34 resultados para The Burnet Institute


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The present data set was used as a training set for a Habitat Suitability Model. It contains occurrence (presence-only) of living Lophelia pertusa reefs in the Irish continental margin, which were assembled from databases, cruise reports and publications. A total of 4423 records were inspected and quality assessed to ensure that they (1) represented confirmed living L. pertusa reefs (so excluding 2900 records of dead and isolated coral colony records); (2) were derived from sampling equipment that allows for accurate (<200 m) geo-referencing (so excluding 620 records derived mainly from trawling and dredging activities); and (3) were not duplicated. A total of 245 occurrences were retained for the analysis. Coral observations are highly clustered in regions targeted by research expeditions, which might lead to falsely inflated model evaluation measures (Veloz, 2009). Therefore, we coarsened the distribution data by deleting all but one record within grid cells of 0.02° resolution (Davies & Guinotte 2011). The remaining 53 points were subject to a spatial cross-validation process: a random presence point was chosen, grouped with its 12 closest neighbour presence points based on Euclidean distance and withheld from model training. This process was repeated for all records, resulting in 53 replicates of spatially non-overlapping sets of test (n=13) and training (n=40) data. The final 53 occurrence records were used for model training.

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The monograph summarizes geological and metallogenic data on the Mid-Atlantic Ridge obtained during research expeditions of the Geological Institute RAS in 2000-2003. Formation of the earth crust in the region, structure of the rift zone, structure of the newly discovered Bogdanov Fracture Zone, neotectonic deformations, metallogenic peculiarities, prospecting criteria of ocean ore mineralization are under consideration.

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The Baltic Sea is a seasonally ice-covered, marginal sea in central northern Europe. It is an essential waterway connecting highly industrialised countries. Because ship traffic is intermittently hindered by sea ice, the local weather services have been monitoring sea ice conditions for decades. In the present study we revisit a historical monitoring data set, covering the winters 1960/1961 to 1978/1979. This data set, dubbed Data Bank for Baltic Sea Ice and Sea Surface Temperatures (BASIS) ice, is based on hand-drawn maps that were collected and then digitised in 1981 in a joint project of the Finnish Institute of Marine Research (today the Finnish Meteorological Institute (FMI)) and the Swedish Meteorological and Hydrological Institute (SMHI). BASIS ice was designed for storage on punch cards and all ice information is encoded by five digits. This makes the data hard to access. Here we present a post-processed product based on the original five-digit code. Specifically, we convert to standard ice quantities (including information on ice types), which we distribute in the current and free Network Common Data Format (NetCDF). Our post-processed data set will help to assess numerical ice models and provide easy-to-access unique historical reference material for sea ice in the Baltic Sea. In addition we provide statistics showcasing the data quality. The website http://www.baltic-ocean.org hosts the post-processed data and the conversion code.

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Genetic sediment types have been identified based on a study of Core PS1599 collected from the eastern continental slope of the Weddell Sea. XRF analysis of 48 samples from this core carried out at the Vernadsky Institute of Geochemistry and Analytical Chemistry (Moscow) yielded the first comprehensive geochemical characteristics of all genetic types. Methods of correlation and factor analyses were used to outline geochemical associations of sediments and examine causes of their formation including the role of grain size composition. The results obtained have revealed fundamental differences between sources, mechanisms, and methods of transportation of sedimentary material for Holocene sediments, on the one hand, and Weichselian sediments, on the other hand.

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Baltic sediments have been studied by Behrens, Munthe, Küppers, Spethmann, Apstein, Sjöstedt, Pratje and the writer. The following types of sediments have been observed: varved and non-varved late-glacial clays, gray and black, post-glacial muds, and sands. The organic content of late-glacial clays ordinarily is less than 1.3 per cent, and of post-glacial muds more than 3 per cent. Sediments containing intermediate quantities are scarce. This can be explained as a result of the changed balance between organic and inorganic sedimentation when the glacial period ended; the abundance of fresh detritus then suddenly ceased and inorganic sedimentation became very much slower than before; consequently, the relative amount of organic detritus increased. As most of the material was not subjected to biological analysis, it has not been possible to distinguish different ages among post-glacial sediments.

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The cores and dredges described in this report were taken on Cruise 16 of the R.R.S. "Discovery" from January until May 1967 by the National Institute of Oceanography, Wormley, United Kingdom. A total of 73 cores and dredges were recovered and are available through the British Oceanographic Data Centre for sampling and study.

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The cores described are taken during the R/V Thomas Washington ROUNDABOUT Cruise from May 1988 until March 1989 by the Scripps Institute of Oceanography. A total of 159 cores and dredges were recovered and are available at Scripps Institute of Oceanography for sampling and study.

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The cores described are taken during the USS San Pablo Cruise 3 from July to August 1949 by the Scripps Institute of Oceanography. A total of 49 cores were recovered and are available at Scripps Institute of Oceanography for sampling and study.

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The cores described are taken during the USS San Pablo Cruises 10 and 11 in 1952 by the Scripps Institute of Oceanography. A total of 21 cores were recovered and are available at Scripps Institute of Oceanography for sampling and study.

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During the "Polarstern"-expeditions ARK-IX/4 (1993) and ARK-XI/1 (1995), organised by the Alfred Wegener Institute (AWI), acoustic subbottom profiles (Parasound) have been collected in the Laptev Sea Shelf, Siberia. These data have been interpreted as an indicator of ice scours frequency and off-shore permafrost patterns. An additional acoustic profile data-base was available by the results of the expedition of the Federal Institute for Geosciences and Natural Resources (BGR) of the year 1994. The area of the expedition was located closer to the shelf, therefore supports a better understanding of ice scours frequency in shallower marine environments. The data-file consists of a 2930 km Parasound-traverse and has been subdivided into 586 working profiles. They are characterised by their location, number of ice scours, interpreted patterns of reflection and their extension and morphology. The data have been evaluated statistically and graphically and were presented in a map. Different patterns of sea floor reflection were established by different environments, outer influences (e.g. size of the icebergs, direction of the drift of icebergs) and the climatic history of the region. In the north-westerly region of the Laptev Sea at the continental slope of Severnaya Zemlya the sea floor in shallower depths has been ploughed intensely by recent icebergs. In some regions (40-60m), as an effect of intensely ploughing, the sea floor is hardly defined in acoustic profiles come along with relocation of marine deposits. Glacial diamiet deposits prevented the development of deep scours. Up to 355m deeper scours result from lower sea levels. The marginal north-easterly region of the Laptev Sea is characterised exclusively by this type of scour. Morphology and depth of these scours can be compared with those of the westerly Vilkitsky-Street so that similar conditions of development may be expected. Both, the north-easterly Laptev Sea and the Vilkitsky-Street, are not dominated by patterns ofrecent icebergs. In contrary the shelf-regions north-easterly ofthe Taimyr peninsula and north-westerly of the New Siberian Islands have been modified evidently by recent icebergs, which drifted with prevalent currents anticlockwise along the shelf edge of the Laptev Sea and cause the deepest scours of the whole region. The off-shore permafrost at the inner shelf regions has an important influence on the scours intensity. The permafrost layer can be recognised by the maximum depth of ice scours. It is represented by a Parasound reflector that can be made up for distances. The age of the ice scours cannot be determined absolutely by Parasound data but a relative order can be estimated whenever two scours are situated close to each other. When the Parasound-traverse ofthe expedition ARK-IX/4 (1993) (77°24'N 133°30'E-77°30'N 133°40'E) was repeated partially in expedition ARK-XI/l (1995) the ice scours of 1993 remained unchanged and uneroded and no new ice scours had been detected. It can be concluded that scours persist for a long time in the Laptev Sea, though after all with an average of 3 ice scours per kilometer there are not many at all in the Laptev Sea.

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The cores and dredges described are taken during the MUKLUK expedition of the R/V Spencer Baird in July-August 1957 by the Scripps Institute of Oceanography. A total of 31 cores and dredges were recovered and are available at Scripps Institute of Oceanography for sampling and study.

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The Kara Sea is an area uniquely suitable for studying processes in the river-sea system. This is a shallow sea, into which two great Siberian rivers, Yenisei and Ob, flow. From 1995 to 2003, the sea was studied by six international expeditions onboard the R/V Akademik Boris Petrov. This publication summarizes the results obtained, within the framework of this project, at the Vernadsky Institute of Geochemistry and Analytical Chemistry, Russian Academy of Sciences. Various hydrogeochemical parameters, concentrations and isotopic composition of organic and carbonate carbon of the sediments, plankton, particulate organic matter, hydrocarbons, and dissolved CO2 were examined throughout the whole sea area at more than 200 sites. The d13C varies from -22 and -24 per mil where Atlantic waters enter the Kara Sea and in the north-eastern part of the water area to -27 per mil in the Yenisei and Ob estuaries. The value of d13C of the plankton is only weakly correlated with the d13C of the organic matter from the sediments and is lower by as much as 3-4 per mil. The paper presents the results obtained from a number of meridional river-sea profiles. It was determined from the relations between the isotopic compositions of plankton and particulate matter that the river waters carry material consisting of 70% detrital-humus matter and 30% planktonogenic material in the river part, and the material contained in the offshore waters consists of 30% terrigenous components, with the contribution of bioproducers amounting to 70%. The carbon isotopic composition of the plankton ranges from -29 to -35 per mil in the riverine part, from -28 to -27 per mil in the estuaries, and from -27.0 to -25 per mil in the marine part. The relative lightness of the carbon isotopic composition of plankton in Arctic waters is explained by the temperature effect, elevated CO2 concentrations, and long-distance CO2 supply to the sea with river waters. The data obtained on the isotopic composition of CO2 in the surface waters of the Kara Sea were used to map the distribution of d13C. The complex of hydrocarbon gases extracted from the waters included methane, C2-C5, and unsaturated C2=-C4= hydrocarbons, for which variations in the concentrations in the waters were studied along river-estuary-sea profiles. The geochemistry of hydrocarbon gases in surface fresh waters is characterized by comparable concentrations of methane (0.3-5 µl/l) and heavier hydrocarbons, including unsaturated ones. Microbiological methane with d13C from -105 to -90 per mil first occurs in the sediments at depths of 40-200 cm. The sediments practically everywhere display traces of methane oxidation in the form of a shift of the d13C of methane toward higher values and the occurrence of autogenic carbonate material, including ikaite, enriched in the light isotope. Ikaite (d13C from -25 to -60 per mil) was found and examined in several profiles. The redox conditions in the sediments varied from normal in the southern part of the sea to highly oxidized along the Novaya Zemlya Trough. Vertical sections through the sediments of the latter exemplify the complete suppression of the biochemical activity of microorganisms. Our data provide insight into the biogeochemistry of the Kara Sea and make it possible to specify the background values needed for ecological control during the future exploration operations and extraction of hydrocarbons in the Kara Sea.

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The Bedford Institute of Oceanography provided ship time on the C.S.S. Hudson during the B.I.0. 1967 Metrology and IODAL Cruise for surveying two separate bottom features in the North Atlantic; the Flemish Cap and the San Pablo Seamount one of the Kelvin Seamounts (also known as the New England Seamounts) about 400 miles SSE of Halifax, Nova Scotia. Underwater photography, dredging, and drilling showed San Pablo seamount to have a very considerable covering of manganese deposit, which may be recoverable by mining. San Pablo Seamount was surveyed and sampled; good hauls were made both on the top and on the slopes, at various depths from 500-1000 fathoms; in all cases samples of an unusual stratified manganese-iron ore were recovered. In the hope of gaining additional information in the immediate sample area, one of the dredges had been previously modified to accommodate underwater photographic equipment. X-ray chemical analyses indicate that the ore contains 20 to 25 per cent MnO2, with similar amounts of Fe2O3. Since bottom photographs indicate that these deposits form a continuous cover 1 foot to 3 feet thick over most of the seamount, it is estimated that there are ore reserves in the order of 10 to 30 M tons above 1,000 fathoms.