1,720,973 research outputs found
An Appraisal of the Surface Geology and Sedimentary Processes within SEA7, the UK Continental Shelf
Full text linkSV Kommandor Jack Cruise 01/05, 11 Jul – 08 Aug 2005. Multibeam bathymetry and high resolution sidescan sonar surveys within the SEA7 area of the UK continental shelf
No full textThe objectives of the SV Kommandor Jack 01/05 cruise were to collect EM120, and where water depths permit, EM1002 multibeam bathymetry and backscatter data, and also where desired, high resolution sidescan sonar data, over Anton Dohrn Seamount, George Bligh and Rosemary Banks, the eastern margin of Rockall Bank and selected areas of Hatton Bank. The aims were toa) create high quality bathymetric maps of the survey areasb) create acoustic backscatter maps over the same areasc) when possible, define the extent of any potential coral habitatsd) create high resolution bathymetric, backscatter and sonar maps of specific features as may be discovered, such as mud diapers, carbonate mounds etc.e) complete, during the cruise, a preliminary interpretation of the above data, to be used as a guide for the sampling and seabed photography cruise which followed immediately.This was a highly successful cruise with virtually all cruise objectives achieved. 6,384 line-km of multibeam bathymetry and backscatter data were obtained in water depths between 150 and 2,400 m. In addition, approximately 240 line-km of high resolution sidescan sonar were collected in depths between 150 and 1,500 m, and 6,323 line-km of high resolution CHIRP profiles were also collected
MV Franklin Cruise 0406, 14-23 Sep 2006. Habitat investigations on the West of Shetland continental slope
Full text linkRRS Charles Darwin Cruise 143, 22 Nov-20 Dec 2002. SCHEHEREZADE II: Geological and biological surveys of the Arabian Sea and the continental slope of Oman
Full text linkThis 28 day cruise was planned to investigate the geophysical and biological interactions in benthic environments in the Gulf of Oman and north-western Arabian Sea. The main objectives of the cruise were to produce a map of the bathymetry of the area and to investigate the geological processes that are, and have in the recent past been, active and look at the influence of the benthic community and activity on sediment acoustic properties.In fact the topography of the study area was vastly different to that indicated on the GEBCO or gravity-derived bathymetry maps, which had indicated a generally smooth continental slope running parallel to the coast. The reality was that this part of the Oman margin is highly incised by numerous submarine canyon systems, some of which are 4km in width in mid-slope and hundreds of metres deep. Thus the cruise objectives were modified slightly to incorporate an investigation of the influence of the canyons on the fauna and the Oxygen Minimum Zone (OMZ).Following successful EM12 multibeam mapping and the production of both contours and acoustic backscatter maps, over 120 stations were occupied to help us characterise the interactions between the biota and sediments, station work included intensive sampling of one transect in the north of the area and a comprehensive southern sampling transect for comparative studies. High resolution geophysics and photographic stations were also undertaken. Virtually all of the interpretive work will be carried out post-cruise
Preparation of a bathymetric map and GIS of the South Atlantic Ocean and a review of available biologically relevant South Atlantic Seamount data for the SEAFO Scientific Committee
Full text linkThis report has brought together various data sets from a number of public sources around the world to produce the most up-to-date regional bathymetric map of the South Atlantic in both printed and digital form. The use of a data control layer in the GIS allows users of this reportan indication of the data accuracy and quality. Physical and chemical parameters have also been included in the GIS, so that the Temperature, Salinity and Oxygen content of the South Atlantic, all primary agents in the distribution of the various forms of biology can be examined, at different critical depths at the same time. These critical depths were determined to be those that had most effect on the biology, and were the sea surface (0m), the lower limit of the photic zone, which we approximated to 200m, and the lower limit of the likely vertical migration of zooplankton, a major source of food at 1000m depth. Other elements presented include biogeographical provinces defined by Longhurst, a geographic depiction of the formally UNbacked named Seamount gazetteer along with a further seamount-science web-based product sponsored by the National Science Foundation in the USA, and a biological catalogue of data supported by the Census of Marine Life
Deep sea habitats - contributing towards completion of a deep sea habitat classification scheme
No full textThe main aim of this project was to analyse data and provide information that could contribute towards a high-level deep water marine seabed habitat classification scheme. This has been achieved by integrating interpreted acoustic and other deep water datasets from around the United Kingdom, with the results presented in a form that is compatible with the EUNIS habitat classification scheme. This project uses an industry-standard package (ESRI), ensuring that the different data layers presented can be utilized in whatever geospatial software is used in future spatial analysis programmes. The GIS classification layers are based on existing interpretation of several acoustic deep marine datasets and further interpretation of newly released acoustic data. BGS seabed sediment maps were combined with and modified by these interpretations. Additional data provided by BGS includes delineation of some occurrences of basalt outcrop at the seabed and areas of iceberg ploughmarks. Five classification layers are provided: Confidence, showing the confidence levels of the data available in the region; Physiography, showing the large-scale morphology of the seafloor; Substrate, showing the type of sediment/rock present; Deposits, showing areas where certain deposit types are present, deposit types relate to conditions of sediment transport and/or deposition, and Modifiers, showing areas of the seafloor which have been modified by some kind of post-deposition event or conditions
RV Colonel Templer Cruises 01 & 02/98, 22 Apr-18 Jun 1998. TOBI surveys of the continental slope north and west of Scotland
Full text linkThe objective of the cruise was to undertake comprehensive TOBI 30 kHz sidescan sonar and 7.5 kHz profiler surveys of several blocks of seafloor to the north and west of the UK which were released for hydrocarbon exploration in 1997 (Fig. 1). All of the license areas with water depth >200 m was to be surveyed. Surface towed 3.5 kHz high resolution profiles were also to be collected along all survey lines. The Research Vessel Colonel Templer was chartered by Geotek Ltd. to undertake the survey work. Although TOBI has a nominal swath width of 6 km, survey lines were typically spaced 4 to 5 km apart to allow for overlap between adjacent swaths, and for some reduction in range in the shallower water areas (typically < 1000 m waterdepth) in the northern survey blocks. This range reduction occurs because of severe temperature stratification in the water column, where warm North Atlantic Water (typically 8-9°C) immediately overlies cold water originating in the Norwegian Sea (typically < 0°C), causing refraction and reflection of the sonar energy. Processing of data and interpretation of results It was planned that a preliminary interpretation of the data would be undertaken during the survey, so that results could be transmitted to a related sampling cruise being carried out on the RRS Charles Darwin. This sampling cruise partly overlapped the sidescan surveys in time, necessitating a rapid turn round in data processing and interpretation. To this end, preliminary image processing was carried out on board, producing sidescan mosaics at a scale of 1:50,000. Sidescan and profile data were then combined into an integrated interpretation which was transmitted in digital form either to Geotek Ltd. or directly to the RRS Charles Darwin.Data annotation All data were recorded with reference to GMT and Julian day numbers.This report was originally issued as part of the AFEN 17th Round Atlantic Margins Environmental Survey data CD-ROM
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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