry, TOPAS seismic reflection profiles, side scan sonar sonographs, Remotely Operated Vehicle video records and seafloor samples allowed describing in detail and ground truthing the submarine landforms and bioconstructions exhibited by the bank. The Concepcion Bank presently rises up to 2,433 m above the adjacent seafloor and exhibits two main domains: an extensive summit plateau and steep flanks. The sub-round summit plateau is 50km by 45 km and ranges from 158 to 1,485 m depth. The steep flanks that bound it descend to depths ranging between 1,700 and 2,500 m and define a seamount base that is 66km by 53 km. This morphology is the result of constructive and erosive processes involving different time scales, volumes of material and rates of change. The volcanic emplacement phase probably lasted 25-30 million years and was likely responsible for most of the 2,730 km3 of material that presently form the seamount. Subsequently, marine abrasion and, possibly, subaerial erosion modulated by global sea level oscillations, levelled the formerly emerging seamount summit plateau, in particular its shallower (<400 m), flatter (<0.5°) eastern half. Subsidence associated to the crustal cooling that followed the emplacement phase further contributed the current depth range of the seamount. The deeper and steeper (2.3°) western half of Concepcion Bank may result from tectonic tilting normal to a NNE-SSW fracture line. This fracture may still be expressed on the seafloor surface at some scarps detected on the seamount's summit. Sediment waves

  13. Seamount physiography and biology in the north-east Atlantic and Mediterranean Sea

    OpenAIRE

    Morato, T.; Kvile, K. Ø.; Taranto, G. H.; Tempera, F.; Narayanaswamy, B. E.; Hebbeln, D.; Menezes, G. M.; Wienberg, C.; Santos, R. S.; Pitcher, T. J.

    2013-01-01

    This work aims at characterising the seamount physiography and biology in the OSPAR Convention limits (north-east Atlantic Ocean) and Mediterranean Sea. We first inferred potential abundance, location and morphological characteristics of seamounts, and secondly, summarized the existing biological, geological and oceanographic in situ research, identifying examples of well-studied seamounts. Our study showed that the seamount population in the OSPAR area (north-east Atlantic) and in the Medite...

  14. HARP MHI- Cross Seamount

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — PIFSC and Scripps Institution of Oceanography (SIO) conducted passive acoustic monitoring for cetaceans at Cross Seamount in 2005 and 2006 using a High-Frequency...

  15. Danish seine - An environmental friendly fishing method?

    DEFF Research Database (Denmark)

    Noack, Thomas; Eggers, Florian; Frandsen, Rikke

    of the total landings where the seine fleet and catches are decreasing. The Danish seine is a specific type of encircling net to catch demersal fish. It is characterized by moderate fuel consumption and no use of heavy weights or doors, probably resulting in a relatively gentle bottom-contact and low...

  16. USE OF MIRROR PATTERN CUTTING OF NETTING MATERIALS FOR CONSTRUCTION OF LAKE BEACH SEINES

    Directory of Open Access Journals (Sweden)

    A. Nazarov

    2014-12-01

    Full Text Available Purpose. Justification and calculation of a new methodological approach to the construction of a standard beach seine (502 / 302 х 3.75 with the use of the properties of mirror netting ensuring the saving of the netting material, reduction of weight, price and drag resistance. Methodology. The carp age group selectivity of the constructed seine was assessed within fish fauna monitoring based on the catch analysis of monitoring gill nets with mesh sizes of 30-130 mm according to generally accepted methods [9, 10]. Calculation of netting materials and ropes was carried out according to generally accepted methods [12-14]. Seine resistance was calculated according to N. T. Senin formula for different netting materials and the angles of the movement of different seine parts in water [2]. The gear reliability and data processing were carried out according to standard methods [11, 14, 15]. Findings. A variant of the construction of the maximum lightweight beach lake seines made of mirror pattern netting taking into account the properties of the mirror pattern netting material, reduction of weight, price and drag resistance has been proposed. The provided recalculation of the properties of a serial seine made of rhombic mesh for the mirror netting seine taking into account netting properties allowed: 1 reducing the seine drag resistance value by 1,4 times; 2 reducing the weight of netting materials by 16.3% compared to the prototype; 3 increasing the seine selectivity when fishing older age groups of carp in non-drainable ponds. Originality. We presented the method of the calculation and construction of lake beach seines made of mirror netting, analyzed the technological stages of the construction of mirror netting, determined main qualitative and technological parameters, which had effect on the conditions of the construction and reliability of such fishing gears. A new method of the use of an insert of the combined netting material cutting ensuring

  17. Morphometry of Concepcion Bank: Evidence of Geological and Biological Processes on a Large Volcanic Seamount of the Canary Islands Seamount Province

    Science.gov (United States)

    Canals, Miquel; Lastras, Galderic; Hermida, Nuria; Amblas, David; Arrese, Beatriz; Martín-Sosa, Pablo; Acosta, Juan

    2016-01-01

    Concepcion Bank is the largest seamount in the Canary Islands Seamount Province (CISP), an oceanic area off NW Africa including 16 main seamounts, the Canaries archipelago and the Selvagens subarchipelago. The Bank is located 90 km northeast of Lanzarote Island and has been identified as a candidate Marine Protected Area (MPA) to be included in the Natura 2000 network. A compilation of complementary datasets consisting of multibeam bathymetry, TOPAS seismic reflection profiles, side scan sonar sonographs, Remotely Operated Vehicle video records and seafloor samples allowed describing in detail and ground truthing the submarine landforms and bioconstructions exhibited by the bank. The Concepcion Bank presently rises up to 2,433 m above the adjacent seafloor and exhibits two main domains: an extensive summit plateau and steep flanks. The sub-round summit plateau is 50km by 45 km and ranges from 158 to 1,485 m depth. The steep flanks that bound it descend to depths ranging between 1,700 and 2,500 m and define a seamount base that is 66km by 53 km. This morphology is the result of constructive and erosive processes involving different time scales, volumes of material and rates of change. The volcanic emplacement phase probably lasted 25–30 million years and was likely responsible for most of the 2,730 km3 of material that presently form the seamount. Subsequently, marine abrasion and, possibly, subaerial erosion modulated by global sea level oscillations, levelled the formerly emerging seamount summit plateau, in particular its shallower (current depth range of the seamount. The deeper and steeper (2.3°) western half of Concepcion Bank may result from tectonic tilting normal to a NNE-SSW fracture line. This fracture may still be expressed on the seafloor surface at some scarps detected on the seamount’s summit. Sediment waves and cold-water coral (CWC) mounds on the bank summit plateau are the youngest features contributing to its final shaping, and may be

  18. Codend selectivity in a commercial Danish anchor seine

    DEFF Research Database (Denmark)

    Noack, Thomas; Frandsen, Rikke; Krag, Ludvig Ahm

    2017-01-01

    Danish seining (or anchor seining) is a fishing technique that is gaining increasing attention because itis considered to be a fuel-efficient fishing method with low environmental impact. However, scientificdocumentation of the selectivity characteristics of Danish seines is lacking, and the gear....... The estimatedselectivity curve of dab indicated, contrary to cod and plaice, low retention of individuals below MLS.Confidence limits for larger length classes of cod and red gurnard were relatively wide. For plaice, theestimated selection factor, which is the length with 50% retention divided by mesh size...

  19. The Effects of Seamounts on Sound Propagation in Deep Water

    International Nuclear Information System (INIS)

    Li Wen; Li Zheng-Lin; Zhang Ren-He; Qin Ji-Xing; Li Jun; Nan Ming-Xing

    2015-01-01

    A propagation experiment was conducted in the South China Sea in 2014 with a flat bottom and seamounts respectively by using explosive sources. The effects of seamounts on sound propagation are analyzed by using the broadband signals. It is observed that the transmission loss (TL) decreases up to 7 dB for the signals in the first shadow zone due to the seamount reflection. Moreover, the TL might increase more than 30 dB in the converge zone due to the shadowing by seamounts. Abnormal TLs and pulse arrival structures at different ranges are explained by using the ray and wave theory. The experimental TLs and arrival pulses are compared with the numerical results and found to be in good agreement. (paper)

  20. Paleomagnetic modeling of seamounts near the Hawaiian Emperor bend

    Science.gov (United States)

    Sager, William W.; Lamarche, Amy J.; Kopp, Christian

    2005-08-01

    The Hawaiian-Emperor Seamount chain records the motion of the Pacific Plate relative to the Hawaiian mantle hotspot for ˜80 m.y. A notable feature of the chain is the pronounced bend at its middle. This bend had been widely credited to a change in plate motion, but recent research suggests a change in hotspot motion as an alternative. Existing paleomagnetic data from the Emperor Chain suggest that the hotspot moved south during the Late Cretaceous and Early Tertiary, but reached its current latitude by the age of the bend. Thus, data from area of the bend are important for understanding changes in plume latitude. In this study, we analyze the magnetic anomalies of five seamounts (Annei, Daikakuji-W, Daikakuji- E, Abbott, and Colahan) in the region of the bend. These particular seamounts were chosen because they have been recently surveyed to collect multibeam bathymetry and magnetic data positioned with GPS navigation. Inversions of the magnetic and bathymetric data were performed to determine the mean magnetization of each seamount and from these results, paleomagnetic poles and paleolatitudes were calculated. Three of the five seamounts have reversed magnetic polarities (two are normal) and four contain a small volume of magnetic polarity opposite to the main body, consistent with formation during the Early Cenozoic, a time of geomagnetic field reversals. Although magnetization inhomogene ties can degrade the accuracy of paleomagnetic poles calculated from such models, the seamounts give results consistent with one another and with other Pacific paleomagnetic data of approximately the same age. Seamount paleolatitudes range from 13.7 to 23.7, with an average of 19.4 ± 7.4 (2σ). These values are indistinguishable from the present-day paleolatitude of the Hawaiian hotspot. Together with other paleomagnetic and geologic evidence, these data imply that the Hawaiian hotspot has moved little in latitude during the past ˜45 m.y.

  1. Quantifying the direct use value of Condor seamount

    Science.gov (United States)

    Ressurreição, Adriana; Giacomello, Eva

    2013-12-01

    Seamounts often satisfy numerous uses and interests. Multiple uses can generate multiple benefits but also conflicts and impacts, calling, therefore, for integrated and sustainable management. To assist in developing comprehensive management strategies, policymakers recognise the need to include measures of socioeconomic analysis alongside ecological data so that practical compromises can be made. This study assessed the direct output impact (DOI) of the relevant marine activities operating at Condor seamount (Azores, central northeast Atlantic) as proxies of the direct use values provided by the resource system. Results demonstrated that Condor seamount supported a wide range of uses yielding distinct economic outputs. Demersal fisheries, scientific research and shark diving were the top-three activities generating the highest revenues, while tuna fisheries, whale watching and scuba-diving had marginal economic significance. Results also indicated that the economic importance of non-extractive uses of Condor is considerable, highlighting the importance of these uses as alternative income-generating opportunities for local communities. It is hoped that quantifying the direct use values provided by Condor seamount will contribute to the decision making process towards its long-term conservation and sustainable use.

  2. Morphology of an uncharted seamount from Central Indian Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Kodagali, V.N.

    The morphology of a seamount at 12 degrees 35'S and 76 degrees 16'E is studied. This conical seamount has a maximum height of 1275 m (water depth 4135 m) and covers an area of about 189 sq km. The maximum basal extension is about 24 km. The mount...

  3. Swath bathymetric investigation of the seamounts located in the Laxmi Basin, eastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Bhattacharya, G.C.; Murty, G.P.S.; Srinivas, K.; Chaubey, A.K.; Sudhakar, T.; Nair, R.R.

    Multibeam (hydrosweep) swath bathymetric investigations revealed the presence of a NNW trending linear seamount chain along the axial part of the Laxmi Basin in the eastern Arabian Sea, between 15~'N, 70~'15'E and 17~'20'N, 69~'E. This chain...

  4. Petrology and Geochemistry of Serpentinized Peridotites from a Bonin Fore-arc Seamount

    Science.gov (United States)

    Tian, L.; Tuoyu, W.; Dong, Y. H.; Gao, J.; Wu, S.

    2016-12-01

    Serpentinites, which contain up to 13 wt.% of water, are an important reservoir for chemical recycling in subduction zones. During the last two decades, many observations documented the occurrence of fore-arc mantle serpentinites in different locations. Here, we present petrology and whole rock chemistry for serpentinized peridotites dredged from the Hahajima Seamount, which is located 20-60 km west of the junction of the Bonin Trench and the Mariana Trench. Combined with published geochemical data of serpentinites from the Torishima Seamount, Conical Seamount and South Chamorro Seamount in the Izu-Bonin-Mariana fore-arc region, it will allow us to better understand the average composition of serpentinized fore-arc mantle overlying the subducting slab and the role of serpentinized mantle playing in the subduction zone geochemical cycle. The studied ultramafic rocks from the Hahajima Seamount are extensively serpentinized and hydrated (73 to 83%), with loss of ignition values ranging between 13 and 15 wt.%. Our results show that the serpentinized peridotites have Mg number from 88 to 90, and the average MgO/SiO2 is 0.93. The average Al2O3 (0.48 wt.%) and CaO (0.23 wt.%) contents are very low, consistent with low clinopyroxene abundances, and the overall depleted character of the mantle harzburgite protoliths. The serpentinized peridotites from the Hahajima Seamount exhibit similar "U" shape rare earth element (REE) patterns ([La/Sm]N = 3.1-3.6), at higher overall abundances, to the Conical and South Chamorro Seamount suites. One exceptional sample shows the similar REE pattern as serpentinized peridotites from the Torishima Seamount, with depleted light REE concentration ([La/Sm]N =0.7). All the serpentinized peridotites from these four fore-arc seamounts show strong enrichment in fluid-mobile and lithophile elements (U, Pb, Sr and Li). The geochemical signature of the serpentinized peridotites from the seamounts in the Izu-Bonin-Mariana fore-arc region could be

  5. Organic matter composition and macrofaunal diversity in sediments of the Condor Seamount (Azores, NE Atlantic)

    Science.gov (United States)

    Bongiorni, Lucia; Ravara, Ascensão; Parretti, Paola; Santos, Ricardo S.; Rodrigues, Clara F.; Amaro, Teresa; Cunha, Marina R.

    2013-12-01

    In recent years increasing knowledge has been accumulated on seamounts ecology; however their sedimentary environments and associated biological communities remain largely understudied. In this study we investigated quantity and biochemical composition of organic matter and macrofaunal diversity in sediments of the Condor Seamount (NE Atlantic, Azores). In order to test the effect of the seamount on organic matter distribution, sediment samples were collected in 6 areas: the summit, the northern and southern flanks and bases, and in an external far field site. Macrofauna abundance and diversity were investigated on the summit, the southern flank and in the far field site. The organic matter distribution reflected the complex hydrodynamic conditions occurring on the Condor. Concentrations of organic matter compounds were generally lower on the whole seamount than in the far field site and on the seamount summit compared to flanks and bases. A clear difference was also evident between the northern and southern slopes of the Condor, suggesting a role of the seamount in conditioning sedimentation processes and distribution of food resources for benthic consumers. Macrofauna assemblages changed significantly among the three sampling sites. High abundance and dominance, accompanied by low biodiversity, characterized the macrofauna community on the Condor summit, while low dominance and high biodiversity were observed at the flank. Our results, although limited to five samples on the seamount and two off the seamount, do not necessarily support the paradigm that seamounts are more biodiverse than the surrounding seafloor. However, the abundance (and biomass), functional diversity and taxonomical distinctiveness of the macrofaunal assemblages from the Condor Seamount suggest that seamounts habitats may play a relevant role in adding to the regional biodiversity.

  6. Constraints from Seamounts on Pacific Plate or Plume Motion Prior to 80 Ma.

    Science.gov (United States)

    Konter, J. G.; Koppers, A. A. P.; Jackson, M. G.; Finlayson, V.; Konrad, K.

    2015-12-01

    The Hawaii-Emperor and Louisville hotspot tracks have long dominated the data set constraining absolute plate motion models. However, prior to ~80 Ma, multiple shorter, discontinuous hotspot trails and oceanic plateaus have been used to constrain absolute plate motion. Based on this earlier work, a clear Hawaii-Emperor style bend seems apparent around 100 Ma in the West Pacific Seamount Province (WPSP). More importantly, the ongoing debate on a plate versus plume motion origin for the Hawaii-Emperor Bend is applicable here, as the ~100 Ma bend may correspond to a global plate reorganization (Matthews et al., EPSL, 2012). Data for a comparison of bends comes from three groups with similar geographic patterns: 1) Mid-Pacific Mountains, Line Islands; 2) Shatsky Rise, Hess Rise, Musician and Wentworth Seamounts; and 3) Wake Seamounts, Marshall Islands, Magellan Seamounts. Both groups 1 and 2 feature a large igneous province (LIP) at their oldest end: Shatsky Rise and the Mid-Pacific Mountains. According to plate reconstructions these LIPs were constructed near all-ridge triple junctions, thus potential plume-ridge interactions need to be clarified before these LIPs can be used to define an absolute mantle reference frame. In contrast, the volcanoes of the third group (Wake, Marshall, Magellan) did erupt truly intra-plate and we therefore argue that this group provides a constraint on plate motion beyond 80 Ma that is independent of plume-ridge interactions. Since the volcanoes in this group are part of the WPSP, which is densely populated with seamounts, a combination of 40Ar/39Ar ages and Sr-Nd-Pb-Hf isotopes is needed to distinguish different hotspot tracks in this region. Backtracking each volcano through its age to its original eruptive location and using compositional color-coding, reveals groupings and patterns that vary by plate motion model, while the temporal patterns of backtracked locations inform us about potential plume motions.

  7. Aet Piel : oluline sisekujunduselement on viltune sein / Gitte Hint

    Index Scriptorium Estoniae

    Hint, Gitte

    2003-01-01

    Poolkaares ehitatud korterelamus on Aet Pieli kujundatud korteris üks sein viltu. Esmapilgul häirivana mõjunud sein sai oluliseks sisekujunduselemendiks. Eritellimusel valmistatud mööbel on tammepuidust. A. Pieli kommentaarid. Ill.: plaan enne ja nüüd, 9 värv. vaadet

  8. A perspective on the importance of oceanic fronts in promoting aggregation of visitors to seamounts

    OpenAIRE

    Morato, T; Miller, PI; Dunn, DC; Nicol, SJ; Bowcott, J; Halpin, PN

    2016-01-01

    Recent evidence has demonstrated that not all seamounts are areas where productivity, biomass and biodiversity of marine life thrive. Therefore, understanding the drivers and mechanisms underlying seamount productivity is a major challenge in today's seamount research. Incorporating oceanographic data in future analyses has been suggested to be of paramount importance to unveil many of the seamount ecology paradigms. Persistent hydrographic features, such as oceanic fronts, have been recogniz...

  9. Seamount Hydrothermal Systems as Analogies for Ocean Worlds: Reaction Paths Throughout the Lo'ihi Seamount (Hawaii Archipelago)

    Science.gov (United States)

    Milesi, V.; Shock, E.

    2018-05-01

    Thermodynamic modeling is performed to investigate the possible reaction paths of sea water throughout the Lo'ihi seamount and the associated geochemical supplies of energy that can support autotrophic microbial communities.

  10. Structural evolution of preexisting oceanic crust through intraplate igneous activities in the Marcus-Wake seamount chain

    Science.gov (United States)

    Kaneda, Kentaro; Kodaira, Shuichi; Nishizawa, Azusa; Morishita, Taisei; Takahashi, Narumi

    2010-10-01

    Multichannel seismic reflection studies and seismic refraction surveys with ocean bottom seismographs in the Marcus-Wake seamount chain in the northwestern Pacific Ocean reveal P wave velocity structures of hot spot-origin seamounts and adjacent oceanic crust. Inside the seamounts are central high-velocity (>6.5 km/s) structures extending nearly to the top that may indicate intrusive cores. Thick sediment layers (up to 4 km) with P wave velocities of 4-5 km/s have accumulated on seafloor that predates seamount formation. Downward crustal thickening of up to 2 km was documented beneath a large seamount cluster, but thickening was not confirmed below a small seamount cluster. Volume ratios of an intrusive core to a seamount body are 15-20%, indicating that most of the supplied magma was consumed in forming the thick sedimentary and volcaniclastic layer constituting the seamount flanks. Underplating and downward crustal thickening may tend to occur when second or later intrusive cores are formed in a seamount. P wave velocities in the lowest crust and in the uppermost mantle below the seamount chain are 0.1-0.2 km/s higher and 0.3-0.5 km/s lower, respectively, than velocities below oceanic crust. We explain this difference as a result of sill-like intrusion of magma into the lower crust and uppermost mantle. Reflected waves observed at offsets >200 km are from mantle reflectors at depths of 30-45 km and 55-70 km. The shallower reflectors may indicate structures formed by intraplate igneous activities, and the deeper reflectors may correspond to the lithosphere-asthenosphere boundary.

  11. Numerical simulation of faulting in the Sunda Trench shows that seamounts may generate megathrust earthquakes

    Science.gov (United States)

    Jiao, L.; Chan, C. H.; Tapponnier, P.

    2017-12-01

    The role of seamounts in generating earthquakes has been debated, with some studies suggesting that seamounts could be truncated to generate megathrust events, while other studies indicate that the maximum size of megathrust earthquakes could be reduced as subducting seamounts could lead to segmentation. The debate is highly relevant for the seamounts discovered along the Mentawai patch of the Sunda Trench, where previous studies have suggested that a megathrust earthquake will likely occur within decades. In order to model the dynamic behavior of the Mentawai patch, we simulated forearc faulting caused by seamount subducting using the Discrete Element Method. Our models show that rupture behavior in the subduction system is dominated by stiffness of the overriding plate. When stiffness is low, a seamount can be a barrier to rupture propagation, resulting in several smaller (M≤8.0) events. If, however, stiffness is high, a seamount can cause a megathrust earthquake (M8 class). In addition, we show that a splay fault in the subduction environment could only develop when a seamount is present, and a larger offset along a splay fault is expected when stiffness of the overriding plate is higher. Our dynamic models are not only consistent with previous findings from seismic profiles and earthquake activities, but the models also better constrain the rupture behavior of the Mentawai patch, thus contributing to subsequent seismic hazard assessment.

  12. Fish biodiversity of the Vitória-Trindade Seamount Chain, southwestern Atlantic: an updated database.

    Directory of Open Access Journals (Sweden)

    Hudson T Pinheiro

    Full Text Available Despite a strong increase in research on seamounts and oceanic islands ecology and biogeography, many basic aspects of their biodiversity are still unknown. In the southwestern Atlantic, the Vitória-Trindade Seamount Chain (VTC extends ca. 1,200 km offshore the Brazilian continental shelf, from the Vitória seamount to the oceanic islands of Trindade and Martin Vaz. For a long time, most of the biological information available regarded its islands. Our study presents and analyzes an extensive database on the VTC fish biodiversity, built on data compiled from literature and recent scientific expeditions that assessed both shallow to mesophotic environments. A total of 273 species were recorded, 211 of which occur on seamounts and 173 at the islands. New records for seamounts or islands include 191 reef fish species and 64 depth range extensions. The structure of fish assemblages was similar between islands and seamounts, not differing in species geographic distribution, trophic composition, or spawning strategies. Main differences were related to endemism, higher at the islands, and to the number of endangered species, higher at the seamounts. Since unregulated fishing activities are common in the region, and mining activities are expected to drastically increase in the near future (carbonates on seamount summits and metals on slopes, this unique biodiversity needs urgent attention and management.

  13. Seamounts along the Iberian continental margins; Los montes submarinos en los margenes continentales de Iberia

    Energy Technology Data Exchange (ETDEWEB)

    Vazquez, J. T.; Alonso, B.; Fernandez-Puga, M. C.; Gomez-Ballesteros, M.; Iglesias, J.; Palomino, D.; Roque, C.; Ercilla, G.; Diaz-del-Rio, V.

    2015-07-01

    Seamounts are first-order morphological elements on continental margins and in oceanic domains, which have been extensively researched over recent decades in all branches of oceanography. These features favour the development of several geological processes, and their study gives us a better understanding of their geological and morphological domains. The seamounts around Iberia are numerous and provide excellent examples of the geo diversity of these morphological elements. Here we present a compilation of 15 seamounts around the Iberian Peninsula. These seamounts have different origins related to the geodynamic evolution (volcanism, extensional or compressive tectonics, and diapirism) of the domains where they are located. The current configuration of their relief has been influenced by Neogene-Quaternary tectonics. Their positioning controls the current morpho-sedimentary processes in the basins and on the margins, and high- lights the fact that downslope processes on seamount flanks (mass flows, turbidite flows, and landslides) and processes parallel to seamounts (contouritic currents) correspond to the major geological features they are associated with them. Biogenic structures commonly develop on the tops of seamounts where occasionally isolated shelves form that have carbonate-dominated sedimentation. (Author)

  14. From the epipelagic zone to the abyss: Trophic structure at two seamounts in the subtropical and tropical Eastern Atlantic - Part II Benthopelagic fishes

    Science.gov (United States)

    Denda, Anneke; Stefanowitsch, Benjamin; Christiansen, Bernd

    2017-12-01

    Specific mechanisms, driving trophic interactions between seamount associated fishes and the pelagic community may be highly variable in different seamount systems. This study investigated the trophic structure and the main prey of benthopelagic fishes from the summit and slope regions of Ampère and Senghor, two shallow seamounts in the subtropical and tropical NE Atlantic, and the adjacent deep-sea plains. For the identification of food sources and nutritional links to the pelagic realm a combination of stomach content and stable isotope ratio (δ13C and δ15N) analyses was used. δ13C ranged from -22.2‰ to -15.4‰ and δ15N covered a total range of 8.0-15.9‰. Feeding types of fish species comprised mainly zooplanktivores and mixed feeders, but also benthivores, piscivores, and predator-scavengers. Based on epipelagic particulate organic matter, they occupied trophic positions between the 2nd and 4th trophic level. Differences in stomach contents and stable isotope signatures indicate a resource partitioning among the benthopelagic fish fauna through distinct habitat choice, vertical feeding positions and prey selection. Topographic trapping of vertically migrating zooplankton on the summit seemed to be of minor importance for food supply of the resident near-bottom fishes, rather horizontal current-driven advection of the planktonic prey was assumed as major factor. Vertically migrating micronekton and mesopelagic fishes show up as key players within the food webs at Ampère and Senghor Seamounts and the adjacent deep-sea plains.

  15. Paleocommunity turnover in an Early Pliocene seamount from southeastern Spain

    Science.gov (United States)

    García-Ramos, Diego Antonio; Zuschin, Martin

    2017-04-01

    Seamounts are topographic elevations under the sea, regardless of their size and relief. They support rich living communities and are important biodiversity hotspots, but many of the fundamental ecological processes that maintain seamount communities remain poorly understood. In contrast to snapshot observations conducted on extant seamounts, fossil examples may provide the opportunity to assess how temporal changes in physico-chemical parameters relate to paleocommunity turnovers in these particular biotopes. Here we deal with an Early Pliocene (Zanclean) small seamount in southeastern Spain. This classic locality is extremely rich in fossil macroinvertebrates and was subject to studies of some taxonomic groups in the late seventies. However, the detailed stratigraphy is herein outlined for the first time. The overall feature is a shallowing upward succession about 35 m thick which onlaps a Miocene volcanic ridge. The occurrence of the planktonic foraminifera Globorotalia margaritae and G. puncticulata allow attribution to the MPl3 biozone of the Mediterranean Pliocene. We measured two sections that can be divided in a lower interval of fine-grained bryozoan-rich deposits and a upper interval of biocalcarenite increasingly rich in rhodoliths upsection. The whole series is bioturbated, with Thalassinoides traces being more common upsection. Biofabrics comprise mostly densely-packed suites of disarticulated and fragmented shells of calcitic fauna (large oysters are often bioeroded by clionid sponges), suggesting relatively low sedimentation rates and reworking by storms (e.g., channelized shell-beds, tubular tempestites). The prevailing taxonomic groups are cheilostome bryozoans, oysters, brachiopods, pectinids, echinoderms, cirripedes and corals. The lower interval contains octocoral internodes (Isididae) (only recorded at the base of the section). Scleratinians like Balanophyllia? decrease in abundance upsection. Bryozoans are extremely abundant and diverse, with

  16. Geophysical study of a seamount located on the continental margin of India

    Digital Repository Service at National Institute of Oceanography (India)

    Bhattacharya, G.C.; Subrahmanyam, V.

    Bathymetric, magnetic, and gravity data obtained over a 2,464 m high seamount located in the Arabian Sea indicate that the seamount (inferred mean density = 2.65 gm/cc) extends for 1 km beneath the seafloor and is locally isostatically compensated...

  17. Benthic Macrofaunal Communities at Newly Explored Caribbean Seamounts in the Greater/Lesser Antilles Transition Zone and a Comparison to Nearby Habitats

    Science.gov (United States)

    Demopoulos, A. W.; Bourque, J. R.; Cordes, E. E.; Chaytor, J. D.; Quattrini, A.

    2016-02-01

    Seamounts are topographically and oceanographically complex features with environmental characteristics, including substrate types, carbon flux, and current patterns, that vary greatly within and among seamounts. While seamounts are reputed to be oases and biodiversity hotspots, comparisons across multiple spatial scales of a seamount chain have yet to be explored. Along the margins of the Caribbean Sea basin, numerous seamounts punctuate the seafloor. In 2013 and 2014, we investigated the deep-sea benthic community ecology at Noroît, Dog, and Conrad Seamounts and nearby ridge, bank, and rift environments at depths ranging from 630 to 2930 m. Sediment push cores were collected to quantify macrofaunal (> 300 μm) density, diversity, community composition, grain size, and organic content. In addition, environmental data collected from CTDs and extracted from high resolution multibeam mapping efforts (e.g. slope, rugosity, roughness, slope orientation), allowed us to evaluate the role of microhabitats in structuring these communities. Preliminary results indicate that macrofaunal density across all sites decreased with depth in both seamount and non-seamount sediments, with the highest densities occurring in non-seamount environments. However, macrofaunal density patterns varied on individual seamounts. Macrofaunal densities on shallow seamounts (Conrad and Dog) increased with depth, whereas densities decreased with depth on the deeper Noroît seamount. The relationship between environmental parameters and macrofaunal community structure and biodiversity varied among seamounts and non-seamount environments. This study represents the first investigation of seamount infauna in the region and places this baseline information on seamount faunal biodiversity, spatial distribution of taxa, and overall ecology into a broader biogeographic context.

  18. Ferromanganese oxides from Mid-Indian ridge, seamounts and abyssal plains from the Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, P.S.; Pattan, J.N.

    .47%) in the seamount crusts. The ferromanganese oxides from the Mid-Indian Ridge, seamount crusts and abyssal nodules appear to be of hydrothermal, hydrogenous and early-diagenetic in origin respectively...

  19. A note on the morphology and tectonics of Kainan Maru Seamount, East Antarctica

    Digital Repository Service at National Institute of Oceanography (India)

    Kodagali, V.N.; Hagen, R.; Schenke, H.W.

    channels cut the northern and eastern flanks of the seamount, whereas the western side shows evidence of large sediment slides and is more gently sloping. The morphology of the seamount, as observed in the bathymetry and satellite gravity data, suggests...

  20. Tectonic and volcanic implications of a cratered seamount off Nicobar Island, Andaman Sea

    Digital Repository Service at National Institute of Oceanography (India)

    KameshRaju, K.A.; Ray, D.; Mudholkar, A.V.; Murty, G.P.S.; Gahalaut, V.K.; Samudrala, K.; Paropkari, A.L.; Ramachandran, R.; SuryaPrakash, L.

    seamount with well-developed crater at the summit was discovered near to the center of the Nicobar swarm. Rock samples collected by TV-guided grab from the seamount crater are dacite, rhyolite and andesite type with a veneer of ferromanganese oxide coating...

  1. Mesozooplankton respiration and community structure in a seamount region of the eastern South Pacific

    Science.gov (United States)

    Frederick, Leissing; Escribano, Ruben; Morales, Carmen E.; Hormazabal, Samuel; Medellín-Mora, Johanna

    2018-05-01

    Seamounts in the Juan Fernandez Ridge, as well as in other seamount regions in the eastern South Pacific and in the world oceans, remain poorly studied ecosystems in terms of structure and functioning. Here, community respiration by epipelagic mesozooplankton in three seamounts of the Juan Fernandez Ridge, including the O`Higgins Seamount close to the coastal upwelling zone and two oceanic seamounts near the Juan Fernandez Archipelago ( 33°S-78°W), was assessed. Oxygen consumption by mixed assemblages was estimated using continuous measurements of dissolved oxygen concentration under controlled temperature during onboard, short-term incubations (2-4 h). Mesozooplankton composition was analyzed with a ZooScan device and expressed in terms of community normalized size spectra, and taxa and size diversity (Shannon-Wiener index). Carbon-specific community respiration rates in the upper 100 m layer were in the range of 0.3-1.9 mg O2 m-2 d-1, indicating that up to 3.1% of the mesozooplankton biomass can be respired on a daily basis. The mesozooplankton community was dominated by small-size copepods but the proportions of small copepods, large copepods, and gelatinous zooplankton (mostly salps) changed between the seamounts, in association with modifications in taxa composition, size diversity, and the slope of the size spectrum. Community respiration was significantly correlated to these community descriptors, suggesting the composition of the pelagic community has a direct impact on the total amount of respired-C. Connectivity between the coastal upwelling zone and the Juan Fernandez Ridge region mediated by mesoscale activity, interacting with the seamounts, is suggested as a most important process in controlling zooplankton community structure and in turn community metabolism.

  2. Caldera formation and varied eruption styles on North Pacific seamounts: the clastic lithofacies record

    Science.gov (United States)

    Portner, Ryan A.; Clague, Dave A.; Paduan, Jennifer B.

    2014-08-01

    Detailed examination of volcaniclastic and sedimentary rocks collected from the Taney (30 Ma), President Jackson (4 Ma), Vance (3 Ma) and Alarcon (2 Ma) near-ridge seamount chains of the North Pacific reveals seven clastic lithofacies that record various modes of eruption, magma fragmentation, and particle dispersal. Lithofacies are distinguished by differences in lithology, bedding habit, compositional heterogeneity, and relationship to volcanic landforms. Breccia lithofacies were produced through mechanical fragmentation during caldera collapse (polymict) or effusive eruptions onto steep slopes (monomict). Rare globular lapilli mudstone lithofacies contain clasts with morphologies formed by magma-sediment mingling processes (peperite). Seamount summit pyroclastic deposits include proximal lapilli tuff with vesicular pyroclasts, and more distal limu o Pele tuff lithofacies. Much finer-grained hydrothermal mudstone/tuff lithofacies occurs around caldera rims and contains greenschist minerals, hydrothermal clays and basaltic ash that record subsurface phreatomagmatic fragmentation processes. Very fine-grained ash is transported to distal regions by oceanic currents and hydrothermal plumes, and is a component of the regional pelagic sediment budget. Pyroclastic lithofacies only occur on seamount summits suggesting formation during the latter stages of seamount evolution. As a seamount drifts away from an adjacent ridge axis and associated heat source, its magma supply is reduced allowing for magmatic gas buildup and mild explosive eruptions. During this stage, the diminished melt supply under the seamount is unable to fully compensate for extension along the ridge axis and vertical seamount growth. Lateral intrusion into spreading-related structures in this stage causes magma withdrawal and caldera formation. Formation of caldera ring faults also promotes seawater ingress into subseafloor hydrothermal cells, which interact with magma conduits causing phreatomagmatic

  3. Seamounts - characteristics, formation, mineral deposits and biodiversity

    Digital Repository Service at National Institute of Oceanography (India)

    Iyer, S.D.; Mehta, C.M.; Das, P.; Kalangutkar, N.G.

    t a , V o l . 1 0 , N º 3 , S e p t e m b e r 2 0 1 2 , 2 9 5 - 3 0 8 D O I : 1 0 . 1 3 4 4 / 1 0 5 . 0 0 0 0 0 1 7 5 8 A v a i l a b l e o n l i n e a t w w w. g e o l o g i c a - a c t a . c o m Seamounts – characteristics, formation... and phenomena such as seismicity, hydrothermal deposits, biodiversity and possibly atmospheric oxygen (Iyer, 2009). Review works pertaining to seamounts independently concern the geological, biological or physical 1 2 1 1 S . D . I Y E R e t a l . G e o...

  4. Structure and evolution of the Afanasy Nikitin seamount, buried hills and 85 degrees E Ridge in the northeastern Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Krishna, K.S.

    Geophysical data of the Afanasy Nikitin seamount (ANS), partly buried hills and 85 degrees E Ridge in the northeastern Indian Ocean were studied together with published seismic refraction results to understand genesis and evolution of the structures...

  5. Aeromagnetic Detection and Definition of Seamounts.

    Science.gov (United States)

    1982-06-01

    airborne gravimetry may be feasible, al- though further testing is necessary. A possible difficulty may result from the problem of obtaining useful data on...high calcium precipitation . Hopefully, the curves will increase the "safety factor" by an under-estimation of seamount peak depths. Another problem

  6. 77 FR 41754 - Fishing Capacity Reduction Program for the Southeast Alaska Purse Seine Salmon Fishery

    Science.gov (United States)

    2012-07-16

    ... Capacity Reduction Program for the Southeast Alaska Purse Seine Salmon Fishery AGENCY: National Marine... program in the Southeast Alaska purse seine salmon fishery. NMFS conducted a referendum to approve the..., Chief, Financial Services Division, NMFS, Attn: SE Alaska Purse Seine Salmon Buyback, 1315 East-West...

  7. 77 FR 26744 - Fishing Capacity Reduction Program for the Southeast Alaska Purse Seine Salmon Fishery

    Science.gov (United States)

    2012-05-07

    ... Capacity Reduction Program for the Southeast Alaska Purse Seine Salmon Fishery AGENCY: National Marine... of reduction payment tender of Southeast Alaska purse seine salmon permits. SUMMARY: The National... Southeast Alaska purse seine salmon fishery. The program authorizes NMFS to make payments to permit holders...

  8. 77 FR 12568 - Fishing Capacity Reduction Program for the Southeast Alaska Purse Seine Salmon Fishery

    Science.gov (United States)

    2012-03-01

    ... Capacity Reduction Program for the Southeast Alaska Purse Seine Salmon Fishery AGENCY: National Marine... Salmon Fishery. NMFS will hold a series of public meetings with Southeast Alaska purse seine salmon... to Paul Marx, Chief, Financial Services Division, NMFS, Attn: SE Alaska Purse Seine Salmon Buyback...

  9. Pelagic communities of the South West Indian Ocean seamounts: R/V Dr Fridtjof Nansen Cruise 2009-410

    Science.gov (United States)

    Rogers, A. D.; Alvheim, O.; Bemanaja, E.; Benivary, D.; Boersch-Supan, P.; Bornman, T. G.; Cedras, R.; Du Plessis, N.; Gotheil, S.; Høines, A.; Kemp, K.; Kristiansen, J.; Letessier, T.; Mangar, V.; Mazungula, N.; Mørk, T.; Pinet, P.; Pollard, R.; Read, J.; Sonnekus, T.

    2017-02-01

    The seamounts of the southern Indian Ocean remain some of the most poorly studied globally and yet have been subject to deep-sea fishing for decades and may face new exploitation through mining of seabed massive sulphides in the future. As an attempt to redress the knowledge deficit on deep-sea benthic and pelagic communities associated mainly with the seamounts of the South West Indian Ridge two cruises were undertaken to explore the pelagic and benthic ecology in 2009 and 2011 respectively. In this volume are presented studies on pelagic ecosystems around six seamounts, five on the South West Indian Ridge, including Atlantis Bank, Sapmer Seamount, Middle of What Seamount, Melville Bank and Coral Seamount and one un-named seamount on the Madagascar Ridge. In this paper, existing knowledge on the seamounts of the southwestern Indian Ocean is presented to provide context for the studies presented in this volume. An account of the overall aims, approaches and methods used primarily on the 2009 cruise are presented including metadata associated with sampling and some of the limitations of the study. Sampling during this cruise included physical oceanographic measurements, multibeam bathymetry, biological acoustics, and net sampling of phytoplankton, macrozooplankton and micronekton/nekton. The studies that follow reveal new data on the physical oceanography of this dynamic region of the oceans, and the important influence of water masses on the pelagic ecology associated with the seamounts of the South West Indian Ridge. New information on the pelagic fauna of the region fills an important biogeographic gap for the mid- to high-latitudes of the oceans of the southern hemisphere.

  10. Heck and Heckle Seamounts, northeast Pacific Ocean: High extrusion rates of primitive and highly depleted mid-ocean ridge basalt on off-ridge seamounts

    Science.gov (United States)

    Leybourne, M. I.; van Wagoner, N. A.

    1991-09-01

    We analyzed, petrographically and chemically, basalt from eight dredge hauls from the Heck and Heckle seamounts, northeast Pacific Ocean. Major elements were determined for mineral, glass, and whole rock samples, and trace and rare earth elements were determined for glass and whole rock samples. The dredge hauls included hyaloclastites and fragments from sheet flows and pillows. The clinkery fragments are interpreted to be deformed sheet flow tops, characteristic of high effusion rates. The hyaloclastites recovered are reworked deposits, as indicated by the wide compositional range of the glass shards, abundance of clay and calcite matrix, and bedding. Most rocks are aphyric, but the analyzed plagioclase and olivine phenocrysts and microcrysts are equilibrium compositions and show minor compositional zonation (up to 7.5% An, chains have a limited range of incompatible element ratios, whereas the adjacent West Valley Segment of the Juan de Fuca Ridge is highly heterogeneous. In contrast, lavas from the East Pacific near-ridge seamounts exhibit a wider range of incompatible element ratios than do the adjacent East Pacific Rise basalts. On the West Valley Segment, magma supply is less robust associated with lower spreading rates compared to the East Pacific Rise at 10°N. In contrast, at fast spreading centers robust melting produces a mixed mantle signature in axial lavas, while suppressed melting at the seamounts reveals the heterogeneities. We suggest that at some spreading ridges, more fertile portions of the mantle are preferentially melted such that the outwelled portions of the mantle tapped by the seamounts are more depleted.

  11. A pair of seamount chains in the Central Indian Basin, identified from multibeam mapping

    Digital Repository Service at National Institute of Oceanography (India)

    Kodagali, V.N.

    Seamounts are major physiographic features on the ocean floor. Their study is important to the understanding of the tectonic history of the seafloor. Over 150 seamounts were identified during the multibeam (Hydrosweep system) mapping of the Central...

  12. Petrology of seamounts in the Central Indian Ocean Basin: Evidence for near-axis origin

    Digital Repository Service at National Institute of Oceanography (India)

    Mukhopadhyay, R.; Batiza, R.; Iyer, S.D.

    Previous studies on the distribution and morphology of ancient seamount chains (>50 Ma) in the Central Indian Ocean basin (CIOB) indicated their generation from the fast spreading Southeast Indian Ridge. The petrology of some of these seamounts...

  13. Seasonal changes in fish assemblage structure at a shallow seamount in the Gulf of California

    Directory of Open Access Journals (Sweden)

    Salvador J. Jorgensen

    2016-09-01

    Full Text Available Seamounts have generally been identified as locations that can promote elevated productivity, biomass and predator biodiversity. These properties attract seamount-associated fisheries where elevated harvests can be obtained relative to surrounding areas. There exists large variation in the geological and oceanographic environment among the thousands of locations that fall within the broad definition of seamount. Global seamount surveys have revealed that not all seamounts are hotspots of biodiversity, and there remains a strong need to understand the mechanisms that underlie variation in species richness observed. We examined the process of fish species assembly at El Bajo Espiritu Santo (EBES seamount in the Gulf of California over a five-year study period. To effectively quantify the relative abundance of fast-moving and schooling fishes in a ‘blue water’ habitat, we developed a simplified underwater visual census (UVC methodology and analysis framework suitable for this setting and applicable to future studies in similar environments. We found correlations between seasonally changing community structure and variability in oceanographic conditions. Individual species responses to thermal habitat at EBES revealed three distinct assemblages, a ‘fall assemblage’ tracking warmer overall temperature, a ‘spring assemblage’ correlated with cooler temperature, and a ‘year-round assemblage’ with no significant response to temperature. Species richness was greatest in spring, when cool and warm water masses stratified the water column and a greater number of species from all three assemblages co-occurred. We discuss our findings in the context of potential mechanisms that could account for predator biodiversity at shallow seamounts.

  14. Seasonal changes in fish assemblage structure at a shallow seamount in the Gulf of California.

    Science.gov (United States)

    Jorgensen, Salvador J; Klimley, A Peter; Muhlia-Melo, Arturo; Morgan, Steven G

    2016-01-01

    Seamounts have generally been identified as locations that can promote elevated productivity, biomass and predator biodiversity. These properties attract seamount-associated fisheries where elevated harvests can be obtained relative to surrounding areas. There exists large variation in the geological and oceanographic environment among the thousands of locations that fall within the broad definition of seamount. Global seamount surveys have revealed that not all seamounts are hotspots of biodiversity, and there remains a strong need to understand the mechanisms that underlie variation in species richness observed. We examined the process of fish species assembly at El Bajo Espiritu Santo (EBES) seamount in the Gulf of California over a five-year study period. To effectively quantify the relative abundance of fast-moving and schooling fishes in a 'blue water' habitat, we developed a simplified underwater visual census (UVC) methodology and analysis framework suitable for this setting and applicable to future studies in similar environments. We found correlations between seasonally changing community structure and variability in oceanographic conditions. Individual species responses to thermal habitat at EBES revealed three distinct assemblages, a 'fall assemblage' tracking warmer overall temperature, a 'spring assemblage' correlated with cooler temperature, and a 'year-round assemblage' with no significant response to temperature. Species richness was greatest in spring, when cool and warm water masses stratified the water column and a greater number of species from all three assemblages co-occurred. We discuss our findings in the context of potential mechanisms that could account for predator biodiversity at shallow seamounts.

  15. Cascadia Seismicity Related to Seamount Subduction as detected by the Cascadia Initiative Amphibious Data

    Science.gov (United States)

    Morton, E.; Bilek, S. L.; Rowe, C. A.

    2016-12-01

    Unlike other subduction zones, the Cascadia subduction zone (CSZ) is notable for the absence of detected and located small and moderate magnitude interplate earthquakes, despite the presence of recurring episodic tremor and slip (ETS) downdip and evidence of pre-historic great earthquakes. Thermal and geodetic models indicate that the seismogenic zone exists primarily, if not entirely, offshore; therefore the perceived unusual seismic quiescence may be a consequence of seismic source location in relation to land based seismometers. The Cascadia Initiative (CI) amphibious community seismic experiment includes ocean bottom seismometers (OBS) deployed directly above the presumed locked seismogenic zone. We use the CI dataset to search for small magnitude interplate earthquakes previously undetected using the on-land sensors alone. We implement subspace detection to search for small earthquakes. We build our subspace with template events from existing earthquake catalogs that appear to have occurred on the plate interface, windowing waveforms on CI OBS and land seismometers. Although our efforts will target the entire CSZ margin and full 4-year CI deployment, here we focus on a previously identified cluster off the coast of Oregon, related to a subducting seamount. During the first year of CI deployment, this target area yields 293 unique detections with 86 well-located events. Thirty-two of these events occurred within the seamount cluster, and 13 events were located in another cluster to the northwest of the seamount. Events within the seamount cluster are separated into those whose depths place them on the plate interface, and a shallower set ( 5 km depth). These separate event groups track together temporally, and seem to agree with a model of seamount subduction that creates extensive fracturing around the seamount, rather than stress concentrated at the seamount-plate boundary. During CI year 2, this target area yields >1000 additional event detections.

  16. Past plate and mantle motion from new ages for the Hawaiian-Emperor Seamount Chain

    Science.gov (United States)

    O'Connor, John; Steinberger, Bernhard; Regelous, Marcel; Koppers, Anthony; Wijbrans, Jan; Haase, Karsten; Stoffers, Peter; Jokat, Wilfried; Garbe-Schoenberg, C.-Dieter

    2014-05-01

    Estimates of the relative motion between the Hawaiian and Louisville hotspots have consequences for understanding the role and character of deep Pacific-mantle return flow. The relative motion between these primary hotspots can be inferred by comparing the age records for their seamount trails. Our new 40Ar/39Ar ages for 18 lavas from 10 seamounts along the Hawaiian-Emperor Seamount Chain (HESC) show that volcanism started in the sharp portion of the Hawaiian-Emperor Bend (HEB) at ≥47.5 Ma and continued for ≥5 Myr (O'Connor et al., 2013). The slope of the along-track distance from the currently active Hawaiian hotspot plotted versus age is remarkably linear between ~57 and 25 Ma in the central ˜1900 km of the seamount chain, including the HEB. This model predicts an age for the oldest Emperor Seamounts that matches published ages, implying that a linear age-distance relationship might extend back to at least 82 Ma. In contrast, Hawaiian age progression was much faster since at least ~15 Ma and possibly as early as ~27 Ma. Linear age-distance relations for the Hawaii-Emperor and Louisville seamount chains predict ~300 km overall hotspot relative motion between 80 and 47.5 Ma, in broad agreement with numerical models of plumes in a convecting mantle, and paleomagnetic data. We show that a change in hotspot relative motion may also have occurred between ~55 Ma and ~50 Ma. We interpret this change in hotspot motion as evidence that the HEB reflects a combination of hotspot and plate motion changes driven by the same plate/mantle reorganization. O'Connor et al. (2013), Constraints on past plate and mantle motion from new ages for the Hawaiian-Emperor Seamount Chain, Geochem. Geophys. Geosyst., 14, 4564-4584, doi:10.1002/ggge.20267.

  17. 78 FR 33810 - Fishing Capacity Reduction Program for the Southeast Alaska Purse Seine Salmon Fishery

    Science.gov (United States)

    2013-06-05

    ... Capacity Reduction Program for the Southeast Alaska Purse Seine Salmon Fishery AGENCY: National Marine... reduction loan for the fishing capacity reduction program in the Southeast Alaska purse seine salmon fishery... July 22, 2012. Since then, all harvesters of Southeast Alaska purse seine salmon must pay the fee and...

  18. Le début du ive s. av. J.-C. dans l’espace culturel sénonais : les habitats de Bois d’Echalas à Ville-Saint-Jacques et de Beauchamp à Varennes-sur-Seine (Seine-et-Marne dans le contexte de l’interfluve Seine-Yonne The beginning of the 4th century BC in the the cultural space of the 'Sénonais': the settlements of Bois d’Echalas at Ville-Saint-Jacques and Beauchamp at Varennes-sur-Seine (Seine-et-Marne in the context of the land separating the Seine and the Yonne

    Directory of Open Access Journals (Sweden)

    Jean-Marc Séguier

    2008-04-01

    Full Text Available L’étude de deux habitats du début du ive s. av. J.-C. installés à proximité de la confluence Seine-Yonne permet de définir le faciès mobilier de cette partie du Bassin parisien au cours de La Tène B1a, notamment grâce à l’association d’un important cortège de céramiques locales et importées et d’un mobilier métallique significatif. L’analyse des structures de conservation et du mobilier conduit à établir une hiérarchie des établissements. Celui de Ville-Saint-Jacques, Bois d’Echalas, occupe une place prééminente dans le système social mis en place dans la région considérée, alors que celui de Varennes-sur-Seine, Beauchamp, se révèle d’un niveau inférieur. Au-delà de la comparaison entre les deux sites, c’est une lecture socio-économique de l’organisation territoriale qui est proposée.The study of two settlements of the beginning of the 4th century BC near the confluence of the Seine and the Yonne enables us to define the movable culture of this part of the Paris basin during La Tène B1a, notably because of the association of an important series of local and imported ceramics and significant metal articles. The analysis of the structures of conservation and of furniture lead to the establishment of a hierachy of settlements. That of Ville-Saint-Jacques, Bois d’Echalas, occupied a prominent place in the social system set up in the region in question, whereas that of Varennes-sur-Seine, Beauchamp, proved to be of a lower level. Beyond the comparison between the two sites, what is presented is a socio-economic lecture on territorial organisation.

  19. Reconstruction of the historical inputs of radionuclides and metal contaminants in the fluvial part of the Seine estuary through the analysis of their sedimentary records

    International Nuclear Information System (INIS)

    Vrel, Anne

    2012-01-01

    The Seine estuary is the outlet of a highly anthropogenized catchment area. Marginal areas of the river have trapped fine-grained sediment particles which a number of contaminants are bound to; they give access to the sedimentary records of the past decades. Corings were carried out in three areas: the Seine River, the upper Seine estuary, and at the river mouth. After dating, these cores have led to reconstruct the history of the inputs particulate elements in each of these areas. The comparison of the time series of elemental concentrations between (i) suspended matter during the last decades and (ii) dated sediments along the cores shows that the latter are representative of the former. Particulate fluxes of 55 stable elements and 18 radionuclides were estimated, from 1960 to 2002. Comparison of data acquired in the Seine River and in the upper estuary led to distinguish and quantify the intra-estuarine sources of contaminants that are dominated by phosphogypsum discharges during the 1970's in the Rouen harbour area (upper estuary). The intensity of tidal pumping up to the upper estuary was quantified using transuranics activity ratios. Based on the atmospheric 137 Cs activities over the last decades and core derived 137 Cs activities, a transfer model from the watershed to the river, based on a solid wash-off transfer function by runoff and erosion, is then proposed. (author) [fr

  20. Magmatic evolution of the Easter microplate-Crough Seamount region (South East Pacific)

    Science.gov (United States)

    Hekinian, R.; Stoffers, P.; Akermand, D.; Binard, N.; Francheteau, Jean; Devey, C.; Garbe-Schonberg, D.

    1995-01-01

    The Easter microplate-Crough Seamount region located between 25?? S-116?? W and 25?? S-122?? W consists of a chain of seamounts forming isolated volcanoes and elongated (100-200 km in length) en echelon volcanic ridges oriented obliquely NE (N 065??), to the present day general spreading direction (N 100??) of the Pacific-Nazca plates. The extension of this seamount chain into the southwestern edge of the Easter microplate near 26??30??? S-115?? W was surveyed and sampled. The southern boundary including the Orongo fracture zone and other shallow ridges ( 0.25) MORBs which are similar in composition to other more recent basalts from the Southwest and East Rifts spreading axes of the Easter microplate. Incompatible element ratios normalized to chondrite values [(Ce/Yb)N = 1-2.5}, {(La/Sm)N = 0.4-1.2} and {(Zr/Y)N = 0.7-2.5} of the basalts are also similar to present day volcanism found in the Easter microplate. The volcanics from the Easter microplate-Crough region are unrelated to other known South Pacific intraplate magmatism (i.e. Society, Pitcairn, and Salas y Gomez Islands). Instead their range in incompatible element ratios is comparable to the submarine basalts from the recently investigated Ahu and Umu volcanic field (Easter hotspot) (Scientific Party SO80, 1993) and centered at about 80 km west of Easter Island. The oblique ridges and their associated seamounts are likely to represent ancient leaky transform faults created during the initial stage of the Easter microplate formation (??? 5 Ma). It appears that volcanic activity on seamounts overlying the oblique volcanic ridges has continued during their westward drift from the microplate as shown by the presence of relatively fresh lava observed on one of these structures, namely the first Oblique Volcanic Ridge near 25?? S-118?? W at about 160 km west of the Easter microplate West Rift. Based on a reconstruction of the Easter microplate, it is suggested that the Crough seamount (Easter Island. ?? 1995

  1. Estimating escapement of fish and invertebrates in a Danish anchor seine

    DEFF Research Database (Denmark)

    Noack, Thomas; Madsen, Niels; Mieske, Bernd

    2017-01-01

    The codend is generally presumed to be the place where the main selectivity of fish occurs in towed fishing gears, but other parts of the net have been found to contribute to the selectivity process of several invertebrate species. This means that conventional selectivity or survival studies may......) invertebrates from the forward parts of the seine net. For seven species of demersal fish, most fish escaped through the lower panel close to the codend. All invertebrate species were found in higher numbers in the collecting bags than in the codend where many organisms escaped in the lower panel of the wings...... or the belly. Mean levels of visible damage ranged from 1.00 to 3.25 for collected invertebrates and were similar for all gear parts. Common starfish (Asterias rubens), however, showed highest damage in the extension part of the net....

  2. Geochemistry of axial seamount lavas: Magmatic relationship between the Cobb Hotspot and the Juan de Fuca Ridge

    Science.gov (United States)

    Rhodes, J. M.; Morgan, C.; Liias, R. A.

    1990-08-01

    Axial Seamount, located along the central portion of the Juan de Fuca Ridge axis and at the eastern end of the Cobb-Eickelberg Seamount Chain, is the current center of the Cobb Hotspot. The Axial Seamount lavas are transitional between N-type and E-type mid-ocean ridge basalt (MORB), characteristics that they share with lavas along the rest of the Juan de Fuca Ridge. There are, however, subtle, but distinct, differences between the seamount lavas and those of the adjoining ridge segments. These include higher Na2O, CaO, and Sr at a given MgO content and lower silica saturation in the seamount lavas as compared with the ridge lavas. Lava chemistry and bathymetry indicate that Axial Seamount is a discrete volcanic unit, with a more productive shallow magmatic plumbing system separate from the adjacent ridge segments. These high magma supply rates have sustained a continuously replenished, steady state magma reservoir that has erupted remarkably homogeneous lavas over a long time period. Despite this classic association of spreading center and hotspot volcanic activity, there is no evidence in the lavas for geochemical or isotopic enrichment typical of hotspot or mantle plume activity. The differences in composition between the Axial Seamount lavas and the Juan de Fuca Ridge lavas are attributed to melting processes rather than to any fundamental differences in their mantle source compositions. The higher magma production rates, higher Sr, and lower silica saturation in the seamount lavas relative to the ridge lavas are thought to be a consequence of melt initiation at greater depths. The melting column producing the seamount lavas is thought to be initiated in the stability field of spinel peridotite, whereas the ridge lavas are produced from a melting column initiated at shallower levels, possibly within or close to the stability field of plagioclase peridotite. Implicit in this interpretation is the conclusion that the Juan de Fuca Ridge lavas, and by analogy most

  3. Characteristics of the mesophotic megabenthic assemblages of the vercelli seamount (north tyrrhenian sea.

    Directory of Open Access Journals (Sweden)

    Marzia Bo

    2011-02-01

    Full Text Available The biodiversity of the megabenthic assemblages of the mesophotic zone of a Tyrrhenian seamount (Vercelli Seamount is described using Remotely Operated Vehicle (ROV video imaging from 100 m depth to the top of the mount around 61 m depth. This pinnacle hosts a rich coralligenous community characterized by three different assemblages: (i the top shows a dense covering of the kelp Laminaria rodriguezii; (ii the southern side biocoenosis is mainly dominated by the octocorals Paramuricea clavata and Eunicella cavolinii; while (iii the northern side of the seamount assemblage is colonized by active filter-feeding organisms such as sponges (sometimes covering 100% of the surface with numerous colonies of the ascidian Diazona violacea, and the polychaete Sabella pavonina. This study highlights, also for a Mediterranean seamount, the potential role of an isolated rocky peak penetrating the euphotic zone, to work as an aggregating structure, hosting abundant benthic communities dominated by suspension feeders, whose distribution may vary in accordance to the geomorphology of the area and the different local hydrodynamic conditions.

  4. Diffuse Volcanism at the Young End of the Walvis Ridge - Tristan - Gough Seamount Province: Geochemical Sampling and Constraints on Plume Dynamics

    Science.gov (United States)

    Class, C.; Koppers, A. A. P.; Sager, W. W.; Schnur, S.

    2014-12-01

    The Walvis Ridge-Tristan/Gough seamount province in the South Atlantic represents 130 Myr of continuous intra-plate volcanism that can be connected to the once conjunct Parana-Etendeka flood basalt province. With this it represents one of the few primary hotspots consistent with the thermal plume model. However, around 60 Ma, the morphological expression of the Walvis Ridge changed drastically from a robust 200 km wide aseismic ridge into a 400 km wide region of diffuse and diminished volcanism. As a result, this part of the plume trail has been described by two subtracks, one ending at Tristan da Cunha and another at Gough Island more than 400 km to the SSE. Where the Walvis Ridge forks into these two tracks there is a center prong. There is also the 39.5°S lineament of seamounts between, but oblique to, the two subtracks, which is parallel to the local fracture zone directions. All these features are at odds with the classical definition of a narrow hotspot track although Rohde et al. (2013) showed that the Tristan and Gough subtracks retain a distinct geochemical signature over 70 Myr and are consistent with a zoned, deep-seated plume. The first Sr-Nd-Hf-Pb isotopic and trace element analyses from the detailed dredge sampling cruise MV1203 show that samples from two prominent seamounts at the western end of the 39.5°S lineament have a Gough-type signature, which makes an upper mantle source for this lineament unlikely but rather indicates that the Gough-type source stretches some 200 km NNW from Gough. Tristan track seamount samples are comparable with published data, however, one new sample has a Gough-type composition suggesting leakage of this component into the Tristan-type plume zone. Seamounts on the middle prong of the Walvis Ridge fork have compositions intermediate to Gough and Tristan domains, suggesting mixing between sources or melts of the two domains. Thus, the Gough-component in the last 60 Myr of plume activity is volumetrically much more

  5. Oceanic sharks clean at coastal seamount.

    Directory of Open Access Journals (Sweden)

    Simon P Oliver

    2011-03-01

    Full Text Available Interactions between pelagic thresher sharks (Alopias pelagicus and cleaner wrasse were investigated at a seamount in the Philippines. Cleaning associations between sharks and teleosts are poorly understood, but the observable interactions seen at this site may explain why these mainly oceanic sharks regularly venture into shallow coastal waters where they are vulnerable to disturbance from human activity. From 1,230 hours of observations recorded by remote video camera between July 2005 and December 2009, 97 cleaner-thresher shark events were analyzed, 19 of which were interrupted. Observations of pelagic thresher sharks interacting with cleaners at the seamount were recorded at all times of day but their frequency declined gradually from morning until evening. Cleaners showed preferences for foraging on specific areas of a thresher shark's body. For all events combined, cleaners were observed to conduct 2,757 inspections, of which 33.9% took place on the shark's pelvis, 23.3% on the pectoral fins, 22.3% on the caudal fin, 8.6% on the body, 8.3% on the head, 2.1% on the dorsal fin, and 1.5% on the gills respectively. Cleaners did not preferentially inspect thresher sharks by time of day or by shark sex, but there was a direct correlation between the amount of time a thresher shark spent at a cleaning station and the number of inspections it received. Thresher shark clients modified their behavior by "circular-stance-swimming," presumably to facilitate cleaner inspections. The cleaner-thresher shark association reflected some of the known behavioral trends in the cleaner-reef teleost system since cleaners appeared to forage selectively on shark clients. Evidence is mounting that in addition to acting as social refuges and foraging grounds for large visiting marine predators, seamounts may also support pelagic ecology by functioning as cleaning stations for oceanic sharks and rays.

  6. Formation and evolution of the near axis 8˚20'N seamount chain: Evidences from the geophysical data analysis

    Science.gov (United States)

    Romano, V.; Gregg, P. M.; Zhan, Y.; Fornari, D. J.; Perfit, M. R.; Battaglia, M.

    2017-12-01

    The OASIS (Off-Axis Seamount Investigations at Siqueiros) expedition is a multidisciplinary effort to systematically investigate the 8˚20'N Seamount Chain to better understand the melting processes in the southern portion of the 9-10˚N segment of the East Pacific Rise (EPR). The 8˚20'N Seamount Chain extends 160 km west from its initiation, 15km northwest of the EPR-Siqueiros ridge transform intersection (RTI). To investigate the emplacement of the 8˚20'N Seamounts, shipboard EM-122 multibeam, BGM-3 gravity, and towed magnetometer data were collected using the R/V Atlantis in November 2016. Multibeam data show that the seamount chain is characterized by discrete seamounts in the distal portion of the chain, while east of 105˚20' W, the chain is a nearly-continuous volcanic ridge comprised of small cones and coalesced edifices. Free Air Anomalies are used to calculate isostatic anomalies along several profiles crossing the main edifices of the seamount chain, and indicate that the seamounts formed within 100 km of the EPR ridge axis. Excess crustal thickness variations of 0.5 to 1 km, derived from the Residual Mantle Bouguer Anomaly, suggest an increase in melt flux eastward along the chain. Consistently high emplacement volumes are observed east of -105 ˚20' W, 130 km from the ridge axis corresponding with lithosphere younger than 2 Myr. Inverted three-dimensional magnetization data indicate that the seamounts have recorded a series of magnetic reversals along the chain, which correlate to reversals recorded in the surrounding seafloor upon which the seamounts were built. However, reversals along the eastern portion of the chain appear skewed to the west indicating that seamount formation is likely long-lived. While the geophysical observations indicate that the overall seamount chain is age progressive, they suggest coeval volcanism in a region 15-100km from the EPR. The seamounts do not follow absolute plate motions, but are located consistently 15-20 km

  7. Survie au cancer du sein à Rabat (Maroc) 2005-2008

    Science.gov (United States)

    Mechita, Nada Bennani; Tazi, Mohammed Adnane; Er-Raki, Abdelouahed; Mrabet, Mustapha; Saadi, Asma; Benjaafar, Noureddine; Razine, Rachid

    2016-01-01

    Introduction Le cancer du sein représente un problème de santé publique au Maroc. L’objectif de ce travail était d’estimer le taux de survie au cancer du sein chez les patientes habitant la ville de Rabat. Méthodes Etude pronostique réalisée chez les patientes diagnostiquées pour cancer du sein de 2005 à 2008, habitant la ville de Rabat et enregistrées au registre des cancers de Rabat. La date d’inclusion dans l’étude correspondait à la date de confirmation histologique du cancer. L’estimation de la survie a été réalisée par la méthode de Kaplan Meier, et la comparaison entre les différentes classes d’une variable a été réalisée par le test de log rank. L’étude des facteurs associés à la survie a été effectuée par le modèle de Cox. Résultats Durant la période d’étude 628 cas de cancer du sein ont été collectés. Le pourcentage de décès était de 19,9%. La survie globale à un an était de 97,1%, elle était de 89,2% à 3 ans et de 80,6 % à 5 ans. En analyse multivariée la survie au cancer du sein était statistiquement moins bonne chez les patientes âgées de plus de 70 ans (p<0,001), ayantune grande taille de tumeur (p<0,001), un stade avancé d’adénopathies (p=0,007), présentant des métastases (p<0,001) et non traitées par hormonothérapie (p=0,002). Conclusion Une grande taille de la tumeur et la présence de métastases sont des facteurs de mauvais pronostic du cancer du sein d’où la nécessité de renforcer les programmes de dépistage. PMID:28292106

  8. Formation of forearc basins by collision between seamounts and accretionary wedges: an example from the New Hebrides subduction zone

    Science.gov (United States)

    Collot, J.-Y.; Fisher, M.A.

    1989-01-01

    Seabeam data reveal two deep subcircular reentrants in the lower arc slope of the New Hebrides island arc that may illustrate two stages in the development of a novel type of forearc basin. The Malekula reentrant lies just south of the partly subducted Bougainville seamount. This proximity, as well as the similarity in morphology between the reentrant and an indentation in the lower arc slope off Japan, suggests that the Malekula reentrant formed by the collision of a seamount with the arc. An arcuate fold-thrust belt has formed across the mouth of the reentrant, forming the toe of a new accretionary wedge. The Efate reentrant may show the next stage in basin development. This reentrant lies landward of a lower-slope ridge that may have begun to form as an arcuate fold-thrust belt across the mouth of a reentrant. This belt may have grown by continued accretion at the toe of the wedge, by underplating beneath the reentrant, and by trapping of sediment shed from the island arc. These processes could result in a roughly circular forearc basin. Basins that may have formed by seamount collision lie within the accretionary wedge adjacent to the Aleutian trenches. -Authors

  9. Three-Dimensional Dynamics of Baroclinic Tides Over a Seamount

    Science.gov (United States)

    Vlasenko, Vasiliy; Stashchuk, Nataliya; Nimmo-Smith, W. Alex M.

    2018-02-01

    The Massachusetts Institute of Technology general circulation model is used for the analysis of baroclinic tides over Anton Dohrn Seamount (ADS), in the North Atlantic. The model output is validated against in situ data collected during the 136th cruise of the RRS "James Cook" in May-June 2016. The observational data set includes velocity time series recorded at two moorings as well as temperature, salinity, and velocity profiles collected at 22 hydrological stations. Synthesis of observational and model data enabled the reconstruction of the details of baroclinic tidal dynamics over ADS. It was found that the baroclinic tidal waves are generated in the form of tidal beams radiating from the ADS periphery to its center, focusing tidal energy in a surface layer over the seamount's summit. This energy focusing enhances subsurface water mixing and the local generation of internal waves. The tidal beams interacting with the seasonal pycnocline generate short-scale internal waves radiating from the ADS center. An important ecological outcome from this study concerns the pattern of residual currents generated by tides. The rectified flows over ADS have the form of a pair of dipoles, cyclonic and anticyclonic eddies located at the seamount's periphery. These eddies are potentially an important factor in local larvae dispersion and their escape from ADS.

  10. BIOMETORE Project - Studying the Biodiversity in the Northeastern Atlantic Seamounts

    Science.gov (United States)

    Dos Santos, A.; Biscoito, M.; Campos, A.; Tuaty Guerra, M.; Meneses, G.; Santos, A. M. P. A.

    2016-02-01

    Understanding the deep-sea ecosystem functioning is a key issue in the study of ocean sciences. Bringing together researchers from several scientific domains, the BIOMETORE project aims to the increase knowledge on deep-sea ecosystems and biodiversity at the Atlantic seamounts of the Madeira-Tore and Great Meteor geological complexes. The project outputs will provide important information for the understanding and sustainable management of the target seamount ecosystems, thus contributing to fulfill knowledge gaps on their biodiversity, from bacteria to mammals, and food webs, as well as to promote future sustainable fisheries and sea-floor integrity. The plan includes the realization of eight multidisciplinary surveys, four done during the summer of 2015 and another four planned for the same season of 2016, in target seamounts: the Gorringe bank, the Josephine, and others in the Madeira-Tore, and selected ones in the Greta Meteor (northeastern Atlantic Ocean). The surveys cover a number of scientific areas in the domains of oceanography, ecology, integrative taxonomy, geology, fisheries and spatial mapping. We present and discuss BIOMETORE developments, the preliminary results from the four 2015 summer surveys, and the planning of the next four surveys.

  11. Constraints on Past Plate and Mantle Motion from New Ages for the Hawaiian-Emperor Seamount Chain

    Science.gov (United States)

    O'Connor, J. M.; Steinberger, B. M.; Regelous, M.; Koppers, A. A.; Wijbrans, J. R.; Haase, K. M.; Stoffers, P.; Jokat, W.; Garbe-Schoenberg, C.

    2013-12-01

    Estimates of the relative motion between the Hawaiian and Louisville hotspots have consequences for understanding the role and character of deep Pacific-mantle return flow. The relative motion between these primary hotspots can be inferred by comparing the age records for their seamount trails. Our new 40Ar/39Ar ages for 18 lavas from 10 seamounts along the Hawaiian-Emperor Seamount Chain (HESC) show that volcanism started in the sharp portion of the Hawaiian-Emperor Bend (HEB) at ≥47.5 Ma and continued for ≥5 Myr (O'Connor et al., 2013). The slope of the along-track distance from the currently active Hawaiian hotspot plotted versus age is remarkably linear between ~57 and 25 Ma in the central ˜1900 km of the seamount chain, including the HEB. This model predicts an age for the oldest Emperor Seamounts that matches published ages, implying that a linear age-distance relationship might extend back to at least 82 Ma. In contrast, Hawaiian age progression was much faster since at least ~15 Ma and possibly as early as ~27 Ma. Linear age-distance relations for the Hawaii-Emperor and Louisville seamount chains predict ~300 km overall hotspot relative motion between 80 and 47.5 Ma, in broad agreement with numerical models of plumes in a convecting mantle, and paleomagnetic data. We show that a change in hotspot relative motion may also have occurred between ~55 Ma and ~50 Ma. We interpret this change in hotspot motion as evidence that the HEB reflects a combination of hotspot and plate motion changes driven by the same plate/mantle reorganization. O'Connor et al. (2013), Constraints on past plate and mantle motion from new ages for the Hawaiian-Emperor Seamount Chain. Geochem. Geophys. Geosyst., in press.

  12. Accreted seamounts in North Tianshan, NW China: Implications for the evolution of the Central Asian Orogenic Belt

    Science.gov (United States)

    Yang, Gaoxue; Li, Yongjun; Kerr, Andrew C.; Tong, Lili

    2018-03-01

    The Carboniferous Bayingou ophiolitic mélange is exposed in the North Tianshan accretionary complex in the southwestern part of the Central Asian Orogenic Belt (CAOB). The mélange is mainly composed of serpentinised ultramafic rocks (including harzburgite, lherzolite, pyroxenite, dunite and peridotite), pillowed and massive basalts, layered gabbros, radiolarian cherts, pelagic limestones, breccias and tuffs, and displays block-in-matrix structures. The blocks of ultramafic rocks, gabbros, basalts, cherts, and limestones are set in a matrix of serpentinised ultramafic rocks, massive basalts and tuffs. The basaltic rocks in the mélange show significant geochemical heterogeneity, and two compositional groups, one ocean island basalt-like, and the other mid-ocean ridge-like, can be distinguished on the basis of their isotopic compositions and immobile trace element contents (such as light rare earth element enrichment in the former, but depletion in the latter). The more-enriched basaltic rocks are interpreted as remnants/fragments of seamounts, derived from a deep mantle reservoir with low degrees (2-3%) of garnet lherzolite mantle melting. The depleted basalts most likely formed by melting of a shallower spinel lherzolite mantle source with ∼15% partial melting. It is probable that both groups owe their origin to melting of a mixture between plume and depleted MORB mantle. The results from this study, when integrated with previous work, indicate that the Junggar Ocean crust (comprising a significant number of seamounts) was likely to have been subducted southward beneath the Yili-Central Tianshan block in the Late Devonian-Early Carboniferous. The seamounts were scraped-off and accreted along with the oceanic crust in an accretionary wedge to form the Bayingou ophiolitic mélange. We present a model for the tectonomagmatic evolution of this portion of the CAOB involving prolonged intra-oceanic subduction with seamount accretion.

  13. Deepwater ichthyofauna communities of two seamounts from the eastern Atlantic Ocean: results from exploratory surveys

    Directory of Open Access Journals (Sweden)

    Rui Pedro Vieira

    2015-11-01

    Demersal fishes from Ampère Seamount, located between Madeira and the Portuguese mainland, were sampled during the P384 cruise of R.V. Poseidon in May 2009 and the M83/2 cruise of R.V. Meteor in November/December 2010, covering water depths from 60 to 4,400 m. A total of 239 fishes were collected; three chondrichthyan species and 31 teleosts in 21 families were identified. The assemblages showed a vertical zonation with little overlap, but indications for an affinity of species to certain water masses were only vague. Although most of the species present new records for Ampère Seamount, all of them have been known for the NE Atlantic and endemic species were not found. Senghor Seamount is an important fishing ground around the Cape Verde archipelago in the central eastern Atlantic. During the cruises M79/3 of R.V. Meteor in September/October 2009 and P423 of R.V. Poseidon in December 2011, a total of 106 deep-sea fishes of 28 species belonging to 18 families were caught on the seamount summit, along the slopes and on the adjacent abyssal plane. We accounted 6 new records for the Cape Verde deep-sea fish fauna. Most species have been known from other areas of the Atlantic Ocean, but these findings are an important contribution to our understanding of the distribution of deepwater fish species. The co-occurrence of northern and southern fish species at Senghor Seamount, or the Cape Verde area in general, can be attributed to the large-scale hydrographic regime with two water masses merging at the Cape Verde Frontal Zone, the North Atlantic Central Water and the South Atlantic Central Water. In general, differences between the adjacent abyssal plain and seamount slopes and summit point to the role of substrate type and habitat complexity in shaping community composition. Additionally, similarities between the fish fauna associated to other Atlantic seamounts supports the hypothesized key role of these physiographic features for species dispersion.

  14. Categorizing vitric lithofacies on seamounts: implications for recognizing deep-marine pyroclastic deposits

    Science.gov (United States)

    Portner, R. A.; Clague, D. A.

    2011-12-01

    Glassy fragmental deposits commonly found capping seamounts have been variably interpreted as the products of quench-fragmentation (hyaloclastite), suppressed steam expansion, and/or explosive fire-fountains (pyroclastite). To better understand these vitriclastic deposits we use a multidisciplinary approach that outlines six lithofacies based on textures, sedimentary structures, geochemical diversity, and associations with seamount landforms. All seamounts studied yield MORB compositions and formed on or near mid-ocean ridge axes of the northeast Pacific Ocean. Consolidated deposits were sampled from the Taney (~29 Ma), President Jackson (~3 Ma), and Vance (~2 Ma) seamounts using ROV manipulator arms and dredge hauls. Unconsolidated deposits from the currently active Axial Seamount of the Juan de Fuca Ridge were sampled using ROV push core and vacuum techniques. Lithofacies occur with talus breccias and pillow basalt on steeply dipping outer flanks and caldera walls, and with pillow and sheet flows on subhorizontal rims and nested caldera floors of the seamounts. Vitric lithofacies within or near steeply dipping regions have very angular textures, coarse grain-sizes and abundant crystalline basalt fragments. Jig-saw fit texture is common in units with monomict geochemistry and closely associated with adjacent pillow basalt, suggesting in-situ fragmentation akin to pillow breccia. Similar units bearing polymodal geochemistry are generally associated with talus breccias along caldera walls and basal slopes, and are interpreted as fault-scarp derived debrites. Laterally these lithofacies abruptly grade into bottom-current reworked lithofacies on flat caldera floors. Reworked lithofacies have >40% muddy matrix with abundant angular mineral fragments, biogenic grains and minor devitrified glass shards. They typically exhibit well-defined planar lamination and locally show sinusoidal ripple forms. Horizontal burrows including Planolites are common. Locally this

  15. Optimal and centralized reservoir management for drought and flood protection via Stochastic Dual Dynamic Programming on the Upper Seine-Aube River system

    Science.gov (United States)

    Chiavico, Mattia; Raso, Luciano; Dorchies, David; Malaterre, Pierre-Olivier

    2015-04-01

    Seine river region is an extremely important logistic and economic junction for France and Europe. The hydraulic protection of most part of the region relies on four controlled reservoirs, managed by EPTB Seine-Grands Lacs. Presently, reservoirs operation is not centrally coordinated, and release rules are based on empirical filling curves. In this study, we analyze how a centralized release policy can face flood and drought risks, optimizing water system efficiency. The optimal and centralized decisional problem is solved by Stochastic Dual Dynamic Programming (SDDP) method, minimizing an operational indicator for each planning objective. SDDP allows us to include into the system: 1) the hydrological discharge, specifically a stochastic semi-distributed auto-regressive model, 2) the hydraulic transfer model, represented by a linear lag and route model, and 3) reservoirs and diversions. The novelty of this study lies on the combination of reservoir and hydraulic models in SDDP for flood and drought protection problems. The study case covers the Seine basin until the confluence with Aube River: this system includes two reservoirs, the city of Troyes, and the Nuclear power plant of Nogent-Sur-Seine. The conflict between the interests of flood protection, drought protection, water use and ecology leads to analyze the environmental system in a Multi-Objective perspective.

  16. Lymphome malin non hodgkinien du sein et VIH: à propos d'un cas ...

    African Journals Online (AJOL)

    Le lymphome malin non-hodgkinien (LNH) représente 0,5% de tous les cancers du sein. Son diagnostic est essentiellement histologique. Nous rapportons un cas de LMNH du sein chez une patiente de 42 ans et chez qui la sérologie VIH est positive. L'objectif de cet article est de discuter les aspects cliniques, ...

  17. Modélisation environnementale de l'estuaire de la Seine

    OpenAIRE

    Bacq, Nicolas; Cugier, Philippe; Grasso, Florent; Le Gendre, Romain; Le Hir, Pierre; Lemoine, Jean-philippe; Riou, Philippe; Schulz, Elisabeth; Thouvenin, Benedicte; Verney, Romaric

    2015-01-01

    Dans le cadre du programme de recherche Seine-Aval 5, différentes stratégies de modélisation numérique sont mises en place pour aider à répondre aux questionnements scientifiques et sociétaux associés au fonctionnement physique, biologique, chimique et écologique de l'estuaire de la Seine (ex. projets RESET et HYMOSED). Les forçages météo-marins (vent, vague, marée) et hydrologique (débit) contrôlent le fonctionnement hydro-morpho-sédimentaire et biogéochimique de l'estuaire, modifiant ainsi ...

  18. US Tune Purse Seine Fleet History & Activity Database

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NMFS SWR has collected historical vessel information on the U.S. tuna cannery baitboat and purse seine fleets for many years. The database's first record of a...

  19. Deepwater fish assemblages at Isla del Coco National Park and Las Gemelas Seamount, Costa Rica

    Directory of Open Access Journals (Sweden)

    Richard M. Starr

    2012-11-01

    Full Text Available The deepwater faunas of oceanic islands and seamounts of the Eastern Tropical Pacific are poorly known. From 11-22 September 2009 we conducted an exploration of the deepwater areas of the Isla del Coco Marine Conservation Area, Costa Rica and a nearby seamount using a manned submersible. The goal of the exploration was to characterize the habitats and biota, and conduct quantitative surveys of the deepwater portions of Isla del Coco National Park and Las Gemelas Seamount, located about 50km southwest of Isla del Coco. We completed a total of 22 submersible dives, spanning more than 80hr underwater, and collected a total of 36hr of video. We surveyed habitats from 50-402m and observed more than 45 species of fishes, some of which have not yet been described and are likely new to science. The diversity of fish species in deep water at Isla del Coco National Park was lower than the diversity of fishes in shallow water, and eight species groups accounted for more than 95% of the total fish biomass. The combined density of all fish species was higher at Las Gemelas Seamount (253 fishes/100m² than at Isla del Coco National Park (138 fishes/100m². The combined density of fishes in habitats comprised primarily of bedrock or large boulders outcrops was more than three times as high at Las Gemelas Seamount as it was at Isla del Coco National Park. This discrepancy was caused by the extremely high concentration of Anthiinae fishes in rocky habitats at Las Gemelas Seamount. Densities of fishes in the other habitats were similar between the two sites. Similarly, when estimates of fish density were plotted by slope categories the density was much greater on steep slopes, which were usually comprised of rock habitats. Also, the density of fishes was greatest on high rugosity habitats. Results of these submersible surveys indicate that seamounts in the tropical eastern Pacific Ocean may be an important source of biodiversity and that more quantitative surveys

  20. Demersal fish assemblages on seamounts and other rugged features in the northeastern Caribbean

    Science.gov (United States)

    Quattrini, Andrea M.; Demopoulos, Amanda W. J.; Singer, Randal; Roa-Varon, Adela; Chaytor, Jason D.

    2017-05-01

    Recent investigations of demersal fish communities in deepwater (>50 m) habitats have considerably increased our knowledge of the factors that influence the assemblage structure of fishes across mesophotic to deep-sea depths. While different habitat types influence deepwater fish distribution, whether different types of rugged seafloor features provide functionally equivalent habitat for fishes is poorly understood. In the northeastern Caribbean, different types of rugged features (e.g., seamounts, banks, canyons) punctuate insular margins, and thus create a remarkable setting in which to compare demersal fish communities across various features. Concurrently, several water masses are vertically layered in the water column, creating strong stratification layers corresponding to specific abiotic conditions. In this study, we examined differences among fish assemblages across different features (e.g., seamount, canyon, bank/ridge) and water masses at depths ranging from 98 to 4060 m in the northeastern Caribbean. We conducted 26 remotely operated vehicle dives across 18 sites, identifying 156 species of which 42% of had not been previously recorded from particular depths or localities in the region. While rarefaction curves indicated fewer species at seamounts than at other features in the NE Caribbean, assemblage structure was similar among the different types of features. Thus, similar to seamount studies in other regions, seamounts in the Anegada Passage do not harbor distinct communities from other types of rugged features. Species assemblages, however, differed among depths, with zonation generally corresponding to water mass boundaries in the region. High species turnover occurred at depths <1200 m, and may be driven by changes in water mass characteristics including temperature (4.8-24.4 °C) and dissolved oxygen (2.2-9.5 mg per l). Our study suggests the importance of water masses in influencing community structure of benthic fauna, while considerably adding

  1. Resolving the Subsidence Anomaly of the East Tasman Plateau Using New Insights from the Cascade Seamount, Southwest Tasman Sea

    Science.gov (United States)

    Vorsanger, S. L.; Scher, H.; Johnson, S.; Mundana, R.; Sauermilch, I.; Duggan, B.; Whittaker, J. M.

    2017-12-01

    The Cascade Seamount is a wave-planated feature located on the microcontinent of the East Tasman Plateau (ETP). The minimum subsidence rate of the Seamount and the ETP can be estimated by dividing the present-day depth of the wave-cut surface (640 m) by the age of Cascade Seamount basalts as determined by potassium-argon (K-Ar) dating (33.4 and 36 Ma). This approach yields a subsidence rate of 18 m/Myr. However, significantly more rapid subsidence rates of the East Tasman Plateau (ETP) — upon which the Cascade Seamount rests — since the Eocene-Oligocene transition have been proposed utilizing a nearby sediment core, Ocean Drilling Program (ODP) Site 1172. Late Eocene paleodepths determined by Stickley et al. (2004) using sedimentological and biostratigraphic techniques, indicate a subsidence rate of 85 m/Myr for the ETP. These two results present a paradox, which implies that the ETP subsided at a rate greater than the Seamount itself, over the same time interval. It also implies that the seamount formed above sea level. The subsidence ambiguity may be attributed to the presence of a turbidity current deposit in the sediment core, or uncertainty in the age and/or location of the K-Ar dated basalts of the Cascade Seamount. Statistical analysis of the published grain size measurements will be used to test for the presence of a turbidity current deposit in ODP Site 1172. We will also measure 87Sr/86Sr ratios of marine carbonate samples from conglomerates obtained from the Cascade Seamount during the August 2016 RV Investigator voyage (IN2016_E01) to confirm the age of the wave planated surfaces by Strontium Isotope Stratigraphy. This will allow for a more robust calculation for the subsidence of the ETP which was a critical barrier in the Tasmanian Gateway that allowed for the formation of the Antarctic Circumpolar Current.

  2. Collision-induced post-plateau volcanism: Evidence from a seamount on Ontong Java Plateau

    Science.gov (United States)

    Hanyu, Takeshi; Tejada, Maria Luisa G.; Shimizu, Kenji; Ishizuka, Osamu; Fujii, Toshiyuki; Kimura, Jun-Ichi; Chang, Qing; Senda, Ryoko; Miyazaki, Takashi; Hirahara, Yuka; Vaglarov, Bogdan S.; Goto, Kosuke T.; Ishikawa, Akira

    2017-12-01

    Many seamounts on the Ontong Java Plateau (OJP) occur near the Stewart Arch, a topographic high that extends parallel to the North Solomon Trench along the southern margins of the plateau. Despite the thick sediment cover, several volcanic cones with strong acoustic reflection were discovered on the submarine flank of the Nuugurigia Seamount. From such volcanic cones, basalts were successfully sampled by dredging. Radiometric dating of basalts and ferromanganese encrustation indicate eruption age of 20-25 Ma, significantly younger than the 122 Ma main OJP plateau and post-plateau basalts. The age range coincides with the collision of the OJP with the Solomon Arc. The Nuugurigia basalts geochemically differ from any other rocks sampled on the OJP so far. They are alkali basalts with elevated Sr, low Zr and Hf, and Enriched Mantle-I (EMI)-like isotopic composition. Parental magmas of these alkali basalts may have formed by small-degree melting of peridotitic mantle impregnated with recycled pyroxenite material having enriched geochemical composition in the OJP's mantle root. We conclude that small-volume alkali basalts from the enriched mantle root migrated through faults or fractures caused by the collision along the Stewart Arch to form the seamount. Our results suggest that the collision of the OJP with the Solomon arc played an important role in the origin of similar post-plateau seamounts along the Stewart Arch.

  3. 76 FR 29707 - Fishing Capacity Reduction Program for the Southeast Alaska Purse Seine Salmon Fishery

    Science.gov (United States)

    2011-05-23

    ... Salmon Fishery AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric... loan for the Southeast Alaska Purse Seine Salmon Fishery (Reduction Fishery). The fee system involves...: SE Alaska Purse Seine Salmon Rulemaking, 1315 East-West Highway, Silver Spring, MD 20910...

  4. Bacterial Community Sstructure and Novel Species of Magnetotactic Bacteria in Sediments from a Seamount in the Mariana Volcanic Arc

    Science.gov (United States)

    PAN, H.; LIU, J.; Zhang, W.; Xiao, T.; Wu, L. F.

    2017-12-01

    Seamounts are unique ecosystems where undersea mountains rise abruptly from the sea floor and interact dynamically with underwater currents, creating peculiar biological habitats with various microbial community structures. Certain bacteria associated with seamounts form conspicuous extracellular iron oxide structures, including encrusted stalks, flattened bifurcating tubes, and filamentous sheaths. To extend knowledge of seamount microorganisms we performed a systematic analysis of the population composition and occurrence of live magnetotactic bacteria (MTB) in sediments of a seamount in the Mariana volcanic arc. Proteobacteria dominated at 13 stations, and were the second in abundance to members of the Firmicutes at a deep station on a steep slope facing the Yap-Mariana trench. We found MTB that synthesize intracellular iron-oxide nanocrystals in biogenic sediments at all 14 stations, at seawater depths ranging from 238 to 2023 m. A novel flagellar apparatus, and the most complex yet reported, was observed in magnetotactic cocci; it comprises one or two bundles of 19 flagella arranged in a 3:4:5:4:3 array. Phylogenetic analysis of 16S rRNA gene sequences identified 16 novel species of MTB specific to this seamount. The geographic properties at the various stations on the seamount appear to be important in shaping the microbial community structure.

  5. 76 FR 61985 - Fishing Capacity Reduction Program for the Southeast Alaska Purse Seine Salmon Fishery

    Science.gov (United States)

    2011-10-06

    ... Salmon Fishery AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric... Southeast Alaska Purse Seine Salmon Fishery (Reduction Fishery). The fee system involves future landings of... Alaska Purse Seine Salmon Rulemaking, 1315 East-West Highway, Silver Spring, MD 20910 or by calling...

  6. Coral Patch seamount (NE Atlantic – a sedimentological and megafaunal reconnaissance based on video and hydroacoustic surveys

    Directory of Open Access Journals (Sweden)

    C. Wienberg

    2013-05-01

    Full Text Available The present study provides new knowledge about the so far largely unexplored Coral Patch seamount which is located in the NE Atlantic Ocean half-way between the Iberian Peninsula and Madeira. For the first time a detailed hydroacoustic mapping (MBES in conjunction with video surveys (ROV, camera sled were performed to describe the sedimentological and biological characteristics of this sub-elliptical ENE-WSW elongated seamount. Video observations were restricted to the southwestern summit area of Coral Patch seamount (water depth: 560–760 m and revealed that this part of the summit is dominated by exposed hard substrate, whereas soft sediment is just a minor substrate component. Although exposed hardgrounds are dominant for this summit area and, thus, offer suitable habitat for settlement by benthic organisms, the benthic megafauna shows rather scarce occurrence. In particular, scleractinian framework-building cold-water corals are apparently rare with very few isolated and small-sized live occurrences of the species Lophelia pertusa and Madrepora oculata. In contrast, dead coral framework and coral rubble are more frequent pointing to a higher abundance of cold-water corals on Coral Patch during the recent past. This is even supported by the observation of fishing lines that got entangled with rather fresh-looking coral frameworks. Overall, long lines and various species of commercially important fish were frequently observed emphasising the potential of Coral Patch as an important target for fisheries that may have impacted the entire benthic community. Hydroacoustic seabed classification covered the entire summit of Coral Patch and its northern and southern flanks (water depth: 560–2660 m and revealed extended areas dominated by mixed and soft sediments at the northern flank and to a minor degree at its easternmost summit and southern flank. Nevertheless, these data also predict most of the summit area to be dominated by exposed bedrock

  7. MENYOAL KESENJANGAN ANTARA DAS SOLLEN ISLAM DENGAN DAS SEIN PRAKSIS KEHIDUPAN KAUM MUSLIMIN

    Directory of Open Access Journals (Sweden)

    Yusuf Suyono

    2016-03-01

    Full Text Available Abstract:This paper embarks from the question why the valuable Islamic ethics cannot be ethos grounded in the nation-state Muslim majority country-including in Indonesia? Phenomena such as the majlis taklim, majlis dhikr, interest pilgrimage exceeds the quota, the Islamic banking activity is equally excited, is real. However, it is not enough. Muslims should master the science, economics, and the strategic role of national politics. Islamic ethics is Dassollen, the Muslims condition is DasSein. ProphetMuḥammad has abled to unite Das sein andDassollenin his life, because Islam hasbecomehis bloodso that he is a mirror and store front of Islampar excellence. Muslims, as his follower, not been able todo like him. Al-Amir ArsalanSyākib, Muḥammad ‘Abduh, MohammadIqbal, Muḥammadal-Ghazālī, Ḥassan Ḥanafihavetried to formulatehow tobridge the gapbetween Das sollenandDasSein forMuslims. Theyhave adeep concern about thewide gapbetweenDasSeinpraxis in life of Muslims with DassollenIslamicteachings in slogan ya’lu walā yu’la ‘alaih. Whileatthe same timetheyseehowthe berufethos of Calvinismcouldencouragethe ethos ofmoderncapitalismto its adherentsin Western Europe, a Zen Buddhistethoscouldpushthe Japaneseintothe Asiantigers, andspirit Confucius encouragethe Korean peopleintothe Asiandragon. Abstrak:Tulisan ini berangkat dari pertanyaan mengapa etika Islam yang adiluhung itu tidak bisa membumi menjadi etos bangsa di negara-negara yang mayoritas penduduknya Muslim–termasuk di Indonesia. Fenomena seperti majlis taklim, majlis zikir, minat menunaikan ibadah haji melebihi kuota, aktivitas perbankan syariah tak kalah bersemangat, adalah nyata. Namun, itu tidak cukup. Umat Islam seharusnya lebih dari itu dalam penguasaan ilmu pengetahuan, ekonomi, dan peran strategis politik kebangsaan. Etika Islam itulah Das Sollen, keadaan kaum Muslimin itulah Das Sein. Muhammad Rasulullah telah mampu menyatukan Das Sein dan Das Sollen dalam hidupnya. Hal

  8. Infection par le VIH chez les patientes atteintes de cancer du sein en ...

    African Journals Online (AJOL)

    L'objectif était de déterminer la prévalence de l'infection à VIH chez les patientes atteintes de cancer du sein et de comparer les caractéristiques anatomocliques et thérapeutiques de ces cancers du sein par rapports aux patientes non infectées par le VIH. Il s'agissait d'une étude rétrospective et analytique comparant les ...

  9. Seamounts an additional tool to confirm the nature of the crust and to locate possible mineral resources for dredging

    Digital Repository Service at National Institute of Oceanography (India)

    Sarma, K.V.L.N.S.; Ramana, M.V.; Subrahmanyam, V.; Krishna, K.S.; Ramprasad, T.; Desa, M.

    Crust with reversed polarity. The seamounts studied provide an environment for possible locations of polymetallic encrustations. Morphology of the seamounts depends on several factors, including physical and chemical composition of the magma, eruption...

  10. 77 FR 19004 - Fishing Capacity Reduction Program for the Southeast Alaska Purse Seine Salmon Fishery

    Science.gov (United States)

    2012-03-29

    ... Capacity Reduction Program for the Southeast Alaska Purse Seine Salmon Fishery AGENCY: National Marine... Salmon Fishery. DATES: Comments must be submitted on or before 5 p.m. EST April 13, 2012. ADDRESSES: Send... Seine Salmon Buyback, 1315 East-West Highway, Silver Spring, MD 20910 (see FOR FURTHER INFORMATION...

  11. New Age and Geochemical Data From Seamounts in the Canary and Madeira Volcanic Provinces: A Contribution to the "Great Plume Debate"

    Science.gov (United States)

    Geldmacher, J.; Hoernle, K.; van den Bogaard, P.; Duggen, S.; Werner, R.

    2004-12-01

    The role of hotspots (mantle plumes) in the formation of intraplate volcanic island and seamount groups is being increasingly questioned, in particular concerning the abundant and somewhat irregularly distributed island and seamount volcanoes off the coast of northwest Africa. However, new 40Ar/39Ar ages and Sr-Nd-Pb isotope geochemistry of volcanic rocks from two seamounts northeast of the Canary Islands and two northeast of the Madeira Islands provide new support for the plume hypothesis. The oldest ages of shield stage volcanism from seamounts and islands northeast of the Canary and Madeira Islands confirm progressions of increasing age to the northeast for both island/seamount chains consistent with northeast directed plate motion. Calculated angular velocities for the average movement of the African plate in both regions gave similar values of about 0.45\\deg plus/minus 0.05\\deg/Ma around a rotation pole located north of the Azores Islands. Furthermore, the curvature of the chains clearly deviates from the E-W orientation of fracture zones in the East Atlantic. A local control of surface volcanism by lithospheric zones of weakness, however, is likely for some E-W elongated seamounts and islands. The isotope geochemistry additionally confirms that the two volcanic provinces are derived from distinct sources, consistent with distinct mantle plumes having formed both volcanic groups. Conventional hotspot models, however, cannot easily explain the wide distribution of seamounts in the Canary region and the long history of volcanic activity at single volcanic centers (e.g. Dacia seamount, 47-4 Ma; Selvagen Islands, 30-3 Ma). A possible explanation could involve interaction of a Canary mantle plume with small-scale upper mantle processes such as edge driven convection at the edge of the NW African craton (e.g. King and Ritsema, 2000, Science 290, 1137-1140).

  12. Detailed seamount-scale studies of ferromanganese crusts reveal new insights into their formation and resource assessment.

    Science.gov (United States)

    Murton, B. J.; Lusty, P.; Yeo, I. A.; Howarth, S.

    2017-12-01

    The seafloor hosts abundant mineral deposits critical for low-carbon economies and emerging technologies. These include ferromanganese crusts (FeMnC) that grow on seamounts. While the broad distribution of FeMnC is known, local controls on growth, composition and formation are not. Here, we describe a detailed study of a gyot in the NE Atlantic (Tropic Seamount) that explores the controls, from the surface to the seafloor, exerted on FeMnC growth from current energy, surface productivity, sediment distribution, seafloor morphology, substrate lithology, sediments mobility and thickness, and seamount subsidence. During cruise JC142 (2016), we mapped the seamount with EM120 multibeam, mapped the 400km2 summit with AUV multibeam, sidescan sonar, sub-bottom profiler and 361,644 photographs. During 28 ROV dives we drilled 58 core and collected 344 individual rock samples. We found FeMnC at all depths, with the thickest (nucleolus for crusts up to 10cm thick, with growth into the sediment. Many substrates are found to comprise semi-consolidated sediment. The presence of thick crusts at the base of the seamount contradicts accepted understanding of FeMnC deposition just below the oxygen minimum zone (OMZ). In areas on the eastern and western spurs, between 2500m and 1000m, where current energy is greatest, sessile fauna are most abundant. Dense coral debris at these locations appears to inhibit crust formation and coral and sponge `gardens' are frequent on near vertical cliffs. The observation that crusts have grown downwards into and over soft sediment is enigmatic since present understanding requires hard substrates to be exposed to seawater for crusts to grow, and any burial would inhibit such growth. Plume tracking shows reduction to background within 1000m. Our study challenges the view that ferromanganese crusts form at the base of the OMZ and grow upwards on solid substrates. Instead, we see an interplay between crust precipitation, the morphological evolution of

  13. Relationship between viral and prokaryotic abundance on the Bajo O’Higgins 1 Seamount (Humboldt Current System off Chile

    Directory of Open Access Journals (Sweden)

    Oscar E. Chiang

    2007-03-01

    Full Text Available There is little known about the ecology of microbial communities living in the water column over seamounts. Here, for the first time, the spatial distribution and abundance of virus-like particles (VLP are described over a seamount. The association between VLP distribution, prokaryotic abundance, and environmental variables is also analyzed. Sampling was conducted in December 2004 on the Bajo O’Higgins 1 seamount (32°54’S, 73°53’W located in the Humboldt Current System off Chile. A oxygen minimum layer (OMZ was clearly present between 130 and 280 m in the water column over the seamount. Water samples were taken with Niskin bottles at 10 oceanographic stations over the seamount at depths of 5, 20, 50, 75, 100, and 150 m and at the benthic boundary layer (BBL; 5-12 m over the sediments. Temperature, salinity, oxygen, chlorophyll , and phaeopigments were measured at each station. Viral and prokaryotic abundances were determined with fluorochrome SYBR Green I. Viral abundance ranged from 1.53 x 109 VLP L-1 - 16.48 x 109 VLP L-1, whereas prokaryotic abundance ranged from 1.78 x 10 8 cell L-1 - 14.91 x 108 cell L-1. The virus-like particle/prokaryote ratio varied widely among the analyzed layers (i.e. surface, OMZ, and BBL, probably due to the presence of different prokaryotic and viral assemblages in each layer. Our results indicate that the environmental conditions, mainly the concentration of dissolved oxygen in the water column over Bajo O’Higgins 1 seamount, shape the association between viral and prokaryotic abundance.

  14. Precision and relative effectiveness of a purse seine for sampling age-0 river herring in lakes

    Science.gov (United States)

    Devine, Matthew T.; Roy, Allison; Whiteley, Andrew R.; Gahagan, Benjamin I.; Armstrong, Michael P.; Jordaan, Adrian

    2018-01-01

    Stock assessments for anadromous river herring, collectively Alewife Alosa pseudoharengus and Blueback Herring A. aestivalis, lack adequate demographic information, particularly with respect to early life stages. Although sampling adult river herring is increasingly common throughout their range, currently no standardized, field‐based, analytical methods exist for estimating juvenile abundance in freshwater lakes. The objective of this research was to evaluate the relative effectiveness and sampling precision of a purse seine for estimating densities of age‐0 river herring in freshwater lakes. We used a purse seine to sample age‐0 river herring in June–September 2015 and June–July 2016 in 16 coastal freshwater lakes in the northeastern USA. Sampling effort varied from two seine hauls to more than 50 seine hauls per lake. Catch rates were highest in June and July, and sampling precision was maximized in July. Sampling at night (versus day) in open water (versus littoral areas) was most effective for capturing newly hatched larvae and juveniles up to ca. 100 mm TL. Bootstrap simulation results indicated that sampling precision of CPUE estimates increased with sampling effort, and there was a clear threshold beyond which increased effort resulted in negligible increases in precision. The effort required to produce precise CPUE estimates, as determined by the CV, was dependent on lake size; river herring densities could be estimated with up to 10 purse‐seine hauls (one‐two nights) in a small lake (50 ha). Fish collection techniques using a purse seine as described in this paper are likely to be effective for estimating recruit abundance of river herring in freshwater lakes across their range.

  15. Chinstrap penguin foraging area associated with a seamount in Bransfield Strait, Antarctica

    Science.gov (United States)

    Kokubun, Nobuo; Lee, Won Young; Kim, Jeong-Hoon; Takahashi, Akinori

    2015-12-01

    Identifying marine features that support high foraging performance of predators is useful to determine areas of ecological importance. This study aimed to identify marine features that are important for foraging of chinstrap penguins (Pygoscelis antarcticus), an abundant upper-trophic level predator in the Antarctic Peninsula region. We investigated the foraging locations of penguins breeding on King George Island using GPS-depth loggers. Tracking data from 18 birds (4232 dives), 11 birds (2095 dives), and 19 birds (3947 dives) were obtained in 2007, 2010, and 2015, respectively. In all three years, penguins frequently visited an area near a seamount (Orca Seamount) in Bransfield Strait. The percentage of dives (27.8% in 2007, 36.1% in 2010, and 19.1% in 2015) and depth wiggles (27.1% in 2007, 37.2% in 2010, and 22.3% in 2015) performed in this area was higher than that expected from the size of the area and distance from the colony (8.4% for 2007, 14.7% for 2010, and 6.3% for 2015). Stomach content analysis showed that the penguins fed mainly on Antarctic krill. These results suggest that the seamount provided a favorable foraging area for breeding chinstrap penguins, with high availability of Antarctic krill, possibly related to local upwelling.

  16. In-situ petrophysical properties of hotspot volcanoes. Results from ODP Leg 197, Detroit Seamount and HSDP II borehole, Hawaii

    Science.gov (United States)

    Kock, I.; Pechnig, R.; Buysch, A.; Clauser, C.

    2003-04-01

    During ODP Leg 197 an extensive logging program was run on Site 1203, Detroit Seamount. This seamount is part of the Emperor seamount chain, a continuation of the Hawaiian volcanic chain. Standard ODP/LDEO logging tool strings were used to measure porosity, density, resistivity, p- and s-wave velocities and gamma ray activity. The FMS-tool yielded detailed high resolution resistivity images of the borehole wall. By interpretation and statistical analysis of the logging parameters a petrophysical classification of the drilled rock content could be derived. The pillow lava recovered in the cores exhibits low porosity, low resistivity and high density. This indicates no or very little vesicles in the non-fractured rock unit. Compared to the pillow basalts, subaerial basalts show increasing porosity, gamma ray and potassium content and decreasing density, resistivity and velocity. A basalt with no or little vesicles and a basalt with average or many vesicles can clearly be distinguished. The volcaniclastics show lower resistivity, lower sonic velocities, higher porosities and lower densities than the basalts. Three different rock types can be distinguished within the volcaniclastics: Tuffs, resedimented tephra and breccia. The tuff shows medium porosity and density, low gamma ray and potassium content. The log responses from the resedimented tephra suggest that the tephra is more easily altered than the tuff. The log responses from the breccia lie between the tuff and tephra log responses, but the breccia can clearly be identified in the FMS borehole images. A similar rock content was found in the Hawaiian Scientific Drilling Project borehole. Gamma ray activity, electrical resistivity and sonic velocity were measured down to 2700 mbsl.. Compared to the 72-76 Ma old Detroit seamount basalts, the HSDP subaerial and submarine lava flows show a significant lower gamma ray activity, while sonic velocity and electrical resistivity are comparable. Deviations between the

  17. Swimming depth of migrating silver eels Anguilla japonica released at seamounts of the West Mariana Ridge, their estimated spawning sites

    OpenAIRE

    Aoyama, J.; Hissmann, Karen; Yoshinaga, T.; Sasai, S.; Uto, T.; Ueda, H.

    1999-01-01

    Five hormone-treated female Japanese silver eels Anguilla japonica were tagged with ultrasonic transmitters and released by submersible in the West Pacific at seamounts of the West Mariana Ridge, their supposed spawning grounds. Four eels were tracked for 60 to 423 min in the vicinity of the seamounts. They did not settle at the seamounts but swam at a mean speed of 0.37 m s-1 into open water above deep ground. Their mean swimming depth ranged from 81 to 172 m. Experiments suggest that pre-ma...

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

    Science.gov (United States)

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

    2013-12-01

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

  19. Biodegradation of Mexel 432 By Bacteria From the Seine River

    International Nuclear Information System (INIS)

    Allonier, A.S.; Khalanski, M.

    1996-01-01

    This report deals with a study of the biodegradation of a filmogenic organic product (Mexel 432) usable in the fight against corrosion, scale and fouling, presenting a certain interest in the research of processes enabling a functional and environmental efficiency for the cooling systems of thermal power stations. The study of the degradation of this product is followed by a global colorimetric method. It shows that the product is stable on the long-term in demineralized water. On the other hand, its rate of disappearance in river waters is significant (50 % in 2 or 3 days). In this phenomenon of disappearance, biodegradation seems to play a part. Some bacteria from the natural environment (river Seine) have been isolated. Two of them seem to play a significant part, since they can degrade the product in three weeks. During the degradation, the amines with long chains (more than six carbons) of the Mexel, measured by the colorimetric method, disappear. The other compounds generated by the biodegradation process are not identified. (authors)

  20. Rapid fish stock depletion in previously unexploited seamounts: the ...

    African Journals Online (AJOL)

    Rapid fish stock depletion in previously unexploited seamounts: the case of Beryx splendens from the Sierra Leone Rise (Gulf of Guinea) ... A spectral analysis and red-noise spectra procedure (REDFIT) algorithm was used to identify the red-noise spectrum from the gaps in the observed time-series of catch per unit effort by ...

  1. On the interaction between ocean surface waves and seamounts

    Science.gov (United States)

    Sosa, Jeison; Cavaleri, Luigi; Portilla-Yandún, Jesús

    2017-12-01

    Of the many topographic features, more specifically seamounts, that are ubiquitous in the ocean floor, we focus our attention on those with relatively shallow summits that can interact with wind-generated surface waves. Among these, especially relatively long waves crossing the oceans (swells) and stormy seas are able to affect the water column up to a considerable depth and therefore interact with these deep-sea features. We quantify this interaction through numerical experiments using a numerical wave model (SWAN), in which a simply shaped seamount is exposed to waves of different length. The results show a strong interaction that leads to significant changes in the wave field, creating wake zones and regions of large wave amplification. This is then exemplified in a practical case where we analyze the interaction of more realistic sea conditions with a very shallow rock in the Yellow Sea. Potentially important for navigation and erosion processes, mutatis mutandis, these results are also indicative of possible interactions with emerged islands and sand banks in shelf seas.

  2. Fecal bacteria in the rivers of the Seine drainage network (France): sources, fate and modelling.

    Science.gov (United States)

    Servais, Pierre; Garcia-Armisen, Tamara; George, Isabelle; Billen, Gilles

    2007-04-01

    The Seine river watershed (France) is a deeply anthropogenically impacted area, due to the high population density, intense industrial activities and intensive agriculture. The water quality and ecological functioning of the different rivers of the Seine drainage network have been extensively studied during the last fifteen years within the framework of a large French multidisciplinary scientific program (PIREN Seine program). This paper presents a synthesis of the main data gained in the scope of this program concerning the microbiological water contamination of the rivers of the Seine drainage network. The more common indicator of fecal contamination (fecal coliforms) was mainly used; some complementary works used E. coli and intestinal enterococci as alternative fecal indicators. Point sources (outfall of wastewater treatment plants) and non point sources (surface runoff and soil leaching) of fecal pollution to the rivers of the watershed were quantified. Results showed that, at the scale of a large urbanised watershed as the Seine basin, the input of fecal micro-organisms by non-point sources is much lower than the inputs by point sources. However, the local impact of diffuse non-human sources (especially surface runoff of pastured fields) can be of major importance on the microbiological quality of small headwater rivers. Fecal contamination of the main rivers of the Seine watershed (Seine, Marne, Oise rivers) was studied showing high level of microbiological pollution when compared to European guidelines for bathing waters. The strong negative impact of treated wastewater effluents outfall on the microbiological quality of receiving rivers was observed in different areas of the watershed. Once released in rivers, culturable fecal bacteria disappeared relatively rapidly due to mortality (protozoan grazing, lysis) or loss of culturability induced by stress conditions (sunlight effect, nutrient concentration, temperature). Mortality rates of E. coli were studied

  3. Progressive enrichment of arc magmas caused by the subduction of seamounts under Nishinoshima volcano, Izu-Bonin Arc, Japan

    Science.gov (United States)

    Sano, Takashi; Shirao, Motomaro; Tani, Kenichiro; Tsutsumi, Yukiyasu; Kiyokawa, Shoichi; Fujii, Toshitsugu

    2016-06-01

    The chemical composition of intraplate seamounts is distinct from normal seafloor material, meaning that the subduction of seamounts at a convergent margin can cause a change in the chemistry of the mantle wedge and associated arc magmas. Nishinoshima, a volcanic island in the Izu-Bonin Arc of Japan, has been erupting continuously over the past 2 years, providing an ideal opportunity to examine the effect of seamount subduction on the chemistry of arc magmas. Our research is based on the whole-rock geochemistry and the chemistry of minerals within lavas and air-fall scoria from Nishinoshima that were erupted before 1702, in 1973-1974, and in 2014. The mineral phases within the analyzed samples crystallized under hydrous conditions (H2O = 3-4 wt.%) at temperatures of 970 °C-990 °C in a shallow (3-6 km depth) magma chamber. Trace element data indicate that the recently erupted Nishinoshima volcanics are much less depleted in the high field strength elements (Nb, Ta, Zr, Hf) than other volcanics within the Izu-Bonin Arc. In addition, the level of enrichment in the Nishinoshima magmas has increased in recent years, probably due to the addition of material from HIMU-enriched (i.e., high Nb/Zr and Ta/Hf) seamounts on the Pacific Plate, which is being subducted westwards beneath the Philippine Sea Plate. This suggests that the chemistry of scoria from Nishinoshima volcano records the progressive addition of components derived from subducted seamounts.

  4. CRED Gridded Bathymetry near Northampton Seamounts (100-004), Northwestern Hawaiian Islands

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — File 100-004b is a 60-m ASCII grid of depth data collected near Northampton Seamounts in the Northwestern Hawaiian Islands as of May 2003. This grid has been...

  5. Geochemistry of dissolved and suspended loads of the Seine River, France: anthropogenic impact, carbonate and silicate weathering

    Science.gov (United States)

    Roy, S.; Gaillardet, J.; Allègre, C. J.

    1999-05-01

    This study focuses on the chemistry of the Seine river system, one of the major rivers in Europe, and constitutes the first geochemical investigation of both suspended and dissolved loads of this river. The Seine river drains a typical Mesozoic-Cenozoic sedimentary basin: the Paris basin, constituted of limestones mixed or interbedded with terrigenous sediments derived from the paleoreliefs bordering the Mesozoic and Cenozoic seas. In the context of quantifying the global influence of carbonate and silicate weathering on atmospheric CO 2 consumption, the Seine river offers the possibility of examining weathering rates in a flat sedimentary environment, under temperate climatic conditions. One of the major problems associated with the Seine river, as with many temperate rivers, is pollution. We propose, in this paper, 2 approaches in order to correct the dissolved load of the Seine river for anthropogenic inputs and to calculate weathering rates of carbonates and silicates. The first uses the dissolved load of rivers and tries to allocate the different solutes to different sources. A mixing model, based on elemental ratios, is established and solved by an inversion technique. The second approach consists in using the suspended load geochemistry. Under steady state conditions, we show that the geochemistry of suspended sediments makes it possible to estimate the amount of solutes released during the chemical weathering of silicates, and thus to calculate weathering rates of silicates. The total dissolved load of the Seine river at Paris can be decomposed into 2% of solutes derived from natural atmospheric sources, 7% derived from anthropogenic atmospheric sources, 6% derived from agriculture, 3% derived from communal inputs, and 82% of solutes derived from rock weathering. During high floods, the contribution of atmospheric and agriculture inputs predominates. The weathering rate of carbonates is estimated to be 48 t/km 2/yr (25 mm/1000 yr). Only 10% of carbonates

  6. Distribution and origin of seamounts in the central Indian Ocean Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Das, P.; Iyer, S.D.; Kodagali, V.N.; Krishna, K.S.

    Approximately 200 seamounts of different dimensions have been identified, from multibeam bathymetry maps of the Central Indian Ocean Basin (CIOB) (9 degrees S to 16 degrees S and 72 degrees E to 80 degrees E), of which 61% form eight chains...

  7. Afrique-sur-Seine: A new trend in Francophone African literature

    Directory of Open Access Journals (Sweden)

    Наталья Сергеевна Найденова

    2011-09-01

    Full Text Available The article deals with the prerequisites and main stage of formation of a new trend in francophone African literature commonly known as Afrique-sur-Seine. The article outlines its main characteristic features and touches upon its development prospects.

  8. Une ferme du début du IIIe s. av. J.-C. au “ Marais du Colombier ”, Varennes-sur-Seine (Seine-et-Marne : analyse archéologique et environnementale A farm from the beginning of the 3rd Century BC at 'Marais du Colombier', Varennes-sur-Seine (Seine-et-Marne: archaeological and environmental analysis

    Directory of Open Access Journals (Sweden)

    Jean-Marc Séguier

    2009-05-01

    Colombier site, Varennes-sur-Seine (Seine-et-Marne enabled us to study a rural establishment dating back to the first half of the 3rd century BC set in a damp low-lying area of the plain situated in the lower reaches of the Seine/Yonne confluence. The establishment, structured around an empty area interpreted as a courtyard or horticultural space, has nearly all the components of a rural establishment: dwellings, granaries and other annexed buildings, silos, wells and ditches. Among the buildings, the dwelling was notable for the adoption of an oval plan probably supporting the hypothesis of a roof structure, which makes it one of the most ancient of the Iron age. Of the many macro vegetal remains, preserved in several pits, the main one being 5003 situated near the house, enabled a palaeobotanical analysis. The combination of archaeological, archaeobotanical (carpology, anthracology, xylology and archaeozoological data enables a reconstruction of a surrounding environment marked by its great diversity and exploitation (plants cultivated, collection environment, livestock farming, hunting. All the elements combine in this agricultural establishment to reveal a production unit providing a comfortable level of life. Its organisation is rather different from that of the most part of the early La Tène period and from the beginning of middle La Tène of the Senonais area and seems to prefigure that of the enclosure sites of the middle and late La Tène. As for the presence of human remains, they bring elements on the funerary practices connected to children dying at a young age and on cultural practices in a domestic context.

  9. Pseudofaults and associated seamounts in the conjugate Arabian and Eastern Somali basins, NW Indian Ocean - New constraints from high-resolution satellite-derived gravity data

    Science.gov (United States)

    Sreejith, K. M.; Chaubey, A. K.; Mishra, Akhil; Kumar, Shravan; Rajawat, A. S.

    2016-12-01

    Marine gravity data derived from satellite altimeters are effective tools in mapping fine-scale tectonic features of the ocean basins such as pseudofaults, fracture zones and seamounts, particularly when the ocean basins are carpeted with thick sediments. We use high-resolution satellite-generated gravity and seismic reflection data to map boundaries of pseudofaults and transferred crust related to the Paleocene spreading ridge propagation in the Arabian and its conjugate Eastern Somali basins. The study has provided refinement in the position of previously reported pseudofaults and their spatial extensions in the conjugate basins. It is observed that the transferred crustal block bounded by inner pseudofault and failed spreading ridge is characterized by a gravity low and rugged basement. The refined satellite gravity image of the Arabian Basin also revealed three seamounts in close proximity to the pseudofaults, which were not reported earlier. In the Eastern Somali Basin, seamounts are aligned along NE-SW direction forming ∼300 km long seamount chain. Admittance analysis and Flexural model studies indicated that the seamount chain is isostatically compensated locally with Effective Elastic Thickness (Te) of 3-4 km. Based on the present results and published plate tectonic models, we interpret that the seamounts in the Arabian Basin are formed by spreading ridge propagation and are associated with pseudofaults, whereas the seamount chain in the Eastern Somali Basin might have probably originated due to melting and upwelling of upper mantle heterogeneities in advance of migrating/propagating paleo Carlsberg Ridge.

  10. Geochemical and iron isotopic insights into hydrothermal iron oxyhydroxide deposit formation at Loihi Seamount

    Science.gov (United States)

    Rouxel, Olivier; Toner, Brandy; Germain, Yoan; Glazer, Brian

    2018-01-01

    Low-temperature hydrothermal vents, such as those encountered at Loihi Seamount, harbor abundant microbial communities and provide ideal systems to test hypotheses on biotic versus abiotic formation of hydrous ferric oxide (FeOx) deposits at the seafloor. Hydrothermal activity at Loihi Seamount produces abundant microbial mats associated with rust-colored FeOx deposits and variably encrusted with Mn-oxyhydroxides. Here, we applied Fe isotope systematics together with major and trace element geochemistry to study the formation mechanisms and preservation of such mineralized microbial mats. Iron isotope composition of warm (oxidation of Fe(II) during mixing of the hydrothermal fluid with seawater. By comparing the results with experimentally determined Fe isotope fractionation factors, we determined that less than 20% of Fe(II) is oxidized within active microbial mats, although this number may reach 80% in aged or less active deposits. These results are consistent with Fe(II) oxidation mediated by microbial processes considering the expected slow kinetics of abiotic Fe oxidation in low oxygen bottom water at Loihi Seamount. In contrast, FeOx deposits recovered at extinct sites have distinctly negative Fe-isotope values down to -1.77‰ together with significant enrichment in Mn and occurrence of negative Ce anomalies. These results are best explained by the near-complete oxidation of an isotopically light Fe(II) source produced during the waning stage of hydrothermal activity under more oxidizing conditions. Light Fe isotope values of FeOx are therefore generated by subsurface precipitation of isotopically heavy Fe-oxides rather than by the activity of dissimilatory Fe reduction in the subsurface. Overall, Fe-isotope compositions of microbial mats at Loihi Seamount display a remarkable range between -1.2‰ and +1.6‰ which indicate that Fe isotope compositions of hydrothermal Fe-oxide precipitates are particularly sensitive to local environmental conditions where

  11. Quantifying seining detection probability for fishes of Great Plains sand‐bed rivers

    Science.gov (United States)

    Mollenhauer, Robert; Logue, Daniel R.; Brewer, Shannon K.

    2018-01-01

    Species detection error (i.e., imperfect and variable detection probability) is an essential consideration when investigators map distributions and interpret habitat associations. When fish detection error that is due to highly variable instream environments needs to be addressed, sand‐bed streams of the Great Plains represent a unique challenge. We quantified seining detection probability for diminutive Great Plains fishes across a range of sampling conditions in two sand‐bed rivers in Oklahoma. Imperfect detection resulted in underestimates of species occurrence using naïve estimates, particularly for less common fishes. Seining detection probability also varied among fishes and across sampling conditions. We observed a quadratic relationship between water depth and detection probability, in which the exact nature of the relationship was species‐specific and dependent on water clarity. Similarly, the direction of the relationship between water clarity and detection probability was species‐specific and dependent on differences in water depth. The relationship between water temperature and detection probability was also species dependent, where both the magnitude and direction of the relationship varied among fishes. We showed how ignoring detection error confounded an underlying relationship between species occurrence and water depth. Despite imperfect and heterogeneous detection, our results support that determining species absence can be accomplished with two to six spatially replicated seine hauls per 200‐m reach under average sampling conditions; however, required effort would be higher under certain conditions. Detection probability was low for the Arkansas River Shiner Notropis girardi, which is federally listed as threatened, and more than 10 seine hauls per 200‐m reach would be required to assess presence across sampling conditions. Our model allows scientists to estimate sampling effort to confidently assess species occurrence, which

  12. Impact of boat generated waves over an estuarine intertidal zone of the Seine estuary (France)

    Science.gov (United States)

    Deloffre, Julien; Lafite, Robert

    2015-04-01

    Water movements in macrotidal estuaries are controlled by the tidal regime modulated seasonally by the fluvial discharge. Wind effect on hydrodynamics and sediment transport is also reported at the mouth. Besides estuaries are frequently man altered our knowledge on the human impact on hydrodynamics and sediment transport is less extended. As an example on the Seine estuary (France) port authorities have put emphasis on facilitating economic exchanges by means of embankment building and increased dredging activity over the last century. These developments led to secure sea vessel traffic in the Seine estuary but they also resulted in a change of estuarine hydrodynamics and sediment transport features. Consequences of boat generated waves are varied: increased water turbidity and sediment transfer, release of nutrient and contaminants in the water column, harmful to users, ecosystems and infrastructures generating important maintenance spending. The aim of this study is to analyse the impact of boat generated waves on sediment transport over an intertidal area. The studied site is located on the left bank in the fluvial part of the Seine estuary. On this site the maximum tidal range ranges between 1.25 and 3.5m respectively during neap and spring tide. The sampling strategy is based on continuous ADV acquisition at 4Hz coupled with turbidimeter and altimeter measurements (1 measurement every minute) in order to decipher sediment dynamics during one year. Our results indicate that sediment dynamics are controlled by river flow while medium term scale evolution is dependent on tidal range and short term dynamics on sea-vessels waves. 64% of boat passages generated significant sediment reworking (from few mm.min-1 to 3cm.min-1). This reworking rate is mainly controlled by two parameters: (i) water height on the site and (ii) vessels characteristics; in particular the distance between seabed and keel that generate a Bernoulli wave (with maximum amplitude of 0.6m

  13. Love and Grace in Heidegger´s 'Sein und Zeit'

    DEFF Research Database (Denmark)

    Östman, Lars

    2014-01-01

    Martin Heidegger’s Sein und Zeit presents one of the most striking reflexions on human facticity, i.e. the fact that Dasein fundamentally exists in a world letting Dasein and world be co-extensive. By quoting two central personages in theology, Pascal and Augustine, Heidegger refers to a concept...... of love that is constitutive for Dasein’s facticity to truth and to knowledge. By investigating the claim that love is as good as absent from Sein und Zeit, the article intends to show that the scanty references to love nevertheless have a central role in Heidegger’s early work and, furthermore, why...... Heidegger returns to it in his later thinking. Interesting in this regard is the connection between the theological concept of love and Heidegger’s concept of ‘world’. The article places Heidegger’s Destruktion of the metaphysical tradition in the realms of his Dasein analysis focussing on facticity. Taking...

  14. Three-dimensional S-wave tomography under Axial Seamount

    Science.gov (United States)

    Baillard, C.; Wilcock, W. S. D.; Arnulf, A. F.; Tolstoy, M.; Waldhauser, F.

    2017-12-01

    Axial Seamount is a submarine volcano located at the intersection of the Juande Fuca Ridge and the Cobb-Eickelberg hotspot 500 km off the coast of thenorthwestern United States. The seamount, which rises 1 km above the seafloor, ischaracterized by a shallow caldera that is elongated in the N-S direction, measure 8km by 3 km and sits on top of a 14 km by 3 km magma reservoir. Two eruptive eventsin 1998 and 2011 motivated the deployment in 2014 of a real time cabled observatorywithin the Axial caldera, as part of the Ocean Observatories Initiative (OOI).Theobservatory includes a network of seven seismometers that span the southern half ofthe caldera. Five months after the observatory came on-line in November 2014, thevolcano erupted on April 24, 2015. Well over 100,000 events were located in thevicinity of the caldera, delineating an outward dipping ring fault that extends fromnear the surface to the magma body at 2 km depth and which accommodatesinflation and deflation of the volcano.The initial earthquake locations have beenobtained with a one-dimensional velocity model but the travel time residuals suggeststrong heterogeneities. A three-dimensional P-wave velocity model, obtained bycombining multichannel and ocean bottom seismometer refraction data, is being usedto refine locations but the three-dimensional S-wave structure is presently unknown.In most mid-ocean ridge settings, the distribution of earthquakes is not conducive forjoint inversions for S-wave velocity and hypocentral parameters because there are fewcrossing ray paths but at Axial the presence of a ring fault that is seismically active atall depths on both the east and west side of the caldera, provides a reasonablegeometry for such efforts. We will present the results of joint inversions that assumethe existing three-dimensional P wave velocity model and solve for VP/VS structure andhypocentral parameters using LOTOS, an algorithm that solves the forward problemusing ray bending.The resulting model

  15. Hydrothermal activity on the summit of Loihi Seamount, Hawaii

    Energy Technology Data Exchange (ETDEWEB)

    Sakai, H; Tsubota, H; Nakai, T; Ishibashi, J; Akagi, T; Gamo, T; Tilbrook, B; Igarashi, G; Kodera, M; Shitashima, K

    1987-01-01

    Loihi Seamount is located about 30km southeast of the Island of Hawaii; it rises from the sea floor at a depth of 4000m and reaches a maximum elevation of 1000m blow sea level. Oceanographic studies including CTD survey of warm sites and bottom photography confirmed several hydrothermal fields on the summit of the seamount. The summit is covered with hydrothermal plumes which are extremely rich in methane, helium, carbon dioxide, iron and manganese; the maximum concentration of helium is 91.8 n1/1, the highest so far reported for open-ocean water. The /sup 3/He//sup 4/He ratio of helium injected into seawater is 14 times the atmospheric level. The 3He/heat and CO/sub 2//heat ratios in the plumes are one to two orders of magnitude greater than those at oceanic spreading centers, implying a more primitive source region for hotspot volcanism. The plumes also show negative pH anomalies up to half a pH unit from ambient owing to the high injection rate of CO/sub 2/. (4 figs, 3 photos, 1 tab, 31 refs)

  16. Geomorphological features in the southern Canary Island Volcanic Province: The importance of volcanic processes and massive slope instabilities associated with seamounts

    Science.gov (United States)

    Palomino, Desirée; Vázquez, Juan-Tomás; Somoza, Luis; León, Ricardo; López-González, Nieves; Medialdea, Teresa; Fernández-Salas, Luis-Miguel; González, Francisco-Javier; Rengel, Juan Antonio

    2016-02-01

    The margin of the continental slope of the Volcanic Province of Canary Islands is characterised by seamounts, submarine hills and large landslides. The seabed morphology including detailed morphology of the seamounts and hills was analysed using multibeam bathymetry and backscatter data, and very high resolution seismic profiles. Some of the elevation data are reported here for the first time. The shape and distribution of characteristics features such as volcanic cones, ridges, slides scars, gullies and channels indicate evolutionary differences. Special attention was paid to recent geological processes that influenced the seamounts. We defined various morpho-sedimentary units, which are mainly due to massive slope instability that disrupt the pelagic sedimentary cover. We also studied other processes such as the role of deep bottom currents in determining sediment distribution. The sediments are interpreted as the result of a complex mixture of material derived from a) slope failures on seamounts and submarine hills; and b) slides and slumps on the continental slope.

  17. Microtopographic analysis of cobalt-rich manganese deposits on a mid-Pacific seamount

    Digital Repository Service at National Institute of Oceanography (India)

    Yamazaki, T.; Sharma, R.; Tsurusaki, K.

    Evaluation of stereo photographs and video data shows a variety of surface features associated with the crusts and nodules across a mid-pacific seamount. The differences in the coverage, distribution and relief are used to classify the surface...

  18. Oceanographic Survey of Cross Seamount and Control Sites (SE0803, EK60)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The goals of the cruise were to collect acoustic backscatter and oceanographic data at Cross Seamount (18?43.285? N, longitude 158? 15.710? W) and at control sites...

  19. Seamount egg-laying grounds of the deep-water skate Bathyraja richardsoni.

    Science.gov (United States)

    Henry, L-A; Stehmann, M F W; De Clippele, L; Findlay, H S; Golding, N; Roberts, J M

    2016-08-01

    Highly localized concentrations of elasmobranch egg capsules of the deep-water skate Bathyraja richardsoni were discovered during the first remotely operated vehicle (ROV) survey of the Hebrides Terrace Seamount in the Rockall Trough, north-east Atlantic Ocean. Conductivity-temperature-depth profiling indicated that the eggs were bathed in a specific environmental niche of well-oxygenated waters between 4·20 and 4·55° C, and salinity 34·95-35·06, on a coarse to fine-grained sandy seabed on the seamount's eastern flank, whereas a second type of egg capsule (possibly belonging to the skate Dipturus sp.) was recorded exclusively amongst the reef-building stony coral Solenosmilia variabilis. The depths of both egg-laying habitats (1489-1580 m) provide a de facto refuge from fisheries mortality for younger life stages of these skates. © 2016 The Authors. Journal of Fish Biology published by John Wiley & Sons Ltd on behalf of The Fisheries Society of the British Isles.

  20. The beach-seine and gill-net fisheries are South Africa's oldest ...

    African Journals Online (AJOL)

    spamer

    Previous works on the South African gill-net and beach-seine ... catch and effort between four different regions along the South ... evaluate participation in and management of the ... mesh on the West Coast and the Southern and Eastern.

  1. Lava bubble-wall fragments formed by submarine hydrovolcanic explosions on Lo'ihi Seamount and Kilauea Volcano

    Science.gov (United States)

    Clague, D.A.; Davis, A.S.; Bischoff, J.L.; Dixon, J.E.; Geyer, R.

    2000-01-01

    Glassy bubble-wall fragments, morphologically similar to littoral limu o Pele, have been found in volcanic sands erupted on Lo'ihi Seamount and along the submarine east rift zone of Kilauea Volcano. The limu o Pele fragments are undegassed with respect to H2O and S and formed by mild steam explosions. Angular glass sand fragments apparently form at similar, and greater, depths by cooling-contraction granulation. The limu o Pele fragments from Lo'ihi Seamount are dominantly tholeiitic basalt containing 6.25-7.25% MgO. None of the limu o Pele samples from Lo'ihi Seamount contains less than 5.57% MgO, suggesting that higher viscosity magmas do not form lava bubbles. The dissolved CO2 and H2O contents of 7 of the limu o Pele fragments indicate eruption at 1200??300 m depth (120??30 bar). These pressures exceed that generally thought to limit steam explosions. We conclude that hydrovolcanic eruptions are possible, with appropriate pre-mixing conditions, at pressures as great as 120 bar.

  2. Cancer du sein au Cameroun, profil histo-épidémiologique: à propos de 3044 cas

    Science.gov (United States)

    Engbang, Jean Paul Ndamba; Essome, Henri; Koh, Valère Mve; Simo, Godefroy; Essam, Jean Daniel Sime; Mouelle, Albert Sone; Essame, Jean Louis Oyono

    2015-01-01

    Décrire les caractéristiques épidémiologiques et histo-pathologiques des tumeurs malignes du sein au Cameroun. Il s'agissait d'une étude rétrospective descriptive portant sur les tumeurs malignes du sein, colligées, dans les registres des différents laboratoires d'Anatomie Pathologique publiques et privés repartis dans cinq régions (centre, littoral, Ouest, Nord-ouest, Sud-ouest), pendant une période de 10 ans (2004-2013). Les paramètres étudiés étaient la fréquence, l’âge, le sexe, la localisation, le type et le grade histologique, et les récepteurs hormonaux. Un total de 3044 cas de cancers du sein a été recensé, soit une fréquence annuelle de 304,4 cas en moyenne. Le sexe féminin était le plus représenté avec 2971 cas (97,60%) et les hommes avec 73 cas (2,40%), soit un sexe ratio (H/F) de 0,02. L’âge moyen des patients était de 46±15,87 ans, avec des extrêmes de 13 et 95 ans. Selon la localisation, le sein gauche était atteint dans 1244 cas (52%) et le sein droit dans 1115 cas (47%). Au plan histologique, on retrouvait essentiellement des carcinomes avec 96,50% des cas, des sarcomes 1,39%, des lymphomes 1,07% et la maladie de Paget du mamelon, 1,03%. Les tumeurs épithéliales étaient infiltrantes dans 2049 cas (84,46%), avec une prédominance du carcinome canalaire infiltrant (1870 cas) et non infiltrantes dans 377 cas (15,54%). Le grade histo-pronostic de SBR avait révélé une prédominance du grade II dans 66% des cas. Les cancers du sein restent une pathologie fréquente au Cameroun et atteignent principalement la population féminine en âge de procréer. Ils sont caractérisés par la prédominance du carcinome canalaire infiltrant. PMID:26523182

  3. Ocean currents and acoustic backscatter data from shipboard ADCP measurements at three North Atlantic seamounts between 2004 and 2015

    OpenAIRE

    Mohn, Christian; Denda, Anneke; Christiansen, Svenja; Kaufmann, Manfred; Peine, Florian; Springer, Barbara; Turnewitsch, Robert; Christiansen, Bernd

    2018-01-01

    Seamounts are amongst the most common physiographic structures of the deep-ocean landscape, but remoteness and geographic complexity have limited the systematic collection of integrated and multidisciplinary data in the past. Consequently, important aspects of seamount ecology and dynamics remain poorly studied. We present a data collection of ocean currents and raw acoustic backscatter from shipboard Acoustic Doppler Current Profiler (ADCP) measurements during six cruises between 2004 and 20...

  4. 3D-Reconstruction of recent volcanic activity from ROV-video, Charles Darwin Seamounts, Cape Verdes

    Science.gov (United States)

    Kwasnitschka, T.; Hansteen, T. H.; Kutterolf, S.; Freundt, A.; Devey, C. W.

    2011-12-01

    As well as providing well-localized samples, Remotely Operated Vehicles (ROVs) produce huge quantities of visual data whose potential for geological data mining has seldom if ever been fully realized. We present a new workflow to derive essential results of field geology such as quantitative stratigraphy and tectonic surveying from ROV-based photo and video material. We demonstrate the procedure on the Charles Darwin Seamounts, a field of small hot spot volcanoes recently identified at a depth of ca. 3500m southwest of the island of Santo Antao in the Cape Verdes. The Charles Darwin Seamounts feature a wide spectrum of volcanic edifices with forms suggestive of scoria cones, lava domes, tuff rings and maar-type depressions, all of comparable dimensions. These forms, coupled with the highly fragmented volcaniclastic samples recovered by dredging, motivated surveying parts of some edifices down to centimeter scale. ROV-based surveys yielded volcaniclastic samples of key structures linked by extensive coverage of stereoscopic photographs and high-resolution video. Based upon the latter, we present our workflow to derive three-dimensional models of outcrops from a single-camera video sequence, allowing quantitative measurements of fault orientation, bedding structure, grain size distribution and photo mosaicking within a geo-referenced framework. With this information we can identify episodes of repetitive eruptive activity at individual volcanic centers and see changes in eruptive style over time, which, despite their proximity to each other, is highly variable.

  5. Lasten ulkovaatteiden kevät-kesämalliston seinäesillepano-ohje : case: Reima Oy

    OpenAIRE

    Järvenoja, Annika

    2014-01-01

    Opinnäytetyö tehtiin Reima Oy:lle. Työn tavoitteena oli kerätä asiakkaiden mielipiteitä lasten ulkovaatteiden seinäesillepanoista. Tutkimuksen pohjalta tehtiin seinäesillepano-ohje kevät-kesämallistolle. Reiman omat myymälät sijaitsevat pääosin Kiinassa, Suomessa ja Venäjällä. Kevät-kesämalliston tuotteiden vaihtelevuus välikausivaatteista ohuisiin aurinkosuojavaatteisiin koettiin myymälässä haasteelliseksi. Tavoitteena on tutkia lisäksi, mistä maiden kulttuurien eroavaisuudet johtuvat, ja mi...

  6. Deep-sea seamount fisheries: a review of global status and future prospects Pesquerías de aguas profundas realizadas en montes submarinos: revision global de su estado y perspectivas futuras

    Directory of Open Access Journals (Sweden)

    Malcolm R Clark

    2009-01-01

    Full Text Available Seamounts support a large number and wide diversity of fish species. A number of these spe-cies can form aggregations for spawning or feeding and are the target of large-scale trawl fisheries. Since the 1970s, seamounts throughout the worlds' oceans have been explored for commercial resources, starting with efforts by the Soviet Union and Japan, which deployed distant water fleets around the world. Since then, a large number of countries have pursued fisheries on seamounts, especially in the deep sea. The total cumula-tive catch from seamount trawl fisheries exceeds two million tonnes. Catch histories for many deep-sea species show rapidly declining landings, and careful management is required to increase the chances of sustain-able fisheries. The low productivity of many seamount species limits the prospects for the large-scale exploita-tion of fish and invertebrate resources on seamounts.Los montes submarinos constituyen el habitat de una vasta y amplia variedad de especies ícticas. Parte de estas especies pueden formar agregaciones reproductivas o alimenticias, siendo objeto de importantes pesquerías de arrastre. A partir de la década de los 70' los montes submarinos en los diversos océanos fueron explorados en busca de recursos comerciales, labores que se iniciaron con la expansion de flotas de aguas distantes de la Unión Soviética y Japón alrededor del mundo. Desde ese momento, un gran número de otros países ha desarrollado pesquerías en montes submarinos, especialmente en aguas profundas. La captura total acumulada que se ha extraído en los montes submarinos excede a dos millones de toneladas. La historia de las faenas pesqueras realizadas en numerosas especies de aguas profundas muestra una rápida disminución en los desembarques, razón por la cual requieren de un cuidadoso manejo para incrementar la oportunidad de lograr la condición de pesquerías sustentables. La baja productividad observada en diversas especies indica

  7. Megafaunal community structure of Andaman seamounts including the back-arc basin - A quantitative exploration from the Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Sautya, S.; Ingole, B.S.; Ray, D.; Stohr, S.; Samudrala, K.; KameshRaju, K.A.; Mudholkar, A.V.

    seamount fauna in the southwest Pacific. Nature 405: 944–947. 4. McClain C (2007) Seamounts: identity crisis or split personality? Journal of Biogeography 34: 2001–2008. 5. Clark MR, Rowden AA, Schlacher T, Williams A, Consalvey M, et al. (2010) The ecology.... 19. Pielou EC (1966) Species diversity and pattern diversity in the study of ecological succession. Journal of Theoretical Biology 10: 372–383. 20. Shannon CE, Weaver W (1963) The Mathematical Theory of Communication. Urbana, Illinois: University...

  8. Bacterial Diversity in Deep-Sea Sediments from Afanasy Nikitin Seamount, Equatorial Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Khandeparker, R.; Meena, R.M.; Deobagkar, D.D.

    Deep-sea sediments can reveal much about the last 200 million years of Earth history, including the history of ocean life and climate. Microbial diversity in Afanasy Nikitin seamount located at Equatorial East Indian Ocean (EEIO) was investigated...

  9. Deepwater fish assemblages at Isla del Coco National Park and Las Gemelas Seamount, Costa Rica

    Directory of Open Access Journals (Sweden)

    Richard M. Starr

    2012-11-01

    Full Text Available The deepwater faunas of oceanic islands and seamounts of the Eastern Tropical Pacific are poorly known. From 11-22 September 2009 we conducted an exploration of the deepwater areas of the Isla del Coco Marine Conservation Area, Costa Rica and a nearby seamount using a manned submersible. The goal of the exploration was to characterize the habitats and biota, and conduct quantitative surveys of the deepwater portions of Isla del Coco National Park and Las Gemelas Seamount, located about 50km southwest of Isla del Coco. We completed a total of 22 submersible dives, spanning more than 80hr underwater, and collected a total of 36hr of video. We surveyed habitats from 50-402m and observed more than 45 species of fishes, some of which have not yet been described and are likely new to science. The diversity of fish species in deep water at Isla del Coco National Park was lower than the diversity of fishes in shallow water, and eight species groups accounted for more than 95% of the total fish biomass. The combined density of all fish species was higher at Las Gemelas Seamount (253 fishes/100m² than at Isla del Coco National Park (138 fishes/100m². The combined density of fishes in habitats comprised primarily of bedrock or large boulders outcrops was more than three times as high at Las Gemelas Seamount as it was at Isla del Coco National Park. This discrepancy was caused by the extremely high concentration of Anthiinae fishes in rocky habitats at Las Gemelas Seamount. Densities of fishes in the other habitats were similar between the two sites. Similarly, when estimates of fish density were plotted by slope categories the density was much greater on steep slopes, which were usually comprised of rock habitats. Also, the density of fishes was greatest on high rugosity habitats. Results of these submersible surveys indicate that seamounts in the tropical eastern Pacific Ocean may be an important source of biodiversity and that more quantitative surveys

  10. Non-Hawaiian lithostratigraphy of Louisville seamounts and the formation of high-latitude oceanic islands and guyots

    Science.gov (United States)

    Buchs, David M.; Williams, Rebecca; Sano, Shin-ichi; Wright, V. Paul

    2018-05-01

    Guyots are large seamounts with a flat summit that is generally believed to form due to constructional biogenic and/or erosional processes during the formation of volcanic islands. However, despite their large abundance in the oceans, there are still very few direct constraints on the nature and formation of guyots, in particular those formed at high latitude that lack a thick cap of shallow-marine carbonate rocks. It is largely accepted based on geophysical constraints and surficial observations/sampling that the summit platform of these guyots is shaped by wave abrasion during post-volcanic subsidence of volcanic islands. Here we provide novel constraints on this hypothesis and the summit geology of guyots with a lithostratigraphic analysis of cores from three Louisville seamounts (South Pacific) collected during Expedition 330 of the Integrated Ocean Drilling Program (IODP). Thirteen lithofacies of sedimentary and volcanic deposits are described, which include facies not previously recognized on the top of guyots, and offer a new insight into the formation of high-latitude oceanic islands on a fast-moving plate. Our results reveal that the lithostratigraphy of Louisville seamounts preserves a very consistent record of the formation and drowning of volcanic islands, with from bottom to top: (i) volcaniclastic sequences with abundant lava-fed delta deposits, (ii) submarine to subaerial shield lava flows, (iii) post-volcanic shallow to deeper marine sedimentary rocks lacking thick reef deposits, (iv) post-erosional rejuvenated volcanic rocks, and (v) pelagic sediments. Recognition of erosional boundaries between subaerial lava flows and shallow-marine sedimentary rocks provides novel support for post-volcanic wave planation of guyots. However, the summit geology of Louisville seamounts is dissimilar to that of high-latitude Hawaiian-Emperor guyots that have emplaced in a similar tectonic and environmental setting and that include thicker lava stacks with apparently

  11. Seabed morphology and the bottom-current pathways around Rosemary Bank seamount, northern Rockall Trough, North Atlantic

    Energy Technology Data Exchange (ETDEWEB)

    Howe, J.A. [Dunstaffnage Marine Laboratory, Scottish Association for Marine Science, Oban, Argyll PA37 1QA, Scotland (United Kingdom); Stoker, M.S.; Bulat, J. [British Geological Survey, Murchison House, West Mains Road, Edinburgh EH9 3LA, Scotland (United Kingdom); Masson, D.G. [Southampton Oceanography Centre, Empress Dock, European Way, Southampton SO14 3ZH (United Kingdom); Pudsey, C.J.; Morris, P.; Larter, R.D. [British Antarctic Survey, High Cross, Madingley Road, Cambridge CB3 OET (United Kingdom)

    2006-02-15

    Rosemary Bank is a broadly domed and elongate seamount with a diameter of 70km, occurring in water depths of between 300 and 2300m, 120km west of the UK mainland in the northern Rockall Trough. Recent multibeam bathymetry and sub-bottom profiles, together with pre-existing current meter and CTD data, seismic reflection profiles and seabed core samples were examined in order to evaluate past and present bottom-current pathways and processes. The multibeam data image volcanic parasitic cones, concave slide scars and the terraced slopes of the bank. Bottom-current sedimentation is interpreted as producing a drift-moat complex surrounding the entire seamount and including two sediment wave-fields, developed to the west and east of the bank in water depths of 1500-2000m. The western drift covers an area of over 1000km{sup 2}. Sediment waves to the west of the bank are up to 150m high with wave lengths of 1.5-2km. Four 100m deep, 3km wide, linear depressions, bisect the waves and are interpreted as 25-30km long extensions of the moat. Seismic reflection profiles show the main phase of drift construction was during the mid-Miocene to Pliocene with the Pliocene to Holocene being an interval of drift maintenance. Cores from sediments draping over and adjacent to the seamount contain sandy and gravelly contourites interbedded with hemipelagites of late Pleistocene to Holocene age. Current meter and CTD data from the western moat indicate Labrador Sea Water flowing northwest, in contrast to the previously assumed anticlockwise circulation pattern around the seamount. (author)

  12. New Cheilostomata (Bryozoa from NE Atlantic seamounts, islands, and the continental slope: evidence for deep-sea endemism

    Directory of Open Access Journals (Sweden)

    Björn Berning

    2017-08-01

    Full Text Available Ten new species belonging to three new genera (Atlantisina gen. nov., Bathycyclopora gen. nov., Calvetopora gen. nov. of umbonulomorph bryozoans from northeastern Atlantic seamounts, islands, and the continental slope are introduced. We furthermore erect the new family Atlantisinidae fam. nov. for these genera. Eight new species belong to the new genus Atlantisina: Atlantisina atlantis gen. et sp. nov. (type species, A. acantha gen. et sp. nov., A. gorringensis gen. et sp. nov., A. inarmata gen. et sp. nov., A. lionensis gen. et sp. nov., A. meteor gen. et sp. nov., A. seinensis gen. et sp. nov., and A. tricornis gen. et sp. nov. The genus Bathycyclopora gen. nov. is introduced for ?Phylactella vibraculata Calvet from the Azores, and also includes Bathycyclopora suroiti gen. et sp. nov. The type species of Calvetopora gen. nov. is Lepralia inflata Calvet from the Gulf of Cadiz; this genus also includes Calvetopora otapostasis gen. et sp. nov. and another species left in open nomenclature. Of the 13 species described herein, 11 occur on seamounts and islands, and nine species are endemic to a single seamount, island or station. The present results show that bryozoans provide striking examples of the function of seamounts as areas of endemism, most likely intrinsically linked to the low dispersal abilities of bryozoan larvae.

  13. Diversity of zoanthids (anthozoa: hexacorallia) on Hawaiian seamounts: description of the Hawaiian gold coral and additional zoanthids.

    Science.gov (United States)

    Sinniger, Frederic; Ocaña, Oscar V; Baco, Amy R

    2013-01-01

    The Hawaiian gold coral has a history of exploitation from the deep slopes and seamounts of the Hawaiian Islands as one of the precious corals commercialised in the jewellery industry. Due to its peculiar characteristic of building a scleroproteic skeleton, this zoanthid has been referred as Gerardia sp. (a junior synonym of Savalia Nardo, 1844) but never formally described or examined by taxonomists despite its commercial interest. While collection of Hawaiian gold coral is now regulated, globally seamounts habitats are increasingly threatened by a variety of anthropogenic impacts. However, impact assessment studies and conservation measures cannot be taken without consistent knowledge of the biodiversity of such environments. Recently, multiple samples of octocoral-associated zoanthids were collected from the deep slopes of the islands and seamounts of the Hawaiian Archipelago. The molecular and morphological examination of these zoanthids revealed the presence of at least five different species including the gold coral. Among these only the gold coral appeared to create its own skeleton, two other species are simply using the octocoral as substrate, and the situation is not clear for the final two species. Phylogenetically, all these species appear related to zoanthids of the genus Savalia as well as to the octocoral-associated zoanthid Corallizoanthus tsukaharai, suggesting a common ancestor to all octocoral-associated zoanthids. The diversity of zoanthids described or observed during this study is comparable to levels of diversity found in shallow water tropical coral reefs. Such unexpected species diversity is symptomatic of the lack of biological exploration and taxonomic studies of the diversity of seamount hexacorals.

  14. Diversity of zoanthids (anthozoa: hexacorallia on Hawaiian seamounts: description of the Hawaiian gold coral and additional zoanthids.

    Directory of Open Access Journals (Sweden)

    Frederic Sinniger

    Full Text Available The Hawaiian gold coral has a history of exploitation from the deep slopes and seamounts of the Hawaiian Islands as one of the precious corals commercialised in the jewellery industry. Due to its peculiar characteristic of building a scleroproteic skeleton, this zoanthid has been referred as Gerardia sp. (a junior synonym of Savalia Nardo, 1844 but never formally described or examined by taxonomists despite its commercial interest. While collection of Hawaiian gold coral is now regulated, globally seamounts habitats are increasingly threatened by a variety of anthropogenic impacts. However, impact assessment studies and conservation measures cannot be taken without consistent knowledge of the biodiversity of such environments. Recently, multiple samples of octocoral-associated zoanthids were collected from the deep slopes of the islands and seamounts of the Hawaiian Archipelago. The molecular and morphological examination of these zoanthids revealed the presence of at least five different species including the gold coral. Among these only the gold coral appeared to create its own skeleton, two other species are simply using the octocoral as substrate, and the situation is not clear for the final two species. Phylogenetically, all these species appear related to zoanthids of the genus Savalia as well as to the octocoral-associated zoanthid Corallizoanthus tsukaharai, suggesting a common ancestor to all octocoral-associated zoanthids. The diversity of zoanthids described or observed during this study is comparable to levels of diversity found in shallow water tropical coral reefs. Such unexpected species diversity is symptomatic of the lack of biological exploration and taxonomic studies of the diversity of seamount hexacorals.

  15. Chemical composition of hydrothermal ores from Mid-Okinawa trough and Suiyo Seamount determined by neutron activation analysis

    International Nuclear Information System (INIS)

    Noguchi, Takuroh; Taira, Naoto; Oomori, Tamotsu; Taira, Hatsuo; Tanahara, Akira; Takada, Jitsuya

    2007-01-01

    Neutron activation analysis of 13 hydrothermal ore samples (70 subsamples) collected from the Mid-Okinawa Trough and Suiyo Seamount revealed higher contents of precious metal such as Au and Ag, and those of As, Sb, Ga, and Hg than those from mid-ocean ridge hydrothermal systems. In addition, the Mid-Okinawa Trough samples were richer in Ag and Sb than those from the Suiyo Seamount. The geochemical differences among these hydrothermal ore deposits are regarded as reflecting both differences in the chemical composition of the hosted magma of hydrothermal system and the abundance of sediments that is reacted with hydrothermal fluids. (author)

  16. ``Distribution and behaviour of plutonium in the waters of the channel and of the seine estuary``; ``Distribution et comportement du plutonium dans les eaux de la manche et de l`estuaire de la seine``

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, K

    1998-12-31

    Excess dissolved plutonium has been measured in the coastal waters of the Channel, from Granville to Boulogne, probably due to sorption-desorption processus. In the Seine estuary, in situ measurements and experimental studies showed that the plutonium desorbs himself from particles in low salinity waters. The desorbed plutonium originates in marine and/or fluvial dissolved Pu. Marine dissolved Pu(V), originating from La Hague plant discharges and from atlantic waters, is reduced and sorbed when the salinity decreases onto estuarial particles: Isotopic Activity Ration {sup 238}Pu/{sup 239}, Pu(IR) of marine dissolved Pu(V) is about 0.7. Fluvial dissolved plutonium originates from atmospheric fallout and from an internal river source: fallout plutonium (IR=0.05) is unreactive with salinity while 45% of river plutonium (IR>1.7) flocculates at 0.5 g l{sup -1}. Desorbed plutonium may have various origins, depending on the Seine liquid discharges and on the tidal coefficient. When the marine waters do not migrate upstream, the low salinity waters encounters particles marked essentially with marine plutonium and the IR of desorbed Pu is about 0.7. The activities of desorbed plutonium are too low to have any influence on the distribution of plutonium in the coastal waters on the Seine Bay. When the marine waters migrate upstream, the low salinity waters meet particles marked essentially with river plutonium (IR>1.7) and desorbed plutonium has a very high IR. These estuarine conditions are encountered five to seven month a year and implicate an increase of the IR of 0.1 of the plutonium present in the coastal waters of the Seine bay (1.2.-1.3.). (author).

  17. Oceanographic Survey of Cross Seamount and Control Sites (OES0703L1, EK60)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The goals of the cruise were to collect acoustic backscatter and oceanographic data at Cross Seamount (18?43.285? N, longitude 158? 15.710? W), with an approximately...

  18. Modelling microbiological water quality in the Seine river drainage network: past, present and future situations

    Directory of Open Access Journals (Sweden)

    P. Servais

    2007-09-01

    Full Text Available The Seine river watershed is characterized by a high population density and intense agricultural activities. Data show low microbiological water quality in the main rivers (Seine, Marne, Oise of the watershed. Today, there is an increasing pressure from different social groups to restore microbiological water quality in order to both increase the safety of drinking water production and to restore the possible use of these rivers for bathing and rowing activities, as they were in the past. A model, appended to the hydro-ecological SENEQUE/Riverstrahler model describing the functioning of large river systems, was developed to describe the dynamics of faecal coliforms (FC, the most usual faecal contamination indicator. The model is able to calculate the distribution of FC concentrations in the whole drainage network resulting from land use and wastewater management in the watershed. The model was validated by comparing calculated FC concentrations with available field data for some well-documented situations in different river stretches of the Seine drainage network. Once validated, the model was used to test various predictive scenarios, as, for example, the impact of the modifications in wastewater treatment planned at the 2012 horizon in the Seine watershed in the scope of the implementation of the european water framework directive. The model was also used to investigate past situations. In particular, the variations of the microbiological water quality in the Parisian area due to population increase and modifications in wastewater management were estimated over the last century. It was shown that the present standards for bathing and other aquatic recreational activities are not met in the large tributaries upstream from Paris since the middle of the 1950's, and at least since the middle of the XIXth century in the main branch of the Seine river downstream from Paris. Efforts carried out for improving urban wastewater treatment in terms

  19. 40Ar/39Ar geochronology and volume estimates of the Tasmantid Seamounts: Support for a change in the motion of the Australian plate

    Science.gov (United States)

    Crossingham, Tracey J.; Vasconcelos, Paulo M.; Cunningham, Toby; Knesel, Kurt M.

    2017-09-01

    New volume estimates and 40Ar/39Ar ages for the Tasmantid Seamounts are reported to investigate the origin of volcanism and potential links between volcanism and changes in the speed and direction of migration of the Australian plate during the Cenozoic. The results show that the average extrusive volume of individual volcanoes along the seamount chain is 2587 ± 3078 km3 (1 s), and that volumes generally increase towards the south. An exception, the Britannia Guyot, located in the middle of the seamount chain, is the most voluminous (11,374 km3). Nineteen new 40Ar/39Ar ages, from Wreck to Gascoyne, show that the emplacement of the Tasmantid Seamounts occurred between 33.2 ± 1.5 and 6.5 ± 0.6 Ma. A single linear regression applied to the age versus latitude data, assuming volcanism to be caused by plate migration over a stationary hotspot, reveals a plate migration rate of 62 ± 2 kmMa- 1 (R2 = 0.97; n = 27) between 33 and 6 Ma. However, the bend in the seamount track, corresponding with the period of largest eruptive volumes, suggests three distinct segments in the Tasmantid age versus latitude data. The northern segment is consistent with a plate migration rate of 75 ± 10 kmMa- 1 (R2 = 0.88; n = 10) and the southern segment reveals a plate migration rate of 64 ± 4 kmMa- 1 (R2 = 0.94; n = 17). The period between these two segments, from 25 to 19 Ma, overlaps with the period of slow migration and change in the direction of the Australian plate derived from the age versus latitude distribution of continental central volcanoes. The new Tasmantid Seamount results support the interpretation that there were changes in the velocity and direction to Australia's northward trajectory, possibly resulting from a series of collisional events.

  20. Pito Seamount revisited: the discovery and mapping of new black smoker vents

    Science.gov (United States)

    Cheadle, M. J.; John, B. E.; German, C. R.; Gee, J. S.; Coogan, L. A.; Gillis, K. M.; Swapp, S.

    2017-12-01

    In February 2017, the RV Atlantis PMaG (PaleoMagnetism and Gabbro) cruise re-visited a black smoker site originally discovered 24 years ago on Pito Seamount, by the submersible Nautile during the French Pito expedition (1993). Pito Seamount (111.639oW, 23.333oS) marks the northern tip of the propagating East Pacific Rise, bounding the east side of the Easter Microplate. There the seafloor rises to 2250mbsl and has a 900m wide, 50m deep axial valley, which hosts at least two separate fields of active hydrothermal vents. AUV Sentry mapping of the summit of Pito seamount (0.5-1m resolution) highlights over 50 active and inactive chimneys amid recent basaltic sheet flows, pillow mounds and ponded lava. The vents occur in two fields/sub-fields; the first covers an area of 800 x 200m, and lies parallel to the ridge axis, along incipient faults forming on the northeastern flank of the axial valley. The second field occurs in a 250m diameter area in the centre of the axial valley. Jason II dive 961 visited, sampled, measured vent orifice temperatures, and acquired 4k video of the chimneys, and re-discovered the active (Magnificent Village) vent first found by Nautile, in the now named Nautile vent field, together with five additional active hydrothermal vents (Jason, Medea, Sentry, Abe and Scotty's Castle). The Magnificent Village, the largest active vent, is 25m tall and has multiple active spires in three main groups surrounding a hollow amphitheater. Measured vent orifice temperatures ranged from 338oC (Magnificent Village) to 370oC (Jason). The vents host a fauna of alvinellid worms, bythograidid crabs, alvincardid shrimps, phymorhynchus gastropods, Corallimorphid anenomes and bathymodiolid mussels, but no vestimentiferan worms. Brisingid brittle stars colonize inactive chimneys.

  1. Characterization of deepwater invertebrates at Isla del Coco National Park and Las Gemelas Seamount, Costa Rica

    Directory of Open Access Journals (Sweden)

    Richard M. Starr

    2012-11-01

    Full Text Available The deepwater faunas of oceanic islands and seamounts of the Eastern Tropical Pacific are poorly known. From 11-22 September 2009, we conducted an exploration of the deepwater areas around Isla del Coco National Park and Las Gemelas Seamount, located about 50km southwest of Isla del Coco, Costa Rica using a manned submersible to survey the seafloor habitats. The goal of the exploration was to characterize the habitats and biota, and conduct quantitative surveys of the deepwater portions of Isla del Coco National Park and Las Gemelas. We completed a total of 22 successful submersible dives, spanning more than 80hr underwater, and collected a total of 36hr of video. With respect to invertebrates, our objectives were to gather quantitative information on species composition, density, distribution and habitat associations as well as to compare the invertebrate communities between the two sites. A total of 7 172 invertebrates were counted from analysis of the video collected on this project. Larger organisms were counted and placed into 27 taxonomic groups to characterize the deepwater invertebrate fauna of Las Gemelas Seamount and Isla del Coco National Park. The Shannon-Weiner Index for biodiversity (H’ was calculated to be 0.14 ± 0.02 for Isla del Coco and 0.07 ± 0.03 for Las Gemelas surveys. Although richness was fairly equal between the two sites, evenness was greater at Isla del Coco (J = 0.04 ± 0.006 when compared to Las Gemelas (J = 0.02 ± 0.01. This lower level of evenness in the community at Las Gemelas was a result of high densities of a few dominant species groups, specifically sea urchins and black corals. We also evaluated invertebrate percent cover at both Isla del Coco and Las Gemelas Seamount with respect to habitat type, slope and rugosity. Results indicated that highly rugose habitats contained the highest frequencies of all invertebrates at both sites, with the exception of glass sponges and polychaetes at Isla del Coco

  2. Geophysical investigations of the Southeast Tyrrhenian Sea (Italy): high resolution DTM of the Marsili seamount

    Science.gov (United States)

    Milano, G.; Passaro, S.; Marsella, E.

    2009-04-01

    The Tyrrhenian Sea is the small extensional back-arc basin in the Central Mediterranean Sea characterized by a peculiar volcanic activity due to the presence of two sub-basin: Vavilov and Marsili. The central sector of the Marsili sub-basin, younger than the Valilov, is occupied by the Marsili Volcano. On November 2007, a geophysical survey was carried out by IAMC-CNR research institute (Naples, Italy) in the southeastern Tyrrhenian Sea within the "Aeolian_2007" cruise onboard the Urania oceanographic vessel. During the second Leg of the survey, detailed multibeam data acquisition was carried out in order to obtain high resolution DTM of the major Seamounts of the southeast Tyrrhenian Sea. Here, we report a new, very high resolution Digital Terrain Model (DTM) of the summit area of the Marsili Seamount. Multibeam data acquisition was carried out with the use of the Reson Seabat 8160 multibeam sonar system, which properly works in the 50-3500 m depth range. The system, interfaced with a Differential Global Positioning System, is mounted on keel of the R/V Urania and is composed of a ping source of 50 KHz, 150° degree for the whole opening of the transmitted pulse and a 126 beams-receiver. The whole dataset has been processed with the use of the PDS2000 swath editor tool, in accordance with the International Hydrographic Organization standard, and subsequently reorganized in an MXN matrix (Digital Terrain Model, DTM) of 25X25 m of grid cell size. The total amount of area coverage consists in more than 500 squared Km of multibeam sonar data. The Marsili volcano shows a global sigmoidal trend extending for about 55 km in the N10°E direction. Both the eastern and the western sides shows equal average slopes. Throughout the framework, crater-like morphologies are not clearly visible. The western side of the seamount reveals furrowed channels showing peculiar rounded sections. The northern sector morphologically differs from the rest of the seamount and seems separated

  3. Impact of Intrathermocline eddies on seamount and oceanic island off Central Chile: Observation and modeling

    Science.gov (United States)

    Hormazabal, Samuel; Morales, Carmen; Cornejo, Marcela; Bento, Joaquim; Valencia, Luis; Auger, Pierre; Rodriguez, Angel; Correa, Marco; Anabalón, Valeria; Silva, Nelson

    2016-04-01

    In the Southeast Pacific, oceanographic processes that sustain the biological production necessary to maintain the ecosystems associated to seamounts and oceanic islands are still poorly understood. Recent studies suggest that the interaction of mesoscale and submesoescale eddies with oceanic islands and seamounts could be playing an important role in the time-space variability of primary production. In this work, research cruises, satellite data and Regional Ocean Modeling System (ROMS) results have been used to describe the main characteristics of intrathermocline eddies (ITE) and their impact on the Juan Fernández archipelago (JFA), off central Chile. The JFA is located off the coast of central Chile (33°S), and is composed of three main islands: Robinson Crusoe (RC), Alejandro Selkirk (AS) and Santa Clara (SC). Between the RC and AS are located the westernmost seamounts (JF6 and JF5) of the Juan Fernández archipelago. Satellite altimetry data (sea surface height from AVISO) were used to detect and track mesoscale eddies through eddy-tracking algorithm. Physical, chemical and biological parameters as temperature, salinity, dissolved oxygen and fluorescence were measured in the water column at JF5 and JF6, and along the coast off central Chile (30-40°S). Results from the research cruise exhibit the interaction between an ITE and the seamount JF6. Eddy-tracking results showed that the ITE observed at the JF6 was formed at the coast off central-southern Chile, traveled ~900 km seaward and after ~9 months reached the JF5 and JF6 region. Observations along the Chilean coast confirmed that the coast corresponds to the formation area of the observed ITE. In this region, ITEs are represented by subsurface lenses (~100 km diameter; 400 m thickness) of homogeneous salinity, nutrient rich and oxygen-poor equatorial subsurface water mass (ESSW) which is transported poleward by the Peru-Chile undercurrent in the coastal band and seaward by ITEs. The effect of ITEs on the

  4. CRED Gridded Bathymetry of East Necker Seamount (100-023) in the Northwestern Hawaiian Islands

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — File 100-023b is a 60-m ASCII grid of depth data collected near E. Necker Seamount in the Northwestern Hawaiian Islands as of May 2003. This grid has been produced...

  5. Fossilized microorganisms from the Emperor Seamounts: implications for the search for a subsurface fossil record on Earth and Mars.

    Science.gov (United States)

    Ivarsson, M; Lausmaa, J; Lindblom, S; Broman, C; Holm, N G

    2008-12-01

    We have observed filamentous carbon-rich structures in samples drilled at 3 different seamounts that belong to the Emperor Seamounts in the Pacific Ocean: Detroit (81 Ma), Nintoku (56 Ma), and Koko Seamounts (48 Ma). The samples consist of low-temperature altered basalts recovered from all 3 seamounts. The maximum depth from which the samples were retrieved was 954 meters below seafloor (mbsf). The filamentous structures occur in veins and fractures in the basalts, where they are attached to the vein walls and embedded in vein-filling minerals like calcite, aragonite, and gypsum. The filaments were studied with a combination of optical microscopy, environmental scanning electron microscopy (ESEM), Raman spectroscopy, and time-of-flight secondary ion mass spectrometry (ToF-SIMS). Minerals were identified by a combination of optical microscopy, X-ray diffraction, Raman spectrometry, and energy dispersive spectrometry on an environmental scanning electron microscope. Carbon content of the filaments ranges between approximately 10 wt % and approximately 50 wt % and is not associated with carbonates. These results indicate an organic origin of the carbon. The presence of C(2)H(4), phosphate, and lipid-like molecules in the filaments further supports a biogenic origin. We also found microchannels in volcanic glass enriched in carbon (approximately 10-40 wt %) compatible with putative microbial activity. Our findings suggest new niches for life in subseafloor environments and have implications for further exploration of the subseafloor biosphere on Earth and beyond.

  6. Seinäjoen kuntosaliohjaajien koulutustaustan, ravitsemusosaamisen ja ohjaustyylin kartoittaminen

    OpenAIRE

    Kumpunen, Miia

    2016-01-01

    Tutkimuksen tavoitteena oli kartoittaa Seinäjoen kuntosaliohjaajien koulutustausta, ravitsemusosaaminen ja ohjaustyyli. Tavoitteena oli, että kuntosalit saavat tutkimuksen avulla tietoonsa mahdolliset koulutustarpeet. Kuntosaliohjaajien koulutuksen ollessa hyvällä tasolla myös asiakkaiden saama ohjaus on laadukkaampaa ja he hyötyvät tästä enemmän. Aineisto kerättiin lomakekyselynä, joka sisälsi strukturoituja ja avoimia kysymyksiä. Ensimmäinen aineisto kerättiin syksyllä 2015 kuntosaliohja...

  7. Analysis of the archaeal sub-seafloor community at Suiyo Seamount on the Izu-Bonin Arc.

    Science.gov (United States)

    Hara, Kurt; Kakegawa, Takeshi; Yamashiro, Kan; Maruyama, Akihiko; Ishibashi, Jun-Ichiro; Marumo, Katsumi; Urabe, Tetsuro; Yamagishi, Akihiko

    2005-01-01

    A sub-surface archaeal community at the Suiyo Seamount in the Western Pacific Ocean was investigated by 16S rRNA gene sequence and whole-cell in situ hybridization analyses. In this study, we drilled and cased holes at the hydrothermal area of the seamount to minimize contamination of the hydrothermal fluid in the sub-seafloor by penetrating seawater. PCR clone analysis of the hydrothermal fluid samples collected from a cased hole indicated the presence of chemolithoautotrophic primary biomass producers of Archaeoglobales and the Methanococcales-related archaeal HTE1 group, both of which can utilize hydrogen as an electron donor. We discuss the implication of the microbial community on the early history of life and on the search for extraterrestrial life. c2005 COSPAR. Published by Elsevier Ltd. All rights reserved.

  8. Sedimentation in a Submarine Seamount Apron at Site U1431, International Ocean Discovery Program Expedition 349, South China Sea

    Science.gov (United States)

    Dadd, K. A.; Clift, P. D.; Hyun, S.; Jiang, T.; Liu, Z.

    2014-12-01

    International Ocean Discovery Program (IODP) Expedition 349 Site U1431 is located near the relict spreading ridge in the East Subbasin of the South China Sea. Holes at this site were drilled close to seamounts and intersected the volcaniclastic apron. Volcaniclastic breccia and sandstone at Site U1431 are dated as late middle Miocene to early late Miocene (~8-13 Ma), suggesting a 5 m.y. duration of seamount volcanism. The apron is approximately 200 m thick and is sandwiched between non-volcaniclastic units that represent the background sedimentation. These comprise dark greenish gray clay, silt, and nannofossil ooze interpreted as turbidite and hemipelagic deposits that accumulated at abyssal water depths. At its base, the seamount sequence begins with dark greenish gray sandstone, siltstone, and claystone in upward fining sequences interpreted as turbidites intercalated with minor intervals of volcaniclastic breccia. Upsection the number and thickness of breccia layers increases with some beds up to 4.8 m and possibly 14.5 m thick. The breccia is typically massive, ungraded, and poorly sorted with angular to subangular basaltic clasts, as well as minor reworked subrounded calcareous mudstone, mudstone, and sandstone clasts. Basaltic clasts include nonvesicular aphyric basalt, sparsely vesicular aphyric basalt, highly vesicular aphyric basalt, and nonvesicular glassy basalt. Mudstone clasts are clay rich and contain foraminifer fossils. The matrix comprises up to 40% of the breccia beds and is a mix of clay, finer grained altered basalt clasts, and mafic vitroclasts with rare foraminifer fossils. Some layers have calcite cement between clasts. Volcaniclastic sandstone and claystone cycles interbedded with the breccia layers have current ripples and parallel laminations indicative of high-energy flow conditions during sedimentation. The breccia beds were most likely deposited as a series of debris flows or grain flows. This interpretation is supported by their

  9. Compositional variation and genesis of ferromanganese crusts of the Afanasiy-Nikitin Seamount, Equatorial Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Rajani, R.P.; Banakar, V.K.; Parthiban, G.; Mudholkar, A.V.; Chodankar, A.R.

    Eight ferromanganese crusts (Fe-Mn crusts) with igneous and sedimentary substrates collected at different water depths from the Afanasiy-Nikitin Seamount are studied for their bulk major, minor and rare earth element composition. The Mn/Fe ratios...

  10. ''Distribution and behaviour of plutonium in the waters of the channel and of the seine estuary''

    International Nuclear Information System (INIS)

    Garcia, K.

    1997-01-01

    Excess dissolved plutonium has been measured in the coastal waters of the Channel, from Granville to Boulogne, probably due to sorption-desorption processus. In the Seine estuary, in situ measurements and experimental studies showed that the plutonium desorbs himself from particles in low salinity waters. The desorbed plutonium originates in marine and/or fluvial dissolved Pu. Marine dissolved Pu(V), originating from La Hague plant discharges and from atlantic waters, is reduced and sorbed when the salinity decreases onto estuarial particles: Isotopic Activity Ration 238 Pu/ 239 , Pu(IR) of marine dissolved Pu(V) is about 0.7. Fluvial dissolved plutonium originates from atmospheric fallout and from an internal river source: fallout plutonium (IR=0.05) is unreactive with salinity while 45% of river plutonium (IR>1.7) flocculates at 0.5 g l -1 . Desorbed plutonium may have various origins, depending on the Seine liquid discharges and on the tidal coefficient. When the marine waters do not migrate upstream, the low salinity waters encounters particles marked essentially with marine plutonium and the IR of desorbed Pu is about 0.7. The activities of desorbed plutonium are too low to have any influence on the distribution of plutonium in the coastal waters on the Seine Bay. When the marine waters migrate upstream, the low salinity waters meet particles marked essentially with river plutonium (IR>1.7) and desorbed plutonium has a very high IR. These estuarine conditions are encountered five to seven month a year and implicate an increase of the IR of 0.1 of the plutonium present in the coastal waters of the Seine bay (1.2.-1.3.). (author)

  11. A comparison of genetic connectivity in two deep sea corals to examine whether seamounts are isolated islands or stepping stones for dispersal

    Science.gov (United States)

    Miller, Karen J.; Gunasekera, Rasanthi M.

    2017-04-01

    Ecological processes in the deep sea are poorly understood due to the logistical constraints of sampling thousands of metres below the ocean’s surface and remote from most land masses. Under such circumstances, genetic data provides unparalleled insight into biological and ecological relationships. We use microsatellite DNA to compare the population structure, reproductive mode and dispersal capacity in two deep sea corals from seamounts in the Southern Ocean. The solitary coral Desmophyllum dianthus has widespread dispersal consistent with its global distribution and resilience to disturbance. In contrast, for the matrix-forming colonial coral Solenosmilia variabilis asexual reproduction is important and the dispersal of sexually produced larvae is negligible, resulting in isolated populations. Interestingly, despite the recognised impacts of fishing on seamount communities, genetic diversity on fished and unfished seamounts was similar for both species, suggesting that evolutionary resilience remains despite reductions in biomass. Our results provide empirical evidence that a group of seamounts can function either as isolated islands or stepping stones for dispersal for different taxa. Furthermore different strategies will be required to protect the two sympatric corals and consequently the recently declared marine reserves in this region may function as a network for D. dianthus, but not for S. variabilis.

  12. Une autre nature en ville: l'aménagement de la boucle nord des Hauts-de-Seine

    Directory of Open Access Journals (Sweden)

    Catherine Carré

    2005-07-01

    Full Text Available Confined to parks and forests, nature in French urban areas has been used as an instrument for urban planners and developers. Recent urban projects have sought to give natural systems a fuller role in territorial development. This new function can be considered a radically new approach. At the same time, current redevelopment projects must also integrate existing facilities. The redevelopment of the banks of the Seine by the Hauts-de-Seine council is a good example of this new role that nature can play in urban revitalisation. Maps show the constraints and issues that must be taken into account.

  13. Petrologic Aspects of Seamount and Guyot Volcanism on the Ancestral Mesozoic Pacific Plate: a Review

    Science.gov (United States)

    Natland, J. H.

    2007-12-01

    Hundreds of large seamounts and guyots are widely scattered almost in a "shotgun-blast" arrangement in an area about the size of the United States west of the Mississippi River on the Mesozoic Pacific plate between the Mariana Trench and the Gilbert Islands. Most of these formed between ~160-100 Ma while the Pacific plate was surrounded by spreading ridges and growing outward in all directions. There is little to no indication that the seamounts and guyots formed along linear seamount chains; existing radiometric-age data show no age progressions. The volcanoes appear to have formed in response to a uniform stress configuration across the plate, which was either not moving or moving very slowly at the time (1, 2), much like the modern Antarctic plate. When the growing plate started to encounter subduction systems in the western Pacific at ~90 Ma, consistent stress patterns began to develop, and the broad linear Gilbert and Line volcanic ridge systems began to form. Even then, however, considerable overlapping of volcanism occurred, and only the most general age progressions are evident in existing data. Petrologic data from samples obtained from dozens of volcanic summits by dredging and beneath several carbonate platforms by drilling reveal considerable diversity in development of differentiated alkalic magmatic lineages rooted in diverse parental basaltic rocks. These include transitional, alkalic and basanitic compositions, with differentiates of hawaiite, mugearite, trachyte and one phonolite. Many of the basaltic rocks are partly to significantly transformed by alteration under oxidative conditions (dredged rocks) and both oxidative and non-oxidative conditions (drilled rocks). This can make estimations of mantle geochemical provenance difficult. Nevertheless, the province has been linked by backtracking techniques to the modern SOPITA region of the South Pacific (3), and its rocks show enrichments in trace elements and isotopic characteristics similar to

  14. A new carnivorous sponge, Chondrocladia robertballardi sp. nov. (Porifera: Cladorhizidae) from two Northeast Atlantic seamounts

    NARCIS (Netherlands)

    Cristobo, J.; Rios, P.; Pomponi, S.A.; Xavier, J.R.

    2015-01-01

    Carnivorous sponges (Porifera: Cladorhizidae) are a particularly interesting group of species typically occurring in deep-sea habitats. In this study a new species, Chondrocladia (Chondrocladia) robertballardi sp. nov., is described from specimens collected on two large north-east Atlantic seamounts

  15. Seamounts in the southeastern Pacific Ocean and biodiversity on Juan Fernandez seamounts, Chile Montes submarinos en el océano Pacífico suroriental y biodiversidad en el cordón de Juan Fernández, Chile

    Directory of Open Access Journals (Sweden)

    Eleuterio Yáñez

    2009-01-01

    Full Text Available Seamounts are vulnerable marine ecosystems. In Chile, information on these ecosystems is quite scarce; thus, a compilation of information on their geographical distribution and biodiversity is presented herein. A total of 118 seamounts distributed in the Chilean EEZ are identified and characterized. Additionally, an in situ assessment was carried out on the Juan Fernandez seamounts 1 and 2 (JF1 and JF2, which were also oceanographically characterized. Phytoplankton, zooplankton, and marine invertebrate samples were collected and an exploratory fishing survey was executed using different gears. According to the bibliographical review, a total of 82 species have been collected on the JF1 and JF2 seamounts, highlighting fmdings of black coral species caught in lobster traps at the Juan Fernandez Archipelago. Submarine images of the marine substrate at JF1 and JF2 reveal characteristics attributable to the impact of bottom dredges, coinciding with the information obtained from the trawling fleet. The fishing activity was carried out primarily at JF2 (4,667 km of trawling. The monthly fishing effort increased considerably in 2002, 2003, and 2005, reaching values above 500 km of trawling and, thus, modifying the spatial structure of the resource aggregates on the JF2 seamount.Los montes submarinos constituyen ecosistemas marinos vulnerables. Chile presenta una escasa información acerca de estos ecosistemas, por lo que este trabajo recopila información sobre distribución geográfica y biodiversidad. Se identifican y caracterizan 118 montes en la ZEE de Chile. Adicionalmente, una evaluación in situ se desarrolló sobre los montes Juan Fernández 1 y 2 (JF1, JF2, caracterizándolos oceanógraficamente. Se recolectaron muestras de fitoplancton, zooplancton e invertebrados marinos, y se realizó pesca exploratoria con diversos artes. La revisión bibliográfica establece que en JF1 y JF2, se han capturado un total de 82 especies, destacándose la

  16. 76 FR 8330 - Hawaii Bottomfish and Seamount Groundfish Fisheries; Modification to Advance Notification Period...

    Science.gov (United States)

    2011-02-14

    .... 101210611-1080-02] RIN 0648-BA58 Hawaii Bottomfish and Seamount Groundfish Fisheries; Modification to... State of Hawaii monitor progress towards the TAC based on commercial bottomfish landings data submitted..., NMFS, the State of Hawaii, and the Council meet to determine the specified date the TAC is projected to...

  17. Geochemical Evolution of the Louisville Seamount Chain

    Science.gov (United States)

    Vanderkluysen, L.; Mahoney, J. J.; Koppers, A. A.; Lonsdale, P. F.

    2007-12-01

    The Louisville seamount chain is a 4300 km long chain of submarine volcanoes in the southwestern Pacific that is commonly thought to represent a hotspot track. It spans an ~80 Myr age range, comparable to that of the Hawaiian-Emperor chain (Koppers et al., G-cubed, 5 (6), 2004). The few previously dredged igneous samples are dominantly basaltic and alkalic, and have been inferred to represent post-shield volcanism (Hawkins et al., AGU Monograph, 43, 235, 1987). Their isotope and trace element signatures suggest an unusually homogenous mantle source (Cheng et al., AGU Monograph, 43, 283, 1987). Dredging in 2006, during the AMAT02RR cruise of the R.V. Revelle, was carried out in the hope of recovering both shield and post-shield samples and of exploring the geochemical evolution of the chain. Igneous rocks were recovered from 33 stations on 23 seamounts covering some 47 Myr of the chain's history. Our study, focusing on the major and trace element and Sr, Nd and Pb isotopic characteristics of these samples, shows that all are alkalic basalts, basanites and tephrites containing normative nepheline. Variations in major and trace elements appear to be controlled predominantly by variable extents of melting and fractional crystallization, with little influence from mantle source heterogeneity. Indeed, age-corrected isotopic values define only a narrow range, in agreement with long-term source homogeneity relative to the scale of melting; e.g., ɛNd varies from +4.1 to +5.7, 206Pb/204Pb from 19.048 to 19.281, and 87Sr/86Sr from 0.70362 to 0.70398. These values broadly fall within the fields of the proposed "C" or "FOZO" mantle end-members. However, small variations are present, with less radiogenic Nd and Pb isotope ratios at the older, western end of the chain, defining a trend toward a broadly EM2-like composition. Although some workers have postulated that the Louisville hotspot was the source of the ~120 Myr Ontong Java Plateau, our samples are isotopically distinct

  18. Water to atmosphere fluxes of 131I in relation with alkyl-iodide compounds from the Seine Estuary (France)

    International Nuclear Information System (INIS)

    Connan, Olivier; Tessier, Emmanuel; Maro, Denis; Amouroux, David; Hebert, Didier; Rozet, Marianne; Voiseux, Claire; Solier, Luc

    2008-01-01

    This study presents an original work on measurements of stable and radioactive iodinated species in the Seine estuary (France), with estimates fluxes of volatile gaseous species from water to the atmosphere. Various iodinated compounds were identified in water and air in particular 131 I in water, what is unusual. Concentrations and behaviour of iodinated elements in the Seine estuary seem similar to what has been observed in other European estuaries. MeI (Methyl Iodide) and Total Volatile Iodine (TVI) fluxes from water to air vary between 392 and 13949 pmol m -2 d -1 and between 1279 and 16484 pmol m -2 d -1 , respectively. Water to air flux of TVI for the Seine river was estimated in the range 4-46 kg y -1 . Measurements of 131 I in water varying between 0.4 and 11.9 Bq m -3 . Fluxes of 131 I from water to atmosphere are in the range 2.4 x 10 5 -1.3 x 10 7 Bq y -1 , close to an annual discharge of 131 I by a nuclear reactor

  19. Comportement de l'espèce “Salmo trutta” dans le bassin de la Seine. Suite et fin

    Directory of Open Access Journals (Sweden)

    ARRIGNON J.

    1968-04-01

    Full Text Available Since a certain time, it is observed, in the spring, in Low Seine, that Salmonidae are coming together. These concentrations concern yearling subjects. Besides, a certain number of adult fisches, marked in Ile de France in 1961-1962-1963, have been captured downstream very far from their introduction point. Because of the investments supported by fishmen for restocking the rivers as well with immediately catchable trouts than with fry and young trouts, it became necessary to try to understand the reasons of the runnings down that has been recorded and to calculate their importance. These investigations have been carried out by a systematic marking of the fishes organized on the whole of the four great hydrographic Regions of the River Seine : — Bassin of the Upper Marne ; — Bassins of the Upper Seine and Upper Aube ; — Bassin of the Upper Aisne. On the 31th October 1967, on 30.030 marked subjects, 3.138 have been caught and recorded. On these 3.138 subjects, 3.049 had not left the Bassin into which they had been introduced. The general mark-returns percentage, reaches 10,15% and the percentage of the distant returns is 3,06‰ The highest returns percentage is this of the Upper Bassin of the River Aisne, where, locally, 34,80% of the marked fishes have been captured. But it can be noted a running down rate in Lower Seine and in the sea of 2,94‰ for the Upper Marne; 2,20‰ for the River Aube and the Upper Seine and 4,71‰ for the Ile de France. The highest removing is this of a trout introduced in Ardennes Country and which has been caught at Dunkerque Harbourgh after a travel of 805 kilometers, 530 of wihch made in fresh water. Investigations by marking have been completed by biometrical studies carried out on samples drawn of Lower Seine, at the time of the big concentrations of the winter end. A certain number of constatations derives from it : — There are groups of fishes which are inclined to run down-stream, more than the others

  20. Stable isotope compositions of serpentinite seamounts in the Mariana forearc: Serpentinization processes, fluid sources and sulfur metasomatism

    Science.gov (United States)

    Alt, J.C.; Shanks, Wayne C.

    2006-01-01

    The Mariana and Izu-Bonin arcs in the western Pacific are characterized by serpentinite seamounts in the forearc that provide unique windows into the mantle wedge. We present stable isotope (O, H, S, and C) data for serpentinites from Conical seamount in the Mariana forearc and S isotope data for Torishima seamount in the Izu-Bonin forearc in order to understand the compositions of fluids and temperatures of serpentinization in the mantle wedge, and to investigate the transport of sulfur from the slab to the mantle wedge. Six serpentine mineral separates have a restricted range of ??18O (6.5-8.5???). Antigorite separates have ??D values of -29.5??? to -45.5??? that reflect serpentinization within the mantle wedge whereas chrysotile has low ??D values (-51.8??? to -84.0???) as the result of re-equilibration with fluids at low temperatures. Fractionation of oxygen isotopes between serpentine and magnetite indicate serpentinization temperatures of 300-375 ??C. Two late cross-fiber chrysotile veins have higher ??18O values of 8.9??? to 10.8??? and formed at lower temperatures (as low as ???100 ??C). Aqueous fluids in equilibrium with serpentine at 300-375 ??C had ??18O = 6.5-9??? and ??D = -4??? to -26???, consistent with sediment dehydration reactions at temperatures arc lavas. ?? 2006 Elsevier B.V. All rights reserved.

  1. Estimating juvenile Chinook salmon (Oncorhynchus tshawytscha) abundance from beach seine data collected in the Sacramento–San Joaquin Delta and San Francisco Bay, California

    Science.gov (United States)

    Perry, Russell W.; Kirsch, Joseph E.; Hendrix, A. Noble

    2016-06-17

    Resource managers rely on abundance or density metrics derived from beach seine surveys to make vital decisions that affect fish population dynamics and assemblage structure. However, abundance and density metrics may be biased by imperfect capture and lack of geographic closure during sampling. Currently, there is considerable uncertainty about the capture efficiency of juvenile Chinook salmon (Oncorhynchus tshawytscha) by beach seines. Heterogeneity in capture can occur through unrealistic assumptions of closure and from variation in the probability of capture caused by environmental conditions. We evaluated the assumptions of closure and the influence of environmental conditions on capture efficiency and abundance estimates of Chinook salmon from beach seining within the Sacramento–San Joaquin Delta and the San Francisco Bay. Beach seine capture efficiency was measured using a stratified random sampling design combined with open and closed replicate depletion sampling. A total of 56 samples were collected during the spring of 2014. To assess variability in capture probability and the absolute abundance of juvenile Chinook salmon, beach seine capture efficiency data were fitted to the paired depletion design using modified N-mixture models. These models allowed us to explicitly test the closure assumption and estimate environmental effects on the probability of capture. We determined that our updated method allowing for lack of closure between depletion samples drastically outperformed traditional data analysis that assumes closure among replicate samples. The best-fit model (lowest-valued Akaike Information Criterion model) included the probability of fish being available for capture (relaxed closure assumption), capture probability modeled as a function of water velocity and percent coverage of fine sediment, and abundance modeled as a function of sample area, temperature, and water velocity. Given that beach seining is a ubiquitous sampling technique for

  2. Infection par le VIH chez les patientes atteintes de cancer du sein en Guinée (Afrique de l'Ouest)

    Science.gov (United States)

    Traore, Bangaly; Diane, Solomana; Sow, Mamadou Saliou; Keita, Mamady; Conde, Mamoudou; Traore, Fodé Amara; Kourouma, Tidiane

    2015-01-01

    L'objectif était de déterminer la prévalence de l'infection à VIH chez les patientes atteintes de cancer du sein et de comparer les caractéristiques anatomocliques et thérapeutiques de ces cancers du sein par rapports aux patientes non infectées par le VIH. Il s'agissait d'une étude rétrospective et analytique comparant les dossiers de patientes atteintes de cancers du sein histologiquement confirmés, infectées ou non par le VIH à l'unité de chirurgie oncologique de Donka, CHU de Conakry, de 2007 à 2012. Nous avons colligé 278 patientes présentant un cancer du sein dont 14 (5,0%) infectées par le VIH et 264 (95,0%) non infectées par le VIH. Les différences observées entre ces deux groupes de patientes étaient respectivement: âge médian (36,8 vs 49,0 ans), la ménopause (21,4% vs 53,4%), le nombre des patientes traitées (50,0% contre 77,1%) et la survenue de décès (78,6% vs 50,8%). Aucune différence n'a été notée dans la présentation clinique, histologique et le retard de consultation. Dans notre étude, la prévalence de l'infection à VIH chez les patients atteints de cancer du sein est élevée. L’âge jeune des patients, la faible accessibilité au traitement et la mortalité élevée doivent être confirmés par une étude sur un échantillon plus large. PMID:26523196

  3. Telepresence and real-time data transmission from Axial Seamount: implications for education and community engagement utilizing the OOI-RSN cabled observatory

    Science.gov (United States)

    Fundis, A. T.; Kelley, D. S.; Sautter, L. R.; Proskurowski, G.; Kawka, O.; Delaney, J. R.

    2011-12-01

    Axial Seamount, the most robust volcanic system on the Juan de Fuca Ridge, is a future site of the cabled observatory component of the National Science Foundation's Ocean Observatories Initiative (OOI) (see Delaney et al; Proskurowski et al., this meeting). In 2014, high-bandwidth data, high-definition video and digital still imagery will be streamed live from the cable observatory at Axial Seamount via the Internet to researchers, educators, and the public. The real-time data and high-speed communications stream will open new approaches for the onshore public and scientists to experience and engage in sea-going research as it is happening. For the next 7 years, the University of Washington and the OOI will collaboratively support an annual multi-week cruise aboard the research vessel Thomas G. Thompson. These "VISIONS" cruises will include scientific and maintenance operations related to the cabled network, the OOI Regional Scale Nodes (RSN). Leading up to 2014, VISIONS cruises will also be used to engage students, educators, scientists and the public in science focused at Axial Seamount through avenues that will be adaptable for the live data stream via the OOI-RSN cable. Here we describe the education and outreach efforts employed during the VISIONS'11 cruise to Axial Seamount including: 1) a live HD video stream from the seafloor and the ship to onshore scientists, educators, and the public; 2) a pilot program to teach undergraduates from the ship via live and taped broadcasts; 3) utilizing social media from the ship to communicate with scientists, educators, and the public onshore; and 4) providing undergraduate and graduate students onboard immersion into sea-going research. The 2011 eruption at Axial Seamount (see Chadwick et al., this meeting) is a prime example of the potential behind having these effective tools in place to engage the scientific community, students, and the public when the OOI cabled observatory comes online in 2014.

  4. Stable isotope compositions of serpentinite seamounts in the Mariana forearc: Serpentinization processes, fluid sources and sulfur metasomatism

    Science.gov (United States)

    Alt, J.C.; Shanks, Wayne C.

    2006-01-01

    The Mariana and Izu-Bonin arcs in the western Pacific are characterized by serpentinite seamounts in the forearc that provide unique windows into the mantle wedge. We present stable isotope (O, H, S, and C) data for serpentinites from Conical seamount in the Mariana forearc and S isotope data for Torishima seamount in the Izu-Bonin forearc in order to understand the compositions of fluids and temperatures of serpentinization in the mantle wedge, and to investigate the transport of sulfur from the slab to the mantle wedge. Six serpentine mineral separates have a restricted range of ??18O (6.5-8.5???). Antigorite separates have ??D values of -29.5??? to -45.5??? that reflect serpentinization within the mantle wedge whereas chrysotile has low ??D values (-51.8??? to -84.0???) as the result of re-equilibration with fluids at low temperatures. Fractionation of oxygen isotopes between serpentine and magnetite indicate serpentinization temperatures of 300-375 ??C. Two late cross-fiber chrysotile veins have higher ??18O values of 8.9??? to 10.8??? and formed at lower temperatures (as low as ???100 ??C). Aqueous fluids in equilibrium with serpentine at 300-375 ??C had ??18O = 6.5-9??? and ??D = -4??? to -26???, consistent with sediment dehydration reactions at temperatures aragonite veins in metabasalt and siltstone clasts within the serpentinite flows have ??18O = 16.7-24.5???, consistent with the serpentinizing fluids at temperatures <250 ??C. ??13C values of 0.1-2.5??? suggest a source in subducting carbonate sediments. The ??34S values of sulfide in serpentinites on Conical Seamount (-6.7??? to 9.8???) result from metasomatism through variable reduction of aqueous sulfate (??34S = 14???) derived from slab sediments. Despite sulfur metasomatism, serpentinites have low sulfur contents (generally < 164 ppm) that reflect the highly depleted nature of the mantle wedge. The serpentinites are mostly enriched in 34S (median ??34Ssulfide = 4.5???), consistent with a 34S

  5. Novel ambler class A carbapenem-hydrolyzing beta-lactamase from a Pseudomonas fluorescens isolate from the Seine River, Paris, France.

    Science.gov (United States)

    Girlich, Delphine; Poirel, Laurent; Nordmann, Patrice

    2010-01-01

    A Pseudomonas fluorescens isolate (PF-1) resistant to carbapenems was recovered during an environmental survey performed with water from the Seine River (Paris). It expressed a novel Ambler class A carbapenemase, BIC-1, sharing 68 and 59% amino acid identities with beta-lactamases SFC-1 from Serratia fonticola and the plasmid-encoded KPC-2, respectively. beta-Lactamase BIC-1 hydrolyzed penicillins, carbapenems, and cephalosporins except ceftazidime and monobactams. The bla(BIC-1) gene was chromosomally located and was also identified in two other P. fluorescens strains isolated from the Seine River 3 months later.

  6. Identification et prise en charge des femmes ayant des antécédents familiaux de cancer du sein

    Science.gov (United States)

    Heisey, Ruth; Carroll, June C.

    2016-01-01

    Résumé Objectif Résumer les meilleures données portant sur les stratégies d’identification et de prise en charge des femmes qui présentent des antécédents familiaux de cancer du sein. Sources d’information Une recherche a été effectuée sur PubMed à l’aide des mots-clés anglais suivants : breast cancer, guidelines, risk, family history, management et magnetic resonance imaging screening, entre 2000 et 2016. La plupart des données sont de niveau II. Message principal Une bonne anamnèse familiale est essentielle lors de l’évaluation du risque de cancer du sein afin d’identifier les femmes qui sont candidates à une recommandation en counseling génétique pour un éventuel test génétique. On peut sauver des vies en offrant aux femmes porteuses d’une mutation au gène BRCA des interventions chirurgicales de réduction des risques (mastectomie bilatérale prophylactique, salpingo-ovariectomie bilatérale). Il faut encourager toutes les femmes qui présentent des antécédents familiaux de cancer du sein à demeurer actives et à limiter leur consommation d’alcool à moins de 1 verre par jour; certaines femmes sont admissibles à la chimioprévention. Il faut offrir aux femmes dont le risque à vie de cancer du sein est de 20 à 25 % ou plus un dépistage poussé par imagerie par résonance magnétique en plus d’une mammographie. Conclusion Une vie saine et la chimioprévention (chez les candidates) pourraient réduire l’incidence du cancer du sein; le dépistage poussé pourrait entraîner une détection plus précoce. Le fait d’aiguiller des femmes porteuses d’une mutation au BRCA vers la chirurgie de réduction des risques sauve des vies. PMID:27737991

  7. The Marsili Volcanic Seamount (Southern Tyrrhenian Sea: A Potential Offshore Geothermal Resource

    Directory of Open Access Journals (Sweden)

    Francesco Italiano

    2014-06-01

    Full Text Available Italy has a strong geothermal potential for power generation, although, at present, the only two geothermal fields being exploited are Larderello-Travale/Radicondoli and Mt. Amiata in the Tyrrhenian pre-Apennine volcanic district of Southern Tuscany. A new target for geothermal exploration and exploitation in Italy is represented by the Southern Tyrrhenian submarine volcanic district, a geologically young basin (Upper Pliocene-Pleistocene characterised by tectonic extension where many seamounts have developed. Heat-flow data from that area show significant anomalies comparable to those of onshore geothermal fields. Fractured basaltic rocks facilitate seawater infiltration and circulation of hot water chemically altered by rock/water interactions, as shown by the widespread presence of hydrothermal deposits. The persistence of active hydrothermal activity is consistently shown by many different sources of evidence, including: heat-flow data, gravity and magnetic anomalies, widespread presence of hydrothermal-derived gases (CO2, CO, CH4, 3He/4He isotopic ratios, as well as broadband OBS/H seismological information, which demonstrates persistence of volcano-tectonic events and High Frequency Tremor (HFT. The Marsili and Tyrrhenian seamounts are thus an important—and likely long-lasting-renewable energy resource. This raises the possibility of future development of the world’s first offshore geothermal power plant.

  8. Modelling the spatial behaviour of a tropical tuna purse seine fleet.

    Directory of Open Access Journals (Sweden)

    Tim K Davies

    Full Text Available Industrial tuna fisheries operate in the Indian, Atlantic and Pacific Oceans, but concerns over sustainability and environmental impacts of these fisheries have resulted in increased scrutiny of how they are managed. An important but often overlooked factor in the success or failure of tuna fisheries management is the behaviour of fishers and fishing fleets. Uncertainty in how a fishing fleet will respond to management or other influences can be reduced by anticipating fleet behaviour, although to date there has been little research directed at understanding and anticipating the human dimension of tuna fisheries. The aim of this study was to address gaps in knowledge of the behaviour of tuna fleets, using the Indian Ocean tropical tuna purse seine fishery as a case study. We use statistical modelling to examine the factors that influence the spatial behaviour of the purse seine fleet at broad spatiotemporal scales. This analysis reveals very high consistency between years in the use of seasonal fishing grounds by the fleet, as well as a forcing influence of biophysical ocean conditions on the distribution of fishing effort. These findings suggest strong inertia in the spatial behaviour of the fleet, which has important implications for predicting the response of the fleet to natural events or management measures (e.g., spatial closures.

  9. Influence of seamount topography on the local facies variation in ferromanganese deposits in the Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Mukhopadhyay, R.; Nath, B.N.

    surfaces, have lowest oxide/nucleus (O/N) ratios, and contain low values of Mn/Fe, Ni and Cu. In contrast, nodules from plains at the base of the seamount show greater abundance, are more spherical, have rougher surfaces, register high O/N ratios...

  10. Interactions between small cetaceans and the purse-seine fishery in western Portuguese waters

    Directory of Open Access Journals (Sweden)

    Laura Wise

    2007-06-01

    Full Text Available Marine mammal interactions with Portuguese purse-seine fisheries operating in four different ports (Figueira da Foz, Sesimbra, Setúbal, Sines were studied (July-October 2003. Observers accompanied commercial fishing vessels and monitored 48 fishing trips. An interview survey of skippers was also carried out (n = 36. Three species of marine mammals were observed in 31 sightings during the commercials trips but only the species Delphinus delphis and the category Delphinidae were observed to interact with fishing activities. Small cetaceans were observed to sink, gather or disperse school fishes and damage gear. Mean CPUE and fishing effort values did not change significantly in the presence of dolphins (H = 0.06 and H = 0, both p>0.05. Results from Figueira da Foz indicate that cetaceans are attracted to fishing grounds with a high abundance of their prey-species. Fishermen reported three by-catch events off Figueira da Foz. Compared with other fisheries, purse-seine fishing does not seem to be among the most damaging to marine mammals.

  11. Residency and spatial use by reef sharks of an isolated seamount and its implications for conservation.

    Science.gov (United States)

    Barnett, Adam; Abrantes, Kátya G; Seymour, Jamie; Fitzpatrick, Richard

    2012-01-01

    Although marine protected areas (MPAs) are a common conservation strategy, these areas are often designed with little prior knowledge of the spatial behaviour of the species they are designed to protect. Currently, the Coral Sea area and its seamounts (north-east Australia) are under review to determine if MPAs are warranted. The protection of sharks at these seamounts should be an integral component of conservation plans. Therefore, knowledge on the spatial ecology of sharks at the Coral Sea seamounts is essential for the appropriate implementation of management and conservation plans. Acoustic telemetry was used to determine residency, site fidelity and spatial use of three shark species at Osprey Reef: whitetip reef sharks Triaenodon obesus, grey reef sharks Carcharhinus amblyrhynchos and silvertip sharks Carcharhinus albimarginatus. Most individuals showed year round residency at Osprey Reef, although five of the 49 individuals tagged moved to the neighbouring Shark Reef (~14 km away) and one grey reef shark completed a round trip of ~250 km to the Great Barrier Reef. Additionally, individuals of white tip and grey reef sharks showed strong site fidelity to the areas they were tagged, and there was low spatial overlap between groups of sharks tagged at different locations. Spatial use at Osprey Reef by adult sharks is generally restricted to the north-west corner. The high residency and limited spatial use of Osprey Reef suggests that reef sharks would be highly vulnerable to targeted fishing pressure and that MPAs incorporating no-take of sharks would be effective in protecting reef shark populations at Osprey and Shark Reef.

  12. Residency and spatial use by reef sharks of an isolated seamount and its implications for conservation.

    Directory of Open Access Journals (Sweden)

    Adam Barnett

    Full Text Available Although marine protected areas (MPAs are a common conservation strategy, these areas are often designed with little prior knowledge of the spatial behaviour of the species they are designed to protect. Currently, the Coral Sea area and its seamounts (north-east Australia are under review to determine if MPAs are warranted. The protection of sharks at these seamounts should be an integral component of conservation plans. Therefore, knowledge on the spatial ecology of sharks at the Coral Sea seamounts is essential for the appropriate implementation of management and conservation plans. Acoustic telemetry was used to determine residency, site fidelity and spatial use of three shark species at Osprey Reef: whitetip reef sharks Triaenodon obesus, grey reef sharks Carcharhinus amblyrhynchos and silvertip sharks Carcharhinus albimarginatus. Most individuals showed year round residency at Osprey Reef, although five of the 49 individuals tagged moved to the neighbouring Shark Reef (~14 km away and one grey reef shark completed a round trip of ~250 km to the Great Barrier Reef. Additionally, individuals of white tip and grey reef sharks showed strong site fidelity to the areas they were tagged, and there was low spatial overlap between groups of sharks tagged at different locations. Spatial use at Osprey Reef by adult sharks is generally restricted to the north-west corner. The high residency and limited spatial use of Osprey Reef suggests that reef sharks would be highly vulnerable to targeted fishing pressure and that MPAs incorporating no-take of sharks would be effective in protecting reef shark populations at Osprey and Shark Reef.

  13. Residency and Spatial Use by Reef Sharks of an Isolated Seamount and Its Implications for Conservation

    Science.gov (United States)

    Barnett, Adam; Abrantes, Kátya G.; Seymour, Jamie; Fitzpatrick, Richard

    2012-01-01

    Although marine protected areas (MPAs) are a common conservation strategy, these areas are often designed with little prior knowledge of the spatial behaviour of the species they are designed to protect. Currently, the Coral Sea area and its seamounts (north-east Australia) are under review to determine if MPAs are warranted. The protection of sharks at these seamounts should be an integral component of conservation plans. Therefore, knowledge on the spatial ecology of sharks at the Coral Sea seamounts is essential for the appropriate implementation of management and conservation plans. Acoustic telemetry was used to determine residency, site fidelity and spatial use of three shark species at Osprey Reef: whitetip reef sharks Triaenodon obesus, grey reef sharks Carcharhinus amblyrhynchos and silvertip sharks Carcharhinus albimarginatus. Most individuals showed year round residency at Osprey Reef, although five of the 49 individuals tagged moved to the neighbouring Shark Reef (∼14 km away) and one grey reef shark completed a round trip of ∼250 km to the Great Barrier Reef. Additionally, individuals of white tip and grey reef sharks showed strong site fidelity to the areas they were tagged, and there was low spatial overlap between groups of sharks tagged at different locations. Spatial use at Osprey Reef by adult sharks is generally restricted to the north-west corner. The high residency and limited spatial use of Osprey Reef suggests that reef sharks would be highly vulnerable to targeted fishing pressure and that MPAs incorporating no-take of sharks would be effective in protecting reef shark populations at Osprey and Shark Reef. PMID:22615782

  14. Pierre Charmoz : La montagne à seins nus, un roman érotique de montagne, ou de la destruction du mythe alpin par le langage Pierre Charmoz: La Montagne à seins nus, or, the Debunking of the Alpine Myth trough Language Pierre Charmoz, La Sierra de los pechos desnudos o la destrucción del mito alpino por el lenguage

    Directory of Open Access Journals (Sweden)

    Michel Mestre

    1996-05-01

    Full Text Available La Montagne à seins nus de Pierre Charmoz est l'un des rares romans de montagne dans lequel l'érotisme joue un rôle important. C'est également une tentative de remise en cause des mythologies sur lesquelles le roman de montagne s'appuie, pour n'en garder que l'aspect léger et humoristique.La Montagne à seins nus, by Pierre Charmoz, is one of these few mountain novels in which eroticism plays a major part, it is also an attempt at debunking the mythologies on which alpine novels traditionally rest. It keeps only laughter and a gentle spirit of derision from it.La Sierra de los pechos desnudos, de Pierre Charmoz, es una de las raras novelas de montaña en las cuales el erotismo ocupa un lugar preponderante. También se empeña en derribar los mitos sobre los cuales suelen construirse las novelas alpinas tradicionales. De éstos permanece la risa, y uno disfruta mientras se hace burla de ellos.

  15. Suivi après le traitement du cancer du sein

    Science.gov (United States)

    Sisler, Jeffrey; Chaput, Geneviève; Sussman, Jonathan; Ozokwelu, Emmanuel

    2016-01-01

    Résumé Objectif Offrir aux médecins de famille un résumé des recommandations fondées sur les données probantes pour guider les soins aux survivantes traitées pour le cancer du sein. Qualité des données Une recherche documentaire a été effectuée dans MEDLINE entre 2000 et 2016 à l’aide des mots-clés anglais suivants : breast cancer, survivorship, follow-up care, aftercare, guidelines et survivorship care plans, en se concentrant sur la revue des lignes directrices publiées récemment par les organismes nationaux de cancérologie. Les données étaient de niveaux I à III. Message principal Les soins aux survivantes comportent 4 facettes : surveillance et dépistage, prise en charge des effets à long terme, promotion de la santé et coordination des soins. La surveillance des récidives ne se traduit que par une mammographie annuelle, et le dépistage d’autres cancers doit suivre les lignes directrices basées sur la population. La prise en charge des effets à long terme du cancer et de son traitement aborde des problèmes courants tels la douleur, la fatigue, le lymphœdème, la détresse et les effets indésirables des médicaments, de même que les préoccupations à long terme comme la santé du cœur et des os. La promotion de la santé met en relief les bienfaits de l’activité chez les survivantes du cancer, avec l’accent mis sur l’activité physique. Les soins aux survivantes sont de meilleure qualité lorsque divers services et professionnels de la santé participent aux soins, et le médecin de famille joue un rôle important dans la coordination des soins. Conclusion Les médecins de famille sont de plus en plus souvent les principaux fournisseurs de soins de suivi après le traitement du cancer du sein. Le cancer du sein doit être considéré comme une affection médicale chronique, même chez les femmes en rémission, et les patientes profitent de la même approche que celle utilisée pour les autres affections chroniques en

  16. Oceanographic data collected during the Davidson Seamount 2002 expedition on the RV Western Flyer, in the North Pacific Ocean, southwest of Monterey, California from May 17, 2002 - May 24, 2002 (NODC Accession 0072306)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This spring, scientists explored the first "undersea island" to be called a seamount. Davidson seamount, located 120 km Southwest of Monterey, California, is one of...

  17. Exploration of Caribbean Seamounts within the Greater and Lesser Antilles Transition Zone: Characterization of the Benthic Ecology and Geology

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Within the Caribbean region, numerous unexplored seamounts punctuate the seafloor holding records of geologic, biologic and oceanographic processes over different...

  18. Exploring Alaska's Seamounts on RV Atlantis in North Pacific Ocean and Gulf of Alaska between 20040730 and 20040823

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Five seamounts (Denson, Dickins, Pratt, Welker and Giacomini) in the Gulf of Alaska that had not previously been observed by manned submersible or ROV were...

  19. Recycled Archean sulfur in the mantle wedge of the Mariana Forearc and microbial sulfate reduction within an extremely alkaline serpentine seamount

    Science.gov (United States)

    Aoyama, Shinnosuke; Nishizawa, Manabu; Miyazaki, Junichi; Shibuya, Takazo; Ueno, Yuichiro; Takai, Ken

    2018-06-01

    The identification of microbial activity under extreme conditions is important to define potential boundaries of the habitable and uninhabitable zones of terrestrial and extraterrestrial living forms. The subseafloor regimes of serpentinite seamounts in the Mariana Forearc are among the most extreme environments for life on earth owing to the widespread presence of highly alkaline fluids with pH values greater than 12. The potential activity of sulfate-reducing microorganisms has been suggested within the South Chamorro serpentinite seamounts on the basis of depletion of sulfate and enrichment of dissolved sulfide in pore water. However, the vertical distribution of sulfate-reducing microorganisms and the origin of sulfate are still uncertain. To address these issues, we analyzed quadruple sulfur isotopes of sulfide minerals and pore water sulfate in the upper 56 m of sedimentary sequences at the summit of the S. Chamorro Seamount and those of dissolved sulfate in upwelling fluids collected as deep as 202 mbsf (meters below the seafloor) in a cased hole near the summit of the same seamount. The depth profiles of the concentrations and the δ34S and Δ33S‧ values of sulfide minerals and pore water sulfate indicate microbial sulfate reduction as deep as 30 mbsf. Further, apparent isotopic fractionations (34ε) and exponents of mass dependent relationships (33λ) during sulfate reduction are estimated to be 62 ± 14‰ and 0.512 ± 0.002, respectively. The upwelling fluids show both the chlorine depletion relative to seawater and the negative δ15N values of ammonia (-4‰). Although these signatures point to dehydration of the subducting oceanic plate, the negative Δ33S‧ values of sulfate (-0.16‰ to -0.26‰ with analytical errors of ±0.01‰) are unlikely to originate from surrounding modern crusts. Instead, sulfate in the upwelling fluid likely possess non-mass-dependent (NMD) sulfur. Because NMD sulfur was produced primarily in the Archean atmosphere, our

  20. STATUS OF SMALL PELAGIC FISHERY IN THE MAKASSAR STRAIT BASED AT THE NORTHERN PART OF JAVA

    Directory of Open Access Journals (Sweden)

    Sri Turni Hartati

    2016-12-01

    Full Text Available The coastal of Makassar Strait is one of main fishing grounds for purse seine vessels from northern part of Java which based at the following landing sites, i.e. Pekalongan, Tegal and Juwana. The purse seine fishery predominantly targets small pelagic fish. This paper attempts to present the current condition of small pelagic fishery in the Makassar Strait. Catch and effort (trip data between 2004 and 2011 from the three landing sites were used to estimate Maximum Sustainable Yield (MSY using Schaefer & Fox models. The results showed a decreasing trend in the catch rate, from 30.83 tons/trip in 2004 to 12.27 tons/trip in 2011. The estimated MSY is at the range of 34,705- 37,930 tons with optimum efforts for 2,234-2,500 purse seine trips. Thus the level of purse seine fishing effort in 2011, i.e. 3,078 trips, was exceeding the optimum effort. The decreasing trend in the catch rate may indicate overfishing is occurring between 2004 and 2011. For management of the small pelagic fisheries in the waters of Makassar Strait, important action recommended is fishing effort restrictions. The effort allowed would be only in the range of 2,234-2,500 purse seine trips, and the fishing capacity needs to be controled.

  1. Platinum group elements and gold in ferromanganese crusts from Afanasiy-Nikitin seamount, equatorial Indian Ocean: Sources and fractionation

    Digital Repository Service at National Institute of Oceanography (India)

    Banakar, V.K.; Hein, J.R.; Rajani, R.P.; Chodankar, A.R.

    The major element relationships in ferromanganese (Fe–Mn) crusts from Afanasiy–Nikitin seamount (ANS), eastern equatorial Indian Ocean, appear to be atypical. High positive correlations (r = 0.99) between Mn/Co and Fe/Co ratios, and lack...

  2. Earlier history of the ≥70-Ma-old Canary hotspot based on the temporal and geochemical evolution of the Selvagen Archipelago and neighboring seamounts in the eastern North Atlantic

    Science.gov (United States)

    Geldmacher, Jörg; Hoernle, Kaj; van den Bogaard, Paul; Zankl, Goor; Garbe-Schönberg, Dieter

    2001-11-01

    Major element, trace element and Sr-Nd-Pb isotope data, combined with 40Ar/39Ar age determinations, of volcanic rocks from the Selvagen Islands and neighboring seamounts in the eastern North Atlantic reveal the earlier history of the ≥70 Ma old Canary hotspot. A basanitic to phonolitic late shield stage intrusive complex (29 Ma) is exposed on Selvagem Pequena. The evolution of Selvagem Grande can be divided into three magmatic phases: a tephritic to phonolitic late shield stage intrusive complex (24-26 Ma) and two rejuvenated or post-erosional stages (8-12 and 3.4 Ma) consisting of alkali basalt, basanite and rare phonolite. During the early to mid-Miocene volcanic hiatus (12-24 Ma), the top of the volcano was beneath sea level as evidenced by marine carbonate sediments (13-24 Ma, dated through correlation of 87Sr/86Sr with the seawater Sr isotope curve). The geochemistry of the shield stage lavas indicates that they derive from plume sources, whereas the post-erosional lavas are derived from metasomatized lithospheric sources. Five sampled seamounts to the east and northeast of the islands range in composition from alkali basalt and basanite to phonolite. Samples from Dacia, Conception Bank and Lars were dated at 9, 17 and 68 Ma, respectively. Geochemical data suggest that the dredged samples come from the post-erosional stage of volcanism, and therefore, the dates represent minimum ages for the seamount volcanoes. The elevation of erosional platforms formed at wave base decrease from Selvagen Grande (∼100 m above sea level) to Lars seamount (∼900 m below sea level), suggesting a southwest to northwest age progression and that all of these seamounts are older than the Selvagen Islands. Trace element and Sr-Nd-Pb isotopic composition of the Selvagen Islands and neighboring seamounts are consistent with their origin from the Canary plume. Interaction of the weak Canary mantle plume with a slow moving plate appears to be responsible for generating a 450-km

  3. Arago Seamount: The missing hotspot found in the Austral Islands

    Science.gov (United States)

    Bonneville, Alain; Le Suavé, Raymond; Audin, Laurence; Clouard, Valérie; Dosso, Laure; Yves Gillot, Pierre; Janney, Philip; Jordahl, Kelsey; Maamaatuaiahutapu, Keitapu

    2002-11-01

    The Austral archipelago, on the western side of the South Pacific superswell, is composed of several volcanic chains, corresponding to distinct events from 35 Ma to the present, and lies on oceanic crust created between 60 and 85 Ma. In 1982, Turner and Jarrard proposed that the two distinct volcanic stages found on Rurutu Island and dated as 12 Ma and 1 Ma could be due to two different hotspots, but no evidence of any recent aerial or submarine volcanic source has ever been found. In July 1999, expedition ZEPOLYF2 aboard the R/V L'Atalante conducted a geophysical survey of the northern part of the Austral volcanic archipelago. Thirty seamounts were mapped for the first time, including a very shallow one (French Navy ship that discovered its summit in 1993, is the missing hotspot in the Cook-Austral history. This interpretation adds a new hotspot to the already complicated geologic history of this region. We suggest that several hotspots have been active simultaneously on a region of the seafloor that does not exceed 2000 km in diameter and that each of them had a short lifetime (<20 m.y.). These short-lived and closely spaced hotspots cannot be the result of discrete deep-mantle plumes and are likely due to more local upwelling in the upper mantle strongly influenced by weaknesses in the lithosphere.

  4. Major and trace element and volatile constraints on magma systematics of seamounts and axial ridge glasses from the East Pacific Rise between 8°N and 12°N

    Science.gov (United States)

    Lytle, M. L.; Kelley, K. A.; Wanless, V. D.; Hauri, E. H.

    2017-12-01

    The East Pacific Rise is a fast spreading mid-ocean ridge system (6-16cm/yr) consisting of many spreading ridges and transform faults. Focusing on a well-studied segment between 8-12°N, we present new SIMS measurements of magmatic volatiles (H2O, CO2, S, Cl, F) and new LA-ICP-MS trace element data in both on-axis and off-axis glasses, coupled with previously published data and use these data to relate melt composition to crystallization and melting processes. The seamounts range in composition from evolved (MgO = 5.54 wt%) to fairly primitive (MgO = 9.70 wt%), whereas on-axis samples have a narrower range of MgO (5.85 - 8.83 wt%). Seamounts span a wide range of enrichment in trace element compositions (La/Sm 0.45 - 4.63; Th/La 0.02 - 0.14; K/Ti 0.02 - 0.66), whereas on-axis glasses reflect NMORB compositions (La/Sm 0.5 - 1; Th/La 0.035 - 0.07; K/Ti 0.05 - 0.15). Light rare earth elements in the seamounts vary from depleted to enriched and have variable Eu anomalies (0.79 - 1.10), while on-axis samples have NMORB patterns with more negative Eu anomalies (0.74 - 1.00). The H2O content of the seamounts ranges from dry (0.05 wt%) to fairly wet (0.96 wt%), whereas on-axis samples have a narrower range (0.15 - 0.31 wt%). Cl contents show variable mixing between seawater and a magmatic component, with seamounts assimilating more seawater. Magmatic liquid lines of descent (LLD), recorded in glass, reflect fractional crystallization of olivine, plagioclase, and clinopyroxene, consistent with modal phenocryst abundances of the rocks. A multi-element approach (e.g., MgO vs. Al2O3, CaO, CaO/Al2O3), constrains LLDs, providing fractionation slopes, allowing mafic basalt compositions to be accurately corrected back to primary melts in equilibrium with Fo90. Using these melts, pressures and temperatures of melt equilibration can be constrained using melt thermobarometry. On-axis samples reflect higher PT conditions (1371°C; 1.37 GPa), although within error of seamounts (1340

  5. Estimating seabed pressure from demersal trawls, seines, and dredges based on gear design and dimensions

    DEFF Research Database (Denmark)

    Eigaard, Ole Ritzau; Bastardie, Francois; Breen, Mike

    2016-01-01

    such as logbook data. Here, we take a different approach starting from the gear itself (design and dimensions) to estimate the physical interactions with the seabed at the level of the individual fishing operation. We defined 14 distinct towed gear groups in European waters (eight otter trawl groups, three beam...... trawl groups, two demersal seine groups, and one dredge group), for which we established gear “footprints”. The footprint of a gear is defined as the relative contribution from individual larger gear components, such as trawl doors, sweeps, and groundgear, to the total area and severity of the gear...... to enable the prediction of gear footprint area and sediment penetration from vessel size. Application of these relationships with average vessel sizes and towing speeds provided hourly swept-area estimates by métier. Scottish seining has the largest overall gear footprint of ∼1.6 km2 h−1 of which 0.08 km2...

  6. Cancer du sein au Maroc: profil phénotypique des tumeurs | Khalil ...

    African Journals Online (AJOL)

    Le cancer du sein est le plus fréquent chez la femme et figure parmi les principales causes de mortalité liée au cancer. La curabilité de ce type tumoral est en augmentation, grâce aux programmes de dépistage et aux progrès thérapeutiques, qui ont certes augmenté la survie des patients. Mais des défis restent à relever en ...

  7. Palaeoceanographic conditions during the formation of ferromanganese crust from the Afanasiy Nikitin seamount, north central Indian Ocean: geochemical evidence

    Digital Repository Service at National Institute of Oceanography (India)

    Banakar, V.K.; Pattan, J.N.; Mudholkar, A.V.

    A ferromanganese crust dredged from the summit of the Afanasiy-Nikitin seamount in the composed of fresh-water phreatic calcite cement, Terebratulinae casts, rounded and ferruginised basalt clasts and weathered coralline algal fragments suggesting...

  8. Environmental Impact of a Submarine Cable: Case Study of the Acoustic Thermometry of Ocean Climate (ATOC)/ Pioneer Seamount Cable

    Science.gov (United States)

    Kogan, I.; Paull, C. K.; Kuhnz, L.; von Thun, S.; Burton, E.; Greene, H. G.; Barry, J. P.

    2003-12-01

    To better understand the potential impacts of the presence of cables on the seabed, a topic of interest for which little data is published or publicly available, a study of the environmental impacts of the ATOC/Pioneer Seamount cable was conducted. The 95 km long, submarine, coaxial cable extends between Pioneer Seamount and the Pillar Point Air Force Station in Half Moon Bay, California. Approximately two thirds of the cable lies within the Monterey Bay National Marine Sanctuary. The cable is permitted to NOAA- Oceanic and Atmospheric Research for transmitting data from a hydrophone array on Pioneer Seamount to shore. The cable was installed unburied on the seafloor in 1995. The cable path crosses the continental shelf, descends to a maximum depth of 1,933 m, and climbs back upslope to 998 m depth near the crest of Pioneer Seamount. A total of 42 hours of video and 152 push cores were collected in 10 stations along cable and control transects using the ROVs Ventana and Tiburon equipped with cable-tracking tools. The condition of the cable, its effect on the seafloor, and distribution of benthic megafauna and infauna were determined. Video data indicated the nature of interaction between the cable and the seafloor. Rocky nearshore areas, where wave energies are greatest, showed the clearest evidence of impact. Here, evidence of abrasion included frayed and unraveling portions of the cable's armor and vertical grooves in the rock apparently cut by the cable. The greatest incision and armor damage occurred on ledges between spans in irregular rock outcrop areas. Unlike the nearshore rocky region, neither the rocks nor the cable appeared damaged along outcrops on Pioneer Seamount. Multiple loops of slack cable added during a 1997 cable repair operation were found lying flat on the seafloor. Several sharp kinks in the cable were seen at 240 m water depths in an area subjected to intense trawling activity. Most of the cable has become buried with time in sediment

  9. Phosphatization Associated Features of Ferromanganese Crusts at Lemkein Seamount, Marshall Islands

    Science.gov (United States)

    Choi, J.; Lee, I.; Park, B. K.; Kim, J.

    2014-12-01

    Old layers of ferromanganese crusts, especially in the Pacific Ocean, have been affected by phosphatization. Ferromanganese crusts on Lemkein seamount in Marshall Islands also are phosphatized (3.3 to 4.2 wt % of P concentration). Furthermore, they have characteristic features that are different from other ferromanganese crusts. These features occur near the phosphorite, which were thought to fill the pore spaces of ferromanganese crusts. Inside the features, ferromanganese crusts are botryoidally precipitated from the round-boundary. The features of the phosphatized lower crusts of Lemkein seamount are observed using microscope and SEM. Elemental compositions of the selected samples were analyzed by SEM-EDS. Based on the observation and analysis of samples, three characteristic structures are identified: (1) phosphate-filled circles, (2) tongue-shaped framboidal crust, and (3) massive framboidal crust. The phosphate-filled circles are mostly composed of phosphorite, and they include trace fossils such as foraminifera. Phosphatized ferromanganese crusts exist at the boundary of this structure. The tongue-shaped crust is connected with the lips downward, and ferromanganese crusts inside the tongue show distinct growth rim. The massive framboidal crust is located below the tongue. Ferromanganese crusts in the massive framboidal crust are enveloped by phosphate, and some of the crusts are phosphatized. Around the structures, Mn oxide phase is concentrated as a shape of corona on BSE image. All of the structures are in the phosphatized crusts that show columnar growth of ferromanganese crusts and have sub-parallel lamination. These observation and chemical analysis of the ferromanganese crusts can provide a clue of diagenetic processes during the formation of ferromanganese crusts.

  10. Socio-natural dynamics of COGEPOMI plans for diadromous-fish management on the Garonne and Seine rivers

    Directory of Open Access Journals (Sweden)

    BARTHÉLÉMY, Carole

    2011-03-01

    Full Text Available Comparison of two Committees for diadromous-fish management on the Garonne and Seine rivers raises questions on the different types of biodiversity management. What are the strong points, the weak points? What lessons may be drawn for collaborative biodiversity management?

  11. A Sein Island in renewable electric power autonomy? Analysis of the Government's project for the Sein Island

    International Nuclear Information System (INIS)

    Flocard, Hubert; Le Gorgeu, Jean-Pierre

    2018-01-01

    Even if the Sein Island emits less CO 2 emissions than 700 vehicles, the Government set an objective of 50 per cent for renewable energy production within its multi-year energy planning (PPE). The objectives of the authors is herein to analyse the credibility of these PPE objectives, more particularly as far as electric power autonomy is concerned. They used available and precise data related to the island's energy consumption. They show that this 50 per cent coverage can indeed be reached, but with investments which are not justified when the population size and current resulting pollution are considered. They also outline that diesel engines will still be used from time to time, and that their emissions will not even be reduced as diesel units will not operate in optimal regime. Therefore, they regret that such objectives have been imposed to the island without any detailed preliminary study

  12. Linking environmental forcing and trophic supply to benthic communities in the Vercelli Seamount area (Tyrrhenian Sea.

    Directory of Open Access Journals (Sweden)

    Anabella Covazzi Harriague

    Full Text Available Seamounts and their influence on the surrounding environment are currently being extensively debated but, surprisingly, scant information is available for the Mediterranean area. Furthermore, although the deep Tyrrhenian Sea is characterised by a complex bottom morphology and peculiar hydrodynamic features, which would suggest a variable influence on the benthic domain, few studies have been carried out there, especially for soft-bottom macrofaunal assemblages. In order to fill this gap, the structure of the meio-and macrofaunal assemblages of the Vercelli Seamount and the surrounding deep area (northern Tyrrhenian Sea - western Mediterranean were studied in relation to environmental features. Sediment was collected with a box-corer from the seamount summit and flanks and at two far-field sites in spring 2009, in order to analyse the metazoan communities, the sediment texture and the sedimentary organic matter. At the summit station, the heterogeneity of the habitat, the shallowness of the site and the higher trophic supply (water column phytopigments and macroalgal detritus, for instance supported a very rich macrofaunal community, with high abundance, biomass and diversity. In fact, its trophic features resembled those observed in coastal environments next to seagrass meadows. At the flank and far-field stations, sediment heterogeneity and depth especially influenced the meiofaunal distribution. From a trophic point of view, the low content of the valuable sedimentary proteins that was found confirmed the general oligotrophy of the Tyrrhenian Sea, and exerted a limiting influence on the abundance and biomass of the assemblages. In this scenario, the rather refractory sedimentary carbohydrates became a food source for metazoans, which increased their abundance and biomass at the stations where the hydrolytic-enzyme-mediated turnover of carbohydrates was faster, highlighting high lability.

  13. Characteristics of Beach Seine Fishery of East Java: Facing Ministerial Decree of Marine Affairs and Fisheries No. 2/2015

    Directory of Open Access Journals (Sweden)

    Dewa Gede Raka Wiadnya

    2017-07-01

    Full Text Available Catch biomass and time-trend perception of Beach seine fishery were studied during 2015, from four different sites in East Java: Padikde Madura, Santan Island Banyuwangi, Prigi Beach Trenggalek, and Dangkal Beach Pacitan. The study aimed to assess the impact of recently Ministerial Decree (No. 2/2015 on this particular fishery. Catch biomass was analyzed based on swept area method. Time trend perception was traced back from fishermen in relation to reduced catch biomass, catch size, habitat degradation, and income contribution from the fishery. The results showed that Beach Seines in East Java are considerably subsistence. It swept fixed-bottom habitats of 1–9 ha. Average catch biomass for all sites was 15±19.4 kg trip-1. With low price of fish catch, fishermen cannot place down their family income solely from this livelihood. Beach seine is more as to maintain tradition of subsistence. Fishermen clearly observed the reduced in catch biomass and catch size compared to what it used to be (±30 years ago. With very low contribution to total catch in the region, negligible impact to habitat degradation, and consumed no fuel subsidy, it is no real reason to include this gear in general ban through Ministerial Decree of Marine Affairs and Fisheries.

  14. A crab swarm at an ecological hotspot: patchiness and population density from AUV observations at a coastal, tropical seamount

    Directory of Open Access Journals (Sweden)

    Jesús Pineda

    2016-04-01

    Full Text Available A research cruise to Hannibal Bank, a seamount and an ecological hotspot in the coastal eastern tropical Pacific Ocean off Panama, explored the zonation, biodiversity, and the ecological processes that contribute to the seamount’s elevated biomass. Here we describe the spatial structure of a benthic anomuran red crab population, using submarine video and autonomous underwater vehicle (AUV photographs. High density aggregations and a swarm of red crabs were associated with a dense turbid layer 4–10 m above the bottom. The high density aggregations were constrained to 355–385 m water depth over the Northwest flank of the seamount, although the crabs also occurred at lower densities in shallower waters (∼280 m and in another location of the seamount. The crab aggregations occurred in hypoxic water, with oxygen levels of 0.04 ml/l. Barcoding of Hannibal red crabs, and pelagic red crabs sampled in a mass stranding event in 2015 at a beach in San Diego, California, USA, revealed that the Panamanian and the Californian crabs are likely the same species, Pleuroncodes planipes, and these findings represent an extension of the southern endrange of this species. Measurements along a 1.6 km transect revealed three high density aggregations, with the highest density up to 78 crabs/m2, and that the crabs were patchily distributed. Crab density peaked in the middle of the patch, a density structure similar to that of swarming insects.

  15. Tectonic structure of Dokdo and adjacent area in the northeastern part of the Ulleung Basin of the East Sea using geophysical data

    Science.gov (United States)

    Kim, C.; Jeong, E.; Park, C.; Kwon, B.; Park, G.; Park, J.

    2008-12-01

    The northeastern part of the Ulleung Basin in the East Sea is composed of volcanic islands (Ulleungdo and Dokdo), seamounts (the Anyongbok Seamount, the Simheungtaek and the Isabu Tablemounts), and a deep pathway (Korea Gap). To understand tectonic structure and geophysical characteristics of Dokdo and adjacent area, We analysed geophysical potential data of KORDI(Korea Ocean Research and Development Institute), KIGAM(Korea Institute of Geoscience and Mineral Resources), and NORI(National Oceanographic Research Institute of Korea) around the Dokdo volcanic body except Ulleung Do because of empty data of its large island. Also, we eliminate the effect of water and sediments from the free-air gravity data to process 3D Moho depth inversion. 3D tectonic structure modelling of the study area was developed using Moho depth inversion result and sediment thickness data of NGDC(National Geophysical Data Center). The free-air gravity anomalies of the study area generally reflect bathymetric effects. Although the Dokdo seamounts have a similar topographic size, the decrease of free-air anomaly toward Isabu suggest that Isabu is oldest among the seaounts and have high degree of isostatic compensation. High Bouguer anomalies in the central part of the Ulleung Basin gradually decreases toward the Oki Bank. This feature suggests that the crust/mantle boundary is shallow in the central part of the Ulleung Basin. The complex magnetic pattern of Dokdo suggests that it might have erupted several times during its formation. The magnetic anomaly amplitude of Isabu is much smaller than that of Dokdo. Such low magnetic anomalies are attributed to a secondary change caused by the metamorphism or weathering of ferromagnetic minerals of the seamount during a long period of time after its formation. Analytic signals show high anomalous zones over volcanoes. Also, there are high analytic signal values in Korea Gap indicating magmatic intrusion in thick sediments. The power spectrum analysis

  16. Hyperiid amphipods around the seamounts and islands off northeastern Brazil

    Directory of Open Access Journals (Sweden)

    Christiane Sampaio de Souza

    Full Text Available Abstract Data collected on large-scale surveys around the seamounts and islands off northeastern Brazil provide information on the hyperiid amphipod populations. Thirty-six species were identified. Most of the species belong to the Infraorder Physocephalata, representing 21 genera and 13 families. Thirteen species (Vibilia australis, L. latissimus, L. macrophthalmus, L. schizogeneios, Phronima atlantica, Phrosina semilunata, Primno brevidens, Eupronoe minuta, Oxycephalus clause, Rhabdosoma whitei, Amphithyrus bispinosus, Leptocotis tenuirostris and Tetrathyrus forcipatus have not previously been recorded in this region. The spatial distribution of the hyperiid amphipods was very patchy. Each area of these amounts and islands off northeastern Brazil has different oceanographic features and can be characterised by a clearly defined group of most abundant species.

  17. Connaissances des médecins généralistes de Mohammedia (Maroc) concernant le dépistage du cancer du sein

    Science.gov (United States)

    Zine, Karima; Nani, Samira; Lahmadi, Imad Ait; Maaroufi, Abderrahmane

    2016-01-01

    Introduction Le cancer du sein représente un problème de santé publique majeur au Maroc. C'est le premier cancer chez la femme. L'objectif de ce travail était d'évaluer les connaissances des médecins généralistes (MG) en matière de dépistage du cancer du sein dans la préfecture de Mohammedia Maroc. Méthodes Nous avons mené une étude transversale, descriptive, exhaustive incluant les 97 MG exerçant dans les établissements de soins de santé de base du secteur public et privé de la province de Mohammedia. Résultats Le taux de participation était de 87%. L'âge moyen des MG était de 49,6 ± 8,1. Quatre-vingt pour cent (n=55) des MG ont donné une incidence incorrecte, 77,6% (n=85) ont reconnu l'existence d'un plan national de prévention et de contrôle du cancer (PNPCC) au Maroc, et 67,1 des MG ont rapporté l'existence d'un registre du cancer au Maroc. Le secteur d'activité était associé significativement avec les connaissances des MG sur le PNPCC et sur l'existence d'un guide de détection précoce du cancer du sein avec respectivement (p=0,003 et p=0,001). Une association significative entre l'ancienneté et l'existence d'un guide de détection précoce du cancer du sein et d'un registre du cancer du sein a été retrouvée avec (respectivement p=0,005 et p=0.002). Conclusion À la lumière de ces résultats il faudra renforcer les connaissances et les pratiques des MG par la promotion de la formation initiale et continue sur le dépistage. PMID:27800098

  18. 50 CFR 216.24 - Taking and related acts incidental to commercial fishing operations by tuna purse seine vessels...

    Science.gov (United States)

    2010-10-01

    ... including the use of the high intensity lighting system. In the event a sundown set occurs where the seine... International Review Panel, prosecution by the United States is not recommended. Any such recommendation will be...

  19. Diffusive transfer of oxygen from seamount basaltic crust into overlying sediments: An example from the Clarion–Clipperton Fracture Zone

    NARCIS (Netherlands)

    Mewes, K.; Mogollón, J.M.; Picard, A.; Rühlemann, C.; Eisenhauer, A.; Kuhn, T.; Ziebis, W.; Kasten, S.

    2016-01-01

    The Clarion–Clipperton Fracture Zone (CCFZ) in the Pacific Ocean is characterized by organic carbon-starved sediments and meter-scale oxygen penetration into the sediment. Furthermore, numerous seamounts occur throughout its deep-sea plain, which may serve as conduits for low-temperature

  20. The genetic link between the Azores Archipelago and the Southern Azores Seamount Chain (SASC): The elemental, isotopic and chronological evidences

    Science.gov (United States)

    Ribeiro, Luisa Pinto; Martins, Sofia; Hildenbrand, Anthony; Madureira, Pedro; Mata, João

    2017-12-01

    New geochemical, isotopic (Sr-Nd-Hf-Pb) and K-Ar data, are presented here on samples from the Southern Azores Seamount Chain (SASC) located south of the Azores Plateau. The SASC also includes the Great Meteor, Small Meteor and Closs seamounts, morphologically connected by a saddle at - 4100 m deep. We conclude that the SASC are characterized by a narrow isotopic variability that falls within the Azores isotopic field. Although each seamount has its own isotopic signature, their mantle source must comprise four local mantle end-members, three of which are common to the Azores, e.g. Plato isotopic signature results from the mixing between HIMU and N-MORB while Great Meteor signature results from this mix with the Azores Common Component (AzCC). A fourth end-member with high 208Pb/204Pb and decoupled Th/U ratios (Δ8/4 up to 59.2) is identified on Great Meteor northern flank. New K-Ar ages on Plato (33.4 ± 0.5 Ma) and Small Hyeres (31.6 ± 0.4 Ma) show nearly coeval volcanism, which is contemporaneous with the E-MORBs erupted at the MAR, drilled on oceanic crust with 30-34 Ma (DSDP82). This study endorses the genetic link between the Azores Archipelago and the SASC to the long-term activity of the Azores plume and the large-scale ridge-hotspot interaction, contributing to better constrain the temporal-spatial evolution of this region of the North Atlantic.

  1. Ocean Observing at Axial Seamount: Details of the Current OOI-RSN Design Within the Context of the April 2011 Eruption

    Science.gov (United States)

    Proskurowski, G.; Kelley, D. S.; Fundis, A. T.; Kawka, O.; Denny, G. F.; Delaney, J. R.

    2011-12-01

    In 2013, the NSF's Ocean Observatories Initiative (OOI) will deploy 22 instrument suites within the caldera of Axial Seamount as part of the cabled observatory component implemented by the Regional Scale Nodes (RSN) at the University of Washington. The cabled infrastructure will initially provide Axial caldera with a total of 8kW of power and 11Gbps of data bandwidth. Only an approximate 20% fraction will be used by "core instrumentation"-instrumentation supported and maintained by OOI-RSN. Thus, the OOI provided infrastructure is highly, and readily, expandable to include community-generated instrumention once the system is commissioned and begins operations in early 2015. Here we present the details of the current design of the cabled observatory at Axial Seamount, including locations of instruments, data products, and sampling rates placed in the context of meter scale resolution bathymetry and down-looking photomosaics of the experimental sites. The April 2011 Axial eruption is a demonstration of the importance of transmitting seismic, video, and vent fluid chemistry information in real-time. The eruptive event, or series of events, in April 2011 went undetected until a series of ROV/AUV cruises, planned separately and years in advance, made observations to discover, confirm, and detail the transformation to Axial (see Chadwick et al., this session). What transpired during, and shortly after, the eruption will remain largely unknown, as the initial extraordinary fluxes of heat, chemistry and biology will have decayed in the intervening three and a half months. Here we detail the response capabilities of the OOI-RSN cabled observatory to a future eruptive event under two scenarios-as built, and an expanded version using existing technology.

  2. The Psychology of Violent Conflict in Failing States: A Review of the Scientific Literature (Psychologie des Conflits Violents au sein d’etats en Deroute: Analyse de Publications Scientifiques)

    Science.gov (United States)

    2010-12-01

    Sommaire ..... Psychologie des conflits violents au sein d’états en déroute: Analyse de publications scientifiques Donald M. Taylor; Michael J. A...in parenthesis at the end of the title) The Psychology of Violent Conflict in Failing States (U) Psychologie des conflits violents au sein d’états en

  3. Mesobathic chondrichthyes of the Juan Fernández seamounts: are they different from those of the central Chilean continental slope?

    Directory of Open Access Journals (Sweden)

    Isabel Andrade

    2008-03-01

    Full Text Available We compared the geographic distribution of groups of chondrychthid fishes of two physically proximal, although geographically different, regions that include the Juan Fernández seamounts and the central Chilean continental slope, both sampled at mesopelagic and mesobenthonic depths. The ridge is in the Nazca Plate, while the slope region in on the South American Plate, and is closer to the South American continent. We found six species of Chondrichthyes for the seamounts (four orders, four families. The slope sampling produced ten species of Chondrichthyes, of which Torpedo tremens De Buen 1959, was the only species in common with the Juan Fernández area. There are clear differences between the Chondrichthyes of the two regions. These fisheries require adequate administrative modes. Rev. Biol. Trop. 56 (1: 181-190. Epub 2008 March 31.

  4. Summer use of the tidal freshwaters of the River Seine by three estuarine fish: Coupling telemetry and GIS spatial analysis

    Science.gov (United States)

    Le Pichon, C.; Coustillas, J.; Zahm, A.; Bunel, M.; Gazeau-Nadin, C.; Rochard, E.

    2017-09-01

    Acoustic telemetry and GIS-based spatial analysis were used to investigate the summer habitat use and movement patterns of three fish species in the tidal freshwaters of the Seine estuary (France). Experimental displacement of tagged individuals of thin-lipped grey mullet (Liza ramada), European eel (Anguilla anguilla), and common bream (Abramis brama) were conducted to test for their spatial fidelity and home range establishment. Most tagged individuals (95%) successfully returned to their previously occupied capture site, showing spatial homing abilities. The studied upstream tidal freshwater segment of the Seine estuary was regularly used by grey mullet as a part of its larger summer home range, while European eel and common bream were resident in this segment. The fidelity of eel to small nocturnal refuges and the regular use of intertidal waterbodies at high tide by grey mullet and bream suggested that they possess a capacity of acquiring spatial memory of habitats in a fluctuating environment. Importantly, the scale of movements travelled by each species was positively related to tidal phase. Grey mullet and bream, both visual feeders, exhibited short-term tidal movements to known habitats, providing food resources and contiguous resting habitat suggesting that they have shown behavioural strategies adaptive to fluctuating environments. Eel, in contrast, was found to have a different strategy strongly related to diel dynamics: it stayed in subtidal habitats rich in refuges that remained available at low tide. The results of this study emphasize the importance of restoring intertidal waterbodies and the relevance of considering the availability of adjacent subtidal habitats providing refuge at low tides.

  5. delineating the jurassic to mid-cretaceous part of the pacific ...

    African Journals Online (AJOL)

    Mgina

    paleomagnetic field. This problem was solved by the formulation of the seamount paleomagnetism technique (Talwani 1965,. Plouff 1976, Parker et al. 1987). Following this, Sager and Pringle (1988) using mainly seamount paleomagnetic data delineated a well defined Pacific ... earth's surface and abuts six major and.

  6. CRED 20 m Gridded bathymetry and IKONOS estimated depths of Northampton Seamounts to Laysan Island, Northwestern Hawaiian Islands, USA (NetCDF format)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Gridded bathymetry and IKONOS estimated depths of the shelf and slope environments of Northampton Seamounts to Laysan Island, Northwestern Hawaiian Islands, Hawaii,...

  7. CRED 20 m Gridded bathymetry and IKONOS estimated depths of Northampton Seamounts to Laysan Island, Northwestern Hawaiian Islands, USA (Arc ASCII format)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Gridded bathymetry and IKONOS estimated depths of the shelf and slope environments of Northampton Seamounts to Laysan Island, Northwestern Hawaiian Islands, Hawaii,...

  8. Marine pollution originating from purse seine and longline fishing vessel operations in the Western and Central Pacific Ocean, 2003-2015.

    Science.gov (United States)

    Richardson, Kelsey; Haynes, David; Talouli, Anthony; Donoghue, Michael

    2017-03-01

    Fisheries observer data recorded between 2003 and 2015 on-board purse seine and longline vessels operating in the Western and Central Pacific Ocean reported more than 10 000 pollution incidents within the exclusive economic zones (EEZs) of 25 Pacific countries and territories, and in international waters. A majority of the reported purse seine pollution incidents related to dumping of plastics waste. Other common pollution incidents related to oil spillages and to abandoned, lost or dumped fishing gear. Data analysis highlighted the need for increased monitoring, reporting, and enforcement of pollution violations by all types of fishing vessels operating in the Pacific region; a regional outreach and compliance assistance programme on marine pollution prevention and improvements in Pacific port waste reception facilities.

  9. Late Paleocene-middle Eocene benthic foraminifera on a Pacific seamount (Allison Guyot, ODP Site 865): Greenhouse climate and superimposed hyperthermal events

    Science.gov (United States)

    Arreguín-Rodríguez, Gabriela J.; Alegret, Laia; Thomas, Ellen

    2016-03-01

    We investigated the response of late Paleocene-middle Eocene (~60-37.5 Ma) benthic foraminiferal assemblages to long-term climate change and hyperthermal events including the Paleocene-Eocene Thermal Maximum (PETM) at Ocean Drilling Program (ODP) Site 865 on Allison Guyot, a seamount in the Mid-Pacific Mountains. Seamounts are isolated deep-sea environments where enhanced current systems interrupt bentho-pelagic coupling, and fossil assemblages from such settings have been little evaluated. Assemblages at Site 865 are diverse and dominated by cylindrical calcareous taxa with complex apertures, an extinct group which probably lived infaunally. Dominance of an infaunal morphogroup is unexpected in a highly oligotrophic setting, but these forms may have been shallow infaunal suspension feeders, which were ecologically successful on the current-swept seamount. The magnitude of the PETM extinction at Site 865 was similar to other sites globally, but lower diversity postextinction faunas at this location were affected by ocean acidification as well as changes in current regime, which might have led to increased nutrient supply through trophic focusing. A minor hyperthermal saw less severe effects of changes in current regime, with no evidence for carbonate dissolution. Although the relative abundance of infaunal benthic foraminifera has been used as a proxy for surface productivity through bentho-pelagic coupling, we argue that this proxy can be used only in the absence of changes in carbonate saturation and current-driven biophysical linking.

  10. Microbial diversity in hydrothermal surface to subsurface environments of Suiyo Seamount, Izu-Bonin Arc, using a catheter-type in situ growth chamber.

    Science.gov (United States)

    Higashi, Yowsuke; Sunamura, Michinari; Kitamura, Keiko; Nakamura, Ko-ichi; Kurusu, Yasurou; Ishibashi, Jun-ichiro; Urabe, Tetsuro; Maruyama, Akihiko

    2004-03-01

    After excavation using a portable submarine driller near deep-sea hydrothermal vents in the Suiyo Seamount, Izu-Bonin Arc, microbial diversity was examined in samples collected from inside the boreholes using an in situ growth chamber called a vent catheter. This instrument, which we devised for this study, consists of a heat-tolerant pipe tipped with a titanium mesh entrapment capsule that is packed with sterilized inorganic porous grains, which serve as an adhesion substrate. After this instrument was deployed inside each of the boreholes, as well as a natural vent, for 3-10 days in the vicinity of hot vent fluids (maxima: 156-305 degrees C), DNA was extracted from the adhesion grains, 16S rDNA was amplified, and randomly selected clones were sequenced. In phylogenetic analysis of more than 120 clones, several novel phylotypes were detected within the epsilon-Proteobacteria, photosynthetic bacteria (PSB)-related alpha-Proteobacteria, and Euryarchaeota clusters. Members of epsilon-Proteobacteria were frequently encountered. Half of these were classified between two known groups, Corre's B and D. The other half of the clones were assigned to new groups, SSSV-BE1 and SSSV-BE2 (Suiyo Seamount sub-vent origin, Bacteria domain, epsilon-Proteobacteria, groups 1 and 2). From this hydrothermal vent field, we detected a novel lineage within the PSB cluster, SSNV-BA1 (Suiyo Seamount natural vent origin, Bacteria domain, alpha-Proteobacteria, group 1), which is closely related to Rhodopila globiformis isolated from a hot spring. A number of archaeal clones were also detected from the borehole samples. These clones formed a novel monophyletic clade, SSSV-AE1 (Suiyo Seamount sub-vent origin, Archaea domain, Euryarchaeota, group 1), approximately between methanogenic hyperthermophilic members of Methanococcales and environmental clone members of DHVE Group II. Thus, this hydrothermal vent environment appears to be a noteworthy microbial and genetic resource. It is also

  11. Equivalence factors for standardizing catch data across multiple beach seine nets to account for differences in relative bias

    Science.gov (United States)

    Hallett, Chris S.; Hall, Norm G.

    2012-06-01

    We describe a method for modelling the relative effects of seine net biases and for deriving equivalence factors to standardize fish abundance data sets collected using multiple sampling gears. Nearshore fish communities were sampled from 10 sites in each of the basin and riverine portions of the Swan-Canning Estuary, Western Australia, using beach seine nets of three different lengths (21.5, 41.5 and 133 m). The resulting data were subjected to generalized linear modelling to derive equivalence factors relating catches from the two larger net types to those from the 21.5 m net. Equivalence factors were derived on the basis of functional habitat guilds of fish (small benthic, small pelagic, demersal, pelagic). Prior to standardization, catches from the 41.5 and 133 m nets consistently underestimated fish densities relative to those from the 21.5 m net. Following standardization, the degree to which fish densities were underestimated by the two larger nets was reduced and/or eliminated for most guilds, and particularly in the case of the 133 m net. For both of the larger nets, standardized estimates of total fish density across all species were far closer to those recorded using the 21.5 m seine, thus indicating that standardization of the fish abundance data had greatly reduced the overall effects of the biases introduced by the different net types. This approach could be applied to other systems and sampling methods, to facilitate more robust comparisons of fish abundances between studies with divergent sampling methodologies.

  12. Re-Os isotope and platinum group elements of a FOcal ZOne mantle source, Louisville Seamounts Chain, Pacific ocean

    Science.gov (United States)

    Tejada, Maria Luisa G.; Hanyu, Takeshi; Ishikawa, Akira; Senda, Ryoko; Suzuki, Katsuhiko; Fitton, Godfrey; Williams, Rebecca

    2015-02-01

    The Louisville Seamount Chain (LSC) is, besides the Hawaiian-Emperor Chain, one of the longest-lived hotspot traces. We report here the first Re-Os isotope and platinum group element (PGE) data for Canopus, Rigil, and Burton Guyots along the chain, which were drilled during IODP Expedition 330. The LSC basalts possess (187Os/188Os)i = 0.1245-0.1314 that are remarkably homogeneous and do not vary with age. A Re-Os isochron age of 64.9 ± 3.2 Ma was obtained for Burton seamount (the youngest of the three seamounts drilled), consistent with 40Ar-39Ar data. Isochron-derived initial 187Os/188Os ratio of 0.1272 ± 0.0008, together with data for olivines (0.1271-0.1275), are within the estimated primitive mantle values. This (187Os/188Os)i range is similar to those of Rarotonga (0.124-0.139) and Samoan shield (0.1276-0.1313) basalts and lower than those of Cook-Austral (0.136-0.155) and Hawaiian shield (0.1283-0.1578) basalts, suggesting little or no recycled component in the LSC mantle source. The PGE data of LSC basalts are distinct from those of oceanic lower crust. Variation in PGE patterns can be largely explained by different low degrees of melting under sulfide-saturated conditions of the same relatively fertile mantle source, consistent with their primitive mantle-like Os and primordial Ne isotope signatures. The PGE patterns and the low 187Os/188Os composition of LSC basalts contrast with those of Ontong Java Plateau (OJP) tholeiites. We conclude that the Re-Os isotope and PGE composition of LSC basalts reflect a relatively pure deep-sourced common mantle sampled by some ocean island basalts but is not discernible in the composition of OJP tholeiites.

  13. Kunnan strateginen johtaminen - tutkimus Seinänaapurikuntien strategiaprosessien ominaispiirteistä ja kunnanjohtajista strategisina johtajina

    OpenAIRE

    Rannisto, Pasi-Heikki

    2005-01-01

    Tutkimusmenetelmät ja tutkimustehtävä Tutkimuksen tehtävänä on selvittää kunnan strategiaprosessi ja strateginen johtaminen kunnanjohtajan kannalta sekä kunnanjohtajan rooli strategian käytäntöön viemisessä. Tutkimuksen kohdekuntina ovat Etelä-Pohjanmaalle sijoittuvan Seinänaapurit -seutukunnan seitsemän kuntaa. Tutkimuksessa tarkastellaan ja arvioidaan kohdekuntien strategiaprosesseja ja kunnanjohtajien toimintaa strategioiden maastouttajina. Lähdeaineistona ovat kansainvälinen strat...

  14. Influence of the water quality improvement on fish population in the Seine River (Paris, France) over the 1990-2013 period.

    Science.gov (United States)

    Azimi, Sam; Rocher, Vincent

    2016-01-15

    Over the past 20 years, rules concerning wastewater treatment and quality of water discharged into the environment have changed considerably. Huge investments have been made in Paris conurbation to improve waste water treatment processes in accordance with the European Water Framework Directive. The interdepartmental association for sewage disposal in Paris conurbation (SIAAP) carried out a monitoring of both fish assemblages and water quality in the Seine River around the Paris conurbation (France) since the early 90's. The main goal of this study was to estimate the influence of the water quality improvement on fish. On one hand, the study confirmed the improvement of the water quality (dissolved oxygen, ammonia nitrogen, organic matter) in the Seine River, mostly focused downstream of Paris conurbation. On the other hand, an increase of the number of species occurred from 1990 (14) to 2013 (21). Moreover, changes in the river Seine assemblages happened over that 23-year period with emergence of sensitive species (ruffe, scalpin and pike-perch). The improvement of the water quality was also reported with respect to the Index of Biotic Integrity (IBI). However, no variation of pollutant concentrations in roach, eel and chub muscles has been observed. An exceedance of the environmental quality standards have even been reported all over this period as regards mercury and organochlorine.

  15. Rare earth element and strontium isotopic study of seamount-type limestones in Mesozoic accretionary complex of Southern Chichibu Terrane, central Japan. Implication for incorporation process of seawater REE into limestones

    International Nuclear Information System (INIS)

    Tanaka, Kazuya; Miura, Noriko; Asahara, Yoshihiro; Kawabe, Iwao

    2003-01-01

    Ishimaki and Tahara limestones occur as exotic blocks juxtaposed in the Mesozoic (Jurassic) accretionary complex of Southern Chichibu Terrane in eastern Aichi Prefecture, central Japan. They are supposed to be of the seamount-type limestone, since they have no terrigenous materials and are intimately associated with greenstones. REE (rare earth elements) and Sr isotopic studies for the limestones have been made in order to know their geochemical characteristics, ages and origins. Their 87 Sr/ 86 Sr ratios, when referred to the seawater 87 Sr/ 86 Sr curve and relevant geological data, suggest that Ishimaki and Tahara limestones are the late Permian and the Carboniferous to the Early Permian, respectively. Two greenstone fragments found inside the Ishimaki limestone block and one greenstone sample associated with Tahara limestone block, resemble the Hawaiian alkali basalt in the their REE and Y patterns. This is supporting the idea that the limestone blocks may be parts of reef limestones on ancient volcanic seamounts. All the limestone samples, except three unusual Tahara ones, show seawater REE and Y signatures in their chondrite-normalized patterns. Their REE/Ca ratios, however, are 10 2 -10 4 times as high as those ratios of modern biogenic carbonates like corals and the seawater. Accordingly, seawater REE and Y were incorporated into the limestones, when originally biogenic carbonates transformed into inorganic calcite and its secondary growths occurred in diagenesis in contact with sufficient seawater. This view is favored by the reported REE partition experiment between calcite overgrowths and seawater solution. The seawater Ce anomaly as a function of water depth in the modern ocean is a key to infer the water depth of the REE and Y incorporation. The Ce anomalies given by log (Ce/Ce*) for about a half of Ishimaki samples and most of Tahara ones are between -0.5 and -0.2, which are compatible with the shallow water origin. Another half of Ishimaki samples

  16. Morphological characteristics and emplacement mechanism of the seamounts in the Central Indian Ocean Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Das, P.; Iyer, S.D.; Kodagali, V.N.

    Minimum elevation High E values characterize a broad somewhat level surface with occasional presence of depressions while low values typify a terrain with isolated relief features standing above extensive level surfaces. The average elevation relief ratio... of 0.788 indicates the region to have a fair number of depressions and highs. We defined the lower cutoff height of 100 m for the seamounts and divided them into three groups: large (N800 m), medium (N400 to 800 m) and small (100 to≤400m...

  17. Justkui tükike Euroopat keset Seinäjoge : Apila-raamatukogu võlub suursuguse arhitektuuriga / Mervi Heikkilä ; intervjueerinud Mariliis Panov

    Index Scriptorium Estoniae

    Heikkilä, Mervi

    2013-01-01

    Intervjuu Seinäjoe Apila-raamatukogu juhatajaga raamatukogust, mis esitati 2013. a maineka Euroopa Liidu moodsa arhitektuuri preemia konkursile, Mies van der Rohe auhinnale, kuigi võitjaks ei valitud

  18. Chelles (Seine-et-Marne). 10-18, rue Sainte-Bathilde.

    OpenAIRE

    Paccard, Nathalie

    2018-01-01

    Après un diagnostic réalisé en 2011, une fouille a été menée durant l’été 2013 sur une emprise de près de 2 000 m2, au sud du centre historique de Chelles. Ce secteur, qui est la zone d’investigation la plus méridionale du bourg médiéval, est encore très mal connu. Il s’agit au xviiie s. d’un espace dévolu au jardin de l’abbaye. La fouille a porté essentiellement sur une aire empierrée, reconnue sur près de 1 000 m2 au sein de l’espace décapé, mais qui se poursuit au-delà des limites d’empris...

  19. CRED 5m Gridded bathymetry of the banktop and slope environments of Northeast Bank (sometimes called "Muli" Seamount), American Samoa (NetCDF Format)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Gridded (5 m cell size) bathymetry of the banktop and slope environments of Northeast Bank (sometimes called "Muli" Seamount), American Samoa, South Pacific. Almost...

  20. A new species of Nidalia Gray, 1835 from Mid-Atlantic seamounts (Octocorallia, Alcyonacea, Nidaliidae)

    Science.gov (United States)

    López-González, Pablo J.; Gili, Josep-Maria

    2008-12-01

    A new soft coral species of the genus Nidalia, from seamounts to the south of the Azores Archipelago is described. The main features of Nidalia aurantia n. sp. are as following: colony torch-like, a capitulum light orange in colour, not laterally flattened, dome-shaped and not distinctly projecting beyond the stalk, an introvert with sparse sclerites transversally placed, and an anthocodial crown with 13 17 sclerite rows. The new species is compared with its closest congeners. This is the first time that a species of Nidalia has been located in the Mid-Atlantic Ocean.

  1. 50 CFR 216.92 - Dolphin-safe requirements for tuna harvested in the ETP by large purse seine vessels.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 7 2010-10-01 2010-10-01 false Dolphin-safe requirements for tuna... MAMMALS REGULATIONS GOVERNING THE TAKING AND IMPORTING OF MARINE MAMMALS Dolphin Safe Tuna Labeling § 216.92 Dolphin-safe requirements for tuna harvested in the ETP by large purse seine vessels. (a) U.S...

  2. Two major Cenozoic episodes of phosphogenesis recorded in equatorial Pacific seamount deposits

    Science.gov (United States)

    Hein, J.R.; Hsueh-Wen, Yeh; Gunn, S.H.; Sliter, W.V.; Benninger, L.M.; Chung-Ho, Wang

    1993-01-01

    The phosphorites occur in a wide variety of forms, but most commonly carbonate fluorapatite (CFA) replaced middle Eocene and older carbonate sediment in a deep water environment (>1000 m). Element ratios distinguish seamount phosphorites from continental margin, plateau, and insular phosphorites. Uranium and thorium contents are low and total rare earch element (REE) contents are generally high. The paleoceanographic conditions initiated and sustained development of phosphorite by accumulation of dissolved phosphorus in the deep sea during relatively stable climatic conditions when oceanic circulation was sluggish. Fluctuations in climate, sealevel, and upwelling that accompanied the climate transitions may have driven cycles of enrichment and depletion of the deep-sea phosphorus reservoir. -from Authors

  3. Recovery of Seamount Precious Coral Beds From Heavy Trawling Disturbance with Links to Carbonate Chemistry Changes

    Science.gov (United States)

    Roark, E. B.; Baco-Taylor, A.; Morgan, N. B.; Shamberger, K.; Miller, K.; Brooks, J.

    2016-12-01

    Increasing anthropogenic impacts in the deep sea make studies of resilience and recovery time critical, with deep-sea hard-substrate habitats and large-scale disturbances having received little attention. Seamount hard-substrate habitats in particular are thought to have low resilience due to the slow growth rates and recruitment limitations of key structure-forming taxa. Seamounts of the far Northwestern Hawaiian Islands and Emperor Chain have had some of the heaviest trawl impacts in the world, from both fish and precious coral fisheries, and include sites that are still trawled and recovering ones that have been protected since establishment of the EEZ in 1977. To test the hypothesis of low resilience we compare these impacted seamounts to untrawled sites. We used the AUV Sentry in 2014 and 2015 to image nine features (three per "treatment") and analyze for substrate and visible megafauna. Sites in the "still trawled" treatment were characterized by extensive areas of bare substrate with abundant trawl scars. Sites in the "recovering" and "never trawled" locations had abundant megafauna in hard substrate areas. Initial comparisons of transects at 700m depth for three sites indicate that Yuryaku in the "still trawled" treatment had lower diversity and abundance of megafauna compared to the "recovering" and "never trawled" locations with a dominance of sea urchins. The "recovering" and "never trawled" sites were dominated by cnidarians, fishes, and echinoderms, but differed in dominant species, diversity, abundances and occurrence of dead coral skeletons. These preliminary results suggest that the recovering sites have not returned to a pre-impact community type in the 38 years since they were trawled. The megafauna distribution, in particular that of deep-sea corals, was compared to environmental water column variables at the study sites across the Northwestern Hawaiian Islands. Deep-sea corals with calcium carbonate skeletons were found living below the

  4. Colonial life under the Humboldt Current System: deep-sea corals from O'Higgins I seamount

    OpenAIRE

    Cañete,Juan I; Haussermann,Verena

    2012-01-01

    A benthic community constituted by an assemblage of at least four species of deep-sea corals collected in only one trawl carried-out on the summit of the O'Higgins I seamount, central Chile. The corals were collected in only one trawl carried-out during a Chilean-Japanese cruise onboard the R/V" Koyo Maru" in December 29, 2004. Presence of oxygenated and cold Antarctic Intermediate Water (>400 m depth) on the plateau was recorded under of the Equatorial Subsurface Water associated to the o...

  5. Colonial life under the Humboldt Current System: deep-sea corals from O'Higgins I seamount

    OpenAIRE

    Cañete, Juan I; Haussermann, Verena

    2012-01-01

    A benthic community constituted by an assemblage of at least four species of deep-sea corals collected in only one trawl carried-out on the summit of the O'Higgins I seamount, central Chile. The corals were collected in only one trawl carried-out during a Chilean-Japanese cruise onboard the R/V" Koyo Maru" in December 29, 2004. Presence of oxygenated and cold Antarctic Intermediate Water (>400 m depth) on the plateau was recorded under of the Equatorial Subsurface Water associated to the oxyg...

  6. Macrobiotic Communities of Vailulu'u Seamount, Samoan Archipelago

    Science.gov (United States)

    Young, C. M.; Lee, R. W.; Pile, A. J.; Hudson, I. R.; Brooke, S. D.; Ted, P.; Staudigel, H.; Hart, S.; Bailey, B. E.; Haucke, L.; Koppers, A.; Konter, J.; Templeton, A.; Tebo, B.

    2005-12-01

    Vailulu'u, the active seamount on the hotspot at the Eastern end of the Samoan volcanic chain, was the focus of two research cruises in April and June 2005 using the Pisces V submersible. Warm-water vents on the summit of a newly formed volcanic cone in the crater supported a low-diversity community dominated by thick microbial mats and the synaphobranchid eel Dysommina rugosa. Isotope and gut analyses indicated that the eels feed not on the mats but on planktonic crustaceans imported to the system from the overlying water column. The microbial mat exhibited isotopic signatures consistent with local chemosynthesis, but not methane-based chemosynthesis; Anutrition from microbes of vent origin, while those on the outside feed on oceanic plankton. The background megafauna of the outer flank was dominated by octocorals and hexactinellid sponges, with occasional asteroids, ophiuroids and crinoids. Most megafaunal organisms collected from the outer flanks were isotopically heavy, with isotope values similar to those of non-vent deep-sea animals. However, the octocoral Anthomastis collected from low-elevation breaches on the cauldera summit were intermediate in isotopic composition, indicating that they may consume particulate material derived from vent C and N.

  7. Seamount mineral deposits: A source of rare metals for high technology industries

    Science.gov (United States)

    Hein, James R.; Conrad, Tracey A.; Staudigel, Hubert

    2010-01-01

    The near exponential growth in Earth’s population and the global economy puts increasing constraints on our planet’s finite supply of natural metal resources, and, consequently, there is an increasing need for new sources to supply high-tech industries. To date, effectively all of our raw-metal resources are produced at land-based sites. Except for nearshore placer deposits, the marine environment has been largely excluded from metal mining due to technological difficulties, even though it covers more than 70% of the planet. The case can be made that deep-water seabed mining is inevitable in the future, owing to the critical and strategic metal needs for human society. In this paper, we evaluate the case that seamounts offer significant potential for mining.

  8. Diversity of Zoanthids (Anthozoa: Hexacorallia) on Hawaiian Seamounts: Description of the Hawaiian Gold Coral and Additional Zoanthids

    OpenAIRE

    シニゲル, フレデリック; OCANA, Oscar; BACO, Amy; SINNIGER, Frederic; OCANA, Oscar; BACO, Amy

    2013-01-01

    The Hawaiian gold coral has a history of exploitation from the deep slopes and seamounts of the Hawaiian Islands as one of the precious corals commercialised in the jewellery industry. Due to its peculiar characteristic of building a scleroproteic skeleton, this zoanthid has been referred as Gerardia sp. (a junior synonym of Savalia Nardo, 1844) but never formally described or examined by taxonomists despite its commercial interest. While collection of Hawaiian gold coral is now regulated, gl...

  9. Seismic constraints on caldera dynamics from the 2015 Axial Seamount eruption.

    Science.gov (United States)

    Wilcock, William S D; Tolstoy, Maya; Waldhauser, Felix; Garcia, Charles; Tan, Yen Joe; Bohnenstiehl, DelWayne R; Caplan-Auerbach, Jacqueline; Dziak, Robert P; Arnulf, Adrien F; Mann, M Everett

    2016-12-16

    Seismic observations in volcanically active calderas are challenging. A new cabled observatory atop Axial Seamount on the Juan de Fuca ridge allows unprecedented real-time monitoring of a submarine caldera. Beginning on 24 April 2015, the seismic network captured an eruption that culminated in explosive acoustic signals where lava erupted on the seafloor. Extensive seismic activity preceding the eruption shows that inflation is accommodated by the reactivation of an outward-dipping caldera ring fault, with strong tidal triggering indicating a critically stressed system. The ring fault accommodated deflation during the eruption and provided a pathway for a dike that propagated south and north beneath the caldera's east wall. Once north of the caldera, the eruption stepped westward, and a dike propagated along the extensional north rift. Copyright © 2016, American Association for the Advancement of Science.

  10. Urban metabolism and river systems: an historical perspective – Paris and the Seine, 1790–1970

    Directory of Open Access Journals (Sweden)

    S. Barles

    2007-11-01

    Full Text Available The aim of this paper is to analyse metabolic interaction between Paris and the Seine during the industrial era, 1790–1970, a period marked by strong population growth, technological changes, and the absence of specific legislation on environmental issues. The viewpoint focuses on exchanges of waters and wastes between city and river, quantifying them and tracing their evolution in the light of the strategies implemented by the stakeholders in charge. The study combines industrial ecology, local history and the history of technology. From 1790 to 1850, waste matters, and especially excreta, were considered as raw materials, not refuse: they generated real profits. The removal of human excreta aimed not only at improving urban hygiene, but at producing the fertilizers needed in rural areas. Discharging them into the river was out of the question. But after the 1860s, several factors upset this exploitation, notably domestic water supply: night soil became more and more liquid, difficult to handle and to turn into fertilizer; once utilised, the water had to be removed from the house; at the same time, the sewerage system developed and had negative impacts on the river. Even so, Parisian engineers continued to process sewage using techniques that would not only ensure hygiene but also conciliate economic and agricultural interests: combined sewerage system and sewage farms. Both of these early periods are thus noteworthy for a relative limitation of the river's deterioration by urban wastes. Not until the 1920s, when domestic water supply had become the standard and excreta came to be considered as worthless waste, was the principle of valorisation abandoned. This led to important and long-lasting pollution of the Seine (despite the construction of a treatment plant, aggravating the industrial pollution that had been in evidence since the 1840s. Analysing the priorities that led to the adoption of one principle or another in matters of urban

  11. Structure and Evolution of Hawaii's Loihi Seamount from High-resolution Mapping

    Science.gov (United States)

    Clague, D. A.; Paduan, J. B.; Moyer, C. L.; Glazer, B. T.; Caress, D. W.; Yoerger, D.; Kaiser, C. L.

    2016-12-01

    Loihi Seamount has been mapped repeatedly using shipboard multibeam sonars with improving resolution over time. Simrad EM302 data with 25m resolution at the 950m summit and 90m at the 5000m base of the volcano were collected from Schmidt Ocean Institute's R/V Falkor in 2014. A contracted multibeam survey in 1997 employing a deep-towed vehicle has 7m resolution for the summit and upper north and south rift zones, but suffered from poor navigation. Woods Hole Oceanographic Institution's AUV Sentry surveyed most of the summit and low-T hydrothermal vents on the base of the south rift in 2013 and 2014. The 2m resolution of most data is more precise than the navigation. The 6 summit surveys were reprocessed using MB-System to remove abundant bad bottom picks and adjust the navigation to produce a spatially accurate map. The 3 summit pits, including Pele's Pit that formed in 1996, are complex collapse structures and nested inside a larger caldera that was modified by large landslides on the east and west summit flanks. The pits cut low shields that once formed a complex of overlapping summit shields, similar to Kilauea before the current caldera formed 1500 to 1790 CE. An 11m section of ash deposits crops out on the east rim of the summit along a caldera-bounding fault and is analogous to Kilauea where the caldera-bounding faults expose ash erupted as the present caldera formed. Most of the Loihi ash section is 3300 to 5880 yr BP, indicating that the larger caldera structure at Loihi is younger than 3300 yr BP. The landslides on the east and west edges of the summit are therefore younger 3300 yr BP. The uppermost south rift has several small pit craters between cones and pillow ridges, also analogous to Kilauea. Two cones near the deep low-T vents are steep pillow mounds with slopes of talus. High-resolution mapping reveals, for the first time, the many similarities between the structure and evolution of submarine Loihi Seamount and subaerial Kilauea Volcano.

  12. The fantastic in Thomas Mann's Der Tod in Venedig and Joseph und seine Brüder

    OpenAIRE

    Nolan, Tom

    2011-01-01

    The thesis includes an introductory survey of recent relevant secondary literature and a coda dealing with the fantastic as a manifestation of Schiller’s ‘Spieltrieb’. Its main body, however, is comprised of three substantial chapters prosecuting two interlinked arguments: (1) that Der Tod in Venedig and Joseph und seine Brüder are fantastic narratives and (2) that the fantastic in these narratives works hand in glove with Mann’s philosophical concerns. In order to demonstrate that the fir...

  13. Denaturing Gradient Gel Electrophoretic Analysis of Ammonia-Oxidizing Bacterial Community Structure in the Lower Seine River: Impact of Paris Wastewater Effluents

    NARCIS (Netherlands)

    Cébron, A.; Coci, M.; Garnier, J.; Laanbroek, H.J.

    2004-01-01

    The Seine River is strongly affected by the effluents from the Achères wastewater treatment plant (WWTP) downstream of the city of Paris. We have shown that the effluents introduce large amounts of ammonia and inoculate the receiving medium with nitrifying bacteria. The aim of the present study

  14. Denaturing gradient gel electrophoretic analysis of ammonia-oxidizing bacterial community structure in the lower Seine River: Impact of Paris wastewater effluents

    NARCIS (Netherlands)

    Cebron, A.; Coci, M.; Garnier, J.; Laanbroek, H.J.

    2004-01-01

    The Seine River is strongly affected by the effluents from the Acheres wastewater treatment plant (WWTP) downstream of the city of Paris. We have shown that the effluents introduce large amounts of ammonia and inoculate the receiving medium with nitrifying bacteria. The aim of the present study was

  15. Hyperquenched hyaloclastites from Axial Seamount

    Science.gov (United States)

    Zezin, D.; Helo, C.; Richard, D.; Clague, D. A.; Dingwell, D. B.; Stix, J.

    2009-12-01

    We determined apparent cooling rates for basaltic hyaloclastites from Axial caldera, Juan de Fuca Ridge. Samples originate from different stratigraphic layers within the unconsolidated volcaniclastic sequences, on flanks of the volcanic edifice. Water depth is ~1400 m below sea level. The hyaloclastite glass fragments comprise two principal morphologies: (1) angular fragments, and (2) thin glassy melt films interpreted as bubble walls, called deep-sea limu o Pele. A natural cooling rate was estimated for each sample of ~50 carefully selected glass shards. The heat capacity was first measured with a differential scanning calorimeter in two heating scans with heating rates of 20 K/min, and a matching cooling rate between those scans. The fictive temperatures Tf were then determined from both heating cycles, and the natural cooling rate derived by the non-Arrhenian relationship between Tf and cooling rate. All samples display hyperquenched states, manifested in a strong exothermic energy release during the initial heating cycle before reaching the glass transition. Cooling rates range from 10 6.73 K/s to 10 3.94 K/s for the limu, and 10 4.92 K/s to 10 2.34 K/s for the angular fragments. Almost all samples of limu shards show elevated cooling rates compared to their angular counterparts of comparable grain mass. In addition, the exothermic part of the enthalpy curves reveal two superimposed relaxation domains, the main broad exothermal peak, ranging from ~350 K to the onset of the glass transition, and a small subordinate peak/shoulder occurring between 550 K and 700 K. The magnitude of the latter varies from clearly identifiable to nearly absent, and tends to be more pronounced in curves obtained from angular fragments. The main exothermal peak is related to the frozen-in structure of the glass and consequently to its thermal history when passing through the glass transition. The subordinate peak may represent strain rate-induced and tensile stress accumulation

  16. Denaturing Gradient Gel Electrophoretic Analysis of Ammonia-Oxidizing Bacterial Community Structure in the Lower Seine River: Impact of Paris Wastewater Effluents

    NARCIS (Netherlands)

    Cébron, A.; Coci, M.; Garnier, J.; Laanbroek, H.J.

    2004-01-01

    The Seine River is strongly affected by the effluents from the Achères wastewater treatment plant (WWTP) downstream of the city of Paris. We have shown that the effluents introduce large amounts of ammonia and inoculate the receiving medium with nitrifying bacteria. The aim of the present study was

  17. Surprising discovery of high-grade pelitic schist on Cavalli Seamount, offshore Northland

    International Nuclear Information System (INIS)

    Mortimer, N.; Walker, N.H.; Herzer, R.H.; Calvert, A.; Seward, D.

    1999-01-01

    Serendipity waits in the world's unexplored places. In March 1999, GNS's ONSIDE expedition to the South Fiji Basin made two dredge hauls on Cavalli seamount expecting to recover Miocene oceanic volcanic rocks. Instead dredge DIA recored 1 kg of 10 cm slickensided and chloritised schist pieces and dredge DIB, which was 1.1 km distant, 100 kg of well-foliated biotite schist, mainly in the form of two large subangular boulders. The presence of calsilicate bands initially suggested a correlation with Buller or Takaka Terranes, but whole rock chemical composition of the schist is more consistent with Murihiku, Waipapa or Pahau Terranes. U-Pb TIMS gheochronometry of individual detrital zircons indicates a maximum 170Ma depositional age for the schist protolith, thus clearly ruling out a Buller or Takaka correlation. Rb-Sr whole rock data suggest a young (Cenozoic?) metamorphic age. (author)

  18. Estuarine conservation and restoration: the Somme and the Seine case studies (English Channel, France).

    Science.gov (United States)

    Ducrotoy, Jean-Paul; Dauvin, Jean-Claude

    2008-01-01

    Megatidal estuaries such as the Seine and the Somme (North-Western France) are rather well delimited and human impacts on them are well understood. Since the middle of the 19th Century, there has been a slow but irreversible degradation of the state of these English Channel estuaries. However, current conservation and restoration strategies tend to freeze habitats in a particular state, their status being defined, most often, through a patrimonial or utilitarian approach. Connectedness between biotopes (sensu habitat+community) has a tendency to be neglected, especially with regard to main ecological gradients, i.e., salinity. In this paper, evaluation methodologies are proposed with the intention of assessing changes to ecosystem functions, under anthropogenic disturbance, controlled or otherwise. The Seine (a heavily industrialised ecosystem) is compared to the Somme (considered here for its pseudo-natural features) in order to discriminate between oceanic processes (siltation and plugging of estuaries) and anthropogenic influences. Preservation and restoration of habitats rely on a robust scientific methodology. The multi-scale approach adopted in the projects presented here relies on sensitive socio-ecological assessment procedures, tools for evaluating ecological quality, and well-built monitoring programmes based upon pertinent indicators. Such managerial tools were used to refine strategies and make them compatible with the sustainable co-development of resources in a European context. This paper demonstrates how scientists were able to acquire and apply knowledge in the field of rehabilitation and restoration. Jointly with managers and policy-makers, they have brought scientific information and socio-economics together in order to answer questions about the restoration of sites or habitats and to anticipate future propositions in the spirit of Integrated Coastal Zone Management (ICZM).

  19. (Medienbildung und Informatik. Informatische Bildung muss mehr als Coding sein!

    Directory of Open Access Journals (Sweden)

    Daniel Autenrieth

    2015-09-01

    Full Text Available Niemand kann die Wichtigkeit der Informatik für unsere Welt abstreiten. Fast jeder Aspekt unseres Lebens steht in einer bestimmten Art in Verbindung mit Software. Es ist daher logisch anzunehmen, dass Kinder die Fähigkeit benötigen die Technik, die sie verwenden, zu verstehen und diese auch kritisch zu betrachten. Dieser Umstand macht Informatik zu einem wichtigen Teilaspekt der Medienbildung. Weiterhin erweitern die Fortschritte aus der Computerentwicklung unsere Fähigkeit Probleme zu lösen in einer bisher unbekannten Dimension. SchülerInnen werden neue Fähigkeiten lernen und einüben müssen (Computational Thinking um diese revolutionären Veränderungen, die der technische Fortschritt mit sich bringt, auszunutzen. Die Schlüsselfrage wird dabei sein, welchen Ansatz man wählen wird, um diese Fähigkeiten auszubilden und welche politischen Beweggründe dahinterstehen. Die aktuelle politische Lage zeigt eine wirtschaftliche Orientierung, die ähnlich ist zur Stärkung der MINT-Fächer vor einigen Jahren, welche ebenfalls von der Wirtschaft gefordert wurde. Bildung muss jedoch mehr sein als die Erfüllung von aus der Wirtschaft stammenden Wünschen. Nobody can deny the importance of computer science for today’s world. Almost every aspect of our daily lives is somehow connected to a piece of software. It is therefore only logical to assume that our children need the ability to comprehend and critically examine the technology they are using, which makes computer science an important issue for media education. Furthermore, advances in computing have expanded our capacity to solve problems at a scale never before imagined, using strategies that have not been available to us before. Students will need to learn and practice new skills — computational thinking skills — to take full advantage of these revolutionary changes brought about by rapid changes in technology. The key issue will be the approach on how to teach children these skills

  20. Methodology for Assessing Disruptions (MAD) Game Part I: Report and Analysis

    Science.gov (United States)

    2012-12-01

    scientifique en chef (BSC) de RDDC et au Réseau des scientifiques en chef (CSNet). Elle pourra également intéresser d’autres intervenants de la...collectivité des S & T au sein de RDDC et des organisations partenaires des FC, notamment le Chef du Développement des Forces et les centres de guerres...creativity of the DRDC S&T professionals in developing futuristic systems that could provide an operational advantage to our CF partners. Part II of the

  1. Spatial and Temporal Changes in Fluid Chemistry and Microbial Community Diversity in Subseafloor Habitats at Axial Seamount Following the 1998 Eruption

    Science.gov (United States)

    Opatkiewicz, A. D.; Butterfield, D. A.; Baross, J. A.

    2006-12-01

    The subseafloor associated with hydrothermal vents has the potential to contribute significantly to primary production and biogeochemical cycling in the ocean. However, too little is known about the phylogenetic and physiological diversity of the microbial communities or their in situ activity to assess this potential. There are previous reports that subseafloor environments at active vent sites harbor a high diversity of microorganisms that include different thermal and metabolic groups of Bacteria and Archaea. However, little is known about how these communities change over time (minutes to years), at different vent sites, or in response to perturbations. In an effort to address these issues, the subseafloor microbial community diversity was examined from five diffuse-flow hydrothermal vent sites (distributed geographically over the seamount between three distinguishable vent fields) over the course of six years following the 1998 eruption at Axial Seamount (45° 58'N; 130° 00' W). PCR-based Terminal Restriction Fragment Length Polymorphism (TRFLP) analyses were used to follow changes in the microbial community structure. 16S rRNA gene sequence analysis was used to identify the specific groups of Bacteria and Archaea from the TRFLP analyses. Deep-sea background seawater microorganisms were detected in hydrothermal fluid samples (Bacteria: Alpha and Gamma Proteobacteria, Archaea: Marine Group I Crenarchaeota and Marine Group II Euryarchaeota). The unique subseafloor phylotypes detected included Epsilon, Delta and Beta Proteobacteria, Methanococcales and thermophilic Euryarchaeota. Temperature and key chemical species, which indicate the degree of mixing of hydrothermal fluid with seawater in the subsurface, have been shown previously to be important in affecting the diversity of the microbial communities (Huber et al., 2003). This work substantiates these earlier findings and furthermore presents evidence that additional chemical species, distinguishing the

  2. Remanence of lead pollution in an urban river system: a multi-scale temporal and spatial study in the Seine River basin, France.

    Science.gov (United States)

    Ayrault, S; Le Pape, P; Evrard, O; Priadi, C R; Quantin, C; Bonté, P; Roy-Barman, M

    2014-03-01

    Total lead (Pb) concentration and Pb isotopic ratio ((206)Pb/(20)7Pb) were determined in 140 samples from the Seine River basin (France), covering a period of time from 1945 to 2011 and including bed sediments (bulk and size fractionated samples), suspended particulate matter (SPM), sediment cores, and combined sewer overflow (CSO) particulate matter to constrain the spatial and temporal variability of the lead sources at the scale of the contaminated Seine River basin. A focus on the Orge River subcatchment, which exhibits a contrasted land-use pattern, allows documenting the relation between hydrodynamics, urbanization, and contamination sources. The study reveals that the Pb contamination due to leaded gasoline that peaked in the 1980s has a very limited impact in the river nowadays. In the upstream Seine River, the isotopic ratio analysis suggests a pervasive contamination which origin (coal combustion and/or gasoline lead) should be clarified. The current SPM contamination trend follows the urbanization/industrialization spatial trend. Downstream of Paris, the lead from historical use originating from the Rio Tinto mine, Spain ((206)Pb/(207)Pb=1.1634 ± 0.0001) is the major Pb source. The analysis of the bed sediments (bulk and grain size fractionated) highlights the diversity of the anthropogenic lead sources in relation with the diversity of the human activities that occurred in this basin over the years. The "urban" source, defined by waste waters including the CSO samples ((206)Pb/(207)Pb=1.157 ± 0.003), results of a thorough mixing of leaded gasoline with "historical" lead over the years. Finally, a contamination mixing scheme related to hydrodynamics is proposed.

  3. Multiconfiguration electromagnetic induction survey for paleochannel internal structure imaging: a case study in the alluvial plain of the River Seine, France

    Science.gov (United States)

    Rejiba, Fayçal; Schamper, Cyril; Chevalier, Antoine; Deleplancque, Benoit; Hovhannissian, Gaghik; Thiesson, Julien; Weill, Pierre

    2018-01-01

    The La Bassée floodplain area is a large groundwater reservoir controlling most of the water exchanged between local aquifers and hydrographic networks within the Seine River basin (France). Preferential flows depend essentially on the heterogeneity of alluvial plain infilling, whose characteristics are strongly influenced by the presence of mud plugs (paleomeander clayey infilling). These mud plugs strongly contrast with the coarse sand material that composes most of the alluvial plain, and can create permeability barriers to groundwater flows. A detailed knowledge of the global and internal geometry of such paleomeanders can thus lead to a comprehensive understanding of the long-term hydrogeological processes of the alluvial plain. A geophysical survey based on the use of electromagnetic induction was performed on a wide paleomeander, situated close to the city of Nogent-sur-Seine in France. In the present study we assess the advantages of combining several spatial offsets, together with both vertical and horizontal dipole orientations (six apparent conductivities), thereby mapping not only the spatial distribution of the paleomeander derived from lidar data but also its vertical extent and internal variability.

  4. A decade of volcanic construction and destruction at the summit of NW Rota-1 seamount: 2004-2014

    Science.gov (United States)

    Schnur, Susan R.; Chadwick, William W.; Embley, Robert W.; Ferrini, Vicki L.; de Ronde, Cornel E. J.; Cashman, Katharine V.; Deardorff, Nicholas D.; Merle, Susan G.; Dziak, Robert P.; Haxel, Joe H.; Matsumoto, Haru

    2017-03-01

    Arc volcanoes are important to our understanding of submarine volcanism because at some sites frequent eruptions cause them to grow and collapse on human timescales. This makes it possible to document volcanic processes. Active submarine eruptions have been observed at the summit of NW Rota-1 in the Mariana Arc. We use remotely operated vehicle videography and repeat high-resolution bathymetric surveys to construct geologic maps of the summit of NW Rota-1 in 2009 and 2010 and relate them to the geologic evolution of the summit area over a 10 year period (2004-2014). We find that 2009 and 2010 were characterized by different eruptive styles, which affected the type and distribution of eruptive deposits at the summit. Year 2009 was characterized by ultraslow extrusion and autobrecciation of lava at a single eruptive vent, producing a large cone of blocky lava debris. In 2010, higher-energy explosive eruptions occurred at multiple closely spaced vents, producing a thin blanket of pebble-sized tephra overlying lava flow outcrops. A landslide that occurred between 2009 and 2010 had a major effect on lithofacies distribution by removing the debris cone and other unconsolidated deposits, revealing steep massive flow cliffs. This relatively rapid alternation between construction and destruction forms one end of a seamount growth and mass wasting spectrum. Intraplate seamounts, which tend to grow larger than arc volcanoes, experience collapse events that are orders of magnitude larger and much less frequent than those occurring at subduction zone settings. Our results highlight the interrelated cyclicity of eruptive activity and mass wasting at submarine arc volcanoes.

  5. Growth of the Afanasy Nikitin seamount and its relationship with the 85 degree E Ridge, northeastern Indian Ocean.

    Digital Repository Service at National Institute of Oceanography (India)

    Krishna, K.S.; Bull, J.M.; Ishizuka, O.; Scrutton, R.A.; Jaishankar, S.; Banakar, V.K.

    –Antarctica Ridge is invoked at a time between anomalies 31 and 25 in order to isolate the hotspot on the Antarc- tic plate. However, there is no evidence found in the linear magnetic anomaly pattern for such a ridge jump at this time, rather observed a con- tinuous... give no evidence for flex- ure of the oceanic basement towards the seamount that would be associated with substantial con- struction of the ANS in an intraplate setting, although small volcanic additions in an intraplate setting cannot be ruled out...

  6. Problématique de la prise en charge des cancers du sein au Sénégal: une approche transversale

    Science.gov (United States)

    Gueye, Serigne Modou Kane; Gueye, Mamour; Coulbary, Sophie Aminata; Diouf, Alassane; Moreau, Jean Charles

    2016-01-01

    L’heure où les thérapeutiques innovantes se multiplient dans le cancer du sein, des pays moins nantis comme le Sénégal accusent encore un retard considérable dans la prise en charge globale de ce type de cancer. Au Sénégal, même si la prise en charge des cancers du sein avancés est actuellement bien codifiée, les résultats en terme de survie et de morbidités sont encore médiocres vu les retards diagnostiques et les traitements mutilants, parfois onéreux et mal tolérés, devenus nécessaires. Pour ces cancers avancés, les défis qui restent à relever résident dans l’érection de centres de soins palliatifs et le développement de la pluridisciplinarité pour améliorer la qualité de vie et l’accompagnement des malades. En revanche, pour les cancers infracliniques ou potentiellement guérissables, les défis restent immenses car il s’agira de les dépister, de bien les localiser et les diagnostiquer aussitôt (biopsie écho guidée ou stéréotaxique) mais également de les opérer de façon précise et entière (repérage – exérèse in sano et radiographie de pièce opératoire) tout en limitant les complications comme celles du curage classique (biopsie du ganglion sentinelle). Il s’agit là autant d’objectifs auxquels nos structures de santé ne sont pas toujours préparées. Cette mise au point est une analyse situationnelle sur les écueils contextuels qui grèvent encore la prise en charge globale des cancers du sein au Sénégal. PMID:28154696

  7. Vivre avec ou par le risque à l’île de Sein ?

    Directory of Open Access Journals (Sweden)

    Annaig Oiry

    2012-02-01

    Full Text Available L’île de Sein, située au large des côtes finistériennes, fait figure de « territoire du risque » par excellence : cette île basse est confrontée à de fréquentes et violentes tempêtes, la population vit « avec le risque » de submersion depuis des générations tout en voyant la probabilité des aléas catastrophiques augmenter en raison de la carence en aménagement et des conséquences probables du réchauffement climatique. L’image du risque, notamment les photographies de tempête, sert de support à la diffusion d’un sentiment anxiogène justifiant des actions de gestion du risque, mais entretient aussi un sentiment de fascination à l’égard des épisodes tempétueux. Cependant, les îliens portent un regard bien plus critique sur le spectaculaire véhiculé par de telles représentations. Le présent article se penche sur ces rapports entre représentations sociales du risque et iconographie du risque.This article stresses on relationships between hazard’s social representations and iconographies. As an illustration, Sein Island (located near by the Brittany coast, in Finistère. This island is considered as a symbol of natural hazard territory: indeed this low island has been confronted for decades to face significant flood hazard that is nowadays strengthened by the consequences of global warming and a lack of infrastructures. Pictures of flood hazards, and more particularly pictures of storms, are used in order to spread around the fear of natural disasters. This fear justifies the management policies implemented on the island. However islanders criticize pictures which are too spectacular and too distorted. Those gaps between hazard’s representations and iconographies are the main subjects of this article.

  8. Subaqueous non-vesicular to poorly-vesicular shards: hydroclastic fragmentation on seamounts and summit calderas

    Science.gov (United States)

    Mueller, W. U.; Dingwell, D. B.; Downey, W. S.; Mastin, L. G.

    2008-12-01

    Recognizing pyroclastic deposits that originate directly from magmatic and phreatomagmatic explosions in a subaqueous setting is based upon sedimentary structures, such as massive, stratified, and graded beds as well as (pyro)clast size. Ideally such deposits form ordered fining-and thinning-upward sequences. Pumice, scoria, glass shards, euhedral and broken crystals, and lithic fragments are constituents that support an explosive heritage. Recent deep-sea ROV and submersible dives have retrieved non-vesicular to vesicle- poor, mm-scale, mafic shards in 5-15 cm-thick massive and/or graded (stratified) deposits, for which a subaqueous explosive origin has been inferred. These sheet hyaloclastites with variable shard shapes were first documented on Seamount 6 as deep-sea Limu O Pele at water depths > 1000 m. We identified in Seamount 6 samples equant to blocky shards with angular to subrounded terminations, but also subordinate hair-like and contorted glassy filaments, warped shards and irregular shards. Shards display internal laminations (flow-banding?) and have local perlitic fractures. Bubble wall shards derived from scoria burst were rare. In combination with all the above and a poor shard vesicularity (tubes and ponded magma in depths > 1000 m. We envision that hydrostatic pressure commensurate with water depth played a significant role. The deposits can be readily explained by a hydroclastic process whereby fragmentation occurred at the milli-second (Limu) to second scale (hyaloclastite). Hence, hyperquenched glass shards or thread-like glass filaments need not require magmatic explosivity. Constant surface interaction between aphyric, low-viscosity, high temperature, magma-lava at depth with seawater causes fragmentation (granulation) that can generate such delicate shards. The transfer of heat to the ambient medium, seawater, favours turbulent convection causing strong water movement that strips glassy rinds and lofts the fine-grained shards and Limu O Pele

  9. A new species of the sponge Raspailia (Raspaxilla) (Porifera: Demospongiae: Axinellida: Raspailiidae) from deep seamounts of the Western Pacific.

    Science.gov (United States)

    Ekins, Merrick; Debitus, CÉcile; Erpenbeck, Dirk; Hooper, John N A

    2018-04-17

    A new species of Raspailia (Raspaxilla) frondosa sp. nov. is described from the deep seamounts of the Norfolk and New Caledonia Ridges. The morphology of the species resembles that of a frond or a fern, and its unique highly compressed axial skeleton of interlaced spongin fibres without spicules in combination with a radial extra axial skeleton of a perpendicular palisade of spicules, differentiate it from all other species of the subgenus. This species is compared morphologically to all 18 other valid species described in Raspailia (Raspaxilla).

  10. 40Ar-39Ar age clustering in the active phonolitic Cadamosto Seamount (Cape Verdes): Indications for periodic magmatic activity

    Science.gov (United States)

    Samrock, L. K.; Hansteen, T. H.; Wartho, J. A.

    2017-12-01

    The Cape Verde archipelago is situated 400-800 km off the west coast of Africa and is comprised of a northern and southern chain of islands and seamounts. Morphological observations and previous radiometric dating of the islands indicate a slow age progression, over 22 Ma, from east to west (Holm et al. 2008). We present the first radiometric ages for Cadamosto Seamount, which is composed of complex evolved volcanics and is situated at the southwestern tip of the Cape Verde archipelago (e.g. Barker et al. 2012). We analyzed five different submarine phonolites that were sampled by remotely operated vehicles (ROV) Kiel 6000 and dredging during the RV Meteor (M80/3) and RV Poseidon (POS320/2) cruises. Fresh sanidine, nepheline, and biotite grains were selected and carefully prepared for 40Ar-39Ar single grain total fusion analysis. Sanidine single grain 40Ar-39Ar ages from 5 samples range from 11.5 ± 6.5 ka to 349.0 ± 20.4 ka (2σ errors), and cluster in several age groupings (using the decay constant and atmospheric air ratio of Steiger & Jäger (1977), and age standard TCS2 (27.87 ± 0.04 Ma; 1σ; M.A. Lanphere, pers. comm.)). Three age groups can be identified within the youngest (0-170 ka) sanidines, which are separated by periods of 52-54 ka. Nepheline grains from one sample yielded much older ages of 169.5 ± 16.5 ka to 1521.5 ± 8.3 ka (2σ). Our data suggests young ages for the Cadamosto Seamount, which is in accordance with recorded seismic activity (Grevemeyer et al. 2010), and its position adjacent to the recently active islands of Fogo (last eruption in 2014/2015) and Brava (recent seismic activity). The different sub-groups of sanidine 40Ar-39Ar ages can be used to identify different activity maxima corresponding to cycles of magmatic productivity in a long-lived magmatic system. Ongoing petrologic investigations will be used to identify the relative importance of processes such as mantle melting rates, magma replenishment and magma chamber processes

  11. NOAA TIFF Image - 4m Backscatter Mosaic, Puerto Rico 2013, Escollo Grappler Seamount, Seafloor Characterization of the US Caribbean - Nancy Foster - NF-13-2 USVI (2013), UTM 20N NAD83

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This image represents a 4 meter resolution backscatter mosaic of a seamount/bank East of Fajardo, Puerto Rico. NOAA's NOS/NCCOS/CCMA Biogeography Team, in...

  12. Potential denitrification and nitrous oxide production in the sediments of the Seine River Drainage Network (France).

    Science.gov (United States)

    Garnier, Josette A; Mounier, Emmanuelle M; Laverman, Anniet M; Billen, Gilles F

    2010-01-01

    To investigate bottom sediment denitrification at the scale of the Seine drainage network, a semi-potential denitrification assay was used in which river sediments (and riparian soils) were incubated for a few hours under anaerobic conditions with non limiting nitrate concentrations. This method allowed the nitrous oxide (N(2)O) concentration in the headspace, as well as the nitrate, nitrite, and ammonium concentrations to be determined during incubation. The rates at which nitrate decreased and N(2)O increased were then used to assess the potential denitrification activity and associated N(2)O production in the Seine River Basin. We observed a longitudinal pattern characterized by a significant increase of the potential rate of denitrification from upstream sectors to large downstream rivers (orders 7-8), from approximately 3.3 to 9.1 microg NO(3)(-)-N g(-1) h(-1), respectively, while the N(2)O production rates was the highest both in headwaters and in large order rivers (0.14 and 0.09 N(2)O-N g(-1) h(-1), respectively) and significantly lower in the intermediate sectors (0.01 and 0.03 N(2)O-N g(-1) h(-1)). Consequently, the ratio N(2)O production:NO(3) reduction was found to reach 5% in headstreams, whereas it averaged 1.2% in the rest of the drainage network, an intermediate percentage being found for the riparian soils. Finally, the ignition loss of sediments, together with other redundant variables (particulate organic carbon content: g C 100 g(-1) dry weight [dw], moisture: g water 100 g(-1) dw, sediment size production.

  13. Phylogenetic and Physiological Diversity of Subseafloor Microbial Communities at Axial Seamount, Juan de Fuca Ridge: Summary of Results From the New Millenium Observatory (NeMO), 1998-2004

    Science.gov (United States)

    Baross, J. A.; Huber, J. A.; Mehta, M. P.; Opatkiewicz, A.; Bolton, S. A.; Butterfield, D. A.; Sogin, M. L.; Embley, R. W.

    2005-12-01

    Axial Seamount (45 ° 58' N; 130 ° 00' W) is an active submarine volcano located on the Juan de Fuca Ridge, approximately 300 miles off the coast of Oregon. Lying at the intersection of a seamount chain and a spreading axis, Axial is a unique study site from both the geological and biological perspective. In January of 1998, Axial experienced a week-long series of earthquakes, and subsequent water column and seafloor observations on the southeast portion of the caldera found temperature and chemical anomalies, extensive new seafloor lava flows, large "snow blower" type vents, and other characteristics commonly associated with diking-eruptive events. Due to its high activity and close proximity to shore, Axial was chosen as a site for a multi-year observatory (New Millenium Observatory, NeMO) to document changes and interactions between geology, chemistry, and biology on the mid-ocean ridge system. From 1998 through 2004, we extensively sampled diffuse vents at Axial Seamount to determine the physiological and phylogenetic diversity of subseafloor microbial communities and their relationship to the geochemical environment. Here we present a summary of those studies, including molecular-based phylogenetic surveys of bacteria, archaea, and potential nitrogen-fixing organisms, culturing results of thermophiles and hyperthermophiles from over 20 sites, and the distribution of one particular group of hyperthermophiles at diffuse vents throughout the caldera and how that distribution may be linked to the geochemical habitat. Results indicate that Axial supports a diverse subseafloor microbial community, including hydrogen and sulfur oxidizers, hyperthermophilic methane producers and heterotrophs, and many organisms with the potential to fix nitrogen. In addition, we find that the species composition of the microbial community changes in response to changes in the physical and chemical conditions at each vent site. The extent of seawater mixing with hydrothermal fluids

  14. Die Entdeckung des Higgs-Teilchens oder wie das Universum seine Masse bekam

    CERN Document Server

    2013-01-01

    Im Oktober 2013 setzte der Nobelpreis für Peter Higgs und François Englert den vorläufigen Höhepunkt in der verrückten Geschichte um das sogenannte Gottesteilchen, das Higgs-Boson. Schon im Juli des Vorjahres hatten die Physiker weltweit gejubelt: Mehr als fünfzig Jahre nachdem Peter Higgs und andere Wissenschaftler die Existenz des Teilchens theoretisch begründet hatten, war es im gigantischen Teilchenbeschleuniger CERN gefunden worden. Jetzt erzählen Harald Lesch und seine Co-Autoren, warum sich rund um das Higgs-Teilchen so viele skurrile Missverständnisse und mediale Sensationen ranken. Gewohnt kurzweilig und gut verständlich enthüllen sie, wie aus dem verzweifelt gesuchten „gottverdammten Teilchen“ das Gottesteilchen wurde, dass der Urknall nicht simuliert werden kann und dass Schwarze Löcher nicht unbedingt alles verschlingende Monster sind. Dabei wird deutlich, dass die Suche nach den geheimnisvollen Kräften, die das Universum, unsere Erde und letztlich auch uns Menschen zusammenhalten...

  15. NOAA TIFF Image - 8m Backscatter Mosaic, Puerto Rico 2013, Northeast Reserve, Haystack Seamount, Seafloor Characterization of the US Caribbean - Nancy Foster - NF-13-2 USVI (2013), UTM 20N NAD83

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This image represents an 8 meter resolution backscatter mosaic of a seamount/bank east of Fajardo, Puerto Rico. NOAA's NOS/NCCOS/CCMA Biogeography Team, in...

  16. Seasonal variations in the characteristics of superficial sediments in a macrotidal estuary (the Seine inlet, France)

    Science.gov (United States)

    Lesourd, S.; Lesueur, P.; Brun-Cottan, J. C.; Garnaud, S.; Poupinet, N.

    2003-09-01

    Seasonal variations in the sedimentary regime in the mouth of the Seine river, a macrotidal estuary, are described for a 3-year period. The aim of this study is to characterize and to understand the main governing mechanisms, using data from more than a thousand of superficial sediment grab samples or box cores gathered throughout the study period. Analyses of lithofacies and rheological properties were carried out. The distribution of sediments is governed by seasonal meteorological variations. The surface covered by mud reaches a maximum (40% of the total mouth area) during winter. After the winter, the soft mud deposits are progressively redistributed throughout the whole estuary area and onto the shelf. During the lowest freshwater flow at the end of summer, the fine-grained sediments cover less than 20% of the river mouth area. These seasonal variations mainly depend on the river discharge intensity, but are also linked to wave activity. In the study area, the amount of fine-grained deposits after high river flow periods depends on (1) volume of mud erodable within the estuary, (2) the duration of the flood tidal influx, and (3) the duration preceding the particular annual high river flow. During the last decades, filling of the estuary upstream from Honfleur has led to a downstream shift of the fine-grained sediment deposition area; following this, the present-day mud deposition area is in the open part of the estuary, in the subtidal shallow area. Subsequently, fresh mud deposits undergo intense hydrodynamical and meteorological effects, and are partly reworked by waves and tidal currents effects. In this study, it is shown that the behaviour of suspended matter and of superficial sediments is strongly influenced by short but intense events including high river flows and gales.

  17. Agriculture and groundwater nitrate contamination in the Seine basin. The STICS-MODCOU modelling chain

    International Nuclear Information System (INIS)

    Ledoux, E.; Gomez, E.; Monget, J.M.; Viavattene, C.; Viennot, P.; Ducharne, A.; Benoit, M.; Mignolet, C.; Schott, C.; Mary, B.

    2007-01-01

    A software package is presented here to predict the fate of nitrogen fertilizers and the transport of nitrate from the rooting zone of agricultural areas to surface water and groundwater in the Seine basin, taking into account the long residence times of water and nitrate in the unsaturated and aquifer systems. Information on pedological characteristics, land use and farming practices is used to determine the spatial units to be considered. These data are converted into input data for the crop model STICS which simulates the water and nitrogen balances in the soil-plant system with a daily time-step. A spatial application of STICS has been derived at the catchment scale which computes the water and nitrate fluxes at the bottom of the rooting zone. These fluxes are integrated into a surface and groundwater coupled model MODCOU which calculates the daily water balance in the hydrological system, the flow in the rivers and the piezometric variations in the aquifers, using standard climatic data (rainfall, PET). The transport of nitrate and the evolution of nitrate contamination in groundwater and to rivers is computed by the model NEWSAM. This modelling chain is a valuable tool to predict the evolution of crop productivity and nitrate contamination according to various scenarios modifying farming practices and/or climatic changes. Data for the period 1970-2000 are used to simulate the past evolution of nitrogen contamination. The method has been validated using available data bases of nitrate concentrations in the three main aquifers of the Paris basin (Oligocene, Eocene and chalk). The approach has then been used to predict the future evolution of nitrogen contamination up to 2015. A statistical approach allowed estimating the probability of transgression of different concentration thresholds in various areas in the basin. The model is also used to evaluate the cost of the damage resulting of the treatment of drinking water at the scale of a groundwater management

  18. Agriculture and groundwater nitrate contamination in the Seine basin. The STICS-MODCOU modelling chain

    Energy Technology Data Exchange (ETDEWEB)

    Ledoux, E. [Centre de Geosciences, ENSMP, UMR Sisyphe, Fontainebleau (France)]. E-mail: emmanuel.ledoux@ensmp.fr; Gomez, E. [Centre de Geosciences, ENSMP, UMR Sisyphe, Fontainebleau (France); Monget, J.M. [Centre de Geosciences, ENSMP, UMR Sisyphe, Fontainebleau (France); Viavattene, C. [Centre de Geosciences, ENSMP, UMR Sisyphe, Fontainebleau (France); Viennot, P. [Centre de Geosciences, ENSMP, UMR Sisyphe, Fontainebleau (France); Ducharne, A. [Laboratoire Sisyphe, CNRS/Universite Pierre et Marie Curie, Paris (France); Benoit, M. [INRA, Station de Recherche SAD, 662 avenue Louis Buffet, 88500 Mirecourt (France); Mignolet, C. [INRA, Station de Recherche SAD, 662 avenue Louis Buffet, 88500 Mirecourt (France); Schott, C. [INRA, Station de Recherche SAD, 662 avenue Louis Buffet, 88500 Mirecourt (France); Mary, B. [INRA, Unite d' Agronomie Laon-Reims-Mons, Laon (France)

    2007-04-01

    A software package is presented here to predict the fate of nitrogen fertilizers and the transport of nitrate from the rooting zone of agricultural areas to surface water and groundwater in the Seine basin, taking into account the long residence times of water and nitrate in the unsaturated and aquifer systems. Information on pedological characteristics, land use and farming practices is used to determine the spatial units to be considered. These data are converted into input data for the crop model STICS which simulates the water and nitrogen balances in the soil-plant system with a daily time-step. A spatial application of STICS has been derived at the catchment scale which computes the water and nitrate fluxes at the bottom of the rooting zone. These fluxes are integrated into a surface and groundwater coupled model MODCOU which calculates the daily water balance in the hydrological system, the flow in the rivers and the piezometric variations in the aquifers, using standard climatic data (rainfall, PET). The transport of nitrate and the evolution of nitrate contamination in groundwater and to rivers is computed by the model NEWSAM. This modelling chain is a valuable tool to predict the evolution of crop productivity and nitrate contamination according to various scenarios modifying farming practices and/or climatic changes. Data for the period 1970-2000 are used to simulate the past evolution of nitrogen contamination. The method has been validated using available data bases of nitrate concentrations in the three main aquifers of the Paris basin (Oligocene, Eocene and chalk). The approach has then been used to predict the future evolution of nitrogen contamination up to 2015. A statistical approach allowed estimating the probability of transgression of different concentration thresholds in various areas in the basin. The model is also used to evaluate the cost of the damage resulting of the treatment of drinking water at the scale of a groundwater management

  19. Cancers du sein bilat?raux synchrones et grossesse a l'institut Joliot Curie de Dakar (S?n?gal)

    OpenAIRE

    Zongo, Nayi; Sawadogo, Yobi Alexis; Some, Some Ollo Roland; Bagre, Sidpawalmd? Carine; Ka, Sidy; Diouf, Doudou; Dieng, Mamadou Moustapha; Gaye, Papa Macoumba; Dem, Ahmadou

    2016-01-01

    D?crire notre strat?gie diagnostique et th?rapeutique dans les cancers du sein bilat?raux synchrones pendant la grossesse. L??ge gestationnel au moment du diagnostic du cancer ?tait respectivement de 7; 21 et 25 semaines. Il s'agissait de stade IV et IIIA respectivement dans deux et un cas. Elles ont toutes b?n?fici? d'une chimioth?rapie dans deux cas pendant la grossesse (6TEC et 3AC) et dans un cas apr?s l'accouchement. Une mastectomie bilat?rale a ?t? r?alis?e dans un cas. Une patiente est...

  20. Oceanographic data collected during the Mountains in the Sea: Exploring the New England Seamount Chain 2003 on RV Atlantis in North Atlantic Ocean from July 11, 2003 - July 19, 2003 (NODC Accession 0072308)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This summer, with the help of the Alvin submersible, a multidisciplinary team of scientists and educators visited several little known seamounts in the North...

  1. Petrology of basalts from Loihi Seamount, Hawaii

    Science.gov (United States)

    Hawkins, James; Melchior, John

    1983-12-01

    Loihi Seamount is the southeasternmost active volcano of the Emperor-Hawaii linear volcanic chain. It comprises a spectrum of basalt compositional varieties including basanite, alkali basalt, transitional basalt and tholeiite. Samples from four dredge collections made on Scripps Institution of Oceanography Benthic Expedition in October 1982 are tholeiite. The samples include highly vesicular, olivine-rich basalt and dense glass-rich pillow fragments containing olivine and augite phenocrysts. Both quartz-normative and olivine-normative tholeiites are present. Minor and trace element data indicate relatively high abundances of low partition coefficient elements (e.g., Ti, K, P. Rb, Ba, Zr) and suggest that the samples were derived by relatively small to moderate extent of partial melting, of an undepleted mantle source. Olivine composition, MgO, Cr and Ni abundances, and Mg/(Mg+Fe), are typical of moderately fractionated to relatively unfractionated "primary" magmas. The variations in chemistry between samples cannot be adequately explained by low-pressure fractional crystallization but can be satisfied by minor variations in extent of melting if a homogeneous source is postulated. Alternatively, a heterogeneous source with variable abundances of certain trace elements, or mixing of liquids, may have been involved. Data for 3He/ 4He, presented in a separate paper, implies a mantle plume origin for the helium composition of the Loihi samples. There is little variation in the helium isotope ratio for samples having different compositions and textures. The helium data are not distinctive enough to unequivocally separate the magma sources for the tholeiitic rocks from the other rock types such as Loihi alkalic basalts and the whole source region for Loihi may have a nearly uniform helium compositions even though other element abundances may be variable. Complex petrologic processes including variable melting, fractional crystallization and magma mixing may have blurred

  2. Effects of heavy metal contamination on the macrobenthic fauna in estuaries: The case of the Seine estuary

    International Nuclear Information System (INIS)

    Dauvin, Jean-Claude

    2008-01-01

    Heavy metal contamination levels are generally higher in estuaries than in the open sea. Some estuaries, the Seine estuary for example, have particularly high pollution levels of metals, yet continue to support a very high benthic biomass and remain quite productive. Measurements of sediment contamination are highly variable due to diverse chemical analysis methods, sediments origin and sources of contaminants found in the estuaries. Salinity appears to be the principal factor controlling contaminant distribution in the sediment and the overlying and/or interstitial waters; it also affects the bioavailability of contaminants in estuarine sediments. Of course, the response to contaminants varies greatly among species and assemblages. Trace metals explain only a small part of the variation in benthic community structure. Some species, such as the shrimp Crangon crangon, appears vulnerable to metal pollution, while other species, such as Scrobicularia plana, are able to tolerate quite high levels of cadmium in their tissue. This paper demonstrates the wide variability of benthic responses to contamination, which is probably due to the high spatio-temporal heterogeneity of the estuary. To reduce the problems due the heterogeneity and variability observed to date in the available results, it will be necessary to encourage integrated estuarine studies, in which sedimentologists, chemists, and biologists work together on the same campaigns at the same sites

  3. Contrasting styles of deep-marine pyroclastic eruptions revealed from Axial Seamount push core records

    Science.gov (United States)

    Portner, Ryan A.; Clague, David A.; Helo, Christoph; Dreyer, Brian M.; Paduan, Jennifer B.

    2015-08-01

    A comprehensive understanding of explosive basaltic eruption processes in the deep-sea relies upon detailed analysis and comparison of the variety of volcaniclastic lithologies on the seafloor, which has been challenged by insufficient sample recovery. A dedicated ROV-based sampling approach using long push cores offers an unparalleled opportunity to fully characterize the diversity of unconsolidated volcaniclastic lithofacies on a recently active seamount. Lithofacies from Axial Seamount record two styles of pyroclastic eruptions, strombolian and phreatomagmatic, at 1.5 km water depth. Strombolian eruptions are represented by abundant fluidal and highly vesicular (up to 50%) vitriclasts within limu o Pele lapilli tuff and tuffaceous mud lithofacies. Lapilli-ash grain size, normal grading, good sorting, rip-up clasts and homogeneous glass geochemistry characterize individual limu o Pele lapilli tuff beds, and imply proximal deposition from a turbidity flow associated with a single eruption (i.e. event bed). Limu o Pele lapilli tuff beds are interbedded with poorly sorted, chemically heterogeneous and bioturbated tuffaceous mud units that preserve reworking and biologic habitation of more distal pyroclastic fallout and dilute turbidity flows. The phreatomagmatic eruption style is preserved by hydrothermal mineral-bearing muddy tuff that exhibits characteristics distinct from lapilli ash and tuffaceous mud lithofacies. Hydrothermal muddy tuff lithofacies are well-sorted and fine-grained with notable components of non-fluidal basaltic ash (∼45%), fluidal ash (∼30%) and accessory lithics (∼25%). Heterogeneous geochemistry of ash shards implies that juvenile components are minimal. The abundance, mineralogy and texture of lithic components (Fe-Mg clays, pyrite, epidote, actinolite, altered glass, basalt/diabase, hydrothermal breccia and agglutinate), and very fine-grain size of basaltic ash, are consistent with phreatomagmatic eruption deposits. A lack of

  4. [Reporting and interviewing delays in contact investigation of tuberculosis, Seine-Saint-Denis, from April to June 2008].

    Science.gov (United States)

    Fourcade, C; Le Mab, G; Vincenti-Delmas, M

    2012-08-01

    In France, one of the main components of the tuberculosis control program is contact investigation around all tuberculosis cases. For this purpose, all cases of tuberculosis are to be reported to the health authorities (Centre de lutte antituberculeuse) within 48 hours of diagnosis. The Centre then conducts an initial patient interview within three days of the report in order to establish a list of contacts requiring evaluation. Given that a delay in action may play a role in the continued disease transmission, it appeared necessary to study more precisely this subject in a French area with a high annual new case rate, the Seine-Saint-Denis. A descriptive and retrospective study included all tuberculosis cases reported and received between April and June 2008. The two periods were statistically analyzed with socio-demographic, clinical-biological and investigations data. For the 148 cases reported during this period, a first interview was required for 123. The average time period between initiation of anti-tuberculosis therapy and reception of the report was 11.08 days. The overly long delay could be explained in part by the inappropriate use of the notification form (45.5%) designed for non-urgent collection of epidemiological data, and in part by the underuse of telephone reporting (8.1%). The first interview was not performed for 19 cases and the average time between reception of the notification and the patient interview was 6.58 days. Having the patient's phone number appeared essential to meet the deadline (odds ratio: 5.3; 95% confidence interval [1.7-16.9]). Few interviews were made in person. Shortage in financial and human resources and the delayed case reporting could be part of the explanations. Deadlines were met much better for cases of pleuro-pulmonary tuberculosis compared with other localizations, for reporting (39.2% versus 13.5%, preports some risk factors associated with delayed action and highlights the need for improved reporting of

  5. Ontogenetic optimal temperature and salinity envelops of the copepod Eurytemora affinis in the Seine estuary (France)

    Science.gov (United States)

    Dur, Gaël; Souissi, Sami

    2018-01-01

    Temperature and salinity are important factors shaping the habitats of estuarine ectotherms. Their respective effect varies along the life history moments of species with a complex life cycle. Estuarine species, particularly those living in the salinity gradient, are concerned by habitat changes that can reduce their fitness. Consequently, efforts to define the importance of those two environmental variables on developmental stages are required to enable forecasting estuarine species' future distributions. The present study focuses on the main component of the Seine estuary's zooplankton, i.e. the calanoid copepod Eurytemora affinis, and aims: (i) to establish the role of temperature and salinity in designing the habitat of E. affinis within the Seine estuary; and (ii) to model the habitat of three groups of E. affinis defined through the life cycle as follows: all larval instars (N1-N6), the first to fourth juvenile instars (C1-C4), and the pre-adult and adults instars (C5-Adults). For this purpose, data from intensive field studies of zooplankton sampling during 2002-2010 were used. The fine-scale data, i.e., every 10-20 min, on density and abiotic conditions (salinity, temperature) provided inputs for the computation. We established regions in salinity-temperature space where the three groups of developmental instars exhibit higher densities. The computed habitats differ between developmental groups. In general, the preferendum of salinity increases with ontogeny. The optima of temperature are rather constant between developmental stages (∼14 °C). Our model can be used to determine E. affinis functional habitat (i.e., the spatial relation with structuring factors), to carry out retrospective analysis, and to test future distributions. The present study also emphasizes the need of data from appropriate sampling strategies to conduct habitat definition.

  6. EFEKTIVITAS ALAT TANGKAP MINI PURSE SEINE MENGGUNAKAN SUMBER CAHAYA BERBEDA TERHADAP HASIL TANGKAP IKAN KEMBUNG (Rastrelliger sp.

    Directory of Open Access Journals (Sweden)

    Ifa Nur Rosyidah

    2009-04-01

    Full Text Available In fish catching activity, the fishermen in Banyuanyar district use mini tools for catching fish (purse seine and use light assist tools for an operation in the night day. The light, that is used, is kerosene pressure lantern and mercury lights or lamp that is used on water surface (surface lamp. This kind of light is used to collect “pelagic” fish that has positive phototaxis characteristic. Puffer fish’s response towards different sourse of light, that’s kerosene pressure lantern and mercury light is needed to be known. Therefore, we can know the source of light that is more effective in order to collect the fish. It is hoped that the productivity of puffer fish will be developed for the fishermen. During the research with ten times repeating, the total account of puffer fish’s haul that is resulted with two different treatment  by using kerosene pressure lantern and mercury light is that 810 kg and 1.460 kg. The data of puffer fish’s haul that is gotten after using Mann-Whitney test shows that the kerosene pressure lantern and mercury light not to really different, especially in the haul of puffer fish in significant standart (0,05 is 2,262, while in Mann-Whitney test account is 0,171. That means the fishermans in Banyuanyar can use kerosene pressure lantern and mercury light for catching fish as the light assist tools for an operation in the night day. Keywords     :   Purse Seine, Mercury Light and Kerosene Pressure Lantern, Puffer Fish (Rastrellinger sp..

  7. NOAA TIFF Image - 4m Backscatter Mosaic, Puerto Rico 2013, Escollo Grappler Seamount, Seafloor Characterization of the US Caribbean - Nancy Foster - NF-13-2 USVI (2013), UTM 20N NAD83 (NCEI Accession 0131855)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This image represents a 4 meter resolution backscatter mosaic of a seamount/bank East of Fajardo, Puerto Rico. NOAA's NOS/NCCOS/CCMA Biogeography Team, in...

  8. Oceanographic data collected during the Deep Water Corals of the Davidson Seamount 2006 expedition aboard the R/V WESTERN FLYER in the North Pacific from January 26, 2006 - February 4, 2006 (NODC Accession 0052881)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Building off the successes of an Office of Ocean Exploration (OE) expedition to Davidson Seamount in 2002, this project will focus on deep-water corals. The...

  9. Maison, immeuble et compagnie : le singulier pluriel du logement de banlieue : enquêtes dans les Hauts-de-Seine 1840-1940

    Directory of Open Access Journals (Sweden)

    Antoine Le Bas

    2012-05-01

    Full Text Available Familier du paysage de proche banlieue parisienne (Hauts-de-Seine, le logement sous appentis a séduit les spéculateurs malgré une promiscuité que rejettent des ouvriers rêvant d’un toit familial. Des philanthropes leur bâtiront des maisons complexes tandis qu’une mixité fonctionnelle (travail, commerce, service de plus en plus rare à Paris, affecte le logement de proche banlieue. En organisant la complexité de l’espace urbain et de ses flux, l’urbanisme opère une distinction fonctionnelle dissolvant cette mixité, par le dépassement des types architecturaux.The tenement building, a familiar type in the suburbs of the Hauts-de-Seine department, close to Paris, was frequently put up by speculative builders, even if the promiscuity they supposed was generally rejected by workers who would have preferred their own, individual homes. Some philanthropical builders offered complex housing types, and buildings associating accommodation and other functions (work, commerce, services affected housing in the suburbs, although such types were rare in the capital itself. Organising the complexity of urban space and its circulations, town planning operated a functional division that dissolved this mixity by going beyond existing building types.

  10. NOAA TIFF Image - 8m Backscatter Mosaic, Puerto Rico 2013, Northeast Reserve, Haystack Seamount, Seafloor Characterization of the US Caribbean - Nancy Foster - NF-13-2 USVI (2013), UTM 20N NAD83 (NCEI Accession 0131855)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This image represents an 8 meter resolution backscatter mosaic of a seamount/bank east of Fajardo, Puerto Rico. NOAA's NOS/NCCOS/CCMA Biogeography Team, in...

  11. Age progressive volcanism opposite Nazca plate motion: Insights from seamounts on the northeastern margin of the Galapagos Platform

    Science.gov (United States)

    Sinton, Christopher W.; Hauff, Folkmar; Hoernle, Kaj; Werner, Reinhard

    2018-06-01

    We present new geochemical and 40Ar/39Ar analyses from seven seamounts located off the northeastern margin of the shallow Galápagos Platform. Initial volcanism at 5.2 Ma created a small island (Pico) over the current location of the hotspot with geochemically enriched lavas. There is no further record of magmatism in the study area until 3.8 to 2.5 Ma, during which four roughly conical volcanoes (Sunray, Grande, Fitzroy, and Beagle) formed through eruption of lavas derived from a depleted mantle source. Sunray, Fitzroy, and Grande were islands that existed for 3 m.y. ending with the submergence of Fitzroy at 0.5 Ma. The youngest seamounts, Largo and Iguana, do not appear to have been subaerial and were active at 1.3 Ma and 0.5 Ma, respectively, with the style of edifice changing from the previous large cones to E-W elongate, composite structures. The progression of magmatism suggests that Pico erupted near 91.5°W near the location of the Galápagos plume while the others formed well east of the plume center. If the locations of initial volcanism are calculated using the eastward velocity of the Nazca plate, there appears to be a progression of younger volcanism toward the east, opposite what would be expected from a fixed mantle plume source. The rate that initial volcanism moves eastward is close to the plate velocity. A combination of higher temperature and geochemical enrichment of the thickened lithosphere of the Galápagos platform could have provided a viscosity gradient at the boundary between the thick lithosphere and the thinner oceanic lithosphere to the northeast. As this boundary moved eastward with the Nazca plate, it progressively triggered shear-driven mantle upwelling and volcanism.

  12. Fractures, not Plumes, Have Controlled Major Seamount Volcanism in the Pacific over 170 Million Years

    Science.gov (United States)

    Natland, J. H.; Winterer, E. L.

    2003-12-01

    The distribution of guyots and atolls and large volcanic islands on the Pacific plate can be used to outline the likely connection between stresses acting on the plate and the gradual development of large, linear volcanic chains over the past 170 Ma. We construe three general periods with different stress regimes in the history of the Pacific plate. 1) During the Jurassic and Early Cretaceous, the Pacific plate was surrounded by ridge segments and there were no major stress alignments within it. Within-plate volcanism thus assumed the scattered arrangement for the condition of no tectonic stress (1), and the large Magellan and Wake seamount clusters formed. Near the eastern boundaries of the plate, complex and shifting patterns of ridge reorganization dictated formation of very long, splayed, near-axis ridges such as Horizon Guyot and Necker Ridge. 2) At about 90 Ma, the growing middle-aged Pacific plate achieved its first persistent stress regime with the formation of subduction boundaries along its western or northwestern margin. The plate was no longer static but began to move over the asthenosphere and into the mantle. Subduction boundaries and the overall direction of subduction are uncertain, but this imparted a general yet not fully stable component of tension across the plate, producing the NNW Gilbert-Marshall, Line and Emperor Seamount ridges, generally orthogonal to the overall direction of least principal stress. The Line Island seamount chain, being near ridge axes, sustained a variable stress regime. It thus has no age progression of rocks dated between 70-90 Ma (2), great width, and a dual orientations of ridges. 3) By 47 Ma, nearly half of the boundaries of the Pacific plate now were trenches spanning from the Aleutians to New Zealand. In addition, northward migration of the Indian plate and Australia caught a major portion of the westerly moving Pacific plate between the northeast corner of the Tonga Trench and the Aleutians. The plate could not

  13. Perspectives d'introduction d'un marketing des services au sein des banques publiques Algériennes : Cas de la B.A.D.R.

    OpenAIRE

    Lachachi-taleb, Meriem

    2014-01-01

    Le premier chapitre présente les fondements théoriques relatifs au marketing des services ainsi qu'au concept de servuction et enfin au marketing mix des services dans le deuxiéme chapitre.Le troisiéme chapitre est consacré au marketing bancaire et au plan marketing dans le chapitre suivant, une étude de cas au sein de la B.A.D.R.Banque.

  14. The new Hamburg Ocean Bottom Tiltmeter: A First Deployment at Columbo Seamount (Aegean Sea, Greece)

    Science.gov (United States)

    Hensch, M.; Hort, M.; Dahm, T.; Winter, S.; Klawonn, M.

    2009-04-01

    Assessing the state of volcanic activity of seamounts is quite more complicated than for onshore volcanoes, due to the difficulty of deploying instruments. At land, various techniques are applied (seismic networks, deformation studies, gas measurements etc.). At sea, mainly seismological observations are used. However, especially onshore deformation studies using INSAR have proven to be valuable in determining recharge of magmatic systems. We therefore developed a free fall, self leveling Ocean Bottom Tiltmeter (OBT) to observe deformation on the seafloor, using a two component high resolution tilt sensor with a resolution of about 1nrad (0.15μ°) and a maximum signal of about 0.045rad (0.5°). It is mounted inside a 17" glass sphere on a levelling stage, which relevels the instrument between ± 5° down to an accuracy of 0.006°. During the measurement this leveling stage is standing on the bottom of the glass sphere. For releveling, the instrument is pulled up by thin nylon strings and then locked to a gimbal system in order to compensate for tilt >5°. This releveling procedure is done once every 48 hours. Data is recorded on an 18bit data logger at 50Hz sampling rate. Additionally to tilt and seismic signals (using a hydrophone), temperature, absolute pressure to measure uplift or subsidence, and orientation (electronic compass) are monitored. 4 OBT systems were deployed between June 2006 and March 2007 at Columbo seamount, a submarine volcano north-east of Santorini island, Aegean Sea, Greece, on a 3 km long profile perpendicular to the first principal stress axis of the regional stressfield. Three of the instruments operated the whole time, one shut down due to a short circuit. First data processing indicates that small regional earthquakes as well as major tectonic earthquakes are properly recorded by the system. We find small, but permanent short-period deformations associated with local earthquakes and also observe long-period deformation processes

  15. 3-minute Stephen Hawking. His life, theories and influence; Stephen Hawking im 3-Minuten-Takt. Sein Leben, sein Werk, sein Einfluss

    Energy Technology Data Exchange (ETDEWEB)

    Parsons, Paul; Dixon, Gail

    2013-09-01

    3-minutes Stephen Hawking offers a compact introduction to life and work of this impressing scientist. This book is devided into three parts: Hawking's life, his theories, his influence. Each part offers fascinating reading material for one hour. The partial themes of this book are served up in practical 3-minute portions.

  16. Polycyclic Aromatic Hydrocarbon (pah) In The Bulk Precipitation of The Seine Estuary, France

    Science.gov (United States)

    Motelay-Massei, A.; Ollivon, D.; Garban, B.; Chevreuil, M.

    The evolution of industry and the rising of population have resulted in deep changes in the quality of the environment. Nowadays much more often the attention of analysts is focused on the presence of organic pollutants in precipitation, such as polycyclic aromatic hydrocarbons or pesticides. Atmospheric inputs play a significant role in semivolatile chemicals cycling and alter so the hydrological cycle. PAHs are semi- volatile organic contaminants of great environmental concern because of their car- cinogenic properties. PAHs are produced primarily during incomplete combustion of fossil fuels and wood. Major sources of PAHs to urban atmosphere include au- tomobile traffic, home heating, municipal incinerators and industrial emissions. De- spite their production in urban and industrial sites, PAHs occur at high concentra- tions in rural areas due to their persistence and ability to be transported over long distances. The aim of this investigation was to obtain information about occurrence of organic trace components in precipitation in the Seine Estuary. It was also of in- terest to investigate the spatial and temporal variability of PAHs in the bulk (wet and dry) deposition occurring in the estuary region and to estimate PAH deposition flux on watershed (urban, industrial or rural). Precipitation samples were collected at four locations in the Seine Estuary: the first is an industrial site (Le Havre), two are urban sites (Rouen, representative of urban area influenced by heavy traffic and Notre-Dame de Gravenchon, near from an industrial center) and the last one is ru- ral (Evreux). Each of the sites is located close to a meteorological station. Sam- pling is performed weekly since March 2001. In our analytical conditions, "total PAH" includes 15 compounds: naphthalene (NAP), acenaphtene (ACE), phenanthrene (PHE), anthracene (ANT), fluoranthene (FTH), pyrene (PYR), benzo(a)anthracene (BaA), chrysene (CHR), benzo(b)fluoranthene (BbF), benzo(k)fluoranthene (Bk

  17. 210Pb, 230Th, and 10Be in Central Indian Basin seamount sediments: Signatures of degassing and hydrothermal alteration of recent origin

    Digital Repository Service at National Institute of Oceanography (India)

    Nath, B.N.; Borole, D.V.; Aldahan, A.; Patil, S; Mascarenhas-Pereira, M.B.L.; Possnert, G.; Ericsson, T.; Ramaswamy, V.; Gupta, S

    , 230 Th, and 10 Be in Central Indian Basin seamount sediments: Signatures of degassing and hydrothermal alteration of recent origin B. N. Nath, 1 D. V. Borole, 1 A. Aldahan, 2 S. K. Patil, 3 M. B. L. Mascarenhas-Pereira, 1 G. Possnert, 4 T. Ericsson, 2... V. Ramaswamy, 1 and S. M. Gupta 1 Received 4 March 2008; revised 17 March 2008; accepted 8 April 2008; published 14 May 2008. [1] Isotopic ( 210 Pb, 238 U- 230 Th, 10 Be), major and trace elements, and micromorphological and microchemical data, were...

  18. NOAA TIFF Image - NF13_PR_Haystack_95khz_bathy_4m.tif, Puerto Rico 2013, Northeast Reserve, Haystack Seamount, Seafloor Characterization of the US Caribbean - Nancy Foster - NF-13-2 USVI (2013), UTM 20N NAD83

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This image represents a 4 meter resolution interpolated bathymetric grid of a seamount East of Fajardo, Puerto Rico. NOAA's NOS/NCCOS/CCMA Biogeography Team, in...

  19. Un modèle cognitif computationnel de représentation de la connaissance au sein des environnements virtuels d’apprentissage

    Directory of Open Access Journals (Sweden)

    Mehdi Najjar

    2005-01-01

    Full Text Available Dans le cadre de la représentation des connaissances au sein des environnements virtuels d’apprentissage (EVA et du fait de la nature relationnelle et structurée de ces connaissances, leur exploitation nécessite de faire appel à des processus d’analyse capables de traiter et de manipuler un grand volume de données structurées. Dans ce sens, un modèle de représentation trouve sa pleine utilité pour la recherche et le traitement automatique d’information guidant le raisonnement, le diagnostic et la prédiction d’un système tuteur dont la tâche est de fournir des suggestions, des exemples et des explications bien adaptés à chaque apprenant. Nous présentons dans cet article un modèle pour représenter la connaissance du domaine et celle des usagers utilisant des EVA. Le modèle s’inspire des recherches en intelligence artificielle sur la modélisation computationnelle et des théories de la psychologie cognitive qui expliquent l’activité cognitive humaine en termes de sous-systèmes de la mémoire et de leurs processus. Ces sous-systèmes (implémentés dans un EVA, parce qu’ils sont similaires à ceux utilisés par l’apprenant, facilitent, d’une part, l’identification de la connaissance acquise correcte ou erronée, et suggèrent, d’autre part, la planification d’une séquence d’activités pédagogiques pour améliorer de manière significative le niveau cognitif de cet apprenant.

  20. Preparation to the question of the sense of being in Martin Heidegger's thought. An introduction to the 'Existential analytic' of Dasein: Sein und Zeit - Was ist Metaphysik - Rektoratsrede

    NARCIS (Netherlands)

    Esengrini, S.

    2004-01-01

    In order to prepare the field for an analysis of the role played by Sein und Zeit inside Heidegger's pathway of thinking, it proves decisive to show the theoretical horizon from which this first fundamental work of his takes its start. That is why, on the basis of Heidegger's hypothesis that the

  1. The new Hamburg Ocean-Bottom-Tiltmeter (OBT): A first deployment at Columbo Seamount (Aegean Sea, Greece)

    Science.gov (United States)

    Huebscher, C.; Hensch, M.; Hort, M.; Dahm, T.; Klawonn, M.; Winter, S.

    2008-12-01

    Assessing the state of volcanic activity of seamounts is quite more complicated than for onshore volcanoes, due to the difficulty of deploying instruments. At land, various techniques are applied (seismic networks, deformation studies, gas measurements etc.). At sea, mainly seismological observations are used. However, especially onshore deformation studies using INSAR have proven to be valuable in determining recharge of magmatic systems. We therefore developed a free fall, self leveling Ocean Bottom Tiltmeter (OBT) to observe deformation on the seafloor, using a two component high resolution tilt sensor with a resolution of about 1nrad (0.15μ°) and a maximum signal of about 0.045rad (0.5°). It is mounted inside a 17~inch glass sphere on a levelling stage, which relevels the instrument between ± 5° down to an accuracy of 0.006°. During the measurement this leveling stage is standing on the bottom of the glass sphere. For releveling, the instrument is pulled up by thin nylon strings and then locked to a gimbal system in order to compensate for tilt. This releveling procedure is done once every 48 hours. Data is recorded on an 18bit data logger at 50Hz sampling rate. Additionally to tilt and seismic signals (using a hydrophone), temperature, absolute pressure to measure uplift or subsidence, and orientation (electronic compass) are monitored. 4 OBT systems were deployed between June 2006 - March 2007 at Columbo seamount, a submarine volcano north-east of Santorini island, Aegean Sea, Greece, on a 3 km long profile perpendicular to the first principal stress axis σ_1 of the regional stressfield. Three of the instruments operated the whole time, one shut down due to a short circuit. First data processing indicates that small regional earthquakes as well as major tectonic earthquakes are properly recorded by the system. We find small, but permanent short- period deformations associated with local earthquakes and also observe long-period deformation processes

  2. Long term prospective of the Seine River system: Confronting climatic and direct anthropogenic changes

    International Nuclear Information System (INIS)

    Ducharne, A.; Baubion, C.; Beaudoin, N.; Benoit, M.; Billen, G.; Brisson, N.; Garnier, J.; Kieken, H.; Lebonvallet, S.; Ledoux, E.; Mary, B.; Mignolet, C.; Poux, X.; Sauboua, E.; Schott, C.; Thery, S.; Viennot, P.

    2007-01-01

    To explore the evolution of a human impacted river, the Seine (France), over the 21st century, three driving factors were examined: climate, agriculture, and point source inputs of domestic and industrial origin. Three future scenarios were constructed, by modification of a baseline representative of recent conditions. A climate change scenario, based on simulations by a general circulation model driven by the SRES-A2 scenario of radiative forcing, accounts for an average warming of + 3.3 deg. C over the watershed and marked winter increase and summer decrease in precipitation. To illustrate a possible reduction in nitrate pollution from agricultural origin, a scenario of good agricultural practices was considered, introducing catch crops and a 20% decrease in nitrogen fertilisation. Future point source pollution was estimated following the assumptions embedded in scenario SRES-A2 regarding demographic, economic and technologic changes, leading to reductions of 30 to 75% compared to 2000, depending on the pollutants. Four models, addressing separate components of the river system (agronomical model, hydrogeological model, land surface model and water quality model), were used to analyse the relative impact of these scenarios on water quality, in light of their impact on hydrology and crop production. The first-order driving factor of water quality over the 21st century is the projected reduction of point source pollution, inducing a noticeable decrease in eutrophication and oxygen deficits downstream from Paris. The impact of climate change on these terms is driven by the warming of the water column. It enhances algal growth in spring and the loss factors responsible for phytoplankton mortality in late summer (grazers and viruses). In contrast, increased seasonal contrasts in river discharge have a negligible impact on river water quality, as do the changes in riverine nitrate concentration, which never gets limiting. The latter changes have a similar magnitude

  3. Modeling interactions of agriculture and groundwater nitrate contaminants: application of The STICS-Eau-Dyssée coupled models over the Seine River Basin

    Science.gov (United States)

    Tavakoly, A. A.; Habets, F.; Saleh, F.; Yang, Z. L.

    2017-12-01

    Human activities such as the cultivation of N-fixing crops, burning of fossil fuels, discharging of industrial and domestic effluents, and extensive usage of fertilizers have recently accelerated the nitrogen loading to watersheds worldwide. Increasing nitrate concentration in surface water and groundwater is a major concern in watersheds with extensive agricultural activities. Nutrient enrichment is one of the major environmental problems in the French coastal zone. To understand and predict interactions between agriculture, surface water and groundwater nitrate contaminants, this study presents a modeling framework that couples the agronomic STICS model with Eau-Dyssée, a distributed hydrologic modeling system to simulate groundwater-surface water interaction. The coupled system is implemented on the Seine River Basin with an area of 88,000 km2 to compute daily nitrate contaminants. Representing a sophisticated hydrosystem with several aquifers and including the megalopolis of Paris, the Seine River Basin is well-known as one of the most productive agricultural areas in France. The STICS-EauDyssée framework is evaluated for a long-term simulation covering 39 years (1971-2010). Model results show that the simulated nitrate highly depends on the inflow produced by surface and subsurface waters. Daily simulation shows that the model captures the seasonal variation of observations and that the overall long-term simulation of nitrate contaminant is satisfactory at the regional scale.

  4. Reactive transport modeling of nitrogen in Seine River sediments

    Science.gov (United States)

    Akbarzadeh, Z.; Laverman, A.; Raimonet, M.; Rezanezhad, F.; Van Cappellen, P.

    2016-02-01

    Biogeochemical processes in sediments have a major impact on the fate and transport of nitrogen (N) in river systems. Organic matter decomposition in bottom sediments releases inorganic N species back to the stream water, while denitrification, anammox and burial of organic matter remove bioavailable N from the aquatic environment. To simulate N cycling in river sediments, a multi-component reactive transport model has been developed in MATLAB®. The model includes 3 pools of particulate organic N, plus pore water nitrate, nitrite, nitrous oxide and ammonium. Special attention is given to the production and consumption of nitrite, a N species often neglected in early diagenetic models. Although nitrite is usually considered to be short-lived, elevated nitrite concentrations have been observed in freshwater streams, raising concerns about possible toxic effects. We applied the model to sediment data sets collected at two locations in the Seine River, one upstream, the other downstream, of the largest wastewater treatment plant (WWTP) of the Paris conurbation. The model is able to reproduce the key features of the observed pore water depth profiles of the different nitrogen species. The modeling results show that the presence of oxygen in the overlying water plays a major role in controlling the exchanges of nitrite between the sediments and the stream water. In August 2012, sediments upstream of the WWTP switch from being a sink to a source of nitrite as the overlying water becomes anoxic. Downstream sediments remain a nitrite sink in oxic and anoxic conditions. Anoxic bottom waters at the upstream location promote denitrification, which produces nitrite, while at the downstream site, anammox and DNRA are important removal processes of nitrite.

  5. Revisiting the vulnerability of juvenile bigeye (Thunnus obesus) and yellowfin (T. albacares) tuna caught by purse-seine fisheries while associating with surface waters and floating objects.

    Science.gov (United States)

    Scutt Phillips, Joe; Pilling, Graham M; Leroy, Bruno; Evans, Karen; Usu, Thomas; Lam, Chi Hin; Schaefer, Kurt M; Nicol, Simon

    2017-01-01

    Tuna fisheries catch over three million tonnes of skipjack tuna (Katsuwonus pelamis) each year, the majority of which come from purse-seine vessels targeting fish associated with man-made fish aggregating devices (FADs). A significant challenge for fisheries management is to maximize the efficiency of skipjack tuna catches whilst minimizing the bycatch of small and immature bigeye (Thunnus obesus) and yellowfin (T. albacares) tuna, for which long-term sustainability is uncertain in 75% of the world's stocks. To better manage the issues common with this fishing method, an improved understanding of tuna behaviour around FADs is necessary. We probabilistically classified the vertical behavioural patterns of 50 bigeye and 35 yellowfin tuna (mean fork length 72cm and 70cm, respectively) electronically tagged throughout the western and central Pacific Ocean into shallow and deep states, using a state-space modelling approach. The occurrence of surface-association behaviours, defined as an individual remaining in a shallow state for 24-hours, was examined in relation to known capture events and FAD density. In general, surface-association events for both species were short and lasted on average less than three days, although events as long as 28 days were observed, and were more common in yellowfin when in archipelagic waters. Events were longest immediately following tagging in 62% and 17% of bigeye and yellowfin, respectively. Surface-association behaviour was not generally estimated just prior to recapture, being either non-existent or shorter than two days for 85% of bigeye and 74% of yellowfin. Current management measures in purse-seine tuna fisheries involve periodic or spatial closures for FAD use. If the chief benefit to purse-seine fishers of surface-association around floating objects is in locating schools in horizontal space at short-term time-scales, rather than holding fish near the surface for extended periods, controlling the number of sets made on FADs

  6. Revisiting the vulnerability of juvenile bigeye (Thunnus obesus and yellowfin (T. albacares tuna caught by purse-seine fisheries while associating with surface waters and floating objects.

    Directory of Open Access Journals (Sweden)

    Joe Scutt Phillips

    Full Text Available Tuna fisheries catch over three million tonnes of skipjack tuna (Katsuwonus pelamis each year, the majority of which come from purse-seine vessels targeting fish associated with man-made fish aggregating devices (FADs. A significant challenge for fisheries management is to maximize the efficiency of skipjack tuna catches whilst minimizing the bycatch of small and immature bigeye (Thunnus obesus and yellowfin (T. albacares tuna, for which long-term sustainability is uncertain in 75% of the world's stocks. To better manage the issues common with this fishing method, an improved understanding of tuna behaviour around FADs is necessary. We probabilistically classified the vertical behavioural patterns of 50 bigeye and 35 yellowfin tuna (mean fork length 72cm and 70cm, respectively electronically tagged throughout the western and central Pacific Ocean into shallow and deep states, using a state-space modelling approach. The occurrence of surface-association behaviours, defined as an individual remaining in a shallow state for 24-hours, was examined in relation to known capture events and FAD density. In general, surface-association events for both species were short and lasted on average less than three days, although events as long as 28 days were observed, and were more common in yellowfin when in archipelagic waters. Events were longest immediately following tagging in 62% and 17% of bigeye and yellowfin, respectively. Surface-association behaviour was not generally estimated just prior to recapture, being either non-existent or shorter than two days for 85% of bigeye and 74% of yellowfin. Current management measures in purse-seine tuna fisheries involve periodic or spatial closures for FAD use. If the chief benefit to purse-seine fishers of surface-association around floating objects is in locating schools in horizontal space at short-term time-scales, rather than holding fish near the surface for extended periods, controlling the number of sets

  7. NOAA TIFF Image - NF13_PR_Haystack_95khz_bathy_4m.tif, Puerto Rico 2013, Northeast Reserve, Haystack Seamount, Seafloor Characterization of the US Caribbean - Nancy Foster - NF-13-2 USVI (2013), UTM 20N NAD83 (NCEI Accession 0131855)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This image represents a 4 meter resolution interpolated bathymetric grid of a seamount East of Fajardo, Puerto Rico. NOAA's NOS/NCCOS/CCMA Biogeography Team, in...

  8. Using the OOI Cabled Array HD Camera to Explore Geophysical and Oceanographic Problems at Axial Seamount

    Science.gov (United States)

    Crone, T. J.; Knuth, F.; Marburg, A.

    2016-12-01

    A broad array of Earth science problems can be investigated using high-definition video imagery from the seafloor, ranging from those that are geological and geophysical in nature, to those that are biological and water-column related. A high-definition video camera was installed as part of the Ocean Observatory Initiative's core instrument suite on the Cabled Array, a real-time fiber optic data and power system that stretches from the Oregon Coast to Axial Seamount on the Juan de Fuca Ridge. This camera runs a 14-minute pan-tilt-zoom routine 8 times per day, focusing on locations of scientific interest on and near the Mushroom vent in the ASHES hydrothermal field inside the Axial caldera. The system produces 13 GB of lossless HD video every 3 hours, and at the time of this writing it has generated 2100 recordings totaling 28.5 TB since it began streaming data into the OOI archive in August of 2015. Because of the large size of this dataset, downloading the entirety of the video for long timescale investigations is not practical. We are developing a set of user-side tools for downloading single frames and frame ranges from the OOI HD camera raw data archive to aid users interested in using these data for their research. We use these tools to download about one year's worth of partial frame sets to investigate several questions regarding the hydrothermal system at ASHES, including the variability of bacterial "floc" in the water-column, and changes in high temperature fluid fluxes using optical flow techniques. We show that while these user-side tools can facilitate rudimentary scientific investigations using the HD camera data, a server-side computing environment that allows users to explore this dataset without downloading any raw video will be required for more advanced investigations to flourish.

  9. Estimation of seafloor impact from demersal trawls, seines and dredges based on gear design and dimensions

    DEFF Research Database (Denmark)

    Eigaard, Ole Ritzau; Bastardie, Francois; Breen, Michael

    a different approach using the gear itself (design and dimensions) for understanding and estimation of the physical interactions with the seafloor at the individual fishing operation level. With reference to the métier groupings of EU logbooks, we defined 17 distinct towed gear groups in European waters (11...... otter trawl groups, 3 beam trawl groups, 2 demersal seine groups, and 1 dredge group), for which we established seafloor “footprints”. The footprint of a gear was defined as the relative contribution from individual larger gear components, such as the trawl doors, sweeps and ground gear, to the total...... types based on a review of the scientific literature. For each defined gear group a vessel-size (kW or total length) – gear size (total gear width or circumference) relationship was estimated to enable the prediction of gear footprint area and sediment penetration from vessel size. The implications...

  10. Biodiversity and species-environment relationships of the demersal fish assemblage at the Great Meteor Seamount (subtropical NE Atlantic), sampled by different trawls

    DEFF Research Database (Denmark)

    Fock, H.; Uiblein, F.; Köster, Fritz

    2002-01-01

    , respectively, to 583.98 ind. m(-1) h(-1) in 1998. Gear effects and an effect of gear over time accounted for 47.1% and 20% of species variability. Further significant factors were time of day and habitat, while season was not significant. A total of 43 species was collected. Including supplementary species...... information, a grand total of 46 species was found associated with the Great Meteor Seamount. Diversity was higher in 1967 and 1970 (Shannon's diversity: H'=2.5 and 1.6) than in 1998 (H'=0.9). Species-environment relationships are discussed in terms of a sound-scattering layer-interception hypothesis, i...

  11. Uranium series disequilibrium dating of coral and shell fragments dredged around islands and seamounts during the 1986 HMNZS Tui cruises

    International Nuclear Information System (INIS)

    McCabe, W.J.; Ditchburn, R.G.; Glasby, G.P.

    1996-01-01

    Nine coral and two shell samples dredged from the flanks of various islands and seamounts in the subtropical SW Pacific were processed through the uranium series analysis system and ages calculated. Although there is a tendency for sample ages to increase with water depth, the presence of corals less than 1000 years old at water depths of 400 to almost 1100 m indicates the influence of recent slumping rather than crustal warping or eustatic changes as reasons for their present position. This phenomenon is related to mass wasting of material down slope. It is possible that samples collected systematically down the slopes of these islands would enable the frequency and times of slumping to be determined. (author). 7 refs., 2 figs., 7 tabs

  12. Competing styles of deep-marine explosive eruptions revealed from Axial seamount and Juan De Fuca ridge push core records

    Science.gov (United States)

    Portner, R. A.; Clague, D. A.; Paduan, J. B.; Martin, J. F.

    2012-12-01

    Pyroclastic lithofacies from Axial seamount record two distinct styles of deep-marine explosive eruption activity at 1.4-1.5 km water depth. The first style is preserved by limu o Pele-rich ash, which is widely distributed and thin bedded. Individual beds are normal to coarse-tail graded with increasing planar grain-fabric and decreasing limu o Pele thickness upward. Grain-size generally ranges from medium lapilli to medium ash, which is well to poorly sorted depending on the abundance of outsized fluidal shards. Fluidal shards include limu o Pele and Pele's hair, and lesser amounts of tendril-like tube pumice and droplet-like shards. Rare blocky to fluidal lapilli contain up to 70% vesicles. Angular plagioclase and basalt lithics occur in minor amounts (2-15%). Most beds display overall upward changes in particle morphology from dense blocky angular lapilli in their bases to fluidal ash in their tops. Shards are most equidimensional near the base, and most varied in the mid-upper parts of most beds where 4-8 mm size limu occur with 1-2 mm blocky shards. This outsized-component association results from drastically different settling speeds for the two morphologies. Outsized fluidal shards become abundant across a relatively sharp boundary in the middle to lower portions of most beds causing a seemingly double-graded appearance. These systematic changes in particle morphology and grain size suggest a cogenetic association of blocky and fluidal shards to the same depositional event and causative eruption. Fluidal-vesicular particle morphologies suggest that this lithofacies represents ash fall from magmatically explosive eruptions. Planar-grain fabric trends, absence of shard imbrication, and grading profiles suggest that beds were deposited via near-vertical suspension fall-out from weak turbidity flows. The second pyroclastic lithofacies is dominated by normal graded greenish grey ashy mud beds. Ash makes up 10-80% of individual beds, and is well-sorted, coarse- to

  13. Mémoire du travail et des expositions professionnelles aux cancérogènes Work account and occupational exposures to carcinogens. Survey in Seine-Saint-Denis (France) Memoria del trabajo y de las exposiciones profesionales a agentes cancerígenos. Encuesta en Seine-Saint-Denis (Francia)

    OpenAIRE

    Annie Thébaud-Mony; Béatrice Leconte

    2010-01-01

    Selon les estimations officielles, en 2000 environ 32 millions de travailleurs européens (de l’Europe des 15) étaient exposés à des cancérogènes. Depuis 2002, considérant la maladie comme « événement-sentinelle » pour la connaissance des activités de travail exposant aux cancérogènes, le Groupement d’intérêt scientifique sur les cancers d’origine professionnelle (GISCOP93) mène une enquête permanente auprès de patients atteints de cancer en Seine Saint Denis (France). S’appuyant sur les récit...

  14. Uses of biogas produced by digestion of wastewater sludge. The SIAAP's experience feedback and projects

    International Nuclear Information System (INIS)

    Amosse, S.; Nedelec, R.

    2010-01-01

    The SIAAP, in charge of the purification of the Great Paris wastewaters (8 M inhabitants), handles 2.7 Mm 3 /day. Five wastewater treatment plants permit to dean these wastewaters before they are discharged into the receiving environment: 'Seine Aval' (Acheres, 1,7 Mm 3 /day), 'Seine Amont' (Valenton, 600 000 m 3 /day), 'Seine Centre' (Colombes, 240 000 m 3 /day), 'Seine Gresillons' (Triel-sur-Seine, 100 000 m 3 /day) and 'Marne Aval' (Noisy-Le-Grand, 40 000 m 3 /day). Biogas produced by digestion of sludge provides a part of the energy required by the five sewage treatment works. Energy recovered from biogas have been used by the SAV site since 1940. As soon as the first part of this plant started up, biogas was used as fuel to heat digester, to produce power through biogas engines and to drive blowers. In the 60's and 70's, dual-fuel engines were brought into service, and then in 1992, a gas turbine was installed. Nowadays, a combined heat and power (cogeneration) project is in progress with the installation of two gas turbines, each generating 5 MW. All of these installations had allowed a 70% energetic autonomy ratio on 'Seine Aval' site. Then, new treatment units were introduced. Thus, energy consumption has increased, with only 60 % of energy demands being covered. By 2020, a complete make-over of the 'Seine Aval' plant will be done. This should allow to cover about 70% of energy demands, partly thanks to biogas reuse. New plants are currently being constructed. All of them will include sludge digestion process providing biogas. With the 'Seine Gresillons' plant upgrading, digestion process will occur on site. Biogas will be used in a cogeneration system to produce both electricity (that would be either used on site or sold commercially, this has not been decided by now) and heat for digesters heating. The new 'Seine Moree' plant will be built in the city of Blanc-Mesnil. A partnership with the Syctom (an association in charge of treatment and reuse of the

  15. Voluminous lava flow from Axial Seamount's south rift constrains extension rate on northern Vance Segment

    Science.gov (United States)

    Le Saout, M.; Clague, D. A.; Paduan, J. B.

    2017-12-01

    Axial Seamount is characterized by a robust magma supply resulting from the interaction between the Cobb hotspot and the Juan de Fuca Ridge. During the last two decades, magmatic activity was focused within the summit caldera and upper and middle portions of the two rift zones, with eruptions in 1998, 2011, and 2015. However, the distal ends of both rift zones have experienced numerous eruptions in the past. The most voluminous flows are located near the extreme ends, greater than 40 kilometers from the caldera. Where Axial's South Rift Zone overlaps with the Vance Segment of the Juan de Fuca Ridge, the 2015 MBARI expedition mapped 16 km2 of the seafloor with our AUV, and collected 33 rocks and 33 sediment cores during two ROV dives. The data were used to confirm the boundaries of an extensive flow tentatively identified using modern ship based bathymetry. This flow is 18 km wide and 6 km long for a total surface area of 63 km2. The flow is modified by superficial ( 5 m deep) and deep (25 to 45 m deep) subsidence pits, with the deepest pits giving an indication of the minimum thickness of the flow. The maximum thickness of 100 m is measured at the margins of the flow. We thus estimate a volume between 2.5 and 6 km3, making this flow the most voluminous known on the global mid ocean ridge system. The minimum volume is equivalent to the present volume of the summit caldera. Radiocarbon ages of foraminifera from the basal sections of sediment cores suggest that this flow is 1000 years old. This flow travelled east and partially filled the axial valley of the adjacent Vance Segment. Since emplacement, this part of the flow has experienced deformation by fissures and faults aligned with the trend of the Vance Segment. The horizontal extension across these features allows us to estimate a local deformation rate of 3 cm/yr of tectonic extension on the northern end of Vance Segment during the last 1000 years.

  16. LA DIVERSITÉ DÉPLOYÉE AU SEIN DE L’UNIVERSITÉ D’ENTREPRISE : L’APPLICATION CONCRÈTE D’UNE VALEUR ADOPTÉE PAR LA DIRECTION GÉNÉRALE

    Directory of Open Access Journals (Sweden)

    Virginia Drummond-Guitel

    2009-09-01

    Full Text Available La diversité devenue une valeur incontournable adoptée par les grands groupes, encore faut-t-il trouver les moyens concrets pour l’intégrer dans les pratiques des ressources humaines et dans les mentalités des personnes. Le présent papier a pour but de montrer comment les valeurs de la diversité adoptées par la direction générale ont été déclinées et appliquées dans un processus de sélection de candidats pour une formation continue au sein d’une grande organisation internationale. A travers l’application d’une méthode qualitative de recherche, 10 (dix dirigeants ayant conçu la formation et 42 (quarante-deux managers ayant suivi le programme confirment l’atteinte du but stratégique de cette formation, autrement dit, l’atteinte d’une vision partagée (SENGE, 1991, à travers la consolidation d’un fort sentiment d’appartenance à la culture organisationnelle (SCHEIN, 1995. Les managers ont été sélectionnés selon leurs différentes professions, cultures nationales et différents secteurs d’activités, confirmant ainsi une promotion de la diversité au sein de l’organisation.

  17. Constraining Seasonal and Vertical Distributions of Planktonic Foraminifera for Paleoclimate Reconstruction Since MIS3 at the Axial Seamount, Juan de Fuca Ridge

    Science.gov (United States)

    Chen, S. L.; Ravelo, A. C.; Clague, D. A.

    2015-12-01

    The California Current is an upwelling region with dynamic interactions between circulation, biological productivity and ecology. A 77 cm piston push core was taken from the Juan de Fuca Ridge Axial Seamount using a Remotely Operated Vehicle (ROV) (2213m, 45.55º N, 130.08º W), an active submarine volcano ~480 km off Oregon's coast. Five radiocarbon dates indicate that the sediment ranges from 42.6 ka at 77 cm to 17.6 ka at 15 cm, with an average sediment accumulation rate of 2.47 cm/ka from 77-15 cm, and an average rate of 0.85 cm/ka during the postglacial period (the core representing subtropical, subartic, and arctic fauna have been used to constrain changes in vertical and seasonal temperature since Marine Isotope Stage 3 (MIS3). Measurements of δ18O of the upwelling species Globigerina bulloides, the thermocline dwelling species Neogloboquadrina dutertrei, and the warm mixed-layer species Orbulina universa are offset from each other, reflecting vertical and seasonal variation among the planktonic foraminifera. Of the three species, G. bulloides shows the least variation in δ18O, possibly indicating that marked changes in temperature are masking changes in the δ18O of seawater due to global ice volume changes. G. bulloides and O. universa δ18O values are similar in MIS 3 and diverge with time, indicating the development of strong seasonal succession of species, since the last glacial maximum. Bulk nitrogen isotopes and nitrogen flux provide additional constraints on upwelling strength and insight into local biological productivity and nutrient dynamics. Obtaining Mg/Ca data will clarify the δ 18O interpretation except deep in the core where metal-bearing authigenic precipitates affect Mg concentrations. These climatic proxies together provide insight into how global climate change and local seamount volcanism impacts regional productivity in the California Current.

  18. Nuclear safety and radiation protection report of the Nogent-sur-Seine nuclear facilities - 2011

    International Nuclear Information System (INIS)

    2012-01-01

    This safety report was established under the article 21 of the French law no. 2006-686 of June 13, 2006 relative to nuclear safety and information transparency. It presents, first, the facilities of the Nogent-sur-Seine nuclear power plant (INB 129 and 130, Aube (FR)). Then, the nuclear safety and radiation protection measures taken regarding the facilities are reviewed: nuclear safety definition, radiation protection of intervening parties, safety and radiation protection improvement paths, crisis management, external and internal controls, technical situation of facilities, administrative procedures in progress. The incidents and accidents which occurred in 2011, are reported as well as the radioactive and non-radioactive (chemical, thermal) effluents discharge in the environment. Finally, The radioactive materials and wastes generated by the facilities are presented and sorted by type of waste, quantities and type of conditioning. Other environmental impacts (noise, microbial proliferation in cooling towers) are presented with their mitigation measures. Actions in favour of transparency and public information are presented as well. The document concludes with a glossary and a list of recommendations from the Committees for health, safety and working conditions. (J.S.)

  19. Nuclear safety and radiation protection report of the Nogent-sur-Seine nuclear facilities - 2010

    International Nuclear Information System (INIS)

    2011-06-01

    This safety report was established under the article 21 of the French law no. 2006-686 of June 13, 2006 relative to nuclear safety and information transparency. It presents, first, the facilities of the Nogent-sur-Seine nuclear power plant (INB 129 and 130, Aube (FR)). Then, the nuclear safety and radiation protection measures taken regarding the facilities are reviewed: nuclear safety definition, radiation protection of intervening parties, safety and radiation protection improvement paths, crisis management, external and internal controls, technical situation of facilities, administrative procedures in progress. The incidents and accidents which occurred in 2010, are reported as well as the radioactive and non-radioactive (chemical, thermal) effluents discharge in the environment. Finally, The radioactive materials and wastes generated by the facilities are presented and sorted by type of waste, quantities and type of conditioning. Other environmental impacts (noise, microbial proliferation in cooling towers) are presented with their mitigation measures. Actions in favour of transparency and public information are presented as well. The document concludes with a glossary and a list of recommendations from the Committees for health, safety and working conditions. (J.S.)

  20. Suspended Sediment Dynamics in the Macrotidal Seine Estuary (France): 2. Numerical Modeling of Sediment Fluxes and Budgets Under Typical Hydrological and Meteorological Conditions

    Science.gov (United States)

    Schulz, E.; Grasso, F.; Le Hir, P.; Verney, R.; Thouvenin, B.

    2018-01-01

    Understanding the sediment dynamics in an estuary is important for its morphodynamic and ecological assessment as well as, in case of an anthropogenically controlled system, for its maintenance. However, the quantification of sediment fluxes and budgets is extremely difficult from in-situ data and requires thoroughly validated numerical models. In the study presented here, sediment fluxes and budgets in the lower Seine Estuary were quantified and investigated from seasonal to annual time scales with respect to realistic hydro- and meteorological conditions. A realistic three-dimensional process-based hydro- and sediment-dynamic model was used to quantify mud and sand fluxes through characteristic estuarine cross-sections. In addition to a reference experiment with typical forcing, three experiments were carried out and analyzed, each differing from the reference experiment in either river discharge or wind and waves so that the effects of these forcings could be separated. Hydro- and meteorological conditions affect the sediment fluxes and budgets in different ways and at different locations. Single storm events induce strong erosion in the lower estuary and can have a significant effect on the sediment fluxes offshore of the Seine Estuary mouth, with the flux direction depending on the wind direction. Spring tides cause significant up-estuary fluxes at the mouth. A high river discharge drives barotropic down-estuary fluxes at the upper cross-sections, but baroclinic up-estuary fluxes at the mouth and offshore so that the lower estuary gains sediment during wet years. This behavior is likely to be observed worldwide in estuaries affected by density gradients and turbidity maximum dynamics.

  1. Spatiotemporal behavior of microearthquakes over an eruption cycle at 9°50'N East Pacific Rise and Axial Seamount

    Science.gov (United States)

    Tan, Y. J.; Tolstoy, M.; Waldhauser, F.; Wilcock, W. S. D.; Bohnenstiehl, D. R.

    2017-12-01

    We explore tidal triggering and other spatiotemporal behavior of microearthquakes as an indicator of the stress state at the mid-ocean ridge environment. Only two mid-ocean ridge sites have had ocean bottom seismic monitoring through an eruption cycle. At the East Pacific Rise (EPR), up to 12 ocean bottom seismometers (OBSs) were deployed and recovered approximately annually in a 4 x 4 km region from October 2003 to January 2007, encompassing an eruption in January 2006. 100,000 precisely located microearthquakes delineate an along-axis oriented hydrothermal circulation cell and mostly concentrate above the axial magma lens at 1.5 km depth (Tolstoy et. al., 2008; Waldhauser et. al., 2011). At Axial Seamount, a seismic network was installed as part of the Ocean Observatory Initiative Cabled Array that has been streaming live data since November 2014, encompassing an eruption in April-May of 2015. In the first year of operation, >100,000 precisely located microearthquakes delineate outward dipping ring faults inferred to have accommodated pre-eruptive inflation and syn-eruptive deflation (Wilcock et. al., 2016). At both EPR and Axial, earthquake timing strongly correlates with semidiurnal tides pre-eruption. This correlation with tides weakens significantly post-eruption. This suggests that in the mid-ocean ridge environment, temporal variation in tidal triggering strength may provide useful insight into the stress state of the system. The large number of earthquakes over an extended time period allows us to look at spatiotemporal variation in tidal triggering strength and microearthquake distribution to infer the stress state of the system with unprecedented temporal coverage and resolution. We will present comparisons of observations at the two sites.

  2. Reproductive patterns of blacktail comber ( Serranus atricauda, Serranidae) from south-west Portugal seamounts

    Science.gov (United States)

    Neves, Ana; Sequeira, Vera; Paiva, Rafaela Barros; Vieira, Ana Rita; Gordo, Leonel Serrano

    2014-03-01

    The knowledge of the reproductive strategy is essential for the comprehensive understanding of the population dynamics of any fish species. This study intends to define the spawning season, verify the type of fecundity regulation and estimate relative annual fecundity for Serranus atricauda inhabiting the south-west of Portugal seamounts (Gorringe, Ampère and Lion). Monthly samples, between September 2010 and December 2011, were obtained from commercial vessels. This species is synchronously hermaphroditic, and mature individuals were found all year round, with gonadosomatic index peak from February to September. No clear relation between hepatosomatic index and Fulton's condition factor and gonadal development was found, and therefore, it is probable that reproductive success depends more on environmental conditions and food availability during the spawning season than on body energy reserves. No gap exists between pre-vitellogenic and vitellogenic oocytes and the oocyte size-frequency distribution during the main spawning season show no dominant cohort progressing through time. The number of standing stock of advanced vitellogenic oocytes showed an increase trend along the spawning season decreasing only at its end and the relative intensity of α-atresia was always low throughout this period with an increase towards the end. All these criteria corroborate the indeterminate fecundity type assigned to S. atricauda in previous studies. Mean relative annual fecundity estimated was 5,655 ± 4,321 oocytes per gram of gutted weight.

  3. Les enseignantes et enseignants sont-ils égaux face aux contraintes organisationnelles au sein des établissements du second degré ?

    OpenAIRE

    Cau-Bareille, Dominique

    2016-01-01

    Cet article présente une partie des résultats d’une recherche-action menée en France dans le champ de l’enseignement du second degré à la demande de deux syndicats. Celle-ci visait à comprendre les rapports de genre au sein des établissements et à éclairer les problèmes de harcèlement au travail évoqués plutôt par des femmes. Nous aborderons ici cette problématique sous l’angle des formes d’engagements dans l’activité professionnelle, en croisant le modèle ergonomique de l’activité de travail...

  4. Uses of biogas produced by digestion of wastewater sludge. The SIAAP's experience feedback and projects; Utilisation du biogaz issu de la digestion des boues d'epuration des eaux residuaires urbaines. Retour d'experience et projets du SIAAP

    Energy Technology Data Exchange (ETDEWEB)

    Amosse, S. [SIAAP - Dir. du Site Seine Aval, 78 - Maisons Laffite (France); Nedelec, R. [SIAAP, Dir. du Developpement et de la Prospective, 92 - Colombes (France)

    2010-07-01

    The SIAAP, in charge of the purification of the Great Paris wastewaters (8 M inhabitants), handles 2.7 Mm{sup 3}/day. Five wastewater treatment plants permit to dean these wastewaters before they are discharged into the receiving environment: 'Seine Aval' (Acheres, 1,7 Mm{sup 3}/day), 'Seine Amont' (Valenton, 600 000 m{sup 3}/day), 'Seine Centre' (Colombes, 240 000 m{sup 3}/day), 'Seine Gresillons' (Triel-sur-Seine, 100 000 m{sup 3}/day) and 'Marne Aval' (Noisy-Le-Grand, 40 000 m{sup 3}/day). Biogas produced by digestion of sludge provides a part of the energy required by the five sewage treatment works. Energy recovered from biogas have been used by the SAV site since 1940. As soon as the first part of this plant started up, biogas was used as fuel to heat digester, to produce power through biogas engines and to drive blowers. In the 60's and 70's, dual-fuel engines were brought into service, and then in 1992, a gas turbine was installed. Nowadays, a combined heat and power (cogeneration) project is in progress with the installation of two gas turbines, each generating 5 MW. All of these installations had allowed a 70% energetic autonomy ratio on 'Seine Aval' site. Then, new treatment units were introduced. Thus, energy consumption has increased, with only 60 % of energy demands being covered. By 2020, a complete make-over of the 'Seine Aval' plant will be done. This should allow to cover about 70% of energy demands, partly thanks to biogas reuse. New plants are currently being constructed. All of them will include sludge digestion process providing biogas. With the 'Seine Gresillons' plant upgrading, digestion process will occur on site. Biogas will be used in a cogeneration system to produce both electricity (that would be either used on site or sold commercially, this has not been decided by now) and heat for digesters heating. The new 'Seine Moree' plant will be

  5. HOBIT-The new Hamburg Ocean Bottom Tiltmeter: A First Deployment at Columbo Seamount, Aegean Sea

    Science.gov (United States)

    Hort, M.; Hensch, M.; Winter, S.; Dahm, T.

    2007-12-01

    Assessing the state of activity of subaerial volcanoes is already quite a difficult task, but assessing the activity of submarine seamounts is even more complicated due to the difficulty of deploying instruments. At land various techniques can be used including seismic networks, deformation studies, gas measurements and others. At sea, it is mainly seismological observations, which are used to assess volcanic activity safe for some measurements with tiltmeters. However, especially at land deformation studies using INSAR have proven to be very valuable in determining recharge of magmatic systems. We therefore developed a free fall, self leveling ocean bottom tiltmeter mounted in a 17 inch glass sphere to observe deformation on the ocean floor. For measuring tilt signals we use a two component high resolution tiltmeter manufactured by Lipmann Geophysikalische Messgeräte (www.l-gm.de). The instrument has a resolution of about 1nrad (0.15μ°) and a maximum signal of about 0.045 rad (0.5°) can be detected. It is mounted on a levelling stage, which can relevel the instrument between ± 5° down to an accuracy of 0.006°. During the measurement this leveling stage is standing on the bottom of the glass sphere. For releveling purposes the instrument can be pulled up by very thin nylon strings and then is looked to a gimbal system in order to compensate for tilt >5°. This releveling procedure is done once every 48 hours. The data are recorded on an 18bit (at 50Hz sampling rate) MLS Geolon logger (www.send.de). Once deployed the instruments sleeps for a prescribed amount of time before the first levelling procedure is initiated. In addition to the tiltmeter and a hydrophone for receiving seismic signals, temperature, absolute pressure (paroscientific pressure sensor) to measure possible uplift or subsidence, and orientation (electronic compass mounted to the system) are monitored. 4 HOBIT systems were deployed for ten months (Jun06-Mar07) at Columbo seamount, a submarine

  6. Hafnium Isotopic Variations in Central Atlantic Intraplate Volcanism

    Science.gov (United States)

    Geldmacher, J.; Hanan, B. B.; Hoernle, K.; Blichert-Toft, J.

    2008-12-01

    Although one of the geochemically best investigated volcanic regions on Earth, almost no Hf isotopic data have been published from the broad belt of intraplate seamounts and islands in the East Atlantic between 25° and 36° N. This study presents 176Hf/177Hf ratios from 61 representative samples from the Canary, Selvagen and Madeira Islands and nearby large seamounts, encompassing the full range of different evolutionary stages and geochemical endmembers. The majority of samples have mafic, mainly basaltic compositions with Mg-numbers within or near the range of magmas in equilibrium with mantle olivine (68-75). No correlation was found between Mg-number and 176Hf/177Hf ratios in the data set. In comparison to observed Nd isotope variations published for this volcanic province (6 ɛNd units), 176Hf/177Hf ratios span a larger range (14 ɛHf units). Samples from the Madeira archipelago have the most radiogenic compositions (176Hf/177Hfm= 0.283132-0.283335), widely overlapping the field for central Atlantic N-MORB. They form a relatively narrow, elongated trend (stretching over >6 ɛHf units) between a radiogenic MORB-like endmember and a composition located on the Nd-Hf mantle array. In contrast, all Canary Islands samples plot below the mantle array (176Hf/177Hfm = 0.282943-0.283067) and, despite being from an archipelago that stretches over a much larger geographic area, form a much denser cluster with less compositional variation (~4 ɛHf units). All samples from the seamounts NE of the Canaries, proposed to belong to the same Canary hotspot track (e.g. Geldmacher et al., 2001, JVGR 111; Geldmacher et al., 2005, EPSL 237), fall within the Hf isotopic range of this cluster. The cluster largely overlaps the composition of the proposed common mantle endmember 'C' (Hanan and Graham, 1996, Science 272) but spans a space between a more radiogenic (depleted) composition and a HIMU-type endmember. Although samples of Seine and Unicorn seamounts, attributed to the Madeira

  7. Assessing the relation between anthropogenic pressure and PAH concentrations in surface water in the Seine River basin using multivariate analysis

    Energy Technology Data Exchange (ETDEWEB)

    Uher, Emmanuelle, E-mail: emmanuelle.uher@irstea.fr [Irstea, UR HBAN Hydrosystèmes et bioprocédés, 1 rue Pierre-Gilles de Gennes, CS 10030, 92761 Antony cedex (France); FIRE, FR-30204 place Jussieu, 75005 Paris (France); Mirande-Bret, Cécile [LISA, 61 avenue du général de Gaulle, 94010 Créteil (France); Gourlay-Francé, Catherine [Anses, 14 rue Pierre et Marie Curie, 94701 Maisons-Alfort Cedex (France)

    2016-07-01

    Understanding the relation between polycyclic aromatic hydrocarbons (PAHs) in freshwater and anthropogenic pressure is fundamental to finding a solution to reduce the presence of PAHs in water, and thus their potential impact on aquatic life. In this paper we propose to gain greater insight into the variability, sources and partitioning of PAHs in labile (or freely dissolved = not associated to the organic matter), dissolved and particulate phases in freshwater. This study was conducted using land use data as a marker of anthropogenic pressure and coupling it with chemical measurements. This study was conducted on 30 sites in the Seine River basin, which is subjected to a strong human impact and exhibits a wide range of land uses. Half of the sites were studied twice. Labile PAHs were measured by semi-permeable membrane devices (SPMDs), and dissolved and particulate phases by grab samples. Partial least squares regressions were performed between chemical measurements and data of anthropogenic pressure. The results indicate different sources for the dissolved phase and particles. Dissolved and labile phases were more related to the population density of the watershed, while particles were more related to a local pressure. Season and land use data are necessary information to correctly interpret and compare PAH concentrations from different sites. Furthermore, the whole data set of the 45 field deployments comprising labile, dissolved, total and particulate PAH concentrations as well as the physico-chemical parameters is available in the supplementary information. - Highlights: • A large-scale deployment of semi-permeable membrane devices was performed at the Seine Catchment scale • Partial least squares regressions were performed between chemical measurements and data of anthropogenic pressure • The results seem to show a PAHs release from particles to dissolved phase slower than in laboratory work • Dissolved and labile phases were related to a pressure at

  8. Annie Crépin, Vers l’armée nationale. Les débuts de la conscription en Seine-et-Marne, 1798-1815

    OpenAIRE

    Catros, Philippe

    2014-01-01

    Spécialiste incontestée de l’histoire sociale du fait militaire au XIXe siècle, Annie Crépin nous propose un nouvel ouvrage dans le prolongement de ses précédents travaux sur la conscription. Son étude est centrée sur la Seine-et-Marne, particulièrement propice à l’étude des conscrits pour avoir fait partie des départements ayant pleinement accepté les levées décidées par l’Empereur. L’auteur a largement puisé dans les archives du Service historique de la Défense – registres matricules des ré...

  9. Explosive processes during the 2015 eruption of Axial Seamount, as recorded by seafloor hydrophones

    Science.gov (United States)

    Caplan-Auerbach, J.; Dziak, R. P.; Haxel, J.; Bohnenstiehl, D. R.; Garcia, C.

    2017-04-01

    Following the installation of the Ocean Observatories Initiative cabled array, the 2015 eruption of Axial Seamount, Juan de Fuca ridge, became the first submarine eruption to be captured in real time by seafloor seismic and acoustic instruments. This eruption also marked the first instance where the entire eruption cycle of a submarine volcano, from the previous eruption in 2011 to the end of the month-long 2015 event, was monitored continuously using autonomous ocean bottom hydrophones. Impulsive sounds associated with explosive lava-water interactions are identified within hydrophone records during both eruptions. Explosions within the caldera are acoustically distinguishable from those occurring in association with north rift lava flows erupting in 2015. Acoustic data also record a series of broadband diffuse events, occurring in the waning phase of the eruption, and are interpreted as submarine Hawaiian explosions. This transition from gas-poor to gas-rich eruptive activity coincides with an increase in water temperature within the caldera and with a decrease in the rate of deflation. The last recorded diffuse events coincide with the end of the eruption, represented by the onset of inflation. All the observed explosion signals couple strongly into the water column, and only weakly into the solid Earth, demonstrating the importance of hydroacoustic observations as a complement to seismic and geodetic studies of submarine eruptions.

  10. Dinoflagellate cyst assemblages from two contrasting sites in the Azores (Portugal) - Horta Bay and D. João de Castro Seamount

    DEFF Research Database (Denmark)

    Ribeiro, Sofia; Amorim, Ana

    , to prevent cyst germination. Laboratory procedures involved wet sieving of ca. 20ml of sediment per site and concentration by centrifugation using a heavy-liquid, to maximize the recovery of the cyst fraction. Permanent slides were mounted with aliquots of the rich cyst fraction and examined under the light...... belonging to 15 different taxa were recovered. The 2 sites had a similar species richness (S=11) but different trophic and taxa composition. The embayment sample (Horta Harbour) was rich in Protoperidinium and Scrippsiella-like cysts (with no and -like cysts (with no calcareous walls probably due...... observed Protoceratium reticulatum maximum abundances in maximum abundances in shelf and slope-rise zone sediments. The fact that D. João de Castro Bank was dominated by recently formed cysts of this species suggests that this seamount constitutes an ecological niche which favours coastal...

  11. Microbial Diversity in Hydrothermal Surface to Sub-surface Environment of Suiyo Seamount

    Science.gov (United States)

    Higashi, Y.; Sunamura, M.; Kitamura, K.; Kurusu, Y.; Nakamura, K.; Maruyama, A.

    2002-12-01

    After excavation trials to a hydrothermal subsurface biosphere of the Suiyo Seamount, Izu-Bonin Arc, microbial diversity was examined using samples collected from drilled boreholes and natural vents with an catheter-type in situ microbial entrapment/incubator. This instrument consisted of a heat-tolerant cylindrical pipe with entrapment of a titanium-mesh capsule, containing sterilized inorganic porous grains, on the tip. After 3-10 day deployment in venting fluids with the maximum temperatures from 156 to 305degC, Microbial DNA was extracted from the grains and a 16S rDNA region was amplified and sequenced. Through the phylogenetic analysis of total 72 Bacteria and 30 Archaea clones, we found three novel phylogenetic groups in this hydrothermal surface to subsurface biosphere. Some new clades within the epsilon-Proteobacteria, which seemed to be microaerophilic, moderate thermophilic, and/or sulfur oxidizing, were detected. Clones related to moderate thermophilic and photosynthetic microbes were found in grain-attached samples at collapsed borehole and natural vent sites. We also detected a new clade closely related to a hyperthermophilic Archaea, Methanococcus jannashii, which has the capability of growing autotrophically on hydrogen and producing methane. However, the later two phylogroups were estimated as below a detection limit in microscopic cell counting, i.e., fluorescence in situ hybridization and direct counting. Most of microbes in venting fluids were assigned to be Bacteria, but difficult in specifying them using any known probes. The environment must be notable in microbial and genetic resources, while the ecosystem seems to be mainly supported by chemosynthetic products through the microbial sulfur oxidation, as in most deep-sea hydrothermal systems.

  12. The exclusion of the body in Sein und Zeit and the denial of a phenomenology of the body in Heidegger’s thought

    Directory of Open Access Journals (Sweden)

    Felipe Johnson

    2016-05-01

    Full Text Available Through a reflection on the lack of a detailed thematization of the human body in Sein und Zeit and, considering the denial of a «phenomenology of the body» in Zollikoner Seminare, this paper aims to develop the methodical advice behind Heidegger’s treatment of human corporality. In this context, we will emphasize the incompatibility between the kind of being of Dasein and the kind of being that make up the traditional interpretation of the body: the body as a thing. Based on the foregoing, this study will discuss on the necessity to concentrate the attention on the ontological belonging of the body to the being of human being by the attempt to deploy an existential consideration of human corporality.

  13. Epibenthic communities of sedimentary habitats in a NE Atlantic deep seamount (Galicia Bank)

    Science.gov (United States)

    Serrano, A.; Cartes, J. E.; Papiol, V.; Punzón, A.; García-Alegre, A.; Arronte, J. C.; Ríos, P.; Lourido, A.; Frutos, I.; Blanco, M.

    2017-12-01

    Galicia Bank is a deep seamount included as Site of Community Importance (SCI) in the Spanish Natura 2000 Network proposal. In the present study, epibenthic assemblages of sedimentary habitats have been described, together with the main environmental factor explaining species and communities distribution. Five epibenthic assemblages have been identified. Depth was the main factor explaining assemblage distribution, and the role of sediment type, water masses, and coral framework presence is also discussed. Three assemblages are located in the summit: the shallowest one (730-770 m), in the boundary between Eastern North Atlantic Central Water (ENACW) and Mediterranean Overflow Water (MOW) water masses is typified by ophiuroids and characterized by medium sands. The second assemblage (770-800 m) typified by the bivalve Limopsis minuta and the solitary coral Flabellum chunii correspond with medium sands and MOW core; and the third typified by the presence of cold-water coral communities dominated by Lophelia pertusa and Madrepora oculata, also on the MOW influence. In the border of the summit, in the bank break, an assemblage located in the range 1000-1200 m is dominated by the urchin Cidaris cidaris and the sponge Thenea muricata. In the flat flanks around the bank, the deepest assemblage (1400-1800 m) is dominated by the holothurian Benthogone rosea, in a depth range dominated by the Labrador water (LSW) and in fine sands with highest contents of organic matter. Most of species appeared in a depth range smaller than 25% of total depth range sampled and in bank.

  14. Subseafloor nitrogen redox processes at Loihi Seamount, Hawai

    Science.gov (United States)

    Wankel, S. D.; Sylvan, J. B.; LaRowe, D.; Huber, J. A.; Moyer, C. L.; Edwards, K. J.

    2014-12-01

    Loihi seamount is a mid-plate hotspot volcano located 30 kilometers off the southeast corner of the Big Island of Hawai'i. We measured temperature, concentrations of nitrate + nitrite (NOx), ammonium (NH4+), nitrite (NO2-) and dissolved silica (dSi), as well as the stable N and O isotopic composition of nitrate (δ15N and δ18O) in end-member hydrothermal fluids and microbial mats during three cruises in 2008, 2009 and 2013. We also sequenced 16S rRNA from archaea and bacteria from the same sites during 2006. NH4+ ranged ~0.71-7.5 μM, was positively correlated to dSi and negatively correlated to NOx. NO2- ranged from below detection to 0.49 μM and was not correlated to NOx, dSi or NH4+. In the microbial mats found at the Ula Nui site at 5000 m, NO2-, dSi and NH4+ all increase with depth in the mat, creating a vertical zonation of niches within these mounds. Measured δ15N and δ18O of nitrate suggest biological production and reduction of nitrate are both occurring. Analysis of δ15N-NH4+ is underway and will help constrain the relative magnitude of nitrification to NO2- and the potential for N-fixation. Using the measured concentrations of NOx, NO2- and NH4+ and other published data from Loihi, Gibbs energy calculations reveal that several catabolic strategies involving the reduction of NO3- and NO2- could provide energy to microbes in Loihi fluids. Thermodynamically feasible electron donors including HS-, CH4, Fe2+ and NH4+, and the amount of energy available, in units of Joules per kg H2O, varies by orders of magnitude from one sample site to the next. Pyrosequencing of the V6 region of bacterial and archaeal 16S rRNA from four sites at Loihi detected groups known to participate in denitrification, N-fixation and NO2- oxidation. Among these, the most abundant putative N-reducing microbes include Caldithrix, Epsilonproteobacteria, Thiohalophilus and members of the SAR324 clade. Putative N-fixers detected include members of the bacterial order Chlorobiales and

  15. Origin of seamount volcanism in northeast Indian Ocean with emphasis on Christmas Island

    Science.gov (United States)

    Taneja, R.; O'Neill, C.; Rushmer, T. A.; Jourdan, F.; Blichert-Toft, J.; Turner, S.; Lackie, M. A.

    2012-12-01

    The Northeast Indian Ocean has been a central point of research in the recent past due to its intraplate geophysical and geochemical characteristics. It is dominated by sub-aerial volcanic islands and submerged guyots and two islands, namely, Cocos (Keeling) Island and Christmas Island. Christmas Island, the focus of this study, consists of limestone and mafic intraplate volcanics. The origin of most of the features in northeast Indian Ocean is not fully understood. Christmas Island has experienced multiple stages of intraplate volcanic activity as previously established by 40Ar/39Ar radioisotopic analyses of basalts from the island (Hoernl et al., 2011). Here, we present new 40Ar/39Ar ages where the rock samples from Waterfall Spring (WS), Ethel Beach (EB) & Dolly Beach (DB) on the east coast of the island yielded plateau and mini-plateau ages of 37.75±0.77 Ma, 37.10±0.66 Ma and 43.37±0.45 Ma respectively, whereas a sample from Flying Fish Cove (FFC) in the north of the island yielded a minimum age of 38.6±0.5 Ma. All these units are part of the Lower Volcanics Series. The samples from the west coast (Winifred Beach, WB) are younger with an age of 4.32 ± 0.17 Ma, and are part of the Upper Volcanic Series. This confirms two stages of volcanism at the island with a gap of around 38 Ma. The 40Ar/39Ar radioisotopic ages were overlayed on Gplates and seismic tomography models to determine its paleo motion. The present position of the island is 10.5°S, 105.5°E. During Eocene its reconstructed position was 30°S latitude. Seismic tomography models have highlighted a low velocity zone beneath the island during Eocene. Geochemically, the two volcanic suites (Upper & Lower) are mostly similar in their major and trace element composition. The majority of localities (WS, EB, and WB) are basanites; where as that from Dolly Beach is basaltic. The Dale's (west coast), are trachyte and appear evolved with high SiO2. They also have low Ba and Sr ~25ppm, whereas those from

  16. Deep-sea benthic habitats modeling and mapping in a NE Atlantic seamount (Galicia Bank)

    Science.gov (United States)

    Serrano, A.; González-Irusta, J. M.; Punzón, A.; García-Alegre, A.; Lourido, A.; Ríos, P.; Blanco, M.; Gómez-Ballesteros, M.; Druet, M.; Cristobo, J.; Cartes, J. E.

    2017-08-01

    This study presents the results of seafloor habitat identification and mapping of a NE Atlantic deep seamount. An ;assemble first, predict later; approach has been followed to identify and map the benthic habitats of the Galicia Bank (NW Iberian). Biotic patterns inferred from the survey data have been used to drive the definition of benthic assemblages using multivariate tools. Eight assemblages, four hard substrates and four sedimentary ones, have been described from a matrix of structural species. Distribution of these assemblages was correlated with environmental factors (multibeam and backscatter data) using binomial GAMs. Finally, the distribution model of each assemblage was applied to produce continuous maps and pooled in a final map with the distribution of the main benthic habitats. Depth and substrate type are key factors when determining soft bottom communities, whereas rocky habitat distribution is mainly explained by rock slope and orientation. Enrichment by northern water masses (LSW) arriving to GB and possible zooplankton biomass increase at vertical-steep walls by ;bottom trapping; can explain the higher diversity of habitat providing filter-feeders at slope rocky breaks. These results concerning vulnerable species and habitats, such as Lophelia and Madrepora communities and black and bamboo coral aggregations were the basis of the Spanish proposal of inclusion within the Natura 2000 network. The aim of the present study was to establish the scientific criteria needed for managing and protecting those environmental values.

  17. IMPLICATION DE CERTAINES MUTATIONS DANS LES GENES BRCA1 ET BRCA2 SUR LA PRÉDISPOSITION AU CANCER DU SEIN ET AU CANCER OVARIEN

    Directory of Open Access Journals (Sweden)

    Lucian Negura

    2007-08-01

    Full Text Available Le cancer du sein, ainsi que celui ovarien, est une maladie fréquente chez les femmes, ayant un traitement assez difficile et, malheureusement, de sérieuses répercutions sur le physique ; c’est pourquoi il s’avère essentiel que la maladie soit dépistée dès les phases précoces. La prédisposition génétique est responsable de 5% des cancers et de 25% des cas apparus avant l’age de 30 ans [Breast Cancer Linkage Consortium, 1997]. Nous présentons ici l’implication des gènes suppresseurs des tumeurs BRCA1 et BRCA2 sur cette prédisposition.

  18. LA DIVERSITÃ DÃPLOYÃE AU SEIN DE LâUNIVERSITÃ DâENTREPRISE : LâAPPLICATION CONCRÃTE DâUNE VALEUR ADOPTÃE PAR LA DIRECTION GÃNÃRALE

    Directory of Open Access Journals (Sweden)

    Virginia Drummond-Guitel

    2009-09-01

    Full Text Available La diversité devenue une valeur incontournable adoptée par les grands groupes, encore faut-t-il trouver les moyens concrets pour lâintégrer dans les pratiques des ressources humaines et dans les mentalités des personnes. Le présent papier a pour but de montrer comment les valeurs de la diversité adoptées par la direction générale ont été déclinées et appliquées dans un processus de sélection de candidats pour une formation continue au sein dâune grande organisation internationale. A travers lâapplication dâune méthode qualitative de recherche, 10 (dix dirigeants ayant conçu la formation et 42 (quarante-deux managers ayant suivi le programme confirment lâatteinte du but stratégique de cette formation, autrement dit, lâatteinte dâune vision partagée (SENGE, 1991, à travers la consolidation dâun fort sentiment dâappartenance à la culture organisationnelle (SCHEIN, 1995. Les managers ont été sélectionnés selon leurs différentes professions, cultures nationales et différents secteurs dâactivités, confirmant ainsi une promotion de la diversité au sein de lâorganisation.

  19. Lessons from Suiyo Seamount studies, for understanding extreme (ancient?) microbial ecosystems in the deep-sea hydrothermal fields

    Science.gov (United States)

    Maruyama, A.; Higashi, Y.; Sunamura, M.; Urabe, T.

    2004-12-01

    Deep-sea hydrothermal ecosystems are driven with various geo-thermally modified, mainly reduced, compounds delivered from extremely hot subsurface environments. To date, several unique microbes including thermophilic archaeons have been isolated from/around vent chimneys. However, there is little information about microbes in over-vent and sub-vent fields. Here, we report several new findings on microbial diversity and ecology of the Suiyo Seamount that locates on the Izu-Bonin Arc in the northwest Pacific Ocean, as a result of the Japanese Archaean Park project, with special concern to the sub-vent biosphere. At first, we succeeded to reveal a very unique microbial ecosystem in hydrothermal plume reserved within the outer rim of the seamount crater, that is, it consisted of almost all metabolically active microbes belonged to only two Bacteria phylotypes, probably of sulfur oxidizers. In the center of the caldera seafloor (ca. 1,388-m deep) consisted mainly of whitish sands and pumices, we found many small chimneys (ca. 5-10 cm) and bivalve colonies distributed looking like gray to black patches. These geo/ecological features of the seafloor were supposed to be from a complex mixing of hydrothermal venting and strong water current near the seafloor. Through quantitative FISH analysis for various environmental samples, one of the two representative groups in the plume was assessed to be from some of the bivalve colonies. Using the Benthic Multi-coring System (BMS), total 10 points were drilled and 6 boreholes were maintained with stainless or titanium casing pipes. In the following submersible surveys, newly developed catheter- and column-type in situ growth chambers were deployed in and on the boreholes, respectively, for collecting indigenous sub-vent microbes. Finally, we succeeded to detect several new phylotypes of microbes in these chamber samples, e.g., within epsilon-Proteobacteria, a photosynthetic group of alpha-Proteobacteria, and hyperthermophile

  20. First data on the age of rocks from the central part of the Vitoria-Trindade Ridge (Brazil Basin, South Atlantic)

    Science.gov (United States)

    Skolotnev, S. G.; Bylinskaya, M. E.; Golovina, L. A.; Ipat'eva, I. S.

    2011-03-01

    Micropaleontological and isotope-geochronological investigations of calcareous sedimentary rocks and volcanites dredged out from the central portion of the submarine Vitoria-Trindade Ridge during the 24th cruise of R/V Akademik Vavilov have been conducted. It has been established based on micropaleontological analysis, which included determination of the species composition of foraminifera and nannoplankton, that the sequence of sedimentary rocks having a pelagic nature formed on the slopes of the volcanic seamounts in the central portion of the Vitoria-Trindade Ridge from the Early to Mid-Miocene to the Holocene; a good correlation between the degree of lithification of these rocks and their age is observed. It has also been established that the carbonate platforms on the abraded tops of the Davis Seamount and the Dogaressa Bank, which are located in the east-central portion of the Vitoria-Trindade Ridge, started forming in the Early Miocene (19-24 Ma). It has been determined using local U-Pb dating of zircon grains with a SHRIMP-II high resolution secondary ion mass spectrometer that the volcanites forming the upper portion of the volcanic rock sequence of the Jaseur Seamount (29.8 ± 6.6 Ma) located in the west-central portion of the Vitoria-Trindade Ridge date to the Oligocene. The investigations conducted have confirmed the opinion that the Vitoria-Trindade Ridge formed in general because of the activity of the hot spot located under the volcanic Trindade and Martin Vaz Islands. However, separate extended lenticular segments of this ridge existed for a long time as single structures, within which the age of the seamounts was not linearly dependent on the distance from the location of the hot spot. Lenses of hot mantle matter that form at the sublithospheric level as a result of impulses of plume activity and move along with the lithospheric plate play a defining role in the development of individual segments forming the Vitoria-Trindade Ridge.

  1. Impacts of Climate Change and of Anthropisation on Water Resources: from the Risk Assessment to Adaptation, the Case of the Seine Basin (including Paris, France)

    Science.gov (United States)

    Habets, F.; Viennot, P.; Thierion, C.; Vergnes, J. P.; Ait Kaci, A.; Caballero, Y.

    2015-12-01

    The Seine river, located in the temperate climate of northern France and flowing over a large sedimentary basins that hosts multilayer aquifers, is characterized by small temporal variations of its discharge. However, the presence of a megacity (Paris) and a wide area of intensive agriculture combined with climate change puts pressure on the water resources both in terms of quality and quantity. Previous research projects have estimated the impact of climate change on the water resource of the Seine basin, with the uncertainties associated to climate projections, hydrological models or downscaling methods. The water resource was projected to decrease by -14 % ± 10 % in 2050 and -28 +/-16% in 2100. This led to new studies that focus on the combined impact of climate change and adaptations. The tested adaptations are: a reduction of the groundwater abstractions, evolution of land use, development of small dams to « harvest water » or artificial recharge of aquifers. The communication of the results of these projects to stakeholders have led to the development on new indicators that better express the risk on the water resource management, especially for the groundwater. For instance maps of the evolution of piezometric head are difficult to interpret. To better express the risk evolution, a new indicator was defined: the evolution of the groundwater crisis duration, ie, the period when the charge of the aquifer is below the crisis piezometric level defined by the stakeholders. Such crisis piezometric levels are used to help defining the period when the groundwater abstraction should be reduced. Such maps are more efficient to communicate with water resources managers. This communication will focus on the results from the MEDDE Explore 2070 and ANR Oracle projects.

  2. JPRS Report Science & Technology Japan STA 1988 White Paper Part 2.

    Science.gov (United States)

    1989-12-13

    capability to survey a broad area of the sea and to reach seamounts of gorges unaccessible to a manned submersible. The construction of a 6,000- meter...development of a technique to measure long-term changes in the environment and the national ecosystem, including the earth-wide environmental and ecological ...Japanese 31 Jan 89 pp 1-499 [Selected portions of the 1988 STA Science and Technology White Paper] CONTENTS Chapter III. Government Policy 1

  3. Parcellaires fossoyés du Haut Empire des plateaux de Brie : Jossigny/Serris et Moissy-Cramayel (Seine-et-Marne. Approche méthodologique de l'étude des réseaux Ditch-marked land division from the Early Roman Empire, the Brie plateau: Jossigny/Serris and Moissy-Cramayel (Seine-et-Marne. Methodological approach to the study of networks

    Directory of Open Access Journals (Sweden)

    Gilles Desrayaud

    2009-05-01

    Full Text Available Deux opérations archéologiques préventives à Jossigny/Serris et à Moissy-Cramayel en Seine-et-Marne (Île-de-France ont permis de révéler l’existence de réseaux de fossés gallo-romains sur plusieurs dizaines d’hectares. Des zones d’habitat et/ou d’activités ont également été décelées. Les bases de ces réseaux sont posées pendant la fin du Ier s. av. J.-C. ou la première moitié du Ier s. ap. J.-C. Au cours du IIIe s. ap. J.-C., les secteurs d’occupation et les fossés sont abandonnés. Ces fossés, pour la plupart rectilignes et couvrant parfois plusieurs centaines de mètres de longueur, pouvaient remplir la triple fonction de drain, de limite parcellaire et d’enclos de contention/protection. Leurs morphologies ainsi que leurs contextes pédologiques et topographiques semblent traduire une volonté de drainage des sols, pouvant correspondre à une mise en culture. Une méthodologie visant à l’analyse des orientations et des localisations des axes supposés des vestiges linéaires (fossés, murs, chemins… a été développée. Elle a permis d'émettre l'hypothèse d'ensembles “ orthogonaux ” contemporains. Des études comparatives et statistiques ont également été menées sur la possible existence de modules de distance et de surface. Il semble que les superficies des lopins enclos “ orthogonaux ” aient pu être fondées sur des modules correspondant ou se rapprochant d’unités antiques connues. Pour les deux sites étudiés, ces éléments nous paraissent constituer de forts indices de la présence d’un réseau de drainage agricole correspondant à un découpage parcellaire au moins en partie orthonormé.Two rescue archaeology excavations, near the French villages of Jossigny/Serris and Moissy-Cramayel (Paris area, Seine-et-Marne, have revealed the presence of Gallo-Roman ditch networks covering tens of acres. Activity areas and/or habitation sites have also been detected. The bases of

  4. Dynamics of phytoplankton productivity and exopolysaccharides (EPS and TEP) pools in the Seine Estuary (France, Normandy) over tidal cycles and over two contrasting seasons.

    Science.gov (United States)

    Morelle, Jérôme; Schapira, Mathilde; Claquin, Pascal

    2017-10-01

    Exopolysaccharides (EPS) play an important role in the carbon flux and may be directly linked to phytoplankton and microphytobenthos production, most notably in estuarine systems. However the temporal and spatial dynamics of estuarine EPS are still not well understood, nor how primary productivity triggers this variability at these different scales. The aim of this study was to investigate the primary productivity of phytoplankton and EPS dynamics in the Seine estuary over a tidal cycle in three different haline zones over two contrasted seasons. The other objectives was to investigate the origin of pools of soluble carbohydrates (S-EPS) and transparent exopolymeric particles (TEP) in phytoplankton, microphytobenthos or other compartments. High frequency measurements of productivity were made in winter and summer 2015. Physical and chemical parameters, biomass and EPS were measured at hourly intervals in sub-surface waters and just above the water sediment-interface. Our results confirmed that high frequency measurements improve the accuracy of primary productivity estimations and associated carbon fluxes in estuaries. The photosynthetic parameters were shown to be strongly controlled by salinity and by the concentrations of suspended particle matter at the smallest temporal and at spatial scales. At these scales, our results showed an inverse relationship between EPS concentrations and biomass and productivity, and a positive relationship with sediment resuspension. Additionally, the distribution of EPS appears to be linked to hydrodynamics with the tide at daily scale and with the winter at seasonal scale. At spatial scale, the maximum turbidity zone played an important role in the distribution of TEP. Our results suggest that, in the Seine estuary, between 9% and 33% of the S-EPS pool in the water column can be attributed to phytoplankton excretion, while only 0.4%-1.6% (up to 6.14% in exceptional conditions) originates from the microphytobenthos compartments

  5. Molecular biomineralization: toward an understanding of the biogenic origin of polymetallic nodules, seamount crusts, and hydrothermal vents.

    Science.gov (United States)

    Wang, Xiaohong; Wiens, Matthias; Schröder, Heinz C; Schloßmacher, Ute; Müller, Werner E G

    2011-01-01

    Polymetallic nodules and crusts, hydrothermal vents from the Deep Sea are economically interesting, since they contain alloying components, e.g., manganese or cobalt, that are used in the production of special steels; in addition, they contain rare metals applied for plasma screens, for magnets in hard disks, or in hybrid car motors. While hydrothermal vents can regenerate in weeks, polymetallic nodules and seamount crusts grow slowly. Even though the geochemical basis for the growth of the nodules and crusts has been well studied, the contribution of microorganisms to the formation of these minerals remained obscure. Recent HR-SEM (high-resolution scanning electron microscopy) analyses of nodules and crusts support their biogenic origin. Within the nodules, bacteria with surface S-layers are arranged on biofilm-like structures, around which Mn deposition starts. In crusts, coccoliths represent the dominant biologically formed structures that act as bio-seeds for an initial Mn deposition. In contrast, hydrothermal vents have apparently an abiogenic origin; however, their minerals are biogenically transformed by bacteria. In turn, strategies can now be developed for biotechnological enrichment as well as selective dissolution of metals from such concretions. We are convinced that the recent discoveries will considerably contribute to our understanding of the participation of organic matrices in the enrichment of those metals and will provide the basis for feasibility studies for biotechnological applications.

  6. Mémoire du travail et des expositions professionnelles aux cancérogènes Work account and occupational exposures to carcinogens. Survey in Seine-Saint-Denis (France Memoria del trabajo y de las exposiciones profesionales a agentes cancerígenos. Encuesta en Seine-Saint-Denis (Francia

    Directory of Open Access Journals (Sweden)

    Annie Thébaud-Mony

    2010-11-01

    Full Text Available Selon les estimations officielles, en 2000 environ 32 millions de travailleurs européens (de l’Europe des 15 étaient exposés à des cancérogènes. Depuis 2002, considérant la maladie comme « événement-sentinelle » pour la connaissance des activités de travail exposant aux cancérogènes, le Groupement d’intérêt scientifique sur les cancers d’origine professionnelle (GISCOP93 mène une enquête permanente auprès de patients atteints de cancer en Seine Saint Denis (France. S’appuyant sur les récits recueillis auprès des patients et sur l’expertise des spécialistes en matière d’exposition, une démarche d’analyse et de classement des activités exposées a été réalisée pour l’élaboration d’un répertoire des activités de travail en présence de produits/procédés cancérogènes. L’objectif de cet article est de mettre en perspective cette nouvelle base de données par rapport à quelques sources d’information concernant l’exposition professionnelle aux cancérogènes, déjà disponibles en ligne, en montrant l’apport d’une méthode de recueil d’information fondée sur l’expérience et la parole des travailleurs.According to official estimates, in the year 2000, approximately 32 million European workers (in Europe 15 were exposed to carcinogens. Since 2002, considering the disease as a "sentinel-event" for understanding the work activities that expose workers to carcinogens, the GISCOP93 research group has been carrying out an ongoing survey on patients with cancer in Seine-Saint-Denis (France. Based on the patients’ narratives and on the expertise of exposure hazard specialists, an analysis and classification of the exposed working activities was carried out to build a new database of work activities in the presence of carcinogenic products/processes. The aim of this article is to present this database in relation to some other sources of information on occupational exposure to carcinogens

  7. Cloud amount/frequency, NITRATE and other data from NEW HORIZON in the NE Pacific from 1989-08-19 to 1989-09-01 (NODC Accession 9200079)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Conductivity, Temperature and Depth (CTD) and other data were collected in NE Pacific (limit-180) as part of Fieberling Seamount project. Data was collected from...

  8. Fine-grained sediment spatial distribution on the basis of a geostatistical analysis: Example of the eastern Bay of the Seine (France)

    Science.gov (United States)

    Méar, Y.; Poizot, E.; Murat, A.; Lesueur, P.; Thomas, M.

    2006-12-01

    The eastern Bay of the Seine (English Channel) was the subject in 1991 of a sampling survey of superficial sediments. Geostatistic tools were used to examine the complexity of the spatial distribution of the fine-grained fraction (discussed. Within this sedimentary unit, the distribution of the fine fraction is very heterogeneous, with mud patches of less than 4000 m diameter; the boundary between these mud patches and their substratum is very sharp. The distribution of this fine fraction appears to be controlled by an anticyclonic eddy located off the Pays de Caux. Under the influence of this, the suspended material expelled from the Seine estuary moves along the coast and swings off Antifer harbour, towards the NW. It is trapped within this eddy because of the settling of suspended particulate matter. Both at a general scale and a local scale the morphology (whether inherited or due to modern processes) has a strong influence on the spatial distribution of the fine fraction. At the general scale, the basin-like shape of the area facilitates the silting, and the presence of the submarine dunes, called "Ridins d'Antifer", clearly determines the northern limit of the muddy zone. At a local scale, the same influence is obvious: paleovalleys trap the fine sediments, whereas isolated sand dunes and ripples limit the silting. This duality of role of the morphology is therefore one of the reasons why the muddy surface is extremely heterogeneous spatially. The presence of an important population of suspension feeding echinoderm, the brittle-star Ophiothrix fragilis Abildgaard, has led to a local increase in the silting, and to the modification of the physicochemical and sedimentological parameters. A complex relationship is shown to occur between the amount of fine fraction and the number of brittle-stars (ind. m -2). Classical statistical methods are not appropriate to study the spatial distribution of the mud fraction, because the spatial component of the percentage of

  9. Colonial life under the Humboldt Current System: deep-sea corals from O'Higgins I seamount La vida colonial bajo el sistema de la corriente de Humboldt: corales de aguas profundas en el monte submarino O'Higgins I

    OpenAIRE

    Juan I Cañete; Verena Haussermann

    2012-01-01

    A benthic community constituted by an assemblage of at least four species of deep-sea corals collected in only one trawl carried-out on the summit of the O'Higgins I seamount, central Chile. The corals were collected in only one trawl carried-out during a Chilean-Japanese cruise onboard the R/V" Koyo Maru" in December 29, 2004. Presence of oxygenated and cold Antarctic Intermediate Water (>400 m depth) on the plateau was recorded under of the Equatorial Subsurface Water associated to the oxyg...

  10. An experimental study on dredge spoil of estuarine sediments in the bay of seine (France): A morphosedimentary assessment

    Science.gov (United States)

    Marmin, Stella; Lesueur, Patrick; Dauvin, Jean Claude; Samson, Sandrine; Tournier, Patrice; Gallicher Lavanne, Albert; Dubrulle-Brunaud, Carole; Thouroude, Coralie

    2016-03-01

    Studies on the consequences of dredging on estuarine morphology and its sedimentary dynamics are common, but the impacts of dumping dredge spoil in coastal open settings are rarely found in scientific literature. An experimental study was conducted over the period 2012-2013 to monitor the physical impacts of dredged material dumped at two adjacent sites (one million cubic metres at each) on the inner shelf of the Bay of Seine in France (eastern part of the English Channel, La Manche). As recently reinforced in the EU Marine Strategy Framework Directive (MSFD), knowledge on the location and intensity of human impacts (e.g. on marine ecosystems) is critical for effective marine management and conservation. So, two methods of disposition were tested to evaluate the impacts of dumping on the environment and thus propose recommendations for future dumping. The strategy is based on a Before-After-Control-Impact (BACI) approach, in which the spatio-temporal variability was studied by analysing the morphological and sedimentological characteristics over a period of 28 months, from November 2011 to April 2014, also including recovery of the seafloor after cessation of the dumping activities. The first experimental dumping operation (MASED) was carried out regularly for 8 months at a single point and generating a conical deposit of 5 m in height, while the second dumping (MABIO) lasted for 12 months involving four steps in the dumping process. In the second case, a wider area was covered, leading to the formation of a smaller deposit of 2 m in height. The dumped deposits consisted of muddy fine sand, whereas the inner shelf seafloor in this area is covered with fine to medium sand. As a result, muddy fine sand accumulated at or near the two dumping sites, with a maximum mud (i.e. particles4 Φ) content of 50% compared todredged material remained at the end of the dumping periods. After dumping ceased, a further 5% of material for MABIO and 20% for MASED, was transported out

  11. L'Escarpement de Malte, le mont Alfeo et les monts de Médine: marges anciennes du bassin Ionien (synthèse des données des campagnes a la mer Escarmed Malta Escarpment, Alfeo and Medina Seamounts: Former Margins of the Ionian Basin

    Directory of Open Access Journals (Sweden)

    Groupe Escarmed

    2006-11-01

    caractéristiques, une forte déclivité et une couverture sédimentaire peu épaisse à une morphogénèse complexe car polyphasée. En effet, en plus du facteur lithologique (parois calcaires imposantes, il y a un facteur tectonique essentiel : l'évolution d'une marge continentale mésozoïque réactivée par des phases tectoniques plus récentes, essentiellement Miocène et Plio-Quaternaire. C'est cette originalité qui distingue l'escarpement de Malte et les monts de Médine des autres marges méditerranéennes occidentales et qui permet leur comparaison avec d'autres marges continentales, atlantiques par exemple. The Comité d'Etudes Pétrolières Marines (CEPM and the Centre National pour I'Exploitation des Océans (CNEXO have carried out a series of subsea surveys of Ionian escarpments to define their origin, age and evolution. The results given here concern the Malta escarpment, the Alfeo and Medina seamounts west and southwest of the deep Ionian basin. They include bathymetric data in the form of a 1:100,000th map accompanying the text, a morphological analysis of reliefs, stratigraphic determinations performed on samples gathered by dredging, coring or diving, a structural analysis from seismic-reflection profiles and dives, and a study of subsidence since the Upper Triassic from actual boreholes drilled in the Maltese shelf and fictitious boreholes on the edge of the Malta escarpment. The conclusions bring out:(a the existence of calcareous platform series of early Jurassic age for the Malta escarpment and the Alfeo seamount and of early Cretaceous age for the Medina seamounts;(b a major paleogeographic change starting in the late Jurassic for the Malta escarpment and in the Albian for the Medina seamounts;(c the development of condensed series dating from this paleogeographic change and the presence of constant erosion until the Present, an erosion in which the various processes have numerous consequences on the sedimentation of such reliefs;(d four main

  12. Microbiological characterization of post-eruption "snowblower" vents at Axial Seamount, Juan de Fuca Ridge

    Directory of Open Access Journals (Sweden)

    Julie L Meyer

    2013-06-01

    Full Text Available Microbial processes within the subseafloor can be examined during the ephemeral and uncommonly observed phenomena known as snowblower venting. Snowblowers are characterized by the large quantity of white floc that is expelled from the seafloor following mid-ocean ridge eruptions. During these eruptions, rapidly cooling lava entrains seawater and hydrothermal fluids enriched in geochemical reactants, creating a natural bioreactor that supports a subseafloor microbial bloom. Previous studies hypothesized that the eruption-associated floc is made by sulfide-oxidizing bacteria; however, the microbes involved were never identified. Here we present the first molecular analysis combined with microscopy of microbial communities in snowblower vents from samples collected shortly after the 2011 eruption at Axial Seamount, an active volcano on the Juan de Fuca Ridge. We obtained fluid samples and white flocculent material from active snowblower vents as well as orange flocculent material found on top of newly formed lava flows. Both flocculent types revealed diverse cell types and particulates when examined by phase contrast and scanning electron microscopy. Distinct archaeal and bacterial communities were detected in each sample type through Illumina tag sequencing of 16S rRNA genes and through sequencing of the sulfide oxidation gene, soxB. In fluids and white floc, the dominant bacteria were sulfur-oxidizing Epsilonproteobacteria and the dominant archaea were thermophilic Methanococcales. In contrast, the dominant organisms in the orange floc were Gammaproteobacteria and Thaumarchaeota Marine Group I. In all samples, bacteria greatly outnumbered archaea. The presence of anaerobic methanogens and microaerobic Epsilonproteobacteria in snowblower communities provides evidence that these blooms are seeded by subseafloor microbes, rather than from microbes in bottom seawater. These eruptive events thus provide a unique opportunity to observe subseafloor

  13. The underwater acoustic environment at SGaan Kinghlas-Bowie Seamount Marine Protected Area: Characterizing vessel traffic and associated noise using satellite AIS and acoustic datasets.

    Science.gov (United States)

    Allen, Ainsley S; Yurk, Harald; Vagle, Svein; Pilkington, James; Canessa, Rosaline

    2018-03-01

    Vessel traffic is one of the most wide-spread anthropogenic contributors to ocean noise worldwide and has the potential to alter ecosystems upon which cetaceans and other acoustically sensitive marine organisms rely. Canada's SGaan Kinghlas-Bowie Seamount Marine Protected Area (SK-B MPA) is one such area whose productive ecosystem could benefit from greater monitoring of human induced threats in order to inform management. Despite earning official designation as a Marine Protected Area under the Oceans Act in 2008, little remains known about vessel traffic in the region and the associated potential impacts on vulnerable marine species. Therefore, to increase our understanding of vessel traffic and accompanying noise at SK-B MPA, satellite AIS and acoustic data were investigated. The results of this study suggest that variations in ambient sound levels in the region are driven by near and distant shipping events, thus having implications for future management of the MPA. Copyright © 2018 Elsevier Ltd. All rights reserved.

  14. Hydrodynamic characteristics of knotted and knotless purse seine netting panels as determined in a flume tank.

    Science.gov (United States)

    Tang, Hao; Xu, Liuxiong; Hu, Fuxiang

    2018-01-01

    Nylon (PA) netting is widely used in purse seines and other fishing gears due to its high strength and good sinking performance. However, hydrodynamic properties of nylon netting of different characteristics are poorly understood. This study investigated hydrodynamic characteristics of nylon netting of different knot types and solidity ratios under different attack angles and flow velocities. It was found that the hydrodynamic coefficient of netting panels was related to Reynolds number, solidity ratio, attack angle, knot type and twine construction. The solidity ratio was found to positively correlate with drag coefficient when the netting was normal to the flow (CD90), but not the case when the netting was parallel to the flow (CD0). For netting panels inclined to the flow, the inclined drag coefficient had a negative relationship with the solidity ratio for attack angles between 0° and 50°, but a positive relationship for attack angles between 50° and 90°. The lift coefficient increased with the attack angle, reaching the culminating point at an attack angle of 50°, before subsequent decline. We found that the drag generated by knot accounted for 15-25% of total drag, and the knotted netting with higher solidity ratio exhibited a greater CD0, but it was not the case for the knotless netting. Compared to knotless polyethylene (PE) netting, the drag coefficients of knotless PA netting were dominant at higher Reynolds number (Re>2200).

  15. Hydrodynamic characteristics of knotted and knotless purse seine netting panels as determined in a flume tank.

    Directory of Open Access Journals (Sweden)

    Hao Tang

    Full Text Available Nylon (PA netting is widely used in purse seines and other fishing gears due to its high strength and good sinking performance. However, hydrodynamic properties of nylon netting of different characteristics are poorly understood. This study investigated hydrodynamic characteristics of nylon netting of different knot types and solidity ratios under different attack angles and flow velocities. It was found that the hydrodynamic coefficient of netting panels was related to Reynolds number, solidity ratio, attack angle, knot type and twine construction. The solidity ratio was found to positively correlate with drag coefficient when the netting was normal to the flow (CD90, but not the case when the netting was parallel to the flow (CD0. For netting panels inclined to the flow, the inclined drag coefficient had a negative relationship with the solidity ratio for attack angles between 0° and 50°, but a positive relationship for attack angles between 50° and 90°. The lift coefficient increased with the attack angle, reaching the culminating point at an attack angle of 50°, before subsequent decline. We found that the drag generated by knot accounted for 15-25% of total drag, and the knotted netting with higher solidity ratio exhibited a greater CD0, but it was not the case for the knotless netting. Compared to knotless polyethylene (PE netting, the drag coefficients of knotless PA netting were dominant at higher Reynolds number (Re>2200.

  16. Tidal influence on the distribution of hydrophobic organic contaminants in the Seine Estuary and biomarker responses on the copepod Eurytemora affinis

    Energy Technology Data Exchange (ETDEWEB)

    Cailleaud, K. [Universite Bordeaux 1, CNRS, ISM-LPTC-UMR 5255, Laboratory of Physico- and Toxico-Chemistry, 351 Cours de la Liberation, 33405 Talence (France) and Universite des Sciences et Technologies de Lille - Lille 1, Laboratoire d' Oceanologie et de Geosciences, UMR CNRS 8187 LOG, Station Marine de Wimereux, 28 Avenue Foch, 62930 Wimereux (France) and Faculte des Sciences et Techniques du Havre, LEMA-UPRES EA3222, Laboratoire d' Ecotoxicologie-Milieux Aquatiques, GDR IMOPHYS, 25 rue Philippe Lebon, 76058 Le Havre (France); Forget-Leray, J. [Faculte des Sciences et Techniques du Havre, LEMA-UPRES EA3222, Laboratoire d' Ecotoxicologie-Milieux Aquatiques, GDR IMOPHYS, 25 rue Philippe Lebon, 76058 Le Havre (France); Peluhet, L.; LeMenach, K. [Universite Bordeaux 1, CNRS, ISM-LPTC-UMR 5255, Laboratory of Physico- and Toxico-Chemistry, 351 Cours de la Liberation, 33405 Talence (France); Souissi, S. [Universite des Sciences et Technologies de Lille - Lille 1, Laboratoire d' Oceanologie et de Geosciences, UMR CNRS 8187 LOG, Station Marine de Wimereux, 28 Avenue Foch, 62930 Wimereux (France); Budzinski, H. [Universite Bordeaux 1, CNRS, ISM-LPTC-UMR 5255, Laboratory of Physico- and Toxico-Chemistry, 351 Cours de la Liberation, 33405 Talence (France)], E-mail: h.budzinski@ism.u-bordeaux1.fr

    2009-01-15

    To elucidate tidally related variations of hydrophobic organic contaminant (HOC) bioavailability and the impact of these contaminants on estuarine ecosystems, both PCB and PAH concentrations were investigated in the dissolved phase and in the suspended particulate material (SPM) of the Seine Estuary. Both PAH and PCB highest levels were observed in surface and bottom water when SPM remobilizations were maximum, in relation to higher speed currents. In parallel, acetylcholinesterase (AChE) and glutathione-S-transferase (GST) activities were investigated in the copepod Eurytemora affinis. Significant decreasing AChE levels were measured during the tidal cycle and between surface and bottom copepods related to salinity and to HOC concentration variations. Significant increasing GST levels were also observed when HOC concentrations in the water column were the highest. This study underlined the need to standardize sampling procedures for biomonitoring studies in order to avoid interfering factors that could modify biomarker responses to chemical exposure. - Variations of contamination of E. affinis and enzymatic responses have been studied over a tide cycle in view to improve the use of this copepod for biomonitoring.

  17. Tidal influence on the distribution of hydrophobic organic contaminants in the Seine Estuary and biomarker responses on the copepod Eurytemora affinis

    International Nuclear Information System (INIS)

    Cailleaud, K.; Forget-Leray, J.; Peluhet, L.; LeMenach, K.; Souissi, S.; Budzinski, H.

    2009-01-01

    To elucidate tidally related variations of hydrophobic organic contaminant (HOC) bioavailability and the impact of these contaminants on estuarine ecosystems, both PCB and PAH concentrations were investigated in the dissolved phase and in the suspended particulate material (SPM) of the Seine Estuary. Both PAH and PCB highest levels were observed in surface and bottom water when SPM remobilizations were maximum, in relation to higher speed currents. In parallel, acetylcholinesterase (AChE) and glutathione-S-transferase (GST) activities were investigated in the copepod Eurytemora affinis. Significant decreasing AChE levels were measured during the tidal cycle and between surface and bottom copepods related to salinity and to HOC concentration variations. Significant increasing GST levels were also observed when HOC concentrations in the water column were the highest. This study underlined the need to standardize sampling procedures for biomonitoring studies in order to avoid interfering factors that could modify biomarker responses to chemical exposure. - Variations of contamination of E. affinis and enzymatic responses have been studied over a tide cycle in view to improve the use of this copepod for biomonitoring

  18. Relationship between spatial distribution of chaetognaths and hydrographic conditions around seamounts and islands of the tropical southwestern Atlantic.

    Science.gov (United States)

    Souza, Christiane S de; Luz, Joana A G; Mafalda, Paulo O

    2014-09-01

    Relationship between spatial distribution of chaetognaths and hydrographic conditions around seamounts and islands off Northeastern Brazil were analyzed from 133 oceanographic stations during the months of January - April of 1997 and April - July of 1998. Oblique zooplankton tows, using 50 cm diameter Bongo nets with 500µm mesh with a flowmeter to determine the filtered volume, were carried out to a maximum of 200m depth. The Superficial Equatorial Water, which had a salinity > 36 PSU and temperature > 20°C, occupied the top 80 to 200m depth. Below this water mass was the South Atlantic Central Water with salinity ranging from 34.5 to 36 PSU and temperature from 6 to 20°C. The community of chaetognaths showed six species: Pterosagitta draco, Flaccisagitta enflata, Flaccisagitta hexaptera, Pseudosagitta lyra, Serratosagitta serratodentata, and Sagitta helenae. Of these species, F. enflata was the most abundant (32.05% in 1997 and 42.18% in 1998) and the most frequent (87.88% in 1997 and 95% in 1998) during both periods. A mesopelagic specie was identified (P. lyra). This specie was more abundant in 1997 (3.42%), when the upwelling was more intense. P. lyra occurred in 22% of the samples during 1997. The abundance of F. enflata, an epiplanktonic species, increased, associated with greater water-column stability.

  19. Relationship between spatial distribution of chaetognaths and hydrographic conditions around seamounts and islands of the tropical southwestern Atlantic

    Directory of Open Access Journals (Sweden)

    CHRISTIANE S. DE SOUZA

    2014-09-01

    Full Text Available Relationship between spatial distribution of chaetognaths and hydrographic conditions around seamounts and islands off Northeastern Brazil were analyzed from 133 oceanographic stations during the months of January – April of 1997 and April – July of 1998. Oblique zooplankton tows, using 50 cm diameter Bongo nets with 500µm mesh with a flowmeter to determine the filtered volume, were carried out to a maximum of 200m depth. The Superficial Equatorial Water, which had a salinity > 36 PSU and temperature > 20°C, occupied the top 80 to 200m depth. Below this water mass was the South Atlantic Central Water with salinity ranging from 34.5 to 36 PSU and temperature from 6 to 20°C. The community of chaetognaths showed six species: Pterosagitta draco, Flaccisagitta enflata, Flaccisagitta hexaptera, Pseudosagitta lyra, Serratosagitta serratodentata, and Sagitta helenae. Of these species, F. enflata was the most abundant (32.05% in 1997 and 42.18% in 1998 and the most frequent (87.88% in 1997 and 95% in 1998 during both periods. A mesopelagic specie was identified (P. lyra. This specie was more abundant in 1997 (3.42%, when the upwelling was more intense. P. lyra occurred in 22% of the samples during 1997. The abundance of F. enflata, an epiplanktonic species, increased, associated with greater water-column stability.

  20. Pelagic ecology of the South West Indian Ocean Ridge seamounts: Introduction and overview

    Science.gov (United States)

    Rogers, A. D.

    2017-02-01

    of globally significant areas of seamounts, submarine plateaus, continental and island slopes.

  1. Contribution of heterotrophic bacterial production to the carbon budget of the river Seine (France).

    Science.gov (United States)

    Servais, P; Garnier, J

    1993-01-01

    Bacterial activity was measured in the river Seine by two methods, (3)H-thymidine incorporation into DNA and (3)H-leucine incorporation into proteins. Both incorporation rates are characterized by low values upstream of Paris, a large increase just downstream of the outfall of the Achères treatment plant effluents, and then decreasing values further downstream. The covariation of both activities is demonstrated by the constancy of the molar ratio (leucine to thymidine incorporation rate) in the range of 6 to 8 for all the samples, except in the perturbed area where it is higher (15 to 35). These high values of molar ratio are linked to the introduction into the river of large sized bacteria ([Symbol: see text]1 µm) with higher incorporation rates per cell or biomass unit than the small autochthonous bacteria (rates of large bacteria were on average 3.7 times higher than those of small bacteria. Bacterial production was calculated with experimentally determined conversion factors (0.5 × 10(18) cells per mole of thymidine incorporated and 900 gC per mole of leucine incorporated) and by taking into account the activity of both size classes of bacteria measured through fractionation experiments (post-incubation filtration). Production estimated in the perturbed area downstream of Ach6res was very high, up to 60 µgC liter(-1)h(-1) in the summer. Carbon consumption by bacteria in the area perturbed by the Ach6res effluents was calculated assuming a growth yield of 0.2 and compared to the load of biodegradable organic matter discharged by the treatment plant. In summer, an additional supply of organic matter is required to account for the intense bacterial activity, suggesting the importance of phytoplankton production in the carbon budget.

  2. Cancers du sein bilatéraux synchrones et grossesse a l'institut Joliot Curie de Dakar (Sénégal)

    Science.gov (United States)

    Zongo, Nayi; Sawadogo, Yobi Alexis; Some, Some Ollo Roland; Bagre, Sidpawalmdé Carine; Ka, Sidy; Diouf, Doudou; Dieng, Mamadou Moustapha; Gaye, Papa Macoumba; Dem, Ahmadou

    2016-01-01

    Décrire notre stratégie diagnostique et thérapeutique dans les cancers du sein bilatéraux synchrones pendant la grossesse. L’âge gestationnel au moment du diagnostic du cancer était respectivement de 7; 21 et 25 semaines. Il s'agissait de stade IV et IIIA respectivement dans deux et un cas. Elles ont toutes bénéficié d'une chimiothérapie dans deux cas pendant la grossesse (6TEC et 3AC) et dans un cas après l'accouchement. Une mastectomie bilatérale a été réalisée dans un cas. Une patiente est décédée. Les autres étaient vivantes mais toutes métastatiques. Une hypotrophie fœtale a été notée dans un cas. Le diagnostic du cancer est tardif dans cette association. La chirurgie est faisable et le type de chirurgie serait seulement fonction du stade du cancer. La chimiothérapie est possible avec moins de complications fœtales aux deux derniers trimestres. PMID:27279967

  3. Les oléoprotéagineux dans les systèmes de culture : évolution des assolements et des successions culturales depuis les années 1970 dans le bassin de la Seine

    Directory of Open Access Journals (Sweden)

    Schott Céline

    2010-09-01

    Full Text Available For the last forty years oilseed and high-protein crops have undergone important changes in terms of area and localisation in France. On the Seine basin example, we show that the specialisation of the farming systems and the agricultural regions has strongly changed the cropping patterns by reducing grasslands which were replaced by a constant increase of the wheat area in a one hand and by a dramatic increase, from the eighties, of the rapeseed, field pea and sunflower areas in another hand. Then from the nineties, rapeseed has gradually replaced field pea and sunflower, the areas of which have fallen. The decrease in the number of cultivated species has led to a clear trend to the simplification and the shortening of the crop successions: short crop successions based on rapeseed (as rapeseedwheat- barley or rapeseed-wheat-wheat and cereal successions (as wheat-wheat-wheat, wheatwheat- barley or wheat-barley-barley have strongly increased on the Seine basin over the last twenty years. The crop succession shortening, that causes crop protection problems towards weeds, insects or diseases, is only possible in relation with an intensive use of pesticides: thus the increase of the rapeseed area is positively correlated with the increase of the average number of plant pest controls, especially with herbicides. These agricultural dynamics have negative impacts on environment and enhance the economical risks the farms have to cop with. As a consequence, a new crop diversification, supported by policy-making and agricultural production networks, seems to be a strong future issue.

  4. Internal waves and modern and ancient hiatuses in pelagic caps of Pacific guyots and seamounts

    Science.gov (United States)

    Mitchell, Neil; Simmons, Harper; Lear, Carrie

    2013-04-01

    Locations of recent non-deposition and ancient hiatuses in the pelagic caps of guyots and seamounts are compared with paleotemperature and physiographic information to speculate on the character of internal tidal waves in the upper Pacific Ocean through the Cenozoic. Internal tidal waves are generated where the ocean barotropic tide passes over the Hawaiian and other major ridges in the Pacific basin. Drill core and geophysical evidence for sediment accumulation, non-deposition or erosion are used to classify broadly sites as either accumulating or eroding/non-depositing in the recent geological past. When these classified sites are compared against results of a numerical model of the internal tide field (Simmons, Ocean Mod. 2008), the sites accumulating particles over the past few million years are all found to lie away from beams of the modeled internal tide, while those that have not been accumulating are in areas of high internal wave energy. Given the correspondence to modern internal wave conditions, we examine whether internal tides can explain ancient hiatuses at the drill sites. For example, Late Cenozoic pelagic caps on guyots among the Marshall Islands contain two hiatuses of broadly similar age, but the dates of the first pelagic sediments deposited following each hiatus do not correlate between guyots, suggesting that they originate not from universal factors (e.g., water chemistry) but local, probably physical factors, such as internal tides. We investigate how changing boundary conditions such as ocean temperature and basin physiography may have affected the geometry and vigour of internal tides through the Cenozoic. Changes in the geometry of ridges underlying the Solomon, Bonin and Marianas Island chains caused by plate tectonics and subsidence may be responsible for sediment hiatuses at these far-field guyot sites.

  5. The isotope systematics of a juvenile intraplate volcano: Pb, Nd, and Srisotope ratios of basalts from Loihi Seamount, Hawaii

    International Nuclear Information System (INIS)

    Staudigel, H.; Zindler, A.; Leslie, T.

    1984-01-01

    Sr, Nd, and Pb isotope ratios for a representative suite of 15 basanites, alkali basalts, transitional basalts and tholeiites from Loihi Seamount, Hawaii, display unusually large variations for a single volcano, but lie within known ranges for Hawaiian basalts. Nd isotope ratios in alkali basalts show the largest relative variation (0.51291 - 0.51305), and include the nearly constant tholeiite value (approx.= 0.51297). Pb isotope ratios show similarly large ranges for tholeiites and alkali basalts and continue Tatsumoto's [31] 'Loa' trend towards higher 206 Pb/ 204 Pb, ratios, resulting in a substantial overlap with the 'Kea' trend. 206 Pb/ 204 Pb ratios for Loihi and other volcanoes along the Loa and Kea trends [31] are observed to correlate with the age of the underlying lithosphere suggesting lithosphere involvement in the formation of Hawaiian tholeiites. Loihi lavas display no correlation of Nd, Sr, or Pb isotope ratios with major element compositions or eruptive age, in contrast with observations of some other Hawaiian volcanoes. Isotope data for Loihi, as well as average values for Hawaiian volcanoes, are not adequately explained by previously proposed two-end-member models; new models for the origin and the development of Hawaiian volcanoes must include mixing of at least three geochemically distinct source regions and allow for the involvement of heterogeneous oceanic lithosphere. (orig.)

  6. Skipjack Tuna Availability for Purse Seine Fisheries Is Driven by Suitable Feeding Habitat Dynamics in the Atlantic and Indian Oceans

    Directory of Open Access Journals (Sweden)

    Jean-Noël Druon

    2017-10-01

    Full Text Available An Ecological Niche model was developed for skipjack tuna (Katsuwonus pelamis, SKJ in the Eastern Central Atlantic Ocean (AO and Western Indian Ocean (IO using an extensive set of presence data collected by the European purse seine fleet (1998–2014. Chlorophyll-a fronts were used as proxy for food availability while mixed layer depth, sea surface temperature, dissolved oxygen, salinity, current intensity, and height anomaly variables were selected to describe SKJ's abiotic environmental preferences. The resultant ecological niche included both mesoscale eddy-type productive features that displayed latitudinal range in the IO to large scale upwelling systems that shrink and swell seasonally in the AO. Overall, 83% of all free swimming school sets (FSC and 75% of drifting fish aggregating device sets (dFAD that contained SKJ occurred within 25 km of favorable feeding habitat. In the AO, 34% of dFAD sets were made more than 100 km away from this habitat, mostly in the surface chlorophyll-a poor environment of the Guinea Current. These distant sets represent 10% of dFAD sets in the IO and 8% of all FSC sets. Our results suggest that the Mozambique Channel in the IO, with its simultaneously favorable feeding and spawning conditions, may seasonally offer a better SKJ nursery habitat than the Guinea Current which shows a substantially poorer feeding capacity. With the exception of this latter area, our results also suggest that fishing accessibility will be higher in months where the size of the favorable feeding habitats are reduced, likely because this reduction drives a geographical contraction in SKJ populations. The observed relationship between the annual size of favorable feeding habitat and both annual catch rates and total catches in the IO is consistent with the near-full exploitation of this stock that has occurred since the 2000s. Moreover, it suggests that annual habitat size could be used as an indicator of growth capacity for this

  7. Montes submarinos de Nazca y Salas y Gómez: una revisión para el manejo y conservación Seamounts of Nazca and Salas y Gómez: a review for management and conservation purposes

    Directory of Open Access Journals (Sweden)

    Mauricio Gálvez-Larach

    2009-01-01

    Full Text Available Con motivo de la creciente preocupación internacional por el manejo y conservación de ecosistemas marinos vulnerables, entre los que se cuentan los montes submarinos y los corales de aguas frías de las cordilleras de Nazca y Salas y Gómez, y en vista de la inminente creación de la Organización Regional de Administración Pesquera del Pacifico Sur, se hace necesaria una revisión de los principales antecedentes científicos sobre estas cadenas montañosas como un insumo para la toma de decisiones. El presente documento atiende dicha necesidad considerando los aspectos geológicos, oceanógraficos, biológicos, ecológicos y pesqueros asociados a Nazca y, Salas y Gómez, junto con identificar las opciones de manejo. A pesar que los estudios en el área son escasos y fragmentados, se destaca su particularidad debido a los altos niveles de ende-mismo, alta diversidad de especies, alta concentración de montes submarinos, presencia de corales de aguas frías, mayor nivel de productividad en relación a las aguas circundantes y su potencialidad para actividades de océano-minería y pesca de fondo. Debido a la lejanía del área y los altos costos involucrados, una mayor cooperación internacional se requerirá para abordar futuros estudios, al tiempo que la creación de una red de Á-reas Marinas Protegidas se identifica como la mejor opción para el manejo y conservación.Due to growing international awareness of the importance of the conservation and management of vulnerable marine ecosystems - of which the seamounts and deep-sea corals of the Nazca and Salas y Gómez submarine ridges are examples - and taking into account the imminent establishment of a South Pacific Regional Fisheries Management Organization, a scientific review of this seamount chain is needed to provide input for decision-making processes. This paper provides such a review, considering geological, oceanographic, biological, ecological, and fisheries issues associated with

  8. High Resolution Seismic Images of Transition Zone Discontinuities beneath the Hawaii-Emperor Seamount Chain

    Science.gov (United States)

    Cao, Q.; Wang, P.; van der Hilst, R. D.; Shim, S.

    2009-12-01

    Taking advantage of the abundance of natural sources (earthquakes) in western Pacific subduction zones and the many seismograph stations in the Americas, we use inverse scattering - a generalized Radon transform - of SS precursors to image the transition zone discontinuities underneath Hawaii and the Hawaii-Emperor seamount chain. The GRT makes use of scattering theory and extracts structural information from broad band data windows that include precursors to SS (which are the specular reflections at the discontinuities that form the main arrivals) as well as non-specular scattered energy (which is often discarded as noise). More than 150,000 seismograms (from the IRIS Data Management Center) are used to form a 3-D image of the transition zone discontinuities beneath the central Pacific. In addition to clear signals near 410, 520, and 660 km depth, the data also reveal scatter interfaces near 370 km dept and between 800-1000 km depth, which may be regional, laterally intermittent scatter horizons. Our images reveal a conspicuous uplift of the 660 discontinuity in a region of 800km in diameter to the west of the active volcanoes of Hawaii. No correspondent localized depression of the 410 discontinuity is found. Instead, we find a smaller scale anomaly suggesting that the 410 discontinuity is locally elevated in the same region. This may indicate the presence of melt or minor chemical constitutes. The lack of correlation between and differences in lateral length scale of the topographies of the 410 and 660 km discontinuities are also consistent with a deep-mantle plume impinging on the transition zone, creating a pond of hot material underneath 660 discontinuity, and with secondary plumes connecting to the present-day hotspot at Earth’s surface. Our observations suggest that more complicated plume morphology and plume dynamics within the Earth's mantle should be taken into account to describe the plumes and, in particular, mass transport across the transition zone

  9. Systematics of Alkali Metals in Pore Fluids from Serpentinite Mud Volcanoes: IODP Expedition 366

    Science.gov (United States)

    Wheat, C. G.; Ryan, J.; Menzies, C. D.; Price, R. E.; Sissmann, O.

    2017-12-01

    IODP Expedition 366 focused, in part, on the study of geo­chemical cycling, matrix alteration, material and fluid transport, and deep biosphere processes within the subduction channel in the Mariana forearc. This was accomplished through integrated sampling of summit and flank regions of three active serpentinite mud volcanoes (Yinazao (Blue Moon), Asùt Tesoro (Big Blue), and Fantangisña (Celestial) Seamounts). These edifices present a transect of depths to the Pacific Plate, allowing one to characterize thermal, pressure and compositional effects on processes that are associated with the formation of serpentinite mud volcanoes and continued activity below and within them. Previous coring on ODP Legs 125 and 195 at two other serpentinite mud volcanoes (Conical and South Chamorro Seamounts) and piston, gravity, and push cores from several other Mariana serpentinite mud volcanoes add to this transect of sites where deep-sourced material is discharged at the seafloor. Pore waters (149 samples) were squeezed from serpentinite materials to determine the composition of deep-sourced fluid and to assess the character, extent, and effect of diagenetic reactions and mixing with seawater on the flanks of the seamounts as the serpentinite matrix weathers. In addition two Water Sampler Temperature Tool (WSTP) fluid samples were collected within two of the cased boreholes, each with at least 30 m of screened casing that allows formations fluids to discharge into the borehole. Shipboard results for Na and K record marked seamount-to-seamount differences in upwelling summit fluids, and complex systematics in fluids obtained from flank sites. Here we report new shore-based Rb and Cs measurements, two elements that have been used to constrain the temperature of the deep-sourced fluid. Data are consistent with earlier coring and drilling expeditions, resulting in systematic changes with depth (and by inference temperature) to the subduction channel.

  10. Faciliter la transition vers un système de gestion électronique des documents: retour d'expérience du déploiement en cours au sein de l'hôpital neuchâtelois

    OpenAIRE

    Beuret, Dominique; Gurtner, Jean-Luc; Thiébaud, Marc

    2016-01-01

    Mettre en place un système de gestion électronique des documents (GED) n'est pas un long fleuve tranquille, encore moins dans une structure aussi complexe qu'un hôpital réunissant plusieurs milliers de collaborateurs. Son impact structurant bouleverse l'organisation du travail, les habitudes et les pratiques des collaborateurs. Ce travail de certificat étudie les réactions générées au sein de l'hôpital neuchâtelois dans le contexte du déploiement d'une GED et se penche plus particulièrement s...

  11. Unexpected HIMU-type late-stage volcanism on the Walvis Ridge

    Science.gov (United States)

    Homrighausen, S.; Hoernle, K.; Geldmacher, J.; Wartho, J.-A.; Hauff, F.; Portnyagin, M.; Werner, R.; van den Bogaard, P.; Garbe-Schönberg, D.

    2018-06-01

    Volcanic activity at many oceanic volcanoes, ridges and plateaus often reawakens after hiatuses of up to several million years. Compared to the earlier magmatic phases, this late-stage (rejuvenated/post-erosional) volcanism is commonly characterized by a distinct geochemical composition. Late-stage volcanism raises two hitherto unanswered questions: Why does volcanism restart after an extended hiatus and what is the origin of this volcanism? Here we present the first 40Ar/39Ar age and comprehensive trace element and Sr-Nd-Pb-Hf isotopic data from seamounts located on and adjacent to the Walvis Ridge in the South Atlantic ocean basin. The Walvis Ridge is the oldest submarine part of the Tristan-Gough hotspot track and is famous as the original type locality for the enriched mantle one (EM I) end member. Consistent with the bathymetric data, the age data indicates that most of these seamounts are 20-40 Myr younger than the underlying or nearby Walvis Ridge basement. The trace element and isotope data reveal a distinct compositional range from the EM I-type basement. The composition of the seamounts extend from the St. Helena HIMU (high time-integrated 238U/204Pb mantle with radiogenic Pb isotope ratios) end member to an enriched (E) Mid-Ocean-Ridge Basalt (MORB) type composition, reflecting a two-component mixing trend on all isotope diagrams. The EMORB end member could have been generated through mixing of Walvis Ridge EM I with normal (N) MORB source mantle, reflecting interaction of Tristan-Gough (EM I-type) plume melts with the upper mantle. The long volcanic quiescence and the HIMU-like geochemical signature of the seamounts are unusual for classical hotspot related late-stage volcanism, indicating that these seamounts are not related to the Tristan-Gough hotspot volcanism. Two volcanic arrays in southwestern Africa (Gibeon-Dicker Willem and Western Cape province) display similar ages to the late-stage Walvis seamounts and also have HIMU-like compositions

  12. Acide alpha-linolénique, anti-oxydants et croissance tumorale mammaire

    Directory of Open Access Journals (Sweden)

    Chajes Véronique

    2000-01-01

    Full Text Available En France, comme dans la plupart des pays occidentaux, le cancer du sein est la première cause de mortalité, avec un nombre annuel de décès proche de 10 000. Chez les femmes, le cancer du sein est celui dont le taux d’incidence est le plus élevé dans la plupart des pays occidentaux. En France, il y a approximativement 35 000 nouveaux cas chaque année. Le taux d’incidence est de 80 pour 100 000 femmes/an. Il existe une disparité géographique dans les taux d’incidence du cancer du sein. Ils sont élevés dans tous les pays développés, à l’exception du Japon et de la Chine. Ajusté sur l’âge, il est le plus élevé aux États-Unis, et le plus bas en Chine, en Inde, au Japon. La France se situe à une position intermédiaire en Europe. L’incidence du cancer du sein est globalement plus faible dans les pays du Sud de l’Europe. Cette disparité géographique ne peut pas être expliquée uniquement par les facteurs génétiques. L’étude des populations migrantes, dont les taux d’incidence du cancer du sein se modifient pour atteindre celui du pays dans lequel elles migrent, a permis de mettre en évidence le rôle des facteurs environnementaux dans l’apparition du cancer du sein. Parmi ceux-là, la part de l’alimentation est estimée à environ 35 % (entre 20 à 60 %, en fonction du site du cancer [1]. Il existe donc un réel potentiel de prévention du cancer du sein, sous réserve que les aliments protecteurs soient mis en évidence et que les nutriments responsables de ces effets protecteurs soient individualisés.

  13. Buffering of suspended sediment transport in lowland river during low water stages: quantification in river Seine using environmental radionuclides

    International Nuclear Information System (INIS)

    Bonte, P.; Le Cloarec, M.F.; Dumoulin, J.P.; Sogon, S.; Tessier, L.; Mouchel, J.M.; Thomas, A.J.

    2000-01-01

    This study was undertaken to test the application of environmental radioactive tracers for estimating sediment mass and sediment residence time in rivers. A continuous sampling of the Seine river suspended matter (SM) using sediment traps was made during two months, between Paris and the estuary, along a 120 km long river section. The hydrological regime corresponded to the low water stage, where the SM transport is reduced. The measured tracers in the SM include short-lived natural ( 7 Be, 234 Th xs ) and artificial ( 131 I) radionuclides, as well as the longer-lived natural 210 Pb xs and its descendant the 210 Po. 137 Cs was used to check grain-size effects. A simple steady state model allowed us to estimate the total sediment mass, i.e. the SM, plus the resuspendable matter (RM), and the sediment residence time. Despite their different half-lives (8 to 53 days) and their different geochemical properties, consistent results were obtained with 131 I, 7 Be and 234 Th xs . The best estimate of the sediment mass present in the river is (24-41)·10 3 tons; it is essentially composed of the RM which is 10-17 times more abundant than the SM. In these hydrological conditions, the sediment residence time is quite long (1.6-2.8 months). (author) [es

  14. High and highly variable cooling rates during pyroclastic eruptions on Axial Seamount, Juan de Fuca Ridge

    Science.gov (United States)

    Helo, Christoph; Clague, David A.; Dingwell, Donald B.; Stix, John

    2013-03-01

    We present a calorimetric analysis of pyroclastic glasses and glassy sheet lava flow crusts collected on Axial Seamount, Juan de Fuca Ridge, NE Pacific Ocean, at a water depth of about 1400 m. The pyroclastic glasses, subdivided into thin limu o Pele fragments and angular, blocky clasts, were retrieved from various stratigraphic horizons of volcaniclastic deposits on the upper flanks of the volcanic edifice. Each analysed pyroclastic sample consists of a single type of fragment from one individual horizon. The heat capacity (cp) was measured via differential scanning calorimetry (DSC) and analysed using relaxation geospeedometry to obtain the natural cooling rate across the glass transition. The limu o Pele samples (1 mm grain size fraction) and angular fragments (0.5 mm grain size fraction) exhibit cooling rates of 104.3 to 106.0 K s- 1 and 103.9 to 105.1 K s- 1, respectively. A coarser grain size fraction, 2 mm for limu o Pele and 1 mm for the angular clasts yields cooling rates at the order of 103.7 K s- 1. The range of cooling rates determined for the different pyroclastic deposits presumably relates to the size or intensity of the individual eruptions. The outer glassy crusts of the sheet lava flows were naturally quenched at rates between 63 K s- 1 and 103 K s- 1. By comparing our results with published data on the very slow quenching of lava flow crusts, we suggest that (1) fragmentation and cooling appear to be coupled dynamically and (2) ductile deformation upon the onset of cooling is restricted due to the rapid increase in viscosity. Lastly, we suggest that thermally buoyant plumes that may arise from rapid heat transfer efficiently separate clasts based on their capability to rise within the plume and as they subsequently settle from it.

  15. No depth limit to hydrovolcanic limu o Pele: analysis of limu from Lō`ihi Seamount, Hawai`i

    Science.gov (United States)

    Schipper, C. Ian; White, James D. L.

    2010-03-01

    Deep-sea limu o Pele are shards of basaltic glass commonly described as “bubble walls.” When first identified they were inferred to form in submarine fire fountains, but were then reinterpreted as the products of hydrovolcanic volcanism, formed when submarine lava flows entrapped and vaporised seawater. Limu discovered below the c 3 km critical depth of seawater, where superheated water exists as a supercritical fluid instead of a vapour, led to the hydrovolcanic model of limu o Pele formation being discarded in favour of a magmatic CO2-driven, “strombolian-like” model. This revised magmatic mechanism has been widely accepted by the scientific community. We describe a newly discovered limu o Pele-rich deposit at ~1,052 mbsl on the northeast summit plateau region of Lō`ihi Seamount, Hawai`i. The limu at this site is concentrated in a chemically monomict ash lens interbedded with thin lava sheets that are separated from overlying volcaniclastic material by a discontinuity. The geometry and geochemistry of the deposit provide compelling evidence for a hydrovolcanic, sheet flow-related origin. The exceptional abundance and preservation of limu at this site allows 4 morphologic subtypes of limu- thin film, plateau-border, convex film, and Pele’s hair- to be identified and linked to portions of the isolated rupturing bubbles from which they are derived. We extend our discussion to beyond this new Lō`ihi deposit, by including a review of limu o Pele occurrences and thermodynamic considerations that demonstrate the hydrovolcanic model of limu formation to be more tenable than the magmatic model at all depths, including below the critical depth of seawater.

  16. SICILIAN JURASSIC PHYSIOGRAPHY AND GEOLOGIC REALMS (ITALY

    Directory of Open Access Journals (Sweden)

    BENEDETTO ABATE

    2004-03-01

    Full Text Available Two tectono-sedimentary domains, which were deformed during the Neogene and evolved into two large structural sectors, characterize the Sicilian Jurassic: the Maghrebides and Peloritani. Africa margin sediments, passing downward to Triassic successions and perhaps originally to Paleozoic deposits, characterize the former. The latter belongs to the European "Calabrian Arc", where the Jurassic transgressively rests on a continental substrate (i.e. the crystalline Variscan basement. These domains are characterized by four sedimentary facies: shallow platform-derived limestones; condensed seamount-type red limestones; nodular limestones with ammonites; deep radiolarites and shales. These facies are illustrated in a dozen of stratigraphic logs. The drowning of most Triassic-Liassic carbonate platforms or ramps and the deepening of adjacent basins came with inferred Jurassic strike-slip tectonics, connected to the relative movement of Africa (Gondwanan part vs Europe (Laurasian part; the same strike-slip tectonics may have caused scattered intraplate volcanic seamounts found in Maghrebides. During the Jurassic the Maghrebide realm was characterized by the interfingering of basins and carbonate platforms. During the Early and Middle Liassic, carbonate platforms and ramps were dominant. Since Toarcian either radiolarites in some basins or Ammonite-bearing calcareous muds developed with intervening basaltic flows, and were accompanied by condensed pelagic carbonates on the ensialic seamount-type highs. The Peloritani realm displays similar characteristics, but with later transgression on the basement, several strike-slip basins and without any volcanoes.

  17. The Nogent-sur-Seine nuclear power plant, at the service of a safe, competitive and CO2-free power generation in the heart of the Champagne-Ardenne region

    International Nuclear Information System (INIS)

    2010-01-01

    In less than 20 years, Electricite de France (EDF) has built up a competitive park of 58 nuclear power plants, with no equivalent elsewhere, which represents an installed power of 63.1 GW (85% of EDF's power generation). Inside this nuclear park, the national power generation centre of Nogent-sur-Seine comprises two production units of 1300 MW each (2600 MW as a whole). The facility generated 14.35 billion kWh in 2009, i.e. 2.8% of the French national power generation and about 1.5 times the energy consumed in the Champagne-Ardenne region. This brochure presents the life of the power plant under various aspects: power generation, safety priority and culture, maintenance investments, respect of the environment, long-term fuel and wastes management, local economical involvement, transparency and public information, key figures and dates. (J.S.)

  18. Trois anciens directeurs régionaux font part d'effets durables de l ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    19 janv. 2011 ... Il s'est acquitté de cette tâche en oeuvrant sur la scène internationale, au sein de tribunes telles que le Groupe d'experts du G8 sur l'accès aux nouvelles technologies, mis sur pied à l'occasion du sommet du G8 qui s'est déroulé à Okinawa, au Japon, en 2001, et le Sommet mondial sur la société de ...

  19. Volcanogenic-hydrothermal iron-rich materials from the southern part of the Central Indian Ocean Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Iyer, S; Gupta, S; Charan, S; Mills, O.P.

    . This may further be corroborated by the E–W elongation of some of the N–S-oriented seamounts, caused by the addition of magmatic materials and are thus indicative of more than one episode of volcanism. There are additional evidences which indicate volcanic...-brown material from the Japan Basin. Mar. Geol. 129, 331–336. Aumento, F., Mitchell, W.S., 1975. Magnetic spherules from the Mid-Atlantic Ridge. Geology 3, 407–410. Barrett, T.J., Friedrichsen, H., 1982. Elemental and isotopic composition of some metalliferous...

  20. Evaluation of a spatialized agronomic model in predicting yield and N leaching at the scale of the Seine-Normandie Basin.

    Science.gov (United States)

    Beaudoin, N; Gallois, N; Viennot, P; Le Bas, C; Puech, T; Schott, C; Buis, S; Mary, B

    2016-09-22

    The EU directive has addressed ambitious targets concerning the quality of water bodies. Predicting water quality as affected by land use and management requires using dynamic agro-hydrogeological models. In this study, an agronomic model (STICS) and a hydrogeological model (MODCOU) have been associated in order to simulate nitrogen fluxes in the Seine-Normandie Basin, which is affected by nitrate pollution of groundwater due to intensive farming systems. This modeling platform was used to predict and understand the spatial and temporal evolution of water quality over the 1971-2013 period. A quality assurance protocol (Refsgaard et al. Environ Model Softw 20: 1201-1215, 2005) was used to qualify the reliability of STICS outputs. Four iterative runs of the model were carried out with improved parameterization of soils and crop management without any change in the model. Improving model inputs changed much more the spatial distribution of simulated N losses than their mean values. STICS slightly underestimated the crop yields compared to the observed values at the administrative district scale. The platform also slightly underestimated the nitrate concentration at the outlet level with a mean difference ranging from -1.4 to -9.2 mg NO 3  L -1 according to the aquifer during the last decade. This outcome should help the stakeholders in decision-making to prevent nitrate pollution and provide new specifications for STICS development.

  1. Nogent-sur-Seine plant - Report on the complementary safety assessment of nuclear facilities in the light of the Fukushima accident

    International Nuclear Information System (INIS)

    2011-01-01

    This CSA (Complementary Safety Assessment) analyses the robustness of the Nogent-sur-Seine plant to extreme situations such as those that led to the Fukushima accident and proposes a series of improvements. Robustness is the ability for the plant to withstand events beyond the level for which the plant was designed. Robustness is linked to safety margins but also to the situations leading to a sudden deterioration of the accident sequence. Safety is not only a matter of design or of engineered systems, it is also a matter of organization. So issues like EDF's crisis organization, the organization of radiation protection, and work organization via subcontracting are also taken into consideration. The creation of a nuclear rapid action force (FARN) is proposed: this will be a national emergency force made up of specialized teams equipped to intervene in less than 24 hours on a nuclear site hit by an accident. This report is divided into 8 main chapters: 1) features of the site, 2) earthquake risk, 3) flooding risk, 4) risks due to other extreme natural disasters, 5) the loss of electrical power supplies and of heat sink, 6) management of severe accidents (accidents with core melt), 7) task subcontracting policy, 8) synthesis and list of improvements. 4 following appendices review: EDF's crisis organization, the FARN, radiation protection organization and accidental event trees. (A.C.)

  2. Cyber Crime & Cyber War – "Part of the Game": Cyber Security, Quo Vadis?

    OpenAIRE

    Karl H. Stingeder

    2015-01-01

    Welche Rolle spielt Cyber Crime gegenwärtig? Was unterscheidet Cyber Crime von Cyber War? Wie muss Cyber Security gestaltet sein, um effektiven Schutz nachhaltig zu gewährleisten? Cyber Crime-Aktivitäten kennzeichnen sich häufig durch eine einfache Zugänglichkeit von betrügerischem Know-How und technischen Hilfsmitteln. Bedingt durch eine schleppende und mangelhafte Umsetzung von koordinierten Gegenmaßnahmen, resultieren Cyber-Delikte in einem Low-Risk und High-Reward Szenario für Cyber-Krimi...

  3. Origin of the Easter Submarine Alignment: morphology and structural lineaments

    Directory of Open Access Journals (Sweden)

    Cristián Rodrigo

    2014-10-01

    Full Text Available The Easter submarine alignment corresponds to a sequence of seamounts and oceanic islands which runs from the Ahu-Umu volcanic fields in the west to its intersection with the Nazca Ridge in the east, with a total length of about 2.900 km and a strike of N85°E. Recent bathymetric compilations that include combined satellite derived and shipboard data (Global Topography and multibeam bathymetric data (from NGDC-NOAA are interpreted both qualitatively and quantitatively by using a morphological analysis, which was comprised of the determination of bathymetric patterns, trends in lineations and structures; height measurements, computation of basal areas and volumes of seamounts, in order to establish clues on the origin of this seamount chain and to establish relationships with the regional tectonics. In the study region 514 seamounts were counted, of which 334 had a basal area less than the reference seamount (Moai. In general, the largest seamounts (>1000 m in height tend to align and to have a larger volume, with an elongation of their bases along the seamount chain. On the other hand, smaller seamounts tend to be distributed more randomly with more circular bases. As a consequence of the morphological analysis, the best possible mechanism that explains the origin of the seamount chain is the existence of a localized hotspot to the west of the Salas y Gómez Island. The corresponding plume would contribute additional magmatic material towards the East Pacific Rise through canalizations, whose secondary branches would feed intermediate volcanoes. It is possible that within the Easter Island region there would be another minor contribution through fractures in the crust, due to the crustal weakening that was produced by the Easter Fracture Zone.

  4. Near Surface Ocean Experimental Technology Workshop Proceedings Held at Naval Ocean Research and Development Activity, NSTL Station, Mississippi on 6-8 November 1979,

    Science.gov (United States)

    1980-02-01

    have been made by Sippican Corporation of Marion, Massachusetts. An example of our use was a survey in ,June 1978 around the 2 km high Caryn Seamount ...Sound. McGraw-Hill, New York, 384 pp. 8. Wishner, K. F., 1979, The biomass and ecology of the deep-sea benthopelagic (near-bottom) zooplankton, Ph.D...COMPONENT PART NOTICE THIS PAPER IS A COMPONENT PART OF THE FOLLOWING COMPILATION REPORT: (TITLE): Near Sarface Ocean Experimental Technology Workshop

  5. The Role of the Submarine Channel Pernambuco in the Brazilian Continental Margin East

    International Nuclear Information System (INIS)

    Torres, L.; Villena, H.

    2010-01-01

    The Brazilian Continental Margin, which coastline measures more than 8,500km gives to Brazil continental dimensions. This huge region is conditioned by the action of process such as, sedimentals, tectonics, geomorphological and climatical, as example, which direct or in conjunction with other ones, since of continental break up between South America and Africa are going on and may be responsible for the current morphology of the margin. In accordance with this point of view, the Oriental part of the Brazilian Continental Margin, presents characteristics of a passive margin and fisiographically ''starved'', in which the continental break occur no more than 100km from de coastline and the sedimentary coverage is mainly carbonatic. The continental slope does not present great extension if compared with other parts of the Brazilian Margin and sharp gradient. The remark presence of the continental plateaus (Rio Grande Plateau and Pernambuco Plateau), which link with the continental rise and additionally the Paraiba, Pernambuco e Bahia seamounts, are the majors features in the morphology of the region between the slope and the continental rise. This paper will concentrate its focus on Bahia Seamount, with emphasis in the mainly erosive feature which cut transversally the seamounts, named Pernambuco Submarine Channel. It will be employed bathymetric multibeam and seismic data carried out by the Brazilian Continental Shelf Project (LEPLAC) in the current year and pieces of information from bibliographic researches in order to present a discussion by the hole of the Pernambuco Submarine Channel in the Occidental region of the Brazilian Continental Margin

  6. Geochemical behaviour of plutonium isotopes in natural media (lakes, rivers, estuaries)

    International Nuclear Information System (INIS)

    Jeandel, C.P.

    1981-10-01

    Artificial radionuclide activities ( 238 Pu, 239+240 Pu) were measured in natural environments. Their distribution and geochemical behaviour are evaluated and compared them to these of the 137 Cs. In a volcanic crater lake, influenced only by atmospheric fallout (Lac Pavin, France), sediments are enriched in 239+240 Pu, whereas 137 Cs stays in the dissolved phase. Diffusion processes and migration of radionuclides is shown to occur in sediments. Remobilization of 239+240 Pu is probable at the sediment/water interface. In the Garonne-Dordogne, Seine and Loire rivers, the 239+240 Pu activity levels in suspended matter are little influenced by the waste discharges of nuclear power plants. The element is essentially transported in the particulate fraction, more than is 137 Cs. In all the esturies studied (Gironde, Seine, Loire) 239+240 Pu concentrations in suspended matter increase between the river and the estuary. Simultaneously a removal of plutonium from the dissolved phase is observed. High plutonium concentrations are measured in the Seine estuary; they are attributed to a ''marine'' contamination: the French nuclear reprocessing plant of La Hague discharges low level radioactive liquid wastes, a part may reach the Seine estuary. There are no decrease in particulate 137 Cs concentrations between the river and the estuary of the Gironde, such as it occurs in the Loire. In this last case, the phenomenon is explained by the presence of ''young caesium'' originating in the power plant effluents and which is more exchangeable than 137 Cs of atmospheric origin. In the Seine estuary, the influence of marine contamination causes an increase of particulate and dissolved 137 Cs concentrations [fr

  7. Neli tellisseina / Pille Nagel

    Index Scriptorium Estoniae

    Nagel, Pille

    2012-01-01

    Konkursile Wienerberger Brick Award tagasivaates vaadeldakse nelja maja seinalahendusi: programmeeritud sein (Gantenbeini veinikoda Šveitsis, Bearth & Deplazes, II preemia 2008. a.), laagerdunud sein (Kolumba Muuseum Kölnis, Peter Zumthor, I preemia 2008. a.), kohalik sein (Bloemsingel kortermaja Groningenis, Marlies Rohmer, nominent 2012. a.), sakraalne sein (Liechtensteini parlamendihooned Vaduzis, Hansjörg Göritz, I preemia 2010. a.)

  8. Analisa Teknis Pemakaian Kombinasi Lampu Metal Halide Dan Led Sebagai Pemikat Ikan Pada Kapal Pukat Cincin (Purse Seine Dan Pengaruhnya Terhadap Konsumsi Bahan Bakar Genset

    Directory of Open Access Journals (Sweden)

    Septian Ragil Wibisono

    2017-01-01

    Full Text Available Saat ini lampu Metal Halide dipakai sebagai pemikat ikan  oleh nelayan Purse Seine. Peggunaan lampu tersebut memerlukan daya Genset yang besar karena satu lampu Metal Halide berdaya 1500 Watt. Semakin banyak lampu Metal Halide yang digunakan semakin besar pula konsumsi bahan bakar Genset. Dalam upaya penghematan energi bahan bakar maka digunakan lampu LED sebagai alternatif pemikat ikan. Lampu LED dikenal sebagai lampu yang hemat energi. Penelitian ini ditujukan untuk mengetahui dan membandingkan konsumsi bahan bakar Genset saat menggunakan kombinasi lampu Metal Halide dan LED. Penelitian ini dilakukan dengan mengambil data konsumsi bahan bakar Genset untuk menyalakan sejumlah lampu Metal Halide dan lampu LED, kemudian dilakukan analisa regresi untuk mendapatkan model persaamaan konsumsi bahan bakar Genset. Selanjutnya dilakukan ekstrapolasi untuk memprediksi konsumsi bahan bakar saat Genset dengan jumlah lampu tertentu. Hasilnya dengan besar fluks cahaya yang hampir sama, saat penggunaan 6 lampu Metal Halide konsumsi bahan bakar sebesar 13.606,03 liter, dan saat menggunakan kombinasi lampu 1 Metal Halide dan 25 lampu LED konsumsi bahan bakar sebesar 13.255,63 liter, yang artinya terjadi penghematan bahan bakar sebesar 2,58%.

  9. Die Frage nach Gerechtigkeit.

    Directory of Open Access Journals (Sweden)

    Martin Jäggle

    2014-07-01

    Full Text Available ENGLISH: In the first part six stages in the author’s path of life are described, which have influenced his engagement with justice. The second part gives an insight into his religious educational work, in which the issue of justice was especially significant on the example of ‘religion in the context of migration’ and of the ecumenic initiative ‘lebens.werte.schule’ (school worth living. The vision of the Kingdom of God and the necessity of participation become apparent. DEUTSCH: Im ersten Teil werden sechs Stationen am Lebensweg des Autors beschrieben, die seine Auseinandersetzung mit Gerechtigkeit geprägt haben. Der zweite Teil gibt Einblick in seine religionspädagogische Arbeit, in der die Frage nach Gerechtigkeit besonders bedeutsam war am Beispiel ‚Religion im Kontext Migration‘ und der ökumenischen Initiative ‚lebens.werte.schule‘. Die Vision vom Reich Gottes und die Notwendigkeit von Partizipation werden dabei deutlich.

  10. Can Cooperative Management of Tuna Fisheries in the Western Pacific Solve the Growth Overfishing Problem?

    NARCIS (Netherlands)

    Bailey, M.L.; Rashid Sumaila, U.; Martell, S.J.D.

    2013-01-01

    Tuna fisheries in the western and central Pacific Ocean are important globally for both food and economic security. Yellowfin and bigeye tuna stocks in this region are declining, in part due to the juvenile bycatch of these species by the purse seine fishery using floating objects and fish

  11. Metal contamination budget at the river basin scale: an original Flux-Flow Analysis (F2A for the Seine River

    Directory of Open Access Journals (Sweden)

    L. Lestel

    2007-11-01

    Full Text Available Material flow analysis and environmental contamination analysis are merged into a Flux-Flow analysis (F2A as illustrated for the metal circulation in the Seine River catchment. F2A combines about 30 metal flows in the anthroposphere (14 million people and/or metal fluxes in the environment (atmosphere, soils, and aquatic system originating from two dozens of sources. The nature and quality of data is very heterogeneous going from downscaled national economic statistics to upscaled daily environmental surveys.

    A triple integration is performed: space integration over the catchment (65 000 km2, time integration for the 1950–2000 trend analysed at 5 year resolution, and a conceptual integration resulting in two F2A indicators.

    Despite the various data sources an average metal circulation is established for the 1994–2003 period and illustrated for zinc: (i metal circulation in the anthroposphere is now two orders of magnitude higher than river outputs, (ii long term metal storage, and their potential leaks, in soils, wastedumps and structures is also orders of magnitude higher than present river fluxes. Trend analysis is made through two F2A indicators, the per capita excess load at the river outlet and the leakage ratio (excess fluxes/metal demand. From 1950 to 2000, they both show a ten fold improvement of metal recycling while the metal demand has increased by 2.5 to 5 for Cd, Cu, Cr, Pb and Zn, and the population by 50%.

  12. Water - The radiological health of rivers: releases are very much controlled downstream power plants. What do hospital releases represent? The Seine reserves a surprise

    International Nuclear Information System (INIS)

    Anon.

    2015-01-01

    After a brief presentation of the role of the IRSN in the control of the radioactivity present in waters and in the control and follow-up of all sources of radioactivity, a first article briefly present the hydro-collector network, indicates that some point samplings of sediment and aquatic species are performed, that a national network of beacons for a continuous radioactivity measurement is installed in the main French rivers, downstream nuclear installations, and that advanced measurement techniques are used to detect very small level of tritium. Maps giving a brief indication of the radiological condition of the Loire and Rhone are provided. A second article addresses the control of releases downstream power plants, and evokes the legal context and the associated objectives and produced documents. The third article discusses the risk associated with hospital wastes and releases (liquid and solid effluents), how radioactivity is controlled between the hospital and tap water distribution. The last article reports and comments the results obtained by an analysis of historical pollutions trapped in the sediments of the Seine: 40 year-old traces of plutonium have been discovered, due to an accidental release from a CEA installation in Fontenay-aux-Roses, with no detrimental impact on population or on sewer workers

  13. Praktische Festigkeitsberechnungen im Maschinenbau

    Science.gov (United States)

    Böge, Gert; Böge, Wolfgang

    Ziel aller Festigkeitsberechnungen ist die Ermittlung der vorhandenen Spannung und der Nachweis, dass ein konstruiertes Bauteil mit Sicherheit "hält". Seine geforderte oder erwartete Tragfähigkeit muss unter allen denkbaren Umständen gewährleistet sein, es darf z. B. auch bei Dauerbelastung in der vorgeschriebenen Lebensdauer nicht brechen oder seine Form bleibend so verändern, dass es seine Funktion nicht mehr ausreichend erfüllt.

  14. Food web functioning of the benthopelagic community in a deep-sea seamount based on diet and stable isotope analyses

    Science.gov (United States)

    Preciado, Izaskun; Cartes, Joan E.; Punzón, Antonio; Frutos, Inmaculada; López-López, Lucía; Serrano, Alberto

    2017-03-01

    Trophic interactions in the deep-sea fish community of the Galicia Bank seamount (NE Atlantic) were inferred by using stomach contents analyses (SCA) and stable isotope analyses (SIA) of 27 fish species and their main prey items. Samples were collected during three surveys performed in 2009, 2010 and 2011 between 625 and 1800 m depth. Three main trophic guilds were determined using SCA data: pelagic, benthopelagic and benthic feeders, respectively. Vertically migrating macrozooplankton and meso-bathypelagic shrimps were identified to play a key role as pelagic prey for the deep sea fish community of the Galicia Bank. Habitat overlap was hardly detected; as a matter of fact, when species coexisted most of them evidenced a low dietary overlap, indicating a high degree of resource partitioning. A high potential competition, however, was observed among benthopelagic feeders, i.e.: Etmopterus spinax, Hoplostethus mediterraneus and Epigonus telescopus. A significant correlation was found between δ15N and δ13C for all the analysed species. When calculating Trophic Levels (TLs) for the main fish species, using both the SCA and SIA approaches, some discrepancies arose: TLs calculated from SIA were significantly higher than those obtained from SCA, probably indicating a higher consumption of benthic-suprabenthic prey in the previous months. During the summer, food web functioning in the Galicia Bank was more influenced by the assemblages dwelling in the water column than by deep-sea benthos, which was rather scarce in the summer samples. These discrepancies demonstrate the importance of using both approaches, SCA (snapshot of diet) and SIA (assimilated food in previous months), when attempting trophic studies, if an overview of food web dynamics in different compartments of the ecosystem is to be obtained.

  15. Meddy trajectories in the Canary Basin measured during the SEMAPHORE experiment, 1993-1995

    Science.gov (United States)

    Richardson, Philip L.; Tychensky, Aude

    1998-10-01

    As part of the Structures des Echanges Mer-Atmosphere, Proprietes des Heterogeneites Oceaniques: Recherche Experimentale (SEMAPHORE) experiment, four Mediterranean water eddies (Meddies) were identified in the Canary Basin and tracked with freely drifting RAFOS floats. One large and energetic Meddy, discovered 1700 km west of Cape Saint Vincent, Portugal, set a distance and speed record as it translated another 1700 km southwestward at 3.9 cm/s during 1.5 years. This Meddy traveled 57% of the distance from Cape Saint Vincent toward the spot McDowell and Rossby [1978] found a possible Meddy north of the Dominican Republic. Two Meddies were observed to interact with the Azores Current as they passed underneath or through it. Three Meddies collided with tall seamounts, which seemed to disrupt the normal swirl velocity, perhaps fatally in two cases. One Meddy appeared to bifurcate when it collided with seamounts.

  16. Geophysical survey of the Eggvin Bank and Logi Ridge - Greenland Sea

    Science.gov (United States)

    Breivik, A. J.; Mjelde, R.; Rai, A. K.; Frassetto, A.

    2012-12-01

    The northern Greenland Sea has a number of features associated with excess volcanism. These include the Jan Mayen island, the Jan Mayen Plateau north of, and the Eggvin Bank west of Jan Mayen, and the Vesteris Seamount far to the north. In the summer of 2011, we colleced an Ocean Bottom Seismometer (OBS) profile across the Eggvin Bank, returning four good data sets. We also collected single-channel reflection seismic (SCS) data along the OBS line. The profile crosses the transform part of the West Jan Mayen Fracture Zone (WJMFZ), which connects seafloor spreading between the Kolbeinsey and Mohn ridges. Between the WJMFZ and the Vesteris Seamount there is a narrow ridge 170-180 km long, ending in a few seamounts in the east. It disturbs the magnetic seafloor anomalies, and has no conjugate on the Norwegian margin. It thus appears to be younger than the Eocene seafloor it lies on. Trend and position points to Traill Ø in East Greenland, which had magmatism at ~36 Ma. We name it the Logi Ridge after Norse mythology, where Logi is the master of fire, brother of Aegir, master of the sea. We have collected five SCS profiles across this ridge in order to study the surrounding sedimentation pattern. We also collected gravity and magnetic data along all profiles. Initial results show two flat-topped seamounts on the Eggvin Bank, and a flat-topped Logi Ridge, indicating that these have been at sealevel. The sedimentary strata show recent vertical movement north of the WJMFZ near the Jan Mayen Plateau, and compression around the Logi Ridge. Sailing line of R/V Håkon Mosby of Bergen. Survey lines are in bold, and OBS positions are marked by circles.

  17. Fishes of the Vitória-Trindade Chain: Biodiversity, Biogeography and Evolution

    OpenAIRE

    Pinheiro, Hudson Tercio

    2016-01-01

    Studies on the ecology and biogeography of seamounts and oceanic islands have advanced substantially in the last 60 years. However, few seamounts have been scientifically characterized, with basic aspects of their biodiversity still unknown and many hypotheses not empirically tested. Consequently, the role of seamounts in the evolution for marine species is still unclear. In the south Atlantic, the Vitória-Trindade Chain (VTC) extends ca. 1,200 km offshore the Brazilian coast. For a long time...

  18. Cod monitoring; results 2015, quarter 3

    NARCIS (Netherlands)

    Reijden, van der K.J.; Machiels, M.A.M.; Trapman, B.K.; Kraan, M.L.

    2015-01-01

    The Cod monitoring program is part of the Dutch cod avoidance plan developed by the Dutch Government together with the Dutch fishing sector. The aim of this cod monitoring program is to provide information on the Catch per Unit Effort (CpUE) in the TR fleet (bottom trawls and seines). This is needed

  19. Cod monitoring : results 2015, quarter 2

    NARCIS (Netherlands)

    Teal, L.R.; Reijden, van der K.J.; Machiels, M.A.M.; Kraan, M.L.

    2015-01-01

    The Cod monitoring program is part of the Dutch cod avoidance plan developed by the Dutch Government together with the Dutch fishing sector. The aim of this cod monitoring program is to provide information on the Catch per Unit Effort (CpUE) in the TR fleet (bottom trawls and seines). This is needed

  20. White shark and other chondrichthyan interactions with the beach ...

    African Journals Online (AJOL)

    Public perception has been that an apparent increase in the nearshore occurrence of white sharks Carcharodon carcharias in False Bay, on the south coast of South Africa, can at least be partly attributed to beach-seine (treknet) operations attracting sharks into this coastal area. To assess the merit of these concerns, ...

  1. Western Indian Ocean - A glimpse of the tectonic scenario

    Digital Repository Service at National Institute of Oceanography (India)

    Bhattacharya, G.C.; Chaubey, A.K.

    is the en echelon displacement of the NW-SE trending ridge axis by numerous NE-SW trending fracture Western Indian Ocean - A Glimpse of the Tectonic Scenario 693 Table 1. Some information from the scientific drilling campaigns in the western Indian Ocean...: Raman Seamount; P: Panikkar Seamount; W: Wadia Guyot; S: SagarKanya Seamount; SR: ShebaRidge; CR: Carlsberg Ridge; CIR: Central Indian Ridge; SWIR: Southwest Indian Ridge; RTJ: Rodrigues Triple Junction; OFZ: Owen Fracture Zone; LR: Laxmi Ridge; MR...

  2. Linking community tolerance and structure with low metallic contamination: a field study on 13 biofilms sampled across the Seine river basin.

    Science.gov (United States)

    Fechner, Lise C; Gourlay-Francé, Catherine; Tusseau-Vuillemin, Marie-Hélène

    2014-03-15

    It is difficult to assess the biological consequences of diffuse water contamination by micropollutants which are present in rivers at low, even sublethal levels. River biofilms, which respond quickly to changes of environmental parameters, are good candidates to acquire knowledge on the response of aquatic organisms to diffuse chemical contamination in the field. The study was designed as an attempt to link biofilm metal tolerance and metallic contamination in a field survey covering 13 different sampling sites in the Seine river basin (north of France) with low contamination levels. Cd and Zn tolerance of heterotrophic communities was assessed using a short-term toxicity test based on β-glucosidase activity. Metal tolerance levels varied between sites but there was no obvious correlation between tolerance and corresponding water contamination levels for Cd and Zn. Indeed, metallic contamination at the sampling sites remained subtle when compared to water quality standards (only two sampling sites had either Zn or both Cu and Zn concentrations exceeding the Environmental Quality Standards set by the EU Water Framework Directive). Yet, multivariate analysis of the data using Partial Least Squares Regression revealed that both metallic and environmental parameters were important variables explaining the variability of metal tolerance levels. Automated Ribosomal Intergenic Spacer Analysis (ARISA) was also performed on both bacterial and eukaryotic biofilm communities from the 13 sampling sites. Multivariate analysis of ARISA fingerprints revealed that biofilms with similar tolerance levels have similar ARISA profiles. Those results confirm that river biofilms are potential indicators of low, diffuse contamination levels of aquatic systems. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. 50 CFR 660.330 - Open access fishery-management measures.

    Science.gov (United States)

    2010-10-01

    ....S./Mexico border) is permitted within the nontrawl RCA with fixed gear only under the following... coordinates at §§ 660.398-.399: Thompson Seamount, President Jackson Seamount, Cordell Bank (50-fm (91-m...

  4. Oceanographic data collected during the Gulf of Alaska 2004 Expedition (alaska2004) on RV Atlantis in Gulf of Alaska from July 30, 2004 - August 23, 2004 (NODC Accession 0072310)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The 2004 Gulf of Alaska Seamount Expedition will use the deep submergence vehicle (DSV) Alvin to explore five large seamounts. Giacomini, Pratt, Welker, Denson, and...

  5. Landward Perspective of Coastal Eutrophication Potential Under Future Climate Change: The Seine River Case (France

    Directory of Open Access Journals (Sweden)

    Mélanie Raimonet

    2018-05-01

    Full Text Available Studies quantifying the impact of climate change have so far mostly examined atmospheric variables, and few are evaluating the cascade of aquatic impacts that will occur along the land–ocean continuum until the ultimate impacts on coastal eutrophication potential. In this study, a new hydro-biogeochemical modeling chain has been developed, based on the coupling of the generic pyNuts-Riverstrahler biogeochemical model and the GR4J-CEMANEIGE hydrological model, and applied to the Seine River basin (France. Averaged responses of biogeochemical variables to climate-induced hydrological changes were assessed using climate forcing based on 12 projections of precipitation and temperature (BC-CORDEX for the stabilization (RCP 4.5 and the increasing (RCP 8.5 CO2 emission scenarios. Beyond the amount of nutrients delivered to the sea, we calculated the indicator of coastal eutrophication potential (ICEP. The models run with the RCP4.5 stabilization scenario show low variations in hydrological regimes and water quality, while five of the six models run with the increasing CO2 emissions scenario (RCP8.5 leads to more intense extreme streamflow (i.e., higher maximum flows, lower and longer minimum flows, resulting in the degradation of water quality. For the driest RCP 8.5 projection, median biogeochemical impacts induced by decreasing discharge (until −270 m3 s−1 in average are mostly located downstream of major wastewater treatment plants. During spring bloom, e.g., in May, the associated higher residence time leads to an increase of phytoplankton biomass (+31% in average, with a simultaneous −23% decrease of silicic acid, followed downstream by a −9% decrease of oxygen. Later during low flow, major increases in nitrate and phosphate concentrations (until +19% and +32% in average are expected. For all considered scenarios, high ICEP values (above zero lasted, indicating that coastal eutrophication is not expected to decrease with changing

  6. Exploitation of political and technical scopes for free play. Energy conservation in buildings - part of a future-oriented energy policy; Politische und technische Handlungsspielraeume nutzen. Energieeinsparung im Gebaeudebereich - Teil einer zukunftsweisenden Energiepolitik

    Energy Technology Data Exchange (ETDEWEB)

    Ehm, H. [Bundesministerium fuer Verkehr, Bau- und Wohnungswesen, Berlin (Germany)

    1999-09-01

    In April of this year, the section of architecture of the University of Kassel conferred on Professor Dr. Herbert Ehm, department head at the federal building ministry, the title of honorary doctor for his achievements in the sector of energy-saving construction. In his address given at the awarding ceremony, entitled 'Energy conservation in buildings - part of a future-oriented energy policy', the recipient underlined the necessity of energy conservation measures in buildings because of the current high energy consumption and outlined approaches. (orig.) [German] Im April dieses Jahres verlieh der Fachbereich Architektur der Universitaet/GSH Kassel Professor Dr. Herbert Ehm, Abteilungsleiter im Bundesbauministerium, die Ehrendoktorwuerde fuer seine Verdienste um das energiesparende Bauen. In seinem Festvortrag 'Energieeinsparung im Gebaeudebereich - Teil einer zukunftsweisenden Energiepolitik' unterstrich der Geehrte wegen des erheblichen Verbrauchs die Notwendigkeit der Sparmassnahmen im Wohnungsbau und skizzierte Loesungswege. (orig.)

  7. Insights From Magnesium Isotopic Compositions on the Oceanic Hydrothermal Circulation: Is Seamount Weathering the Solution?

    Science.gov (United States)

    Galy, A.; Carder, E.; Elderfield, H.

    2006-12-01

    and concentration data are consistent with the preferential incorporation of heavy isotopes of Mg during the weathering and already similar to the mechanisms found in soil (Tipper et al., 2006a, doi:10.1016/j.epsl.2006.04.033). The fractionation factor (α) is around 1.001 for the high-T° fluids, while the low temperature fluids, samples off axis during the ODP Leg 168 (Est of Juan de Fuca Ridge), requires a more variable and higher α of 1.001 to 1.003. At low temperature, the α is somehow greater that the estimate made from the soil formation but the T-α relationship is consistent with the expected behaviour for an equilibrium isotopic fractionation. However, such a large α implies that the significant flux of the low-T component of the hydrothermal circulation required to fulfil the heat budget of the oceanic lithosphere would buffer any isotopic mass balance calculation of the oceanic Mg to an unsustainable value (e.g. Tipper et al., 2006b, doi:10.1016/j.epsl.2006.07.037). Therefore, either the low-T hydrothermal circulation leaves the Mg unaffected, or the off axis fluids from the ODP Leg 168 are not representative of the global low-T hydrothermal circulation. Given that Mg gets significantly re-incorporated in soil processes, we favour the later hypothesis and propose that a significant part of the low-T hydrothermal circulation is occurring around relief of the oceanic floor, including seamounts, with a different residence-time and chemistry than what have been described in the ODP Leg 168 setting.

  8. Morphology and molecular phylogeny of Paragorgia rubra sp. nov. (Cnidaria: Octocorallia), a new bubblegum coral species from a seamount in the tropical Western Pacific

    Science.gov (United States)

    Li, Yang; Zhan, Zifeng; Xu, Kuidong

    2017-07-01

    A new species of bubblegum coral, Paragorgia rubra sp. nov., discovered from a seamount at a water depth of 373 m near the Yap Trench is studied using morphological and molecular approaches. Paragorgia rubra sp. nov. is the fourth species of the genus found in the tropical Western Pacific. The new gorgonian is red-colored, uniplanar, and measures approximately 530 mm high and 440 mm wide, with autozooids distributed only on one side of the colony. Paragorgia rubra sp. nov. is most similar to P. kaupeka Sánchez, 2005, but differs distinctly in the polyp ovals with large and compound protuberances (vs. small and simple conical protuberances) and the medullar spindles possessing simple conical protuberances (vs. compound protuberances). Moreover, P. rubra sp. nov. differs from P. kaupeka in the smaller length/width ratio of surface radiates (1.53 vs. 1.75). The genetic distance of the mtMutS gene between P. rubra sp. nov. and P. kaupeka is 0.66%, while the intraspecific distances within Paragorgia Milne-Edwards & Haime, 1857 except the species P. regalis complex are no more than 0.5%, further supporting the establishment of the new species. Furthermore, the ITS2 secondary structure of P. rubra sp. nov. is also different from those of congeners. Phylogenetic analyses indicate Paragorgia rubra sp. nov. and P. kaupeka form a clade, which branched early within Paragorgia and diversified approximately 15 Mya.

  9. Cold-Water Coral Distributions in the Drake Passage Area from Towed Camera Observations – Initial Interpretations

    Science.gov (United States)

    Waller, Rhian G.; Scanlon, Kathryn M.; Robinson, Laura F.

    2011-01-01

    Seamounts are unique deep-sea features that create habitats thought to have high levels of endemic fauna, productive fisheries and benthic communities vulnerable to anthropogenic impacts. Many seamounts are isolated features, occurring in the high seas, where access is limited and thus biological data scarce. There are numerous seamounts within the Drake Passage (Southern Ocean), yet high winds, frequent storms and strong currents make seafloor sampling particularly difficult. As a result, few attempts to collect biological data have been made, leading to a paucity of information on benthic habitats or fauna in this area, particularly those on primarily hard-bottom seamounts and ridges. During a research cruise in 2008 six locations were examined (two on the Antarctic margin, one on the Shackleton Fracture Zone, and three on seamounts within the Drake Passage), using a towed camera with onboard instruments to measure conductivity, temperature, depth and turbidity. Dominant fauna and bottom type were categorized from 200 randomized photos from each location. Cold-water corals were present in high numbers in habitats both on the Antarctic margin and on the current swept seamounts of the Drake Passage, though the diversity of orders varied. Though the Scleractinia (hard corals) were abundant on the sedimented margin, they were poorly represented in the primarily hard-bottom areas of the central Drake Passage. The two seamount sites and the Shackleton Fracture Zone showed high numbers of stylasterid (lace) and alcyonacean (soft) corals, as well as large numbers of sponges. Though data are preliminary, the geological and environmental variability (particularly in temperature) between sample sites may be influencing cold-water coral biogeography in this region. Each area observed also showed little similarity in faunal diversity with other sites examined for this study within all phyla counted. This manuscript highlights how little is understood of these isolated

  10. Cold-water coral distributions in the drake passage area from towed camera observations--initial interpretations.

    Directory of Open Access Journals (Sweden)

    Rhian G Waller

    Full Text Available Seamounts are unique deep-sea features that create habitats thought to have high levels of endemic fauna, productive fisheries and benthic communities vulnerable to anthropogenic impacts. Many seamounts are isolated features, occurring in the high seas, where access is limited and thus biological data scarce. There are numerous seamounts within the Drake Passage (Southern Ocean, yet high winds, frequent storms and strong currents make seafloor sampling particularly difficult. As a result, few attempts to collect biological data have been made, leading to a paucity of information on benthic habitats or fauna in this area, particularly those on primarily hard-bottom seamounts and ridges. During a research cruise in 2008 six locations were examined (two on the Antarctic margin, one on the Shackleton Fracture Zone, and three on seamounts within the Drake Passage, using a towed camera with onboard instruments to measure conductivity, temperature, depth and turbidity. Dominant fauna and bottom type were categorized from 200 randomized photos from each location. Cold-water corals were present in high numbers in habitats both on the Antarctic margin and on the current swept seamounts of the Drake Passage, though the diversity of orders varied. Though the Scleractinia (hard corals were abundant on the sedimented margin, they were poorly represented in the primarily hard-bottom areas of the central Drake Passage. The two seamount sites and the Shackleton Fracture Zone showed high numbers of stylasterid (lace and alcyonacean (soft corals, as well as large numbers of sponges. Though data are preliminary, the geological and environmental variability (particularly in temperature between sample sites may be influencing cold-water coral biogeography in this region. Each area observed also showed little similarity in faunal diversity with other sites examined for this study within all phyla counted. This manuscript highlights how little is understood of these

  11. Les dispositifs de fiction cinématographique au sein du documentaire Récits d’Ellis Island, de Georges Perec et Robert Bober (1980

    Directory of Open Access Journals (Sweden)

    Cécile Tourneur

    2009-12-01

    Full Text Available Traces et Mémoires, les titres des deux parties qui composent Récits d’Ellis Island réalisé par Georges Perec et Robert Bober entre 1978 et 1980, peuvent être perçus comme résumant les enjeux majeurs du film : la restitution, à partir de vestiges, de ce que fut ce lieu de passage de millions d’émigrants, devenu « lieu de mémoire » et une volonté de considérer ces destins dans leur singularité. Dans la première partie, Traces, le texte écrit et lu par Georges Perec relie Ellis Island à un questionnement personnel sur leurs propres origines et leur identité. Perec et Bober ne s’attachent pas à une reconstitution exacte du passé, projet voué à l’échec, mais vont créer un espace fictionnel au sein du projet documentaire à travers la mise en scène de photographies (la plupart sont de Lewis Hine et datent du début du XXe siècle dans les lieux même où furent réalisées les prises de vue. Photographie et cinéma ainsi confrontés leur permettent de mener à bien une réflexion sur l’exil, la transmission d’une histoire et d’y projeter leur propre questionnement autobiographique, de l’ordre du possible, du potentiel.

  12. 50 CFR 660.382 - Limited entry fixed gear fishery management measures.

    Science.gov (United States)

    2010-10-01

    ... (between 42° N. lat. south to the U.S./Mexico border) using no more than 12 hooks, “Number 2” or smaller....399: Thompson Seamount, President Jackson Seamount, Cordell Bank (50 fm (91 m) isobath), Harris Point...

  13. Distribution and migration of aftershocks of the 2010 Mw 7.4 Ogasawara Islands intraplate normal-faulting earthquake related to a fracture zone in the Pacific plate

    Science.gov (United States)

    Obana, Koichiro; Takahashi, Tsutomu; No, Tetsuo; Kaiho, Yuka; Kodaira, Shuichi; Yamashita, Mikiya; Sato, Takeshi; Nakamura, Takeshi

    2014-04-01

    describe the aftershocks of a Mw 7.4 intraplate normal-faulting earthquake that occurred 150 km east Ogasawara (Bonin) Islands, Japan, on 21 December 2010. It occurred beneath the outer trench slope of the Izu-Ogasawara trench, where the Pacific plate subducts beneath the Philippine Sea plate. Aftershock observations using ocean bottom seismographs (OBSs) began soon after the earthquake and multichannel seismic reflection surveys were conducted across the aftershock area. Aftershocks were distributed in a NW-SE belt 140 km long, oblique to the N-S trench axis. They formed three subparallel lineations along a fracture zone in the Pacific plate. The OBS observations combined with data from stations on Chichi-jima and Haha-jima Islands revealed a migration of the aftershock activity. The first hour, which likely outlines the main shock rupture, was limited to an 80 km long area in the central part of the subsequent aftershock area. The first hour activity occurred mainly around, and appears to have been influenced by, nearby large seamounts and oceanic plateau, such as the Ogasawara Plateau and the Uyeda Ridge. Over the following days, the aftershocks expanded beyond or into these seamounts and plateau. The aftershock distribution and migration suggest that crustal heterogeneities related to a fracture zone and large seamounts and oceanic plateau in the incoming Pacific plate affected the rupture of the main shock. Such preexisting structures may influence intraplate normal-faulting earthquakes in other regions of plate flexure prior to subduction.

  14. High-resolution AUV mapping of the 2015 flows at Axial Seamount, Juan de Fuca Ridge

    Science.gov (United States)

    Paduan, J. B.; Chadwick, W. W., Jr.; Clague, D. A.; Le Saout, M.; Caress, D. W.; Thomas, H. J.; Yoerger, D.

    2016-12-01

    Lava flows erupted in April 2015 at Axial Seamount were mapped at 1-m resolution with the AUV Sentry in August 2015 and the MBARI Mapping AUVs in July 2016 and observed and sampled with ROVs on those same expeditions. Thirty percent of terrain covered by new flows had been mapped by the MBARI AUVs prior to the eruption. Differencing of before and after maps (using ship-collected bathymetry where the AUV had not mapped before) allows calculation of extents and volumes of flows and shows new fissures. The maps reveal unexpected fissure patterns and shifts in the style of flow emplacement through a single eruption. There were 11 separate flows totaling 1.48 x 108 m3 of lava erupted from numerous en echelon fissures over 19 km on the NE caldera floor, on the NE flank, and down the N rift zone. Flows in and around the caldera have maximum thicknesses of 5-19 m. Most erupted as sheet flows and spread along intricate channels that terminated in thin margins. Some utilized pre-existing fissures. Some flows erupted from short fissures, while at least two longer new fissures produced little or no lava. A flow on the upper N rift has a spectacular lava channel flanked by narrow lava pillars supporting a thin roof left after the flow drained. A shatter ring still emanating warm fluid is visible in the map as a 15-m wide low cone. Hundreds of exploded pillows were observed but are not discernable in the bathymetry. The northern-most three flows deep on the N rift are similar in area to the others but comprise the bulk of the eruption volume. Differencing of ship-based bathymetry shows only these flows. Near the eruptive fissures they are sheet flows, but as they flowed downslope they built complexes of coalesced pillow mounds up to 67-128 m thick. Changes in flow morphology occurred through the course of the eruption. Large pillow mounds had molten cores that deformed as the eruption progressed. One flow began as a thin, effusive sheet flow but as the eruption rate decreased, a

  15. Generalized study of the return to equilibrium of a particle in a plasma (Fokker-Planck formalism) (1961); Etude generale du retour a l'equilibre d'une particule au sein d'un plasma (formalisme de Fokker-Planck) (1961)

    Energy Technology Data Exchange (ETDEWEB)

    Salmon, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Faculte des Sciences de Caen, 14 (France)

    1961-07-01

    The author examines the problem of the return to equilibrium of a particle in a plasma and completely explains Fokker-Planck equation. After that, he studies the possibility of interpreting the return of the test particle to Maxwellian distribution, using the development - which is obtained. He discusses the validity limits of the Rosenbluth, MacDonald and Judd approximation. (author) [French] Examinant le probleme du retour a l'equilibre d'une particule test au sein d'un plasma en equilibre, l'auteur cherche a expliciter completement l'expression de l'operateur de Fokker-Planck. Il etudie ensuite les conditions de coherence, c'est-a-dire la possibilite pour le developpement obtenu de traduire le retour de la particule test a l'etat maxwellien et discute des limites de validite de la formule de 'Rosenbluth, Mac Donald et Judd'. (auteur)

  16. Concept de service innovant et d'incitation au développement durable: étude de faisabilité d'un système d'échange implémenté au sein d'un réseau de parties prenantes

    OpenAIRE

    Nginamau, Maria Prisca Mbuilu; Fragnière, Emmanuel; Place, Christophe

    2014-01-01

    implémenté au sein d’un réseau de parties prenantes. En réaction à la crise financière de 2008 et après un vote unanime le 29 mai 2013 à l’Assemblée Générale d’APRÈS-GE, qui regroupe près de 250 membres, la Chambre de l’Économie Sociale et Solidaire a décidé de coopérer dans le processus de création d’une monnaie complémentaire porté par le groupe Monnaie Grand Genève ou Grand Genève : une monnaie solidaire et APRÈS-GE, comptant près de 70 personnes bénévoles actives. Ce projet débutera effec...

  17. Alkylphenolic compounds and bisphenol A contamination within a heavily urbanized area: case study of Paris.

    Science.gov (United States)

    Cladière, Mathieu; Gasperi, Johnny; Lorgeoux, Catherine; Bonhomme, Céline; Rocher, Vincent; Tassin, Bruno

    2013-05-01

    This study evaluates the influence of a heavily urbanized area (Paris Metropolitan area), on receiving water contamination by both bisphenol A (BPA) and alkylphenol ethoxylate (APE) biodegradation product. The study began by investigating concentrations within urban sources. In addition to the more commonly studied wastewater treatment plant effluent, wet weather urban sources (including combined sewer overflows, urban runoff, and total atmospheric fallout) were considered. The initial results highlight a significant contamination of all urban sources (from a few nanograms per liter in atmospheric fallout to several micrograms per liter in the other sources) with clearly distinguishable distribution patterns. Secondly, concentration changes along the Seine River from upstream of the Paris Metropolitan area to downstream were investigated. While the concentrations of BPA and nonylphenoxy acetic acid (NP₁EC) increase substantially due to urban sources, the 4-nonylphenol concentrations remain homogeneous along the Seine. These results suggest a broad dissemination of 4-nonylphenol at the scale of the Seine River basin. Moreover, the relationship between pollutant concentrations and Seine River flow was assessed both upstream and downstream of the Paris conurbation. Consequently, a sharp decrease in dissolved NP1EC concentrations relative to Seine River flow underscores the influence of single-point urban pollution on Seine River contamination. Conversely, dissolved 4-nonylphenol concentrations serve to reinforce the hypothesis of its widespread presence at the Seine River basin scale.

  18. Population ecology of the tonguefish Symphurus thermophilus (Pisces; Pleuronectiformes; Cynoglossidae) at sulphur-rich hydrothermal vents on volcanoes of the northern Mariana Arc

    Science.gov (United States)

    Tunnicliffe, Verena; Tyler, Jennifer; Dower, John F.

    2013-08-01

    Flatfish are a major component of the hydrothermal vent community on three seamounts of the northern Mariana Volcanic Arc in the northwest Pacific. Nikko, Kasuga-2 and Daikoku seamounts host vent fields between 375 and 480 m depth where high temperature vents release molten sulphur. The small cynoglossid tonguefish, Symphurus thermophilus Munroe and Hashimoto, is ubiquitous in all vent habitats observed on these seamounts: among extensive fields of tubeworms and mussels and on solid sulphur surfaces on Nikko; on sulphur-rich sediments and barnacle-covered boulders on Kasuga-2; and on recent sulphur flows and on broad areas of loose and semi-consolidated sediments on Daikoku. We recorded repeated forays by individuals onto flows of molten sulphur as these surfaces cooled. Based on observations using ROVs, the mean density is 90 fish/m2 with maximum counts over 200 fish/m2 on Daikoku sediments. Compared to collected tonguefish from Daikoku and Kasuga-2, those from Nikko have significantly greater lengths and, on average, six times the mass. Otolith data indicate upper ages of 13 years with Nikko tonguefish growing significantly faster. Diets of tonguefish on the three seamounts reflect the different habitats and prey availability; in Daikoku specimens, small crustaceans and polychaetes are most common while on Nikko, gut contents are predominantly larger shrimp. We made the unusual observation of stunned midwater fish falling to the seafloor near the vents where S. thermophilus immediately attacked them. This tonguefish has a wide diet range and foraging behaviour that likely influence the differing growth rates and sizes of fish inhabiting the different vent sites. Limited genetic data suggest that larval exchange probably occurs among sites where the common habitat factor is high levels of elemental sulphur forming hard and partly unconsolidated substrata. Here, in the northern range of the Mariana Trench Marine National Monument, S. thermophilus, despite having an

  19. Global Analysis of the Shallow Geology of Large-Scale Ocean Slopes.

    Science.gov (United States)

    1983-05-01

    R. Sparks, S. Carey , and T. Huang (1980). Volcanogenic Sedimentation in the Lesser Antilles Arc. Jour. Geol., v. 88, p. 523- 540. 105 Silver, E., J...Visual Observations of the Volcanic Micromorphology of Tortuga , Lorraine and Tutu Seamounts; and Petrology and Chemistry of Ridge and Seamount Features in

  20. Sub-millimeter scale magnetostratigraphy and environmental magnetism of ferromanganese crusts using a scanning SQUID microscope

    Science.gov (United States)

    Oda, H.; Noguchi, A.; Yamamoto, Y.; Usui, A.; Ito, T.; Kawai, J.; Takahashi, H.

    2017-12-01

    Ferromanganese crusts are chemical sedimentary rock composed mainly of iron-manganese oxide. Because the ferromanganese crusts grow very slowly on the sea floor at rates of 3-10 mm/Ma, long-term deep-sea environmental changes can be reconstructed from the ferromanganese crusts. Thus, it is important to provide reliable age model for the crusts. For the past decades 10Be/9Be dating method has been used extensively to give age models for crusts younger than 15 Ma. Alternatively, sub-millimeter scale magnetostratigraphic study on a ferromanganese crust sample using a scanning SQUID (superconducting quantum interference device) microscope (Kawai et al., 2016; Oda et al., 2016) has been applied successfully (e.g. Oda et al., 2011; Noguchi et al. 2017). Also, environmental magnetic mapping was successful for the ferromanganese crust from the Takuyo Daigo Seamount (Noguchi et al., 2017). The ferromanganese crust used in this study was sampled from the Hanzawa Seamount, Ryukyu trench and the Shotoku Seamount. The vertical component of the magnetic field above thin section samples of the ferromanganese crust was measured using the scanning SQUID microscope on 100 μm grids. Magnetic mapping of the Hanzawa Seamount shows sub-millimeter scale magnetic stripes parallel to lamina. By correlating the boundaries of magnetic stripes with known geomagnetic reversals, we estimated that average growth rate of the Hanzawa Seamount is 2.67 +/- 0.04 mm/Ma , which is consistent with that deduced from the 10Be/9Be dating method (2.56 +/- 0.04 mm/Ma). The crust sample from the Shotoku Seamount used by Oda et al. (2011) shows prominent periodical lamination. Further details are going to be discussed together with the environmental magnetic mapping.

  1. Der Cranach-Altar im Veitsdom - seine Entstehung und sein Untergang

    Czech Academy of Sciences Publication Activity Database

    Šroněk, Michal; Horníčková, Kateřina

    2010-01-01

    Roč. 58, č. 1 (2010), s. 2-16 ISSN 0049-5123 R&D Projects: GA AV ČR IAA800330902 Institutional research plan: CEZ:AV0Z80330511; CEZ:AV0Z90090514 Keywords : St Vitus cathedral * Lucas Cranach * Prague * altar decoration Subject RIV: AL - Art , Architecture, Cultural Heritage

  2. Transmission investment in the Peruvian electricity market: Theory and applications

    International Nuclear Information System (INIS)

    Ruiz, Erix; Rosellón, Juan

    2012-01-01

    This research presents an application of the mechanism in (HRV) to promote electricity transmission network expansion in the Peruvian electricity transmission system known as SEIN (Sistema Eléctrico Interconectado Nacional). The HRV mechanism combines the merchant and regulatory approaches to promote investment into transmission grids. This mechanism gives incentives for efficient investment in expansion of the network by rebalancing over time the fixed and variable charges of a two-part tariff in the framework of a wholesale electricity market with locational pricing. The expansion of the network is carried out through the sale of Financial Transmission Rights (FTRs) for the congested lines. The mechanism is applied for 103 nodes of the SEIN using detailed characteristics of generators, nodes and transmission lines. Under Laspeyres weights and linear cost of expansion of transmission capacity, it is shown that prices converge to lower price levels as a result of increased transmission capacity.

  3. Entretiens avec Tanguy Viel

    Directory of Open Access Journals (Sweden)

    Stephan Nowotnick

    2016-11-01

    Full Text Available Ausgehend vom Thema, zu dem Tanguy Viel im November 2015 an die Bergische Universität Wuppertal eingeladen wurde: "Un auteur français sur les pistes du roman américain", entwickelt der Autor in einem einleitenden Vortrag seine Ideen zur Intertextualität und zur Intermedialität, kommentiert eingehend seine schriftstellerische Entwicklung, die Entfaltung seines narrativen Werkes sowie den eigenen Schreibprozess. In der sich anschließenden Diskussion, in der sich Tanguy Viel mit Fragen aus dem Publikum auseinandersetzt, geht der Autor detailliert auf seine literarische Verpflichtungen, die Ästhetik und metanarrative Dimension seiner Texte und sein Verhältnis zum Leser ein. Auch die Bedeutung des Verlags Editions de Minuit als Sammelbecken einer bestimmten Ausprägung der literarischen Avantgarde in Frankreich wird beleuchtet. In der Summe eignet sich die Wiedergabe dieser "rencontre littéraire" sehr gut, um sich ein authentisches Bild von dem literarischen Selbstverständnis eines bedeutenden Autors der französischen Gegenwartsliteratur zu machen.

  4. „Relax. You’re Dressed!“. Der Herrenanzug im Career Building und seine Thematisierung in Musicvideoclips

    Directory of Open Access Journals (Sweden)

    Gudrun Schäfer

    2009-07-01

    Full Text Available Gudrun Schäfer zeigt an Beispielen aus der aktuellen Zeitschriftenwerbung und aus Karriereratgebern sowie anhand von zwei aktuellen Musikvideoclips, dass der Herrenanzug – selbst da, wo er als problematisches Symbol für Konventionalität fungiert, – nach wie vor als Referenzpunkt für ‚unangreifbare‘, universale professionelle Bekleidung gelten kann. Vor allem als Dresscode für Bewerbungsgespräche wird der Herrenanzug bzw. das Kostüm oder der Hosenanzug als weibliches Pendant als ein „Rettungsanker“ in einem Meer von Unsicherheiten angesehen. Seine Funktion als Symbol männlicher Souveränität und Universalität wird jedoch zunehmend in Frage gestellt, und der universale Geltungsanspruch des Herrenanzugs erodiert: Konventionelle ‚Banker- und Managerkleidung‘ wird abgelehnt, da die Berufstände durch die aktuelle Wirtschafts- und Finanzkrise stark in Misskredit geraten sind. In IT-Berufen geht der Trend zu deutlich informellerer Kleidung. Der höhere Anteil an Mitarbeiterinnen führt in einigen Unternehmen dazu, dass variierte – wenn auch adaptierte – Dresscodes gelten. Nicht zuletzt ist ein Trend zur stärkeren Körperbetonung und damit Individualisierung der Anzugmode zu verzeichnen, der mit der zunehmenden Pflicht zur zur ‚Körperarbeit‘ und Körperdarstellung auch bei Männern zusammenhängt.Using advertizing found in current magazines and career guides as well as two music video clips, Gudrun Schäfer shows that the man’s suit continues to be understood as a reference point for “intangible” and universal professional clothing, even when it also functions as a problematic symbol for conventionality. The suit, as well as the female equivalent of skirt suit or pantsuit, is considered dress code for job interviews and in this manner becomes the “anchor” in a sea of uncertainty. However, increasingly more people are questioning its function as a symbol of masculine sovereignty and universality, thus eroding

  5. Management of the post accidental situation applied to Nogent-Sur-Seine nuclear power plant environment. First results of the decontamination of soil and food chain working group

    International Nuclear Information System (INIS)

    Allain, E.; Mignon, F.; Cessac, B.; Gallay, F.; Metivier, J.M.; Reales, N.; Gofette, R.; Mahot, M.

    2004-01-01

    From the beginning of 2002, Troyes prefecture has initiated a reflection about the management of a nuclear crisis caused by an accident at the Nogent-sur-Seine nuclear power plant. Five workshops have been created, dealing with the following themes: 'Administrative and economic organization', 'Health risk assessment and the epidemiology', 'Monitoring of environment', 'Movement in the contaminated area' and 'Decontamination of soil and Food chain'. The first results of the 'Decontamination of soil and Food chain' working group, which involves the District Agricultural and Forestry Department, the Farmer's Association, the Institute for Radiological Protection and Nuclear Safety and the Veterinary Division are presented in the poster. The scenario that had been developed for the accident considers the release of 3 radionuclides ( 131 I, 134 Cs and 137 Cs) in the environment. The scale of the crisis didn't require the evacuation and the sheltering of the population during the emergency phase. The consequences on the local agricultural products (cereal, beetroot, vine, milk, cow meat...) have been assessed up to 50 km and different strategies of agricultural countermeasures have been studied regarding to the local constraints (soil types, surfaces and quantities concerned) and to the consequences of their implementation (waste types and quantities, costs). Then, decision-making diagrams summed up the technical results and allowed to deepen the global thought. (author)

  6. Alboran Basin, southern Spain - Part I: Geomorphology

    Energy Technology Data Exchange (ETDEWEB)

    Munoz, A. [Secretaria General de Pesca Maritima, Corazon de Maria, 8, 28002 Madrid (Spain); Ballesteros, M.; Rivera, J.; Acosta, J. [Instituto Espanol de Oceanografia, Corazon de Maria, 8, 28002 Madrid (Spain); Montoya, I. [Universidad Juan Carlos I, Campus de Mostoles, Madrid (Spain); Uchupi, E. [Woods Hole Oceanographic Institution, Woods Hole, MA 02543 (United States)

    2008-01-15

    Bathymetric, 3D relief and shaded relief maps created from multibeam echo-sounding data image the morphology of the Alboran Basin, a structural low along the east-west-trending Eurasian-African plates boundary. Topographic features in the basin are the consequence of volcanism associated with Miocene rifting, rift and post-rift sedimentation, and recent faulting resulting from the convergence of the African-Eurasian plates. Pleistiocene glacially induced regressions/transgressions when the sea level dropped to about 150 m below its present level gas seeps and bottom currents. Recent faulting and the Pleistocene transgressions/regressions led to mass-wasting, formation of turbidity currents and canyon erosion on the basin's slopes. Recent fault traces at the base of the northern basin slope have also served as passageways for thermogenic methane, the oxidation of which by bacteria led to the formation of carbonate mounds along the fault intercepts on the sea floor. Expulsion of thermogenic or biogenic gas has led to the formation of pockmarks; erosion by bottom currents has resulted in the formation of moats around seamounts and erosion of the seafloor of the Alboran Ridge and kept the southern edge of the 36 10'N high sediment free. (author)

  7. Case series

    African Journals Online (AJOL)

    ebutamanya

    10 févr. 2015 ... Key words: Cancer du sein bilatéral synchrone, Facteurs de risque, histologie, traitement, Pronostic ... avaient six fois plus de risque de développer un cancer au niveau du sein controlatéral que les femmes âgées de plus de 40 ans. .... définition d´un cancer du sein bilatéral simultané, ce qui rend l'étude ...

  8. Focused volcanism and growth of a slow spreading segment (Mid-Atlantic Ridge, 35°N)

    Science.gov (United States)

    Rabain, Aline; Cannat, Mathilde; Escartín, Javier; Pouliquen, Gaud; Deplus, Christine; Rommevaux-Jestin, Céline

    2001-02-01

    Using off axis bathymetry, gravity and magnetic data, we studied the formation of a prominent seamount chain across segment OH1 (Mid-Atlantic Ridge, 35°N), and its relation to the past segmentation of the area. We also studied the size and shape of the seamounts to understand the processes leading to their formation. The chain is elongated in the spreading direction, and extends from the present day segment center to ˜6 Ma on both flanks. It coincides with a pronounced low in the residual mantle Bouguer gravity anomaly, suggesting thicker crust and thus more abundant magmatism than in surrounding areas. Magnetic anomalies are well defined over the seamount chain, consistent with formation on or near the axis. The seamounts within the chain are larger on average than those from other areas of the Mid-Atlantic Ridge, reflecting higher magma volumes and fluxes during eruptions. The distribution of seamounts suggests a focused magmatic source, located beneath the eastern side of the ridge axis, at a constant distance (˜45 km) from the Oceanographer transform fault. A V-shaped trend defines the southern end of OH1 and indicates that the segment propagated rapidly southwards, increasing in length from 50 to 90 km. The onset of propagation at ˜6 Ma coincided with the initiation of the volcanic chain, suggesting that magma supply at that time was focused at the end of the segment rather than at its center, as is typical for Mid-Atlantic Ridge segments. We propose that this unusual configuration is a consequence of the cold edge effect of the Oceanographer fracture zone. We also propose that enhanced and focused magmatism beneath the seamount chain may have caused the rapid southward propagation of OH1 over the past ˜6 Ma.

  9. Seafloor geomorphology and geology of the Kingman Reef-Palmyra Atoll region, Central Pacific Ocean

    Science.gov (United States)

    Eakins, Barry; Barth, Ginger; Scheirer, Dan; Mosher, Dave; Armstrong, Andy

    2017-04-01

    Kingman Reef and Palmyra Atoll are the exposed summits of two seamounts within the Line Islands Volcanic Chain in the Central Pacific Ocean. Both are U.S. Territories, and the Exclusive Economic Zone around the islands was partially surveyed in 1991 with GLORIA sidescan sonar and seismic reflection profiling. New multibeam swath sonar surveys were conducted in 2010, 2015, and 2016 around the islands, in support of U.S. Extended Continental Shelf investigations. Numerous transits through the region by research vessels have collected additional multibeam swath sonar data. We present new, detailed maps of bathymetry, sidescan sonar imagery, geology, and sediment isopachs of the seafloor surrounding the islands, and how these have informed our understanding of the islands' margins. The islands are the last subaerial remnants of a complex, horse-shoe-shaped volcanic platform spanning roughly 200 km in diameter. The elevated platform from which the seamounts arise comprises at least 10 individual volcanic centers that have heights exceeding 3000m above the nearby abyssal plains. Gravity modeling suggests that the elevated platform is compensated by thickened crust. Strong carbonate caps and voluminous sediment accumulations flanking the platform indicate that the volcanoes were once shallow-water or emergent systems. These systems produced vast quantities of carbonate sediment that were shed to a deep interior basin to the east of Palmyra Atoll, and to nearby abyssal plains. The identification of mass failures, sediment reworking and bedforms, and channel networks provide evidence for extensive sedimentary processes around these volcanic centers. Analysis of the seamounts atop the elevated platform and in the seamount province to the northwest shows that flat-topped seamounts ("guyots") are principally found at depths shallower than 1300 meters, while peaked seamounts are almost exclusively found at greater depths. This constrains the amount of regional subsidence that

  10. Structures within the oceanic crust of the central South China Sea basin and their implications for oceanic accretionary processes

    Science.gov (United States)

    Ding, Weiwei; Sun, Zhen; Dadd, Kelsie; Fang, Yinxia; Li, Jiabiao

    2018-04-01

    Internal structures in mature oceanic crust can elucidate understanding of the processes and mechanism of crustal accretion. In this study, we present two multi-channel seismic (MCS) transects across the northern flank of the South China Sea basin to reveal the internal structures related to Cenozoic tectono-magmatic processes during seafloor spreading. Bright reflectors within the oceanic crust, including the Moho, upper crustal reflectors, and lower crustal reflectors, are clearly imaged in these two transects. The Moho reflection displays varied character in continuity, shape and amplitude from the continental slope area to the abyssal basin, and becomes absent in the central part of the basin where abundant seamounts and seamount chains formed after the cessation of seafloor spreading. Dipping reflectors are distinct in most parts of the MCS data but generally confined to the lower crust above the Moho reflection. These lower crustal reflectors merge downward into the Moho without offsetting it, probably arising from shear zones between the crust and mantle characterized by interstitial melt, although we cannot exclude other possibilities such as brittle faulting or magmatic layering in the local area. A notable feature of these lower crustal reflector events is their opposite inclinations. We suggest the two groups of conjugate lower crustal reflector events observed between magnetic anomalies C11 and C8 were associated with two unusual accretionary processes arising from plate reorganizations with southward ridge jumps.

  11. Observation and modeling of hydrothermal response to the 2015 eruption at Axial Seamount, Northeast Pacific: An OOI Cabled Observatory case study

    Science.gov (United States)

    Xu, G.; Chadwick, W. W., Jr.; Wilcock, W. S. D.; Bemis, K. G.; Nooner, S. L.; Sasagawa, G. S.; Zumberge, M. A.; Delaney, J. R.

    2017-12-01

    The 2015 eruption at Axial Seamount, an active volcano at a depth of 1500 m in the Northeast Pacific, marked the first time a seafloor eruption was detected and monitored by a cabled observatory - the Cabled Array operated by Ocean Observatories Initiative (OOI). Following the eruption, eight cabled and non-cabled instruments recorded a temperature increase across the southern half of the caldera and neighboring areas. These temperature signals were very different from those observed after the 2011 and 1998 Axial eruptions. The 2015 temperature increase occurred later (3.5 days after deflation started versus 6-18 hours) and had a larger amplitude ( 0.7°C versus 0.2-0.5°C), a much slower increase and decay and smaller short-term fluctuations. Most remarkably, the 2015 temperature signals were synchronous and uniform across the 3 x 4.5 km2 area covered by the eight instruments. We hypothesize that the eruption triggered the release of a hydrothermal brine stored in the crust. In this interpretation, the observed temperature increases were due to a dense, bottom-hugging layer of warm salty water that was created when hot brine in the crust was flushed out after the dike intersected the zone where the brine was stored. In the absence of near-bottom salinity observations, we test this hypothesis by using a numerical model of ocean flow and transport to simulate the thermal response within the vicinity of the caldera following a brine injection. We set up the model with realistic background flows, hydrography, and seafloor topography. We simulate brine release as seafloor heat and salt inputs at locations inferred from seismic and geologic observations. Comparison of model bottom temperature with measurements shows a reasonable match. If our interpretation is correct, this is the first time that the release of a hydrothermal brine has been observed due to a submarine eruption. Prior to the next eruption, the Cabled Array observatory should be enhanced to improve the

  12. Analysis of dissimilatory sulfite reductase and 16S rRNA gene fragments from deep-sea hydrothermal sites of the Suiyo Seamount, Izu-Bonin Arc, Western Pacific.

    Science.gov (United States)

    Nakagawa, Tatsunori; Ishibashi, Jun-Ichiro; Maruyama, Akihiko; Yamanaka, Toshiro; Morimoto, Yusuke; Kimura, Hiroyuki; Urabe, Tetsuro; Fukui, Manabu

    2004-01-01

    This study describes the occurrence of unique dissimilatory sulfite reductase (DSR) genes at a depth of 1,380 m from the deep-sea hydrothermal vent field at the Suiyo Seamount, Izu-Bonin Arc, Western Pacific, Japan. The DSR genes were obtained from microbes that grew in a catheter-type in situ growth chamber deployed for 3 days on a vent and from the effluent water of drilled holes at 5 degrees C and natural vent fluids at 7 degrees C. DSR clones SUIYOdsr-A and SUIYOdsr-B were not closely related to cultivated species or environmental clones. Moreover, samples of microbial communities were examined by PCR-denaturing gradient gel electrophoresis (DGGE) analysis of the 16S rRNA gene. The sequence analysis of 16S rRNA gene fragments obtained from the vent catheter after a 3-day incubation revealed the occurrence of bacterial DGGE bands affiliated with the Aquificae and gamma- and epsilon-Proteobacteria as well as the occurrence of archaeal phylotypes affiliated with the Thermococcales and of a unique archaeon sequence that clustered with "Nanoarchaeota." The DGGE bands obtained from drilled holes and natural vent fluids from 7 to 300 degrees C were affiliated with the delta-Proteobacteria, genus Thiomicrospira, and Pelodictyon. The dominant DGGE bands retrieved from the effluent water of casing pipes at 3 and 4 degrees C were closely related to phylotypes obtained from the Arctic Ocean. Our results suggest the presence of microorganisms corresponding to a unique DSR lineage not detected previously from other geothermal environments.

  13. Tod in den Anden. Ein Brief Francis Halls an Humboldt 1831 und seine historischen und politischen Hintergründe

    Directory of Open Access Journals (Sweden)

    Thomas Schmuck

    2013-12-01

    Full Text Available Zusammenfassung Der Forschungsreisende Francis Hall kam als Soldat nach Südamerika und betätigte sich hier auch als Pflanzensammler, Reiseschriftsteller und Bergsteiger. Er war Freund und Briefpartner Jeremy Benthams und versuchte gemeinsam mit Jean-Baptiste Boussingault den Chimborazo zu besteigen. Der liberale Journalist wurde 1833 in bürgerkriegsähnlichen Unruhen in Ecuador ermordet. Der einzige Brief Halls an Humboldt, in dem er diesen für die Naturerschließung des Landes zu gewinnen versucht, eine Sammlung andiner Pflanzen übersendet und seine Einschätzung zur politischen Lage und Zukunft Südamerikas kundtut, wird hier veröffentlicht und kommentiert. Abstract The British explorer Francis Hall was active in South-America as a soldier, a collector of plants, a writer of travelogues and a mountaineer. Together with Jean-Baptiste Boussingault he failed in ascending the Chimborazo. Friend and correspondent of Jeremy Bentham and also liberal journalist, Hall was killed during riots in Ecuador in 1833. In one single letter addressed to Humboldt, which is presented here, Hall tries to awaken interest for Ecuador, develops his views on the political future of South America and sends a collection of plants from the Andes. Resumen El explorador británico Francis Hall llegó a América del Sur como soldado y allí también se dedicó a la colección de plantas, a escribir sobre viajes y a hacer alpinismo. Intentó subir al Chimborazo con Jean-Baptiste Boussingault. El periodista liberal, amigo de Jeremy Bentham con el que también mantenía correspondencia, fue asesinado en los disturbios de 1833 en Ecuador. En la única carta de Hall a Humboldt, que está publicada y comentada aquí, Hall intenta despertar el interés de Humboldt por la naturaleza del país enviando una colección de plantas andinas y dando su opinión sobre la situación política y el futuro de América del Sur. (Traducción: Christine Lebas

  14. Boundaries of magnetic anomaly sources in the Tyrrhenian region

    Directory of Open Access Journals (Sweden)

    A. Rapolla

    1998-06-01

    Full Text Available Analysis of the analytic signal of the aeromagnetic field in the Tyrrhenian region allowed the systematic location of the boundaries of magnetic shallow sources. This method was chosen because of its independence from the magnetization and inducing field direction, and the results were similar to those of the boundary analysis of the horizontal gradient of the pseudogravity transformed field. The analytic signal was computed by a stable algorithm based on the second order horizontal derivatives of the field and Laplace equation. The complexity of the investigated area is well reflected in the aeromagnetic field and an objective and systematic study, such as boundary analysis, provided a rather complete description of the main regional structures. Significant trends indicated the existence of structures, whose nature was still unknown or uncertain. These included structures located between the Vavilov and De Marchi seamounts, NW of Stromboli Island, south of Ponza Island, a buried horst immediately south of the Cilento coastline, a body located northwest of the Cassinis seamount and other small magnetized structures located south of the Tuscanian archipelago. In many cases, a better definition of several structures previously recognized was obtained as in the case of some tectonic alignments (e.g., the Elba ridge, the Romolo and Selli lines, etc., a large number of igneous seamounts (e.g., Magnaghi, Marsili, Vavilov, Anchise, Quirra, Enarete, Eolo and Sisifo seamounts and several crystalline outcrops (e.g., Ichnusa, Vercelli, M. della Rondine, Tiberino, Cassinis, Traiano, Glauco and Augusto seamounts.

  15. Archaeoglobus infectus sp. nov., a novel thermophilic, chemolithoheterotrophic archaeon isolated from a deep-sea rock collected at Suiyo Seamount, Izu-Bonin Arc, western Pacific Ocean.

    Science.gov (United States)

    Mori, Koji; Maruyama, Akihiko; Urabe, Tetsuro; Suzuki, Ken-Ichiro; Hanada, Satoshi

    2008-04-01

    A novel thermophilic, strictly anaerobic archaeon, designated strain Arc51T, was isolated from a rock sample collected from a deep-sea hydrothermal field in Suiyo Seamount, Izu-Bonin Arc, western Pacific Ocean. Cells of the isolate were irregular cocci with single flagella and exhibited blue-green fluorescence at 436 nm. The optimum temperature, pH and NaCl concentration for growth were 70 degrees C, pH 6.5 and 3 % (w/v), respectively. Strain Arc51T could grow on thiosulfate or sulfite as an electron acceptor in the presence of hydrogen. This strain required acetate as a carbon source for its growth, suggesting that the reductive acetyl CoA pathway for CO2 fixation was incomplete. In addition, coenzyme M (2-mercaptoethanesulfonic acid), which is a known methyl carrier in methanogenesis, was also a requirement for growth of the strain. Analysis of the 16S rRNA gene sequence revealed that the isolate was similar to members of the genus Archaeoglobus, with sequence similarities of 93.6-97.2 %; the closest relative was Archaeoglobus veneficus. Phylogenetic analyses of the dsrAB and apsA genes, encoding the alpha and beta subunits of dissimilatory sulfite reductase and the alpha subunit of adenosine-5'-phosphosulfate reductase, respectively, produced results similar to those inferred from comparisons based on the 16S rRNA gene sequence. On the basis of phenotypic and phylogenetic data, strain Arc51T represents a novel species of the genus Archaeoglobus, for which the name Archaeoglobus infectus sp. nov. is proposed. The type strain is Arc51T (=NBRC 100649T=DSM 18877T).

  16. Gisbertus Voetius (1589-1676). Sein Theologieverständnis und seine Gotteslehre

    NARCIS (Netherlands)

    Beck, A.J.

    2007-01-01

    Gisbertus Voetius was the first rector and 'primarius theologiae professor' of Utrecht University in its beginning years. Although he is regarded as one of the most important and influential Reformed theologians of the 17th century, his extensive oeuvre, which predominantly resulted from active

  17. IMPORTANCE OF SHALLOW AREAS OF THE UPPER PART OF THE KANIV RESERVOIR IN THE MAINTENANCE OF ITS ICHTHYOFAUNA

    Directory of Open Access Journals (Sweden)

    O. Gurbyk

    2014-09-01

    Full Text Available Purpose. Determination of the relative number of fish juveniles on biotopes of the upper part of the Kanev reservoir in the aspect of evaluation of these areas in general propagation of ichthyofauna. Methodology. The work is based on data of fish juvenile surveys conducted in the Kaniv reservoir during 2011—2013. Data collection and processing were performed according to generally accepted methods. Fish juveniles were caught using a beach seine made of mill gauze № 7, length 10 m, height 1 m. Relative number of fish juveniles on different sites has been calculated based on the areas of fish nursing biotopes under assumption of the constancy of catchability coefficients. Shannon-Weaver diversity index was used for comparing species diversity of the commercial ichthyofauna of different sites. Findings. The majority of the studied littoral sites of the upper part of the Kaniv reservoir were characterized by sufficiently high indices of biodiversity ― Shannon index values varied within 2,07—3,24 bit./ind. Twenty six species were recorded in the composition of the fish juvenile communities that was 80 % of total number of species in the reservoir. It was found that despite a decrease of the relative number of the juveniles of valuable commercial species compared to previous years, the upper part of the reservoir remains the major site for recruitment of commercial fish stock ― 70 % of bream (Abramis brama, tench (Tinca tinca, pike (Esox lucius, roach (Rutilus rutilus and wels (Vimba vimba of the Kaniv reservoir are reproduced here. Taking into account the especial value of the upper part in formation of the spawning fund of the reservoir, any hydroenhancement works here should be limited exclusively by navigable channel. Originality. For the first time we quantitatively evaluated (in spatial aspect the number of fish fauna recruitment in the Kanev reservoir under current state of spawning areas. Practical value. Results of the work will be

  18. A new species of the deep-sea spongicolid genus Spongicoloides (Crustacea, Decapoda, Stenopodidea) and a new species of the glass sponge genus Corbitella (Hexactinellida, Lyssacinosida, Euplectellidae) from a seamount near the Mariana Trench, with a novel commensal relationship between the two genera

    Science.gov (United States)

    Kou, Qi; Gong, Lin; Li, Xinzheng

    2018-05-01

    A new species of the deep-sea spongicolid genus Spongicoloides Hansen, 1908 and a new species of the euplectellid genus Corbitella Gray, 1867 are described and illustrated based on the material recently collected by the remotely operated vehicle 'Faxian' at a seamount near the Mariana Trench. The new deep-sea spongicolid species can be distinguished from the congeneric species by a series of morphological features and the validity of the new species was supported by the molecular phylogenetic analysis. By means of the microscleres of regular hexasters and onychohexasters, the new sponge species can easily be distinguished from other Corbitella species. The new euplectellid sponge species is the host of the new spongicolid shrimp species: this is the first discovery of an association between Spongicoloides and Corbitella. The present study increases the species diversity of both genera as well as yielding new insight into the commensal relationships between spongicolid shrimps and their sponge hosts.

  19. Benthic megafaunal community structure of cobalt-rich manganese crusts on Necker Ridge

    Science.gov (United States)

    Morgan, Nicole B.; Cairns, Stephen; Reiswig, Henry; Baco, Amy R.

    2015-10-01

    In the North Pacific Ocean, the seamounts of the Hawaiian Archipelago and the Mid-Pacific Mountains are connected by Necker Ridge, a 600 km-long feature spanning a depth range of 1400-4000 m. The Necker Ridge is a part of a large area of the central and western Pacific under consideration for cobalt-rich manganese crust mining. We describe the fauna and community structure of the previously unsampled Necker Ridge based on explorations with the submersible Pisces IV. On five pinnacles and a portion of the Ridge ranging from 1400 to 2000 m deep, 27 transects were recorded using HD video, and voucher specimens were collected to aid in species identification. The video was analyzed to identify and count the megafauna found on each transect and to characterize the substrate. Diversity increased from south to north along the feature. There was a significant difference in community structure between southern and northern pinnacles, with southern pinnacles dominated by crinoids of the Family Charitometridae and northern pinnacles dominated by octocorals, especially the Families Isididae and Chrysogorgiidae. DistLM demonstrated a correlation between community structure on the pinnacles and at least six environmental variables, including latitude, sediment cover, and oxygen concentration, but not including depth. The discontinuous and patchy nature of these distinct megafaunal communities highlights growing evidence that cobalt-rich seamounts are highly heterogeneous habitats, and that managing seamounts may require more complex regulations than treating them as a single ecological unit. These results suggest that extensive community analysis should occur at a given site to determine management priority areas, prior to consideration of that site for exploitation of natural resources.

  20. Application of RNA Stable Isotope Probing (SIP) to Link Community Activity with Microorganisms Responsible for Autotrophy in the Subseafloor at Axial Seamount

    Science.gov (United States)

    Huber, J. A.; Fortunato, C. S.

    2014-12-01

    The global ocean comprises the Earth's largest biome, with microorganisms playing a dominant biogeochemical role. However, the potential for production of new microbial biomass within the subseafloor is rarely considered in traditional oceanographic paradigms of carbon cycling or microbial food webs. In this study, we used RNA Stable Isotope Probing (RNA SIP) to determine the microbial community composition and genetic repertoire of active subseafloor autotrophs in warm venting fluids from Axial Seamount. RNA is a responsive biomarker because it is a reflection of cellular activity independent of replication, and RNA SIP thus provides access to both the function of a microbial community and the phylogeny of the organisms accountable for key functions. Diffuse fluids were incubated shipboard at 30°C, 55°C, and 80°C with 13DIC and H2. Metatranscriptomic sequencing of both the enriched and non-enriched RNA was carried out from 13C and 12C controls. In addition, filtered fluid samples were preserved in situ for comparative meta -transcriptomic and -genomic analyses. Diverse lineages of bacteria and archaea and accompanying metabolisms were detected in situ, but RNA SIP results show dominance of three different groups of autotrophs active under each experimental condition. At 30°C, members of the Sulfurimonas genus dominated, with genes for hydrogen oxidation, nitrate reduction, and carbon fixation via the rTCA cycle highly expressed. At 55°C, both Caminibacter and Nautilia transcripts were detected for rTCA cycle, hydrogen oxidation, and nitrate reduction. At 80°C, transcripts for hydrogenotrophic methanogenesis mediated by members of Methanocaldococcus were detected. These results suggest the subseafloor hosts various anaerobic chemolithoautotrophs that span a wide temperature range, with hydrogen playing a key role in microbial metabolism. Complementary experiments are currently being carried out on the seafloor with a novel in situ incubator unit to provide

  1. Causes of earthquake spatial distribution beneath the Izu-Bonin-Mariana Arc

    Science.gov (United States)

    Kong, Xiangchao; Li, Sanzhong; Wang, Yongming; Suo, Yanhui; Dai, Liming; Géli, Louis; Zhang, Yong; Guo, Lingli; Wang, Pengcheng

    2018-01-01

    Statistics about the occurrence frequency of earthquakes (1973-2015) at shallow, intermediate and great depths along the Izu-Bonin-Mariana (IBM) Arc is presented and a percent perturbation relative to P-wave mean value (LLNL-G3Dv3) is adopted to show the deep structure. The correlation coefficient between the subduction rate and the frequency of shallow seismic events along the IBM is 0.605, proving that the subduction rate is an important factor for shallow seismic events. The relationship between relief amplitudes of the seafloor and earthquake occurrences implies that some seamount chains riding on the Pacific seafloor may have an effect on intermediate-depth seismic events along the IBM. A probable hypothesis is proposed that the seamounts or surrounding seafloor with high degree of fracture may bring numerous hydrous minerals into the deep and may result in a different thermal structure compared to the seafloor where no seamounts are subducted. Fluids from the seamounts or surrounding seafloor are released to trigger earthquakes at intermediate-depth. Deep events in the northern and southern Mariana arc are likely affected by a horizontal propagating tear parallel to the trench.

  2. Origin of depleted components in basalt related to the Hawaiian hot spot: Evidence from isotopic and incompatible element ratios

    Science.gov (United States)

    Frey, F. A.; Huang, S.; Blichert-Toft, J.; Regelous, M.; Boyet, M.

    2005-02-01

    The radiogenic isotopic ratios of Sr, Nd, Hf, and Pb in basaltic lavas associated with major hot spots, such as Hawaii, document the geochemical heterogeneity of their mantle source. What processes created such heterogeneity? For Hawaiian lavas there has been extensive discussion of geochemically enriched source components, but relatively little attention has been given to the origin of depleted source components, that is, components with the lowest 87Sr/86Sr and highest 143Nd/144Nd and 176Hf/177Hf. The surprisingly important role of a depleted component in the source of the incompatible element-enriched, rejuvenated-stage Hawaiian lavas is well known. A depleted component also contributed significantly to the ˜76-81 Ma lavas erupted at Detroit Seamount in the Emperor Seamount Chain. In both cases, major involvement of MORB-related depleted asthenosphere or lithosphere has been proposed. Detroit Seamount and rejuvenated-stage lavas, however, have important isotopic differences from most Pacific MORB. Specifically, they define trends to relatively unradiogenic Pb isotope ratios, and most Emperor Seamount lavas define a steep trend of 176Hf/177Hf versus 143Nd/144Nd. In addition, lavas from Detroit Seamount and recent rejuvenated-stage lavas have relatively high Ba/Th, a characteristic of lavas associated with the Hawaiian hot spot. It is possible that a depleted component, intrinsic to the hot spot, has contributed to these young and old lavas related to the Hawaiian hot spot. The persistence of such a component over 80 Myr is consistent with a long-lived source, i.e., a plume.

  3. Cruise Report RV Poseidon cruise POS 295 [POS295], Lisbon 20.03.03 - Las Palmas 01.04.03

    OpenAIRE

    Christiansen, Bernd

    2003-01-01

    The cruise was a pilot cruise in the framework of the EU-project OASIS (Oceanic seamounts: an integrated study) which studies the functioning ecology of seamounts in the NE-Atlantic. The research programme during the cruise included measurements of the physical properties of the water column (temperature and salinity), the sampling of particulate organic matter, measurements of primary production and export fluxes and the sampling of zooplankton.

  4. Role of a unique population of lithotrophic, Fe-oxidizing bacteria in forming microbial Fe-mats at the Loihi Seamount.

    Science.gov (United States)

    Emerson, D.; Rentz, J. A.; Moyer, C. L.

    2005-12-01

    The Loihi Seamount, located 30 km SE of the island of Hawai'i, is among the most active volcanos on Earth. The summit, at a depth of 1100m, includes a 250m deep caldera (Pele's Pit) formed by an eruption in 1996. The summit, and especially Pele's Pit, are the site of extensive low to intermediate temperature (10° to 65°C) hydrothermal venting, emanating both from diffuse fissures and orifices that have substantial flow rates. The vent fluid is characterized by a low sulfide content, high CO2 concentrations and Fe(II) amounts in the 10s to 100s of μM. Associated with all vents are extensive deposits of iron oxyhydroxides that typically have 107 to 108 bacterial cells/cc associated with them. The morphology of the Fe-oxides are indicative of biological origins. We have isolated microaerophilic, obligately lithotrophic Fe-oxidizing bacteria from Loihi and describe here `Mariprofundus ferroxydans' a unique bacterium that forms a filamentous iron oxide mineral. `M. ferroxydans' is the first cultured representative of a novel division of the Proteobacteria, known previously only from clones from different hydrothermal vent sites. Molecular evidence from Loihi mats based on clone libraries and terminal restriction length polymorphism (T-RFLP) analysis of 16S rRNA genes indicate that this lineage of Fe-oxidizing organisms are common inhabitants at Loihi. We speculate that this organism and its relatives form the basis of an active microbial mat community that owe their existence to the inherent gradients of Fe(II) and O2 that exist at the Loihi vents. In a geological context this is interesting because the Loihi summit and caldera are in an O2-minima zone; O2 concentrations in the bulk seawater are around 0.5 mg/l. In effect, Loihi could serve as a proxy for the late Archaean and early Proterozoic periods when the Earth's atmosphere went from reducing to oxidizing, and it is speculated that abundant Fe(II) in the Earth's oceans served as a major sink for O2 production

  5. The End of Monterey Submarine Canyon Incision and Potential River Source Areas-Os, Nd, and Pb Isotope Constraints from Hydrogenetic Fe-Mn Crusts

    Science.gov (United States)

    Conrad, T. A.; Nielsen, S.; Ehrenbrink, B. P. E.; Blusztajn, J.; Hein, J. R.; Paytan, A.

    2015-12-01

    The Monterey Canyon off central California is the largest submarine canyon off North America and is comparable in scale to the Grand Canyon. The age and history of the Monterey Canyon are poorly constrained due to thick sediment cover and sediment disruption from turbidity currents. To address this deficit we analyzed isotopic proxies (Os, Pb, Nd) from hydrogenetic ferromanganese (Fe-Mn) crusts, which grow over millions of years on elevated rock surfaces by precipitation of metals from seawater. Fe-Mn crusts were studied from Davidson Seamount near the base of the Monterey submarine fan, the Taney Seamount Chain, and from Hoss Seamount, which serves as a regional control (Fig.). Fe-Mn crusts were dated using Os isotope ratios compared to those that define the Cenozoic Os isotope seawater curve. Four Fe-Mn crust samples from Davidson and Taney Seamounts deviate from the Os isotopic seawater curve towards radiogenic values after 4.5±1 Ma. Osmium is well mixed in the global ocean and is not subject to significant diffusive reequilibration in Fe-Mn crusts. We therefore attribute deviations from the Os isotope seawater curve to large-scale terrestrial input that ended about 4.5±1 Ma. The two Davidson samples also show more radiogenic Nd isotope values from about 4.5±1 Ma. Lead isotopes in one Davidson Seamount crust, measured by LA-ICPMS, deviate from regional values after 4.5±1 Ma for about 500 ka towards terrestrial sources. The Taney Seamount Fe-Mn crust does not deviate from regional Nd nor Pb isotope values due to its greater distance from Monterey Canyon and the shorter marine residence times of Nd and Pb. Isotope plots of our crust data and compiled data for potential source rocks indicate that the river that carved Monterey Canyon carried sediment with values closer to the Sierra Nevada than to a Colorado Plateau source, with cessation of major riverine input occurring approximately 4.5±1 Ma, an age that we interpret as the end of the Monterey Canyon

  6. Odoo-toiminnanohjausjärjestelmän käyttöönotto openSUSE Linux -järjestelmässä.

    OpenAIRE

    Hietala, Jesse

    2016-01-01

    Seinäjoen ammattikorkeakoululla on käynnissä projekti teollisen internetin laboratorion rakentamiseksi. Laboratoriota tullaan käyttämään opetukseen ja tutkimiseen. Tämän työn tarkoituksena oli tuottaa toimiva toiminnanohjausjärjestelmä rakenteilla olevaan teollisen internetin laboratorioon. Tämän lisäksi tuli myös kirjoittaa tehdystä työstä mahdollisimman yksityiskohtainen ohje Seinäjoen ammattikorkeakoulun käyttöön. Työn toimeksiantajana toimi Seinäjoen ammattikorkeakoulun Tekniikan yksi...

  7. Preliminary observations on the benthic marine algae of the Gorringe seabank (northeast Atlantic Ocean)

    Science.gov (United States)

    Tittley, Ian; da Silva Vaz Álvaro, Nuno Miguel; de Melo Azevedo Neto, Ana Isabel

    2014-06-01

    Examination of marine samples collected in 2006 from the Gettysburg and Ormonde seamounts on the Gorringe seabank southwest of Portugal has revealed 29 benthic Chlorophyta, Phaeophyceae (Ochrophyta), and Rhodophyta that were identified provisionally to genus and to species. Combining lists for the present and a previous expedition brings the total of algae thus far recorded to 48. The brown alga Zonaria tournefourtii and the red alga Cryptopleura ramosa were the most abundant species in the present collections. The kelp Laminaria ochroleuca was present only in the Gettysburg samples while Saccorhiza polyschides was observed only on the Ormonde seamount. Comparisons with the benthic marine algae recorded on seamounts in the mid-Atlantic Azores archipelago show features in common, notably kelp forests of L. ochroleuca at depths below 30 m and Z. tournefortii dominance in shallower waters.

  8. Uranium-series disequilibria of inflated sections of the Juan de Fuca Ridge: Implications for mantle melting

    Science.gov (United States)

    Dreyer, B. M.; Gill, J. B.; Ramos, F. C.; Clague, D. A.; Scott, S. R.

    2010-12-01

    U-Th disequilibria are reported for the two inflated portions (defined by bathymetric highs) of the Juan de Fuca Ridge (JdFR): Axial Seamount and the northern Endeavour segment. Both have broad axis-centered bathymetric plateaus, commonly attributed to the influence of the adjacent Heckle and Cobb melt anomalies, respectively. We explore structural and geochemical contrasts between them that imply fundamental differences in magma plumbing and/or transport processes. The depth to the axial magma chamber (AMC) within the JdFR crust is shallowest beneath Axial Seamount and deepest and most variable beneath Endeavour. Lavas from Endeavour include the most enriched and diverse compositions of the JdFR. Endeavour N-MORBs are most similar to Axial basalts in K2O/TiO2, La/Yb, Na8, and Fe8 although most Axial basalts have lower MgO. Major element trends suggest clinopyroxene saturation at higher MgO at Endeavour. Additional basalt types from Endeavour (i.e., those with K2O/TiO2 >0.15), the West Valley segment to the north, and Southwest Seamount to the west share similar enrichments in incompatible trace elements (Th, Nb) and radiogenic-Pb. Similar characteristics are absent from basalts from the adjacent Heck and Heckle seamount chains, which are highly-depleted N-MORBs, precluding the hypothesis that thickened and inflated crust at Endeavour is associated with increased melt supply due to transit over the seamount source. In contrast, Axial basalts are more chemically homogeneous, and share selected geochemical characteristics with the adjacent Cobb seamount chain. New uranium-series data suggest fundamental differences in melting parameters between inflated and non-inflated portions of the JdFR. Average Th/U at Endeavour (3.03 ± 6, n=10) is nearly indistinguishable from Axial (2.83 ± 9, n=17), but both are distinct from elsewhere on the JdFR (~2.1-2.5). That is, basalts erupted from regions of inflated crust have higher Th/U. Despite high overall compositional

  9. New 40Ar/39Ar age progression for the Louisville hot spot trail and implications for inter-hot spot motion

    Science.gov (United States)

    Koppers, Anthony A. P.; Gowen, Molly D.; Colwell, Lauren E.; Gee, Jeffrey S.; Lonsdale, Peter F.; Mahoney, John J.; Duncan, Robert A.

    2011-12-01

    hot spot motions, therefore provide a better fit to the new Louisville age data. The fit is particularly good for seamounts younger than 50 Ma, a period for which there is little predicted motion for the Louisville hot spot and little inter-hot spot motion with Hawaii. However, discrepancies in the Louisville age-distance record prior to 50 Ma indicate there is an extra source of inter-hot spot motion between Louisville and the other Pacific hot spots that was not corrected for in the global S04G model. Finally, based on six new 40Ar/39Ar age dates, the 169°W bend in the Louisville seamount trail seems to have formed at least 3 Myr before the formation of the Hawaiian-Emperor bend. The timing of the most acute parts of both bends thus appears to be asynchronous, which would require other processes (e.g., plume motions) than a global plate motion change between 50 and 47 Ma to explain these two observations.

  10. Mass balance and decontamination times of Polycyclic Aromatic Hydrocarbons in rural nested catchments of an early industrialized region (Seine River basin, France).

    Science.gov (United States)

    Gateuille, David; Evrard, Olivier; Lefevre, Irène; Moreau-Guigon, Elodie; Alliot, Fabrice; Chevreuil, Marc; Mouchel, Jean-Marie

    2014-02-01

    Accumulation of Polycyclic Aromatic Hydrocarbons (PAHs) in soils and their subsequent release in rivers constitute a major environmental and public health problem in industrialized countries. In the Seine River basin (France), some PAHs exceed the target concentrations, and the objectives of good chemical status required by the European Water Framework Directive might not be achieved. This investigation was conducted in an upstream subcatchment where atmospheric fallout (n=42), soil (n=33), river water (n=26) and sediment (n=101) samples were collected during one entire hydrological year. PAH concentrations in atmospheric fallout appeared to vary seasonally and to depend on the distance to urban areas. They varied between 60 ng·L(-1) (in a remote site during autumn) and 2,380 ng·L(-1) (in a built-up area during winter). PAH stocks in soils of the catchment were estimated based on land use, as mean PAH concentrations varied between 110 ng·g(-1) under woodland and 2,120 ng·g(-1) in built-up areas. They ranged from 12 to 220 kg·km(-2). PAH contamination in the aqueous phase of rivers remained homogeneous across the catchment (72 ± 38 ng·L(-1)). In contrast, contamination of suspended solid was heterogeneous depending on hydrological conditions and population density in the drainage area. Moreover, PAH concentrations appeared to be higher in sediment (230-9,210 ng·g(-1)) than in the nearby soils. Annual mass balance calculation conducted at the catchment scale showed that current PAH losses were mainly due to dissipation (biodegradation, photo-oxidation and volatilization) within the catchments (about 80%) whereas exports due to soil erosion and riverine transport appeared to be of minor importance. Based on the calculated fluxes, PAHs appeared to have long decontamination times in soils (40 to 1,850 years) thereby compromising the achievement of legislative targets. Overall, the study highlighted the major role of legacy contamination that supplied the bulk of

  11. Long-Term Low Tide Monitoring Data for Fishes, Shrimps, & Crabs in Oyster Landing Creek, North Inlet Estuary, Georgetown, South Carolina: 1983-2003.

    Data.gov (United States)

    Baruch Institute for Marine and Coastal Sciences, Univ of South Carolina — Seine samples of the nekton community were taken every 2 weeks with a 6-millimeter mesh bag seine at low tide, in an intertidal creek pool in the Oyster Landing...

  12. Deep-sea scleractinian coral age and depth distributions in the northwest Atlantic for the last 225,000 years

    Science.gov (United States)

    Robinson, L.F.; Adkins, J.F.; Scheirer, D.S.; Fernandez, D.P.; Gagnon, A.; Waller, R.G.

    2007-01-01

    Deep-sea corals have grown for over 200,000 yrs on the New England Seamounts in the northwest Atlantic, and this paper describes their distribution both with respect to depth and time. Many thousands of fossil scleractinian corals were collected on a series of cruises from 2003-2005; by contrast, live ones were scarce. On these seamounts, the depth distribution of fossil Desmophyllum dianthus (Esper, 1794) is markedly different to that of the colonial scleractinian corals, extending 750 m deeper in the water column to a distinct cut-off at 2500 m. This cut-off is likely to be controlled by the maximum depth of a notch-shaped feature in the seamount morphology. The ages of D. dianthus corals as determined by U-series measurements range from modern to older than 200,000 yrs. The age distribution is not constant over time, and most corals have ages from the last glacial period. Within the glacial period, increases in coral population density at Muir and Manning Seamounts coincided with times at which large-scale ocean circulation changes have been documented in the deep North Atlantic. Ocean circulation changes have an effect on coral distributions, but the cause of the link is not known. ?? 2007 Rosenstiel School of Marine and Atmospheric Science of the University of Miami.

  13. FY 1992 Report on the results of the research and development of manganese nodule collection system. Total system (Test schedules); 1992 nendo mangan dankai saiko system no kenkyu kaihatsu (mangan dankai saiko system) seika hokokusho. 2/5. Total system (jikken keikaku) hen

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1993-03-01

    This project is aimed at development of the fluid dredging type technologies for collecting manganese nodules on deep sea beds (4,000 to 6,000m deep), in order to secure stable supply of the non-ferrous metal resources and improve marine development technologies. The test sea area determined is the seamount JA-4 south of the Minami-Torishima Island. The test schedule preparation working group has drawn the draft test schedules; the phase 1 tests (including water lifting and towing tests) at the TA-GA area, a sea area with a relatively thick acoustic transparent layer, located on the east side of the center of the flat peak of the seamount, and phase 2 tests (including mineral lifting tests) at the TA-GB area, a terrace on the south-east side of the flat peak of the seamount, where seamount manganese nodules are massively occurring. The studies for preparing the test schedules are started, based on the drafts, and also the studies are implemented for the test implementation manuals, including those suitable for No.3 Hakuryu as the test vessel. The other items studied include the basic studies on the air lift system for collecting minerals on a commercial scale, and on economic evaluation. (NEDO)

  14. Effects of isolation and fishing on the marine ecosystems of Easter Island and Salas y Gómez, Chile

    Science.gov (United States)

    Friedlander, Alan M.; Ballesteros, Enric; Beets, Jim; Berkenpas, Eric; Gaymer, Carlos F.; Gorny, Matthias; Sala, Enric

    2013-01-01

    1. An expedition to Salas y Gómez and Easter islands was conducted to develop a comprehensive baseline of the nearshore marine ecosystem, to survey seamounts of the recently created Motu Motiro Hiva Marine Park (MMHMP) – a no-take marine reserve of 150 000 km2 – and to compare these results with Easter Island where the marine ecosystem is similar but has no marine protection. 2. Live coral cover was surprisingly high at both Easter Island (53%) and Salas y Gómez (44%), especially considering their sub-tropical location, high wave energy environments, and geographic isolation. 3. Endemic and regionally-endemic species comprised 77% of the fish abundance at Easter Island and 73% at Salas y Gómez. Fish biomass at Salas y Gómez was relatively high (1.2 t ha-1) and included a large proportion of apex predators (43%), whereas at Easter Island it was almost three times lower (0.45 t ha-1) with large predators accounting for less than 2% of the biomass, despite good habitat quality. 4. The large cohort of small sharks and the absence of larger sharks at Salas y Gómez suggest mesopredator release consistent with recent shark fishing. The fish fauna at the seamounts between Easter Island and Salas y Gómez, outside of MMHMP, harboured 46% endemic species, including a new species of damselfish (Chromis sp. nov.) and probably a new species of Chimaera (Hydrolagus). Numerous seamounts adjacent to Salas y Gómez are currently not included in the MMHMP. 5. This expedition highlights the high biodiversity value of this remote part of the Pacific owing to the uniqueness (endemicity) of the fauna, large apex predator biomass, and geographic isolation.

  15. Avoidance of damages in hot water heating systems. Part 1. Corrosion and hot water - locating; Vermeidung von Schaeden in Warmwasserheizungen. Teil 1. Korrosion und Heizungswasser - eine Standortbestimmung

    Energy Technology Data Exchange (ETDEWEB)

    Lapp, I.; Hannemann, M.

    2003-01-01

    In the following article the most important working fluids are presented, their influence on heating systems as also the most important water treatment possibilities are shown. (GL) [German] Praktisch in jeder Heizung wird Wasser als Waermetraeger verwendet. Aus diesem Grunde ist es in jedem Fall ratsam, die Eigenschaften dieses speziellen Waermetraegers, seine Wechselwirkungen mit den Heizungswerkstoffen und andere Besonderheiten zu kennen. In dem folgenden Artikel werden die wichtigsten Eigenschaften gebraeuchlicher Waesser und deren Auswirkungen auf die Heizungsanlagen dargelegt sowie die wichtigsten Behandlungsverfahren vorgestellt. (orig.)

  16. Einkauf trifft Industrie 4.0

    OpenAIRE

    Henke, Michael; Schulte, Axel T.

    2016-01-01

    Der digitale Strukturwandel wird ohne den Einkauf nicht erfolgreich sein. Allerdings gehen die Meinungen über seine Rolle weit auseinander. Sie reichen von "aktiver Treiber" bis "lediglich Unterstützer". Deshalb muss sich der Einkauf stärker in die Diskussion um Industrie 4.0 einschalten

  17. Energy policy and the scope of action of the EC; Die energiepolitischen Handlungsmoeglichkeiten der EG

    Energy Technology Data Exchange (ETDEWEB)

    Brand, E. [Universitaet Lueneburg, Lueneburg (Germany); Witthohn, A. [IHK Hannover (Germany)

    2002-04-01

    This contribution examines the legal basis of authorization and the scope of action of the European legislator with respect to legislation on the energy policy of the EC. The analysis starts with summarising the evolution of the primary law, looking inter alia at the constitutent treaties of the ECSC, EURATOM, and the EEC, and discusses further developments and treaties, as there is no specific, uniform basis of legislative power of the EC in the energy sector of EC. Subsequently, the basis for and secondary law making is discussed, the concluding part of the article giving an outlook on the future. (orig./CB) [German] Zentrale Frage des folgenden Beitrags ist, woraus der europaeische Gesetzgeber seine Kompetenz im Energiebereich ableitet und wie weit seine Regelungen in dem Bereich gehen duerfen. Um diese Fragen zu beantworten, wird zunaechst die Entwicklung des europaeischen Primaerrechts bzw. der Gruendungsvertraege im Energiebereich beleuchtet und werden die einschlaegigen Ermaechtigungsgrundlagen dargestellt. Im Anschluss daran stehen dann die wichtigsten sekundaerrechtlichen Regelungen im Mittelpunkt. Abschliessend wird ein Ausblick auf die weitere Entwicklung gegeben. (orig./CB)

  18. Limfjordens Fiskeri 1890-1925

    DEFF Research Database (Denmark)

    Jacobsen, A. Lif Lund

    2003-01-01

    not be used. Traditionally the majority of the fishermen were against seine fishing, because it disturbed fishing with standing gear, and the government had in the 1907-fisherylaw illegalized the technology. But because of the economic crises the fishermen in 1922 agreed to request the government to ease......Fishing the Limfjord 1890-1925 – biology, economy and management. The subject of research is why the Danish government in 1923 and 1925 passed a law, which in the Limfjord allowed the use of motor driven winches for pulling seines on board. In order to examine the question, I analyze the fishery...... of gear used in the Limfjord was the so-called “standing gears”, which is pound nets, gillnets, traps and hooks. Even though the Danish-seine in 1848 was invented in the Limfjord, by a local fisherman, the use of all types of seine was limited. The fishermen still preferred to invest in standing gears...

  19. 76 FR 28457 - In the Matter of Certain Toner Cartridges and Components Thereof; Determination Not To Review an...

    Science.gov (United States)

    2011-05-17

    ...'l, Ltd. of Zhuhai, China; Ninestar Technology Co., Ltd. of Zhuhai, China; Ninestar Management Co., Ltd. of Zhuhai, China; Zhuhai Seine Technology Co. of Zhuhai, China; Seine Image Int'l Co. of Shatin...; Nano Pacific Corp. of South San Francisco, California; Ninestar Tech. Co., Ltd. of City of Industry...

  20. Case series

    African Journals Online (AJOL)

    abp

    30 janv. 2017 ... dominés respectivement par le cancer du sein dans 27,6% des cas, les cancers digestifs dans 15,8% .... vessie, de l'utérus (corps ou col) et du sein qui métastasent au foie .... Distant metastases from head and neck cancer.

  1. KARAKTERISTIK TEKNIS ALAT TANGKAP PUKAT CINCIN DI PERAIRAN TELUK APAR, KABUPATEN PASER - KALIMANTAN TIMUR

    Directory of Open Access Journals (Sweden)

    Mahiswara Mahiswara

    2016-04-01

    Full Text Available Pukat cincin merupakan salah satu alat tangkap yang dioperasikan nelayan di Perairan Teluk Apar, Kalimantan Timur. Pukat cincin Teluk Apar tergolong pukat cincin jaring lingkar dan menggunakan material sederhana dalam konstruksinya. Penelitian pukat cincin bertujuan untuk mengetahui karakteristik secara teknis. Metode deskriptif-observatif digunakan untuk menghimpun data. Analisis data digunakan untuk menentukan nilai rasio antara daya tenggelam dan daya apung. Hasil analisis menunjukkan bahwa, nilai rasio antara daya tenggelam dan daya apung pukat cincin Teluk Apar adalah 1,68. Penggunaan material polyvynil chloride (PVC dan batu kali, mengurangi efektivitas pukat cincin. Penggunaan material yang tepat (kuningan untuk cincin, timah hitam untuk pemberat, penambahan waktu rendam rumpon dan meningkatkan kemampuan jangkauan daerah penangkapan dapat mengoptimalkan kinerja pukat cincin Teluk Apar.  Purse seine is one of the fishing gear that operated in Teluk Apar water, East Kalimantan. Teluk apar purse seine is categorized a ring net and constructed by using simple materials. The aims of study is to determine the technical characteristics of teluk apar purse seine. Descriptive and observation methods are used to gather data. Analysis of the data used to determine the value of the ratio between the sinking force and buoyancy. The result showed that the ratio between the sinking force and buoyancy of teluk apar purse seine is 1,68. The use of polyvynil chloride (PVC and the stone, reducing the effectiveness of purse seine. The use of appropriate materials (bronze for ring and plumbum for sinker, the addition of FADs soak time and improve the fishing ground coverage can optimize the performance of Teluk Apar purse seine.

  2. Cruise Summary Report - MEDWAVES survey (MEDiterranean out flow WAter and Vulnerable EcosystemS)

    OpenAIRE

    Orejas, Covadonga; Addamo, Anna; Alvarez, Marta; Aparicio, Alberto; Alcoverro, Daniel; Arnaud-Haond, Sophie; Bilan, Meri; Boavida, Joana; Cainzos, Veronica; Calderon, Ruben; Cambeiro, Peregrino; Castano, Monica; Fox, Alan; Gallardo, Marina; Gori, Andrea

    2017-01-01

    The MEDWAVES (MEDiterranean out flow WAter and Vulnerable EcosystemS) cruise targeted areas under the potential influence of the MOW within the Mediterranean and Atlantic realms. These include seamounts where Cold-water corals (CWCs) have been reported but that are still poorly known, and which may act as essential “stepping stones” connecting fauna of seamounts in the Mediterranean with those of the continental shelf of Portugal, the Azores and the Mid-Atlantic Ridge. During MEDWAVES samplin...

  3. Sedimentologic and volcanologic investigation of the deep tyrrhenian sea: preliminary result of cruise VST02

    Directory of Open Access Journals (Sweden)

    A. Bertagnini

    2006-06-01

    Full Text Available The VST02 cruise carried out in the summer of 2002 was focused at sedimentologic and volcanologic researches over selected areas of the deep portion of the Tyrrhenian sea. Chirp lines and seafloor samples were collected from the Calabrian slope surrounding Stromboli island, in the Marsili deep sea fan, in the Vavilov basin and in the Vavilov seamount. Submarine volcanic activity, both explosive and effusive, is occuring in the Stromboli edifice. Explosive submarine volcanism affects also the shallowest areas of the Vavilov seamount. Submarine carbonate lithification has been observed on the sediment-starved flanks of the Vavilov seamount. Acoustic transparent layers make up the recentmost infill of the Gortani basin, the easternmost portion of the Vavilov basin. Channels comprised of a variety of architectural elements and depositional lobes are the main elements of the Marsili deep-sea fan where, apparently, sedimentation occurs mainly through debris flow processes.

  4. Zwischen Commonsense und Wissenschaft Mathematik in der Erziehungsphilosophie A. N. Whiteheads

    Science.gov (United States)

    Sölch, Dennis

    Obwohl Whitehead heute wie selbstverständlich als Philosoph rezipiert wird, so hat er seine wissenschaftliche Laufbahn doch als Mathematiker begonnen. Lange Zeit war er gemeinsam mit Bertrand Russell als Autor der Principia Mathematica unter Mathematikern und mathematischen Logikern deutlich besser bekannt als unter Philosophen. Doch selbst von denjenigen, die sich mit Whiteheads Überlegungen zur Metaphysik, zur Wissenschaftsgeschichte und zur Theologie befassen, werden seine Schriften zur Philosophie von Erziehung und Bildung häufig kaum beachtet. So entgeht es leicht, dass Whitehead nicht nur ein auf theoretischem Gebiet brillanter Mathematiker war, sondern sein theoretisches Fachwissen im Hinblick auf pädagogische und didaktische Relevanz fortwährend reflektiert hat.

  5. Multibeam Bathymetry Mapping for U.S. UNCLOS Concerns: A Gold Mine for Marine Geology

    Science.gov (United States)

    Gardner, J. V.; Mayer, L. A.; Armstrong, A.

    2007-12-01

    Since 2003, the University of New Hampshire's Center for Coastal and Ocean Mapping-Joint Hydrographic Center has conducted mapping of several U.S. continental margins in areas where a potential exists for an extended continental shelf as defined under Article 76 of the United Nations Convention on the Law of the Sea. UNH was directed by Congress, through funding to NOAA, to map the bathymetry in areas in the Arctic Ocean, Bering Sea, Gulf of Alaska, Atlantic, Gulf of Mexico, Philippine Sea, and slopes of Kingman Reef and Palmyra Atoll. These new data can be used to accurately locate the 2500-m isobath and to determine the location of the maximum change in gradient at the base of the continental slopes. To achieve these objectives, the area between ~1000 m and ~5000 m isobaths are mapped. The program has mapped >900,000 km2 as of September 2007. The bathymetry data are collected with multibeam echosounders navigated with inertial-aided DGPS and are fully motion compensated. An integral part of the data collection is measurements of the sound-speed profile in the water column to correct for refraction. The data are fully processed at sea. Most cruises also collect 3.5-kHz high-resolution profiles and some have included gravity measurements. All processed bathymetry and associated acoustic backscatter data are immediately available one the web and the raw multibeam datagrams and processed gravity data are archived at NOAA/NGDC. The new data provide a wealth of new information on the geomorphology of the continental margins. The mapping discovered many new features on the U.S. margins, as well as better defined features known to exist but either poorly mapped or mapped with obsolete mapping technology. New features discovered during the surveys include an undiscovered seamount, christened Healy Seamount and a series of huge sediment ridges striking normal to the Barrow margin in the Arctic Ocean; a series of plateaus and ridges north of Bowers Ridge in the Bering Sea

  6. Small-scale Forearc Structure from Residual Bathymetry and Vertical Gravity Gradients at the Cocos-North America Subduction Zone offshore Mexico

    Science.gov (United States)

    Garcia, E. S. M.; Ito, Y.

    2017-12-01

    The subduction of topographic relief on the incoming plate at subduction zones causes deformation of the plate interface as well as the overriding plate. Whether the resulting geometric irregularities play any role in inhibiting or inducing seismic rupture is a topic of relevance for megathrust earthquake source studies. A method to discern the small-scale structure at subduction zone forearcs was recently developed by Bassett and Watts (2015). Their technique constructs an ensemble average of the trench-perpendicular topography, and the removal of this regional tectonic signal reveals the short-wavelength residual bathymetric anomalies. Using examples from selected areas at the Tonga, Mariana, and Japan subduction zones, they were able to link residual bathymetric anomalies to the subduction of seamount chains, given the similarities in wavelength and amplitude to the morphology of seamounts that have yet to subduct. We focus here on an analysis of forearc structures found in the Mexico segment of the Middle America subduction zone, and their potential mechanical interaction with areas on the plate interface that have been previously identified as source regions for earthquake ruptures and aseismic events. We identified several prominent residual bathymetric anomalies off the Guerrero and Oaxaca coastlines, mainly in the shallow portion of the plate interface and between 15 and 50 kilometers away from the trench axis. The residual amplitude of these bathymetric anomalies is typically in the hundreds of meters. Some of the residual bathymetric anomalies offshore Oaxaca are found landward of seamount chains on the incoming Cocos Plate, suggesting that these anomalies are associated with the prior subduction of seamounts at the margin. We also separated the residual and regional components of satellite-based vertical gravity gradient data using a directional median filter to isolate the possible gravity signals from the seamount edifices.

  7. Coaching im Zeitalter der Hyperkomplexität

    DEFF Research Database (Denmark)

    Stelter, Reinhard

    deutsche Soziologe und Systemtheoretiker Nicklas Luhmann den Begriff „Kontingenz“ eingeführt, der beschreibt wie etwas ist (war, sein wird), sein kann, aber auch anders möglich ist. Kontingenz beschreibt den frustrierenden Zustand, dass alles auch anders beschrieben, erklärt und gelöst werden kann. Doch...

  8. 50 CFR 600.725 - General prohibitions.

    Science.gov (United States)

    2010-10-01

    .... Longline. F. Recreational fishery F. Hook and line, rod and reel, spear. 9. Atlantic Bluefish Fishery (FMP.... Purse seine, seine. C. Mixed species pot and trap fishery C. Pot, trap. D. Bluefish, croaker, flounder... Bluefish Fishery (FMP): A. Bluefish, croaker, and flounder trawl fishery A. Trawl. B. Pelagic longline and...

  9. First record of the Two-striped Box Crab Calappa bilineata Ng, Lai & Aungtonya, 2002 (Brachyura: Calappidae from St. Martin’s Island, Bangladesh

    Directory of Open Access Journals (Sweden)

    Muntasir Akash

    2017-01-01

    Full Text Available As part of survey of a BS (hons study tour conducted by the Department of Zoology, University of Dhaka, two specimens of box crab were caught with a beach seine net from the northern beach in front of the Hotel Prince Heaven (20038’07.50”N & 92019’34.68”E on new moon of 07th December 2012.  Those box crabs were identified as the Two Striped Box Crab Calappa bilineata Ng, Lai & Aungtonya, 2002 which is turned out as a new record for Bangladesh and a record for the northern part of the Bay of Bengal. 

  10. Impact of water overstock on groundwater quality of the Bassee plain area (France)

    Science.gov (United States)

    Gourcy, L.; Pettenati, M.; Baran, N.; Durand, P. Y.

    2009-04-01

    The project, inspired by the structural flood plain management measures of the Rhine River, consists in the temporal removal of a maximum amount of water from the Seine River in order to leave priority to the water from the River Yonne. Yonne River and the Seine are presenting their maximum water flow usually at a same time. The space located between Bray-sur-Seine and Montereau-Fault-Yonne corresponding to the La Bassée plain (agricultural area of 23 km2) is well adapted to this project of temporary and artificial flood. The objective of the project financed by the Institution Interdépartementale des barrages Réservoirs du Bassin de la Seine (IIBRBS), the BRGM, the Seine-Normandie Water Agency, the European Communauty through the Interreg IIIB SAND project is the evaluation, at a local scale, of the impact on groundwater quality of the temporal Seine water storage. Indeed, the water over storage i) changes hydraulic conditions and therefore modify water and pollutants transfers through the unsaturated and saturated zones and ii) bring at soil surface a water (Seine River) potentially containing contaminants that may move to groundwater and consequently changed physico-chemicals conditions (redox) of groundwater. The estimation of the vulnerability of groundwater to changes and loads needs hydraulic and geochemical modelling of transfer through the unsaturated zone as well as the study of pollutants fate in static conditions. Retention properties of some metals (Pb, Ni, Cu, Cr, Zn) in soils and materials of the unsaturated zone by chemical processes were performed determining adsorption coefficient (Kd) by laboratory experiments. These experiments are showing that nickel mobility is lower in the argillous layers than in the sandy part of the unsaturated zone. Ni mobility is controlled by iron hydroxides and precipitation of other secondary minerals. Its complexation on organic ligands increases its mobility in soils. Copper concentration is influenced by CaCO3

  11. S- and Sr-isotopic compositions in barite-silica chimney from the Franklin Seamount, Woodlark Basin, Papua New Guinea: constraints on genesis and temporal variability of hydrothermal fluid

    Science.gov (United States)

    Ray, Durbar; Banerjee, Ranadip; Balakrishnan, S.; Paropkari, Anil L.; Mukhopadhyay, Subir

    2017-07-01

    Isotopic ratios of strontium and sulfur in six layers across a horizontal section of a hydrothermal barite-silica chimney from Franklin Seamount of western Woodlark Basin have been investigated. Sr-isotopic ratios in barite samples (87Sr/86Sr = 0.70478-0.70493) are less radiogenic than seawater (87Sr/86Sr = 0.70917) indicating that substantial leaching of sub-seafloor magma was involved in the genesis of hydrothermal fluid. The SO2 of magma likely contributed a considerable amount of lighter S-isotope in fluid and responsible for the formation of barite, which is isotopically lighter (δ34S = 19.4-20.5 ‰) than modern seawater (δ34S 21 ‰). The systematic changes in isotopic compositions across the chimney wall suggest temporal changes in the mode of mineral formation during the growth of the chimney. Enrichment of heavy S- and Sr-isotopes (δ34S = 20.58 ‰; 87Sr/86Sr = 0.70493) in the outermost periphery of the chimney indicates that, at the initial stage of chimney development, there was a significant contribution of seawater sulfate during barite mineralization. Thereafter, thickening of chimney wall occurred due to precipitation of fluid carrying more magmatic components relative to seawater. This led to a gradual enrichment of lighter isotopes (δ34S = 20.42-19.48 ‰; 87Sr/86Sr = 0.70491-0.704787) toward the inner portion of the chimney wall. In contrast, the innermost layer surrounding the fluid conduit is characterized by heavier and more radiogenic isotopes (δ34S = 20.3 ‰; 87Sr/86Sr = 0.7049). This suggests there was increasing influence of percolating seawater on the mineral paragenesis at the waning phase of the chimney development.

  12. SlideDog / Siim Sein

    Index Scriptorium Estoniae

    Sein, Siim

    2015-01-01

    SlideDog on multimeediumi esitluse tööriist, mis võimaldab ühendada PowerPointi esitlused, PDF-failid, Prezi esitlused, videoklipid, helifailid, veebilehed ja palju muud üheks sujuvaks esitluskogemuseks konverentsil, seminaril või muul üritusel

  13. Virtual Investigations of an Active Deep Sea Volcano

    Science.gov (United States)

    Sautter, L.; Taylor, M. M.; Fundis, A.; Kelley, D. S.; Elend, M.

    2013-12-01

    Axial Seamount, located on the Juan de Fuca spreading ridge 300 miles off the Oregon coast, is an active volcano whose summit caldera lies 1500 m beneath the sea surface. Ongoing construction of the Regional Scale Nodes (RSN) cabled observatory by the University of Washington (funded by the NSF Ocean Observatories Initiative) has allowed for exploration of recent lava flows and active hydrothermal vents using HD video mounted on the ROVs, ROPOS and JASON II. College level oceanography/marine geology online laboratory exercises referred to as Online Concept Modules (OCMs) have been created using video and video frame-captured mosaics to promote skill development for characterizing and quantifying deep sea environments. Students proceed at their own pace through a sequence of short movies with which they (a) gain background knowledge, (b) learn skills to identify and classify features or biota within a targeted environment, (c) practice these skills, and (d) use their knowledge and skills to make interpretations regarding the environment. Part (d) serves as the necessary assessment component of the laboratory exercise. Two Axial Seamount-focused OCMs will be presented: 1) Lava Flow Characterization: Identifying a Suitable Cable Route, and 2) Assessing Hydrothermal Vent Communities: Comparisons Among Multiple Sulfide Chimneys.

  14. Post-Cretaceous intraplate volcanism in the Central Indian Ocean Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Mukhopadhyay, R.

    , recent findings such as inconsistent and non-uniform growth of basinal seamounts in the geological past, often influenced by local factors such as magma availability, con- duit geometry, and eruption style (Mukhopadhyay and Khadge, 1994), availability... of that evolutionary trend (Batiza et al., 1989). Major- ity of the CIOB seamounts are found to be covered with pillow lava, suggesting a slow rate of effusion, and indicating that magma is less evolved. In con- trast, dredging carried out at the enlarged portions...

  15. Le Phénomène Wolf-Rayet au Sein des Etoiles chaudes de Populations I et II: Histoire des Vents stellaires et Impact sur la Structure nébulaire circumstellaire

    Science.gov (United States)

    Grosdidier, Yves

    2000-12-01

    -pics de BD +30 3639 suggère une anisotropie transitoire de la distribution des fragments dans le vent; (3) Le phénomène WR apparaît purement atmosphérique: la cinématique des sous-pics, les amplitudes et les échelles de temps caractéristiques des variations, ainsi que les accélérations observées sont similaires pour les deux populations. Mais, pour HD 826, une accélération maximale d'environ 70 m/s2 est détectée, valeur significativement plus importante que celles rapportées pour les autres étoiles WR pop. I & II (environ 15 m/s2). La petitesse du rayon de HD 826 en serait la cause; (4) Comme pour les WR pop. I, de grands paramètres (β supérieur ou égal à 3-10) sont requis pour ajuster les accélérations observées avec une loi de vitesse de type beta. La loi beta sous-estime systématiquement les gradients de vitesse au sein de la région de formation de la raie CIIIl5696; (5) Les vents WR pop. II étant fragmentés, l'estimation des taux de perte de masse actuels à partir de méthodes supposant les atmosphères homogènes conduit à une surestimation i) des taux de perte de masse eux-mêmes, et ii) des masses initiales des étoiles avant qu'elles n'entrent dans la phase WR. IMPACT DES VENTS: (1) Au périastre, de la poussière est détectée dans l'environnement de la binaire WC+OB WR 137. La formation de poussières est soit facilitée, soit provoquée par la collision des deux vents chauds; le rôle capital de la fragmentation des vents (fournissant une compression localisée supplémentaire du plasma) est suggéré (2) La nébuleuse M 1-67 affiche une interaction avec le milieu interstellaire (MIS) non-négligeable (``bow-shock''). Les champs de densité et de vitesse sont très perturbés. Ces perturbations sont reliées, d'une part, à l'histoire des vents issus de WR 124 durant sa propre évolution, d'autre part, à l'interaction avec le MIS. Les fonctions de structure des champs de densitéet de vitesse de M 1-67 ne révèlent aucun indice

  16. MRI in dementia-type diseases; MRT bei demenziellen Erkrankungen

    Energy Technology Data Exchange (ETDEWEB)

    Bodea, S.V.; Muehl-Benninghaus, R. [Universitaetsklinikum des Saarlandes, Klinik fuer Diagnostische und Interventionelle Neuroradiologie, Homburg (Germany)

    2015-05-01

    Dementia-inducing conditions represent a leading cause of disability and are a major health concern in industrialized countries. The burden these conditions put on society is certain to rise in the context of an ever-increasing elderly population. As these conditions feature an insidious onset and overlapping clinical features, imaging is a powerful tool in refining the diagnosis and assessing the progression of dementing conditions. The radiologist needs to be aware of and be able to detect underlying pathologies which could be reversible. Furthermore, imaging is important not only in excluding other pathologies but also in improving diagnostic accuracy. This article presents the typical clinical presentations as well as magnetic resonance imaging (MRI) features of the degenerative and the non-degenerative causes of dementia. The focus is on the core knowledge for MRI diagnostics in dementing conditions and a brief presentation of the latest MRI techniques which may become a part of standard imaging protocols in the future. (orig.) [German] Demenzielle Erkrankungen gehoeren in den Industrielaendern zu den haeufigsten Ursachen fuer Beeintraechtigungen im Alltag. Durch eine stetig alternde Population nimmt auch die Belastung fuer die Gesellschaft immer weiter zu. Bei haeufig schleichendem Symptombeginn sowie sich ueberlappender Klinik mit anderen Krankeitsbildern kann die Bildgebung ein gutes Werkzeug zur Praezisierung der Diagnose und Beurteilung eines Progresses sein. Der Radiologe sollte andere und reversible Pathologien erkennen und von demenztypischen Veraenderungen abgrenzen koennen. Dieser Artikel beschreibt typische klinische Symptome und auch bildmorphologische Veraenderungen verschiedener Demenzformen, die durch neurodegenerative und nichtdegenerative Ursachen bedingt sein koennen. Ausserdem werden aktuellste MRT-Techniken vorgestellt. Diese koennten kuenftig im Standartprotokoll zur Bildgebung bei der Abklaerung demenzieller Syndrome verankert sein. (orig.)

  17. Diversity and Petrogenesis of Bonin Rear-Arc

    Science.gov (United States)

    Heywood, L. J.; DeBari, S. M.; Schindlbeck, J. C.; Escobar-Burciaga, R. D.; Gill, J.

    2016-12-01

    The Izu Bonin subduction zone has a history of abundant rhyolite production that is relevant to the development of intermediate to silicic middle crust. This study presents major and trace elemental compositions (via electron microprobe and LA-ICP-MS) of unaltered volcanic glass and phenocrysts from select medium- to high-K tephra intervals from IODP Site 1437 (Expedition 350, Izu Bonin Rear Arc). These data provide a time-resolved record of regional explosive magmatism ( 4.4Ma to present). Tephra from Site 1437 is basaltic to rhyolitic glass with accompanying phenocrysts, including hornblende. Glass compositions form a medium-K magmatic series with LREE enrichment (LaN/YbN = 2.5-6) whose trace element ratios and isotopic compositions are distinct from magmas with similar SiO2 contents in the main Izu Bonin volcanic front. Other workers have shown progressive enrichment in K and other trace element ratios moving from volcanic front westwards through the extensional region to the western seamounts in the rear arc. The <4.4 Ma rear-arc rhyolites from Site 1437 show pronounced negative Eu anomalies, high LaN/SmN (2-3.5), Ba/La <25 and Th of 1.5-4 ppm. These rhyolites show the highest variability for a given SiO2 content among all rear-arc magmas (rhyolites have 1.5-3.5 wt% K2O, Zr/Y of 1-8, LaN of 5-9 ppm) consistent with variability in literature reports of other rhyolite samples dredged from surrounding seamounts. Rhyolites have been dredged from several nearby seamounts with other high-K rhyolites dredged as close as nearby Meireki Seamount ( 3.8 Ma) and further afield in the Genroku seamount chain ( 1.88 Ma), which we compare to Site 1437 rhyolites. An extremely low-K rhyolite sill (13.6 Ma) was drilled lower in the section at Site U1437, suggesting that the mechanism for producing rhyolites in the Western Seamounts region changed over time. Rhyolites are either produced by differentiation of mafic magmas, by melting of pre-existing arc crust (as hypothesized in

  18. Falsche und richtige lexikographische Definitionen

    DEFF Research Database (Denmark)

    Bergenholtz, Henning

    2005-01-01

    Lexikographische Definitionen sollten wahr sein, man kann dabei relativ leicht die fehlerhaften aussortieren. Das lexikographisch Interessante besteht in Begründungen für die Wahl zwischen mehreren wahren Möglichkeiten.......Lexikographische Definitionen sollten wahr sein, man kann dabei relativ leicht die fehlerhaften aussortieren. Das lexikographisch Interessante besteht in Begründungen für die Wahl zwischen mehreren wahren Möglichkeiten....

  19. Connaissances, attitudes et pratiques des prestataires de santé des ...

    African Journals Online (AJOL)

    ... des prestataires interrogés avaient respectivement une bonne connaissance des facteurs de risque et des moyens de dépistage. Les signes évocateurs et les examens complémentaires nécessaires au diagnostic du cancer du sein étaient connus par 15,3 % des prestataires. La définition du cancer du sein et les moyens ...

  20. Jurassic-Paleogene intra-oceanic magmatic evolution of the Ankara Mélange, North-Central Anatolia, Turkey

    Science.gov (United States)

    Sarifakioglu, E.; Dilek, Y.; Sevin, M.

    2013-11-01

    Oceanic rocks in the Ankara Mélange along the Izmir-Ankara-Erzincan suture zone (IAESZ) in North-Central Anatolia include locally coherent ophiolite complexes (~179 Ma and ~80 Ma), seamount or oceanic plateau volcanic units with pelagic and reefal limestones (96.6 ± 1.8 Ma), metamorphic rocks with ages of 187.4 ± 3.7 Ma, 158.4 ± 4.2 Ma, and 83.5 ± 1.2 Ma, and subalkaline to alkaline volcanic and plutonic rocks of an island arc origin (~67-63 Ma). All but the arc rocks occur in a shaly-graywacke and/or serpentinite matrix, and are deformed by south-vergent thrust faults and folds that developed in the Middle to Late Eocene due to continental collisions in the region. Ophiolitic volcanic rocks have mid-ocean ridge (MORB) and island arc tholeiite (IAT) affinities showing moderate to significant LILE enrichment and depletion in Nb, Hf, Ti, Y and Yb, which indicate the influence of subduction-derived fluids in their melt evolution. Seamount/oceanic plateau basalts show ocean island basalt (OIB) affinities. The arc-related volcanic rocks, lamprophyric dikes and syeno-dioritic plutons exhibit high-K shoshonitic to medium-to high-K calc-alkaline compositions with strong enrichment in LILE, REE and Pb, and initial ϵNd values between +1.3 and +1.7. Subalkaline arc volcanic units occur in the northern part of the mélange, whereas the younger alkaline volcanic rocks and intrusions (lamprophyre dikes and syeno-dioritic plutons) in the southern part. The Early to Late Jurassic and Late Cretaceous epidote-actinolite, epidote-chlorite and epidote-glaucophane schists represent the metamorphic units formed in a subduction channel in the Northern Neotethys. The Middle to Upper Triassic neritic limestones spatially associated with the seamount volcanic rocks indicate that the Northern Neotethys was an open ocean with its MORB-type oceanic lithosphere by the Early Triassic. The Latest Cretaceous-Early Paleocene island arc volcanic, dike and plutonic rocks with

  1. Structural factors controlling inter-plate coupling and earthquake rupture process

    Science.gov (United States)

    Kodaira, S.

    2007-05-01

    Recent availability of a large number of ocean bottom seismographs (OBSs), a large volume of air-gun array and a long streamer cable for academics provide several new findings of lithospheric scale structures in subduction seismogenic zones. JAMSTEC has acquired long-offset seismic data using a super-densely deploy OBS (i.e. 1 - 5 km spacing OBSs along 100 - 500 km long profiles) in the Nankai seismogeinc zone, SW. Japan, since 1999. Long-offset multichannel seismic (MCS) data by a two-ship experiment, as well as conventional 2D MCS data, have been also acquired at a part of the profiles. Some of those profiles have been designed as combined onshore - offshore profiles for imaging a land-ocean transition zone. One of the most striking findings is an image of several scales of subducted seamounts/ridges in the Nankai trough seismogenic zone. We detected the subducted seamount/ridges, which are 50 - 100 km wide, distributing from near trough axis to ~ 40 km deep beneath the Japanese island. From a point of seismogenic process, an important aspect is that those structures are strongly correlated with slip zones of magnitude 8-class earthquakes, i.e.; subducted seamounts/ridge control the rupture propagations. Moreover, the most recent seismic study crossing the segmentation boundary between M=8 class earthquakes detected a high seismic velocity body forming a strongly coupled patch at the segmentation boundary. The numerical simulation incorporating all those structures explained the historic rupture patterns, and shows the occurrence of a giant earthquake along the entire Nankai trough, a distance of over 600 km long (Mw=8.7). The growth processes of a rupture revealed from the simulation are; 1) prior to the giant earthquake, a small slow event (or earthquake) occurs near the segmentation boundary, 2) this accelerates a very slow slip (slower than the plate convergent rate), at the strong patch, which reduces a degree of coupling, 3) then a rupture easily propagates

  2. Plan de negocio en soluciones de energía renovable para servicios eléctricos básicos de empresas

    OpenAIRE

    Lafitte Vega, Jorge Leonidas; Ignacio Esteban, Giancarlo; Gutiérrez Ramírez, Hugo Daniel

    2016-01-01

    La empresa Clean Energy S.A.C. plantea el uso de energías renovables a través de paneles fotovoltaicos. Esta tecnología permite reducir el costo del consumo de servicios básicos de electricidad que se toman de empresas de distribución eléctrica. El estudio de mercado indica que hay una oportunidad para penetrar en el segmento de empresas que forman parte del Sistema Eléctrico Interconectado Nacional (SEIN), principalmente, transmisores, distribuidores y clientes libres. Se sabe que las tarifa...

  3. Interpretation of bathymetric and magnetic data from the easternmost segment of Australian-Antarctic Ridge, 156°-161°E

    Science.gov (United States)

    Choi, H.; Kim, S.; Park, S.

    2013-12-01

    From 2011 to 2013, Korea Polar Research Institute (KOPRI) conducted a series of geophysical and geochemical expeditions on the longest and easternmost segment of Australian-Antarctic Ridge, located at 61°-63°S, and 156°-161°E. This ridge segment plays an important role in constraining the tectonics of the Antarctic plate. Using IBRV ARAON, the detailed bathymetric data and eleven total magnetic profiles were collected. The studied ridge has spread NNW-SSE direction and tends to be shallower to the west and deeper to the east. The western side of the ridge (156°-157.50°E) shows a broad axial high and a plenty of seamounts as an indicative of massive volcanism. Near the center of the ridge (158°-159°E), a seamount chain is formed stretching toward the south from the ridge. Also, the symmetric seafloor fabric is clearly observed at the eastern portion (158.50°-160°E) of the seamount chain. From the topographic change along the ridge axis, the western part of the ridge appears to have a sufficient magma supply. On the contrary, the eastern side of the ridge (160°-161°E) is characterized by axial valley and relatively deeper depth. Nevertheless, the observed total magnetic field anomalies exhibit symmetric patterns across the ridge axis. Although there have not been enough magnetic survey lines, the spreading rates of the ridge are estimated as the half-spreading rate of 37.7 mm/y and 35.3 mm/y for the western portion of the ridge and 42.3 mm/y for the eastern portion. The studied ridge can be categorized as an intermediate spreading ridge, confirming previous studies based on the spreading rate of global ridge system. Here we will present the preliminary results on bathymetric changes along the ridge axis and its relationship with melt supply distribution, and detailed magnetic properties of the ridge constrained by the observed total field anomalies.

  4. Structure and Dynamics of the Southeast Indian Ridge, 129°E to 140°E, and Off-axis Volcanism: Preliminary Results of the STORM Cruise

    Science.gov (United States)

    Briais, Anne; Barrère, Fabienne; Boulart, Cédric; Ceuleneer, Georges; Ferreira, Nicolas; Hanan, Barry; Hémond, Christophe; Macleod, Sarah; Maia, Marcia; Maillard, Agnès; Merkuryev, Sergey; Park, Sung-Hyun; Révillon, Sidonie; Ruellan, Etienne; Schohn, Alexandre; Watson, Sally; Yang, Yun-Seok

    2016-04-01

    We present observations of the South-East Indian Ridge (SEIR) collected during the STORM cruise (South Tasmania Ocean Ridge and Mantle) on the N/O L'Atalante early 2015. The SEIR between Australia and Antarctica displays large variations of axial morphology despite an almost constant intermediate spreading rate. The Australia-Antarctic Discordance (AAD) between 120°E and 128°E is a section of the mid-ocean ridge where the magma budget is abnormally low, and which marks the boundary between Indian and Pacific mantle domains with distinct geochemical isotopic compositions. The STORM project focuses on the area east of the discordance from 128 to 140°E, where gravity highs observed on satellite-derived maps of the flanks of the SEIR reveal numerous volcanic seamounts. A major objective of the STORM cruise was to test the hypothesis of a mantle flow from the Pacific to the Indian domains. We collected multibeam bathymetry and magnetic data between 136 and 138°E to map off-axis volcanic ridges up to 10 Ma-old crust. We mapped the SEIR axis between 129 and 140°E, and the northern part of the George V transform fault. We collected rock samples on seamounts and in the transform fault, basaltic glass samples along the ridge axis, and near-bottom samples and in-situ measurements in the water column. Our observations reveal that the off-axis seamounts form near the SEIR axis, are not associated to off-axis deformation of the ocean floor, and are often located near the traces of ridge axis discontinuities. We also observe a general shallowing of the ridge axis from the AAD to the George V TF and the presence of robust axial segments near the transform fault. Our new data allow us to describe the complex evolution of the transform fault system. They also permit to locate new hydrothermal systems along the ridge axis.

  5. Seismically active column and volcanic plumbing system beneath the island arc of the Izu-Bonin subduction zone

    Science.gov (United States)

    Špičák, Aleš; Vaněk, Jiří; Hanuš, Václav

    2009-12-01

    A detailed spatio-temporal analysis of teleseismic earthquake occurrence (mb > 4.0) along the convergent margin of the Izu-Bonin-Mariana arc system reveals an anomalously high concentration of events between 27° and 30.5°N, beneath a chain of seamounts between Tori-shima and Nishino-shima volcanoes. This seismicity is dominated by the 1985/1986 earthquake swarm represented in the Engdahl-van der Hilst-Buland database by 146 earthquakes in the body wave magnitude range 4.3-5.8 and focal depth range 1-100 km. The epicentral cluster of the swarm is elongated parallel to the volcanic chain. Available focal mechanisms are consistent with an extensional tectonic regime and reveal nodal planes with azimuths close to that of the epicentral cluster. Earthquakes of the 1985/1986 swarm occurred in seven time phases. Seismic activity migrated in space from one phase to the other. Earthquake foci belonging to individual phases of the swarm aligned in vertically disposed seismically active columns. The epicentral zones of the columns are located in the immediate vicinity of seamounts Suiyo and Mokuyo, recently reported by the Japanese Meteorological Agency as volcanically active. The three observations-episodic character of earthquake occurrence, column-like vertically arranged seismicity pattern, and existence of volcanic seamounts at the seafloor above the earthquake foci-led us to interpret the 1985/1986 swarm as a consequence of subduction-related magmatic and/or fluid activity. A modification of the shallow earthquake swarm magmatic model of D. Hill fits earthquake foci distribution, tectonic stress orientation and fault plane solutions. The 1985/1986 deep-rooted earthquake swarm in the Izu-Bonin region represents an uncommon phenomenon of plate tectonics. The portion of the lithospheric wedge that was affected by the swarm should be composed of fractured rigid, brittle material so that the source of magma and/or fluids which might induce the swarm should be situated at a

  6. Upper Triassic limestones from the northern part of Japan: new insights on the Panthalassa Ocean and Hokkaido Island

    Science.gov (United States)

    Peyrotty, Giovan; Peybernes, Camille; Ueda, Hayato; Martini, Rossana

    2017-04-01

    In comparison with the well-known Tethyan domain, Upper Triassic limestones from the Panthalassa Ocean are still poorly known. However, these carbonates represent a unique opportunity to have a more accurate view of the Panthalassa Ocean during the Triassic. Their study will allow comparison and correlation of biotic assemblages, biostratigraphy, diagenesis, and depositional settings of different Triassic localities from Tethyan and Panthalassic domains. Moreover, investigation of these carbonates will provide data for taxonomic revisions and helps to better constrain palaeobiogeographic models. One of the best targets for the study of these carbonates is Hokkaido Island (north of Japan). Indeed, this island is a part of the South-North continuity of Jurassic to Paleogene accretionary complexes, going from the Philippines to Sakhalin Island (Far East Russia). Jurassic and Cretaceous accretionary complexes of Japan and Philippines contain Triassic mid-oceanic seamount carbonates from the western Panthalassa Ocean (Onoue & Sano, 2007; Kiessling & Flügel, 2000). They have been accreted either as isolated limestone slabs or as clasts and boulders, and are associated with mudstones, cherts, breccias and basaltic rocks. Two major tectonic units forming Hokkaido Island and containing Triassic limestones have been accurately explored and extensively sampled: the Oshima Belt (west Hokkaido) a Jurassic accretionary complex, and the Cretaceous Sorachi-Yezo Belt (central Hokkaido). The Sorachi-Yezo Belt is composed of Cretaceous accretionary complexes in the east and of Cretaceous clastic basin sediments deposited on a Jurassic basement in the west (Ueda, 2016), both containing Triassic limestones. The origin of this belt is still matter of debate especially because of its western part which is not in continuity with any other accretionary complex known in the other islands of Japan and also due to the lack of data in this region. One of the main goals of this study is to

  7. L’Entrepreneuriat au sein de la famille. Marchands et entrepreneurs en Inde Entrepreneurship in the Family Context: Merchants and Entrepreneurs in India

    Directory of Open Access Journals (Sweden)

    Harald Tambs-Lyche

    2013-06-01

    Full Text Available Malgré le déni de Max Weber, l’essor actuel de l’économie indienne montre que non seulement l’esprit du capitalisme, mais aussi l’entrepreneuriat, sont bien présents en Inde. Dans cet article, j’analyse les stratégies commerciales des Gauda Saraswat Brahmanes du Sud Kanara (autour de Mangalore, sur la côte Ouest de l’Inde, en utilisant le modèle d’entrepreneuriat proposé par Fredrik Barth (1962, 1967. Fidèle à la tradition du « capitalisme de portefeuille » (Baily 1989, ces marchands distribuent leur capital entre des filières sûres mais modérément rentables, et des projets novateurs et profitables mais risqués. L’entrepreneur, ici, n’est que rarement l’individu, car il s’agit le plus souvent d’une stratégie orchestrée par la famille, qui se confond à son tour avec la firme familiale. Cette orchestration exige des chefs de famille un souci constant de management qui se manifeste en écoutant les idées des cadets et en leur confiant des rôles qui les gratifient au sein de l’entreprise familiale, tout en gardant la main sur la stratégie globale de la firme.In spite of Max Weber’s views, the present growth in the Indian economy shows rather conclusively the presence both of the spirit of capitalism and of entrepreneurship in India. In this article, I analyse the commercial strategies of the Gauda Saraswat Brahmins of South Kanara (around Mangalore, on the West coast of India, using the model of entrepreneurship proposed by Fredrik Barth (1962, 1967. True to the tradition of portefeuille capitalism (Baily 1989, these merchants distribute their capital between safe but moderately remunerative ventures, and projects that are profitable but risky. The entrepreneur, here, is rarely an individual, rather we see a strategy orchestrated by the family, which in its turn corresponds to the family firm. This organisation demands constant attention from the head of the family, who must listen to the ideas of

  8. Ein Ausblick auf Supply-Chain-Management im Jahr 2016

    DEFF Research Database (Denmark)

    Wieland, Andreas

    2016-01-01

    Wie sieht Supply-Chain-Management im Jahr 2016 aus? Was erwartet uns? Vieles deutet darauf hin, dass SCM in Zukunft sogar noch mehr auf den Kunden gerichtet sein könnte als bisher.......Wie sieht Supply-Chain-Management im Jahr 2016 aus? Was erwartet uns? Vieles deutet darauf hin, dass SCM in Zukunft sogar noch mehr auf den Kunden gerichtet sein könnte als bisher....

  9. The Supreme Allied Commander’s Operational Approach

    Science.gov (United States)

    2014-05-22

    the Seine below Paris , and then began converging toward the northern line of march just below the first. A third line broke off from the second in a...toward the Seine Basin and Paris .” Therefore, in the aftermath of Goodwood Eisenhower felt both disappointed and deceived. After Goodwood, Eisenhower...command. Simultaneously, Bradley’s armies were to “[capture] Brest , [protect] the southern flank of the

  10. Kada parašytas vadinamasis Krauzės žodynas

    Directory of Open Access Journals (Sweden)

    Vincentas Drotvinas

    2011-12-01

    Full Text Available WANN WURDE DAS SOGENANNTE WÖRTERBUCH VON KRAUSE GESCHRIEBEN?ZusammenfassungDer Beitrag hat das Ziel, das Entstehungsdatum des sogenannten handschriftlichen deutsch-litauischen Wörterbuches von Krause nachzuprüfen. Bisher besteht die Meinung (J. Lebedys, daß dieses Wörterbuch im 17. Jh. geschrieben worden ist und sein Autor (oder der Besitzer Andreas Krause (gest. 1655 gewesen sein könnte. Mit Hilfe von Wasserzeichenanalyse haben wir aber fest­gestellt, daß das Wörterbuch auf Papier der Papiermühle von Johann Wilhelm Steinmetz (1720— 1749, ehem. O