dbf2e081-b332-4d20-b242-2daa5fed25ae 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 2024-10-07 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 Basal Elevation and Reflectivity beneath Rutford Ice Stream from ground-based 3D migrated radar data acquired in 2017/18 within two 3x3km2 areas 2024-10-07 creation 2024-10-07 revision 2024-10-07 publication 2024-10-07 released 1.0 https://doi.org/10.5285/dbf2e081-b332-4d20-b242-2daa5fed25ae doi GB/NERC/BAS/PDC/01917 https://data.bas.ac.uk/ NE/G014159/1 award NE/G013187/1 award NE/F015879/1 award Please cite this item as: Schlegel, R., Smith, A., Brisbourne, A., Clark, R., & Booth, A. (2024). Basal Elevation and Reflectivity beneath Rutford Ice Stream from ground-based 3D migrated radar data acquired in 2017/18 within two 3x3km2 areas (Version 1.0) [Data set]. NERC EDS UK Polar Data Centre. https://doi.org/10.5285/dbf2e081-b332-4d20-b242-2daa5fed25ae High-resolution basal topography and basal properties were calculated from two 3x3 km2 radar datasets acquired approximately 50 km upstream of the grounding line of Rutford Ice Stream in West Antarctica. The provided datasets contain several csv-files including the coordinates, bed elevation below the WGS84 ellipsoid and the reflectivity of the bed reflection. The X and Y coordinates are projected in EPSG:3031 - WGS 84 / Antarctic Polar Stereographic coordinate system. Radar data were acquired between December 2017 and late January 2018 using the British Antarctic Survey's ground-based DELORES system as part of the BEAMISH project. Data acquisition and processing was compliant with 3D processing and migration. Radar data were frequency filtered and 3D migrated (using a 3D Kirchhoff Time Migration approach in SeisSpace/ProMAX (LGCHalliburton Software) and migration velocity of 0.168 m ns-1), followed by the picking of the bed reflection using Petrel (Schlumberger Software). For the interpretation of variation of bed properties, basal reflectivity was calculated as described in Schlegel et al., 2022 and Schlegel et al., 2024. This work was funded by NERC AFI award numbers NE/G014159/1, NE/G013187/1 and NE/F015879/1, and NERC National Capability Science: Strategic Research and Innovation Short Projects. Geophysical equipment was provided by NERC's Geophysical Equipment Facility, loan number 887. We thank BAS Operations and N. Gillett for fieldwork support and B. Craven for software support. University of Leeds acknowledges support of this work by Landmark Software and Services, a Landmark Company and use of SeisSpace/ProMAX via the Landmark University Grant Program, Agreements 2004-COM-024982, 2008-CON-010888 and subsequent renewals. The British Antarctic Survey acknowledges support of this work by Landmark Software and Services, a Landmark Company. No credit. completed Schlegel, Rebecca Tubingen University Researcher author Smith, Andrew British Antarctic Survey Researcher author Brisbourne, Alex British Antarctic Survey Researcher author Clark, Roger University of Leeds Researcher author Booth, Adam University of Leeds 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 > Cryosphere > Glaciers/Ice Sheets > Glacier Topography/Ice Sheet Topography EARTH SCIENCE > Spectral/Engineering > Radar > Radar Reflectivity EARTH SCIENCE > Cryosphere > Glaciers/Ice Sheets 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 3D radar data bed properties ice dynamics ice stream subglacial topography theme Rutford Ice Stream, West Antarctica Antarctica place Elevation 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 Data supplied under Open Government Licence v3.0 otherRestrictions No restrictions apply. doi doi crossReference doi doi crossReference doi doi crossReference doi doi crossReference doi doi crossReference url url largerWorkCitation url url crossReference textTable eng utf8 geoscientificInformation -83.9888 -83.7937 -78.1707 -78.0926 2017-12-27 2018-02-02 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 text/csv text/plain bytes 716800 http://ramadda.data.bas.ac.uk/repository/entry/show?entryid=dbf2e081-b332-4d20-b242-2daa5fed25ae WWW:LINK-1.0-http--link Get Data Download data download bytes 716800 http://ramadda.data.bas.ac.uk/repository/entry/show?entryid=dbf2e081-b332-4d20-b242-2daa5fed25ae WWW:LINK-1.0-http--link Get Data Download data download dataset Methodology: The dataset is composed of two 3*3km² grids which were acquired in 2017/18. Spatial sampling is compatible with 3D migration (2 m along-track, 20 m across-track). Processing of the densely spaced grids includes regularisation of the acquired grid by interpolation, bandpass filtering, correction for geometric spreading and 3D Kirchhoff Time migration (horizontal resolution of 24 m in both along- and cross-track directions). 3D topography: Data in both grids are compliant with 3D migration. For the application of the migration data were interpolated into a regular grid with regular line and trace spacing. Following this, data were frequency filtered and 3D migrated using a Kirchhoff Time migration approach (migration velocity of 0.168 m ns-1) in SeisSpace/ProMAX. The bed reflection was picked using a semi-automated 3D seeded picking algorithm in Petrel software (Landmark). The two-way traveltime of the bed reflection was then converted into ice thickness using a conversation speed of 0.168m/ns. The resulting bed elevation relative to the WGS84 ellipsoid was calculated by subtracting the ice thickness from the surface elevation (which was acquired by a dual frequency GPS during acquisition). Radar reflectivity: The amplitude of the reflection was corrected for englacial attenuation and geometric spreading. Following this, the bed reflectivity was calculated as described in Schlegel et al. (2022) (using a 280 ns window). Data collection: Instrumentation: Surface radar data were acquired using the British Antarctic Survey (BAS) DELORES radar system (King et al., 2007). Dual-frequency GPS antennas were mounted on the system for positioning. Data quality: The 3D migrated radar data shows more details of the bed topography compared to the 2D migrated data. Even though most parts of the bed show a clear reflection, the steep flanks of bedforms lack a clear return in the 3D migrated data. The centre frequency of the DELORES dataset presented here is 3 MHz, the wavelength in ice (wave speed in ice=0.168 m ns-1) is 56 m. Lines were acquired perpendicular to the ice flow, with a 20 m spacing between them. The along-track sampling is around 2 m. Topography data has been 3D migrated, the theoretical horizontal resolution of the dataset after 3D migration is 12 m. asNeeded completed