1158843c-d238-439a-ad42-9645f37ac582 eng utf8 dataset dataset NERC EDS UK Polar Data Centre +44 (0)1223 221400 British Antarctic Survey, High Cross, Madingley Road Cambridge Cambridgeshire CB3 0ET United Kingdom polardatacentre@bas.ac.uk https://www.bas.ac.uk/team/business-teams/information-services/uk-polar-data-centre/ information pointOfContact 2019-07-22 ISO 19115 Geographic Information - Metadata ISO 19115:2003(E) European Petroleum Survey Group (EPSG) Geodetic Parameter Registry 2008-11-12 publication European Petroleum Survey Group EPSGadministrator@iogp.org https://www.epsg-registry.org/ EPSG Geodetic Parameter Dataset The EPSG Geodetic Parameter Dataset is a structured dataset of Coordinate Reference Systems and Coordinate Transformations, accessible through this online registry. information publisher urn:ogc:def:crs:EPSG::3031 6.18.3 A bathymetric compilation around the South Orkney Islands, 1987-2017 2019-07-22 creation 2019-07-22 revision 2019-07-22 publication 2019-07-22 released 1.0 https://doi.org/10.5285/1158843c-d238-439a-ad42-9645f37ac582 doi GB/NERC/BAS/PDC/01196 https://data.bas.ac.uk/ NE/K012843/1 award NE/N018095/1 award Please cite this item as: Abrahamsen, E. (2019). A bathymetric compilation around the South Orkney Islands, 1987-2017 (Version 1.0) [Data set]. UK Polar Data Centre, Natural Environment Research Council, UK Research & Innovation. https://doi.org/10.5285/1158843c-d238-439a-ad42-9645f37ac582 We present a new bathymetric compilation around the South Orkney Islands here defined by the following bounding box: 47 to 37 W, 63 to 59 S. This bathymetry grid was compiled from a variety of multibeam swath bathymetry data acquired during 46 different cruises (see lineage). The data is available as a grid of approximately 100 m resolution in a GMT-compatible (2-D) NetCDF format using geographic coordinates on the WGS84 datum. Three versions of the grid are available: the first one shows only swath bathymetry data while the second and third have been merged with the global compilations from the General Bathymetric Chart of the Oceans (GEBCO), GEBCO_2014 (version 20150318) and GEBCO_2019, respectively. Quick views are also available in the corresponding folder. Funding was provided by the NERC grants NE/K012843/1 and NE/N018095/1 as well as national capability No credit. completed Abrahamsen, E. Povl British Antarctic Survey, Natural Environment Research Council, UK Research & Innovation Researcher author NERC EDS UK Polar Data Centre +44 (0)1223 221400 British Antarctic Survey, High Cross, Madingley Road Cambridge Cambridgeshire CB3 0ET United Kingdom PDCServiceDesk@bas.ac.uk https://www.bas.ac.uk/team/business-teams/information-services/uk-polar-data-centre/ information pointOfContact asNeeded completed EARTH SCIENCE > Land Surface > Topography > Landforms EARTH SCIENCE > Oceans > Bathymetry/Seafloor Topography > Bathymetry EARTH SCIENCE > Oceans > Bathymetry/Seafloor Topography > Seafloor Topography EARTH SCIENCE > Oceans > Bathymetry/Seafloor Topography > Water Depth EARTH SCIENCE > Oceans > Bathymetry/Seafloor Topography theme Global Change Master Directory (GCMD) Science Keywords 2026-01-27 publication 23 Global Change Data Center, Science and Exploration Directorate, Goddard Space Flight Center (GSFC) National Aeronautics and Space Administration (NASA) Greenbelt MD United States of America https://earthdata.nasa.gov/about/gcmd/global-change-master-directory-gcmd-keywords Global Change Master Directory (GCMD) Keywords The information provided on this page seeks to define how the GCMD Keywords are structured, used and accessed. It also provides information on how users can participate in the further development of the keywords. information publisher Bathymetry Multibeam Orkney Passage Scotia Sea South Orkney Islands South Orkney Trough Wedell Sea theme South Orkney Islands Antarctica Scotia Sea Antarctica Wedell Sea Antarctica Orkney Passage Antarctica South Orkney Trough Antarctica place Land cover Oceanographic geographical features theme GEMET - INSPIRE themes, version 1.0 2021-01-06 revision otherRestrictions no limitations to public access otherRestrictions no limitations license Open Government Licence v3.0 otherRestrictions This data is governed by the NERC Data Policy: https://www.ukri.org/who-we-are/nerc/our-policies-and-standards/nerc-data-policy/ otherRestrictions Further by downloading this data the user acknowledges that they agree with the NERC data policy (), and the following conditions: 1. To cite the data Abrahamsen, E. P. (2019). A bathymetric compilation around the South Orkney Islands, 1987-2017 (Version 1.0) [Data set]. UK Polar Data Centre, Natural Environment Research Council, UK Research & Innovation. https://doi.org/10.5285/1158843c-d238-439a-ad42-9645f37ac582 2. The user recognizes the limitations of data and will not use this data for navigation purposes. Use of the data is at the users' own risk, and there is no warranty as to the quality or accuracy of any data, or the fitness of the data for your intended use. The data are not necessarily fully quality assured and cannot be expected to be free from measurement uncertainty, systematic biases, or errors of interpretation or analysis, and may include inaccuracies in error margins quoted with the data. otherRestrictions None url url dependency doi doi crossReference doi doi crossReference doi doi crossReference doi doi crossReference doi doi crossReference doi doi crossReference doi doi crossReference doi doi crossReference doi doi crossReference doi doi crossReference doi doi crossReference doi doi crossReference doi doi crossReference doi doi crossReference url url crossReference url url dependency doi doi crossReference textTable eng utf8 elevation geoscientificInformation oceans -47.0 -37.0 -63.0 -59.0 1987-01-01 2017-12-31 It is recommended that careful attention be paid to the contents of any data, and that the author be contacted with any questions regarding appropriate use. If you find any errors or omissions, please report them to polardatacentre@bas.ac.uk. NERC EDS UK Polar Data Centre +44 (0)1223 221400 British Antarctic Survey, High Cross, Madingley Road Cambridge Cambridgeshire CB3 0ET United Kingdom PDCServiceDesk@bas.ac.uk https://www.bas.ac.uk/team/business-teams/information-services/uk-polar-data-centre/ information distributor application/x-hdf5 application/x-hdf application/pdf text/csv bytes 299892736 https://ramadda.data.bas.ac.uk/repository/entry/show?entryid=1158843c-d238-439a-ad42-9645f37ac582 WWW:LINK-1.0-http--link Get Data Download data download bytes 299892736 https://ramadda.data.bas.ac.uk/repository/entry/show?entryid=1158843c-d238-439a-ad42-9645f37ac582 WWW:LINK-1.0-http--link Get Data Download data download bytes 299892736 https://ramadda.data.bas.ac.uk/repository/entry/show?entryid=1158843c-d238-439a-ad42-9645f37ac582 WWW:LINK-1.0-http--link Get Data Download data download bytes 299892736 https://ramadda.data.bas.ac.uk/repository/entry/show?entryid=1158843c-d238-439a-ad42-9645f37ac582 WWW:LINK-1.0-http--link Get Data Download data download dataset Methodology: The bathymetry map was compiled from a variety of different data sources. The primary data are multibeam swath bathymetry collected from scientific cruises undertaken by British Antarctic Survey (BAS), Alfred Wegener Institute (AWI), or acquired during RV Nathaniel B. Palmer, RRS James Cook and ESPS RV Hesperides expeditions. The complete list of the cruises used for the compilation is available in the supplementary documents (Source_data.csv file). The multibeam data are merged with GEBCO_2014 (version 20150318) and GEBCO_2019 (doi: 10.5285/836f016a-33be-6ddc-e053-6c86abc0788e). Both of these grids are available from https://www.gebco.net. The grid with bathymetry data only was created using the mbgrid program from MB-system version 5.5.2336 , using the parameters "-E100/100/meters -R-47/-37/-63/-59 -G3 -A2 -T25 -W4 -N -M -C5/1 -P1 -F1 -V". This uses a Gaussian weighted mean filter. Values are interpolated using a spline (tension 25) up to five grid cells from the nearest data point only if additional data are found in two opposite directions. To merge with the global grids, the resulting grid is then loaded into Matlab R2019a. A subset of the GEBCO_2014 grid at 30 arcseconds or GEBCO_2019 at 15 arcseconds resolution is loaded into Matlab and interpolated onto the same grid. The grids are then subtracted, and the resulting grid is expanded by one grid cell in all directions, with the new cells filed with zeros. A list of the resulting values (excluding those that do not have any multibeam data) is exported to a temporary text file. This file is then run through mbgrid with parameters "-G3 -A2 -T50 -C9999/3 -W50 -V", resulting in a grid of differences between the multibeam and background data, with all data gaps filled with a spline. This offset is then subtracted from the background data, and the resulting values substituted into the gaps in the multibeam grid. The Matlab codes are available on GitHub at the following address: https://gist.github.com/PovlAbrahamsen/6ebce11cc637e8f434267c03672a354b Data quality: Quality control was undertaken manually to remove any outliers in the source datasets. This involved cleaning much of the raw data using the "mbedit" program from MB-system. For data processed in this way, edit files have been submitted to the Polar Data Centre. In source files that were ingested as text files, outliers were manually removed. To verify the accuracy of the resulting dataset, bottom depths were compared against CTD casts on cruise JR16005, excluding casts that were performed when the ship was moving and those where the CTD did not get within altimeter range of the bottom. Bottom depths were calculated from the CTD altimeter when near the bottom, and these were compared against the gridded dataset. On 81 casts, the median difference between the CTD-derived depths and gridded depths was 4.1 m with a standard deviation of 18.9 m. This compares favourably with GEBCO_2014, which had a median offset of 4.6 m with a standard deviation of 73.4 m, and GEBCO_2019, which has a median offset of 0.5 m but a standard deviation of 89.4 m. asNeeded completed