147baf64-b9af-4a97-8091-26aec0d3c0bb 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 2019-08-14 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 Seismic refraction data from two sites on Antarctica's Larsen C Ice Shelf, Nov 2017, following the calving of Iceberg A68 2019-08-14 creation 2019-08-14 revision 2019-08-14 publication 2019-08-14 released 1.0 https://doi.org/10.5285/147baf64-b9af-4a97-8091-26aec0d3c0bb doi GB/NERC/BAS/PDC/01226 https://data.bas.ac.uk/ NE/E013414/1 award NE/R012334/1 award Please cite this item as: Booth, A., White, J., Pearce, E., Cornford, S., Brisbourne, A., Luckman, A., & Kulessa, B. (2019). Seismic refraction data from two sites on Antarctica's Larsen C Ice Shelf, Nov 2017, following the calving of Iceberg A68 (Version 1.0) [Data set]. UK Polar Data Centre, Natural Environment Research Council, UK Research & Innovation. https://doi.org/10.5285/147baf64-b9af-4a97-8091-26aec0d3c0bb Seismic refraction data were acquired at two sites on Antarctica's Larsen C Ice Shelf, in November 2017. The acquisition was performed to measure seismic anisotropy, a proxy for the stress condition, in the ice shelf following the calving of Iceberg A68 in July 2017. 2D seismic profiles were acquired at two sites: S1, close to the new calving front of the ice shelf, and S2, advected downstream from the site surveyed in the NERC funded project NE/E013414/1 (SOLIS). Profiles were rotated about a common midpoint to examine the variation in seismic properties with azimuth. Throughout, 24 geophones were deployed at 10 m offset, with data recorded at a Geometrics GEODE system; data are presented here in SEG-2 format. All acquisitions were performed by Dr Jim White (British Geological Survey) and Emma Pearce (University of Leeds, School of Earth and Environment), with support from BAS. The data is part of the NERC RACE project, NE/R012334/1. No credit. completed Booth, Adam University of Leeds Researcher author White, Jim British Geological Survey Researcher author Pearce, Emma University of Leeds Researcher author Cornford, Stephen Swansea University Researcher author Brisbourne, Alex British Antarctic Survey Researcher author Luckman, Adrian Swansea University Researcher author Kulessa, Bernd Swansea University 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 > Ice Sheets EARTH SCIENCE > Cryosphere > Snow/Ice > Snow Stratigraphy EARTH SCIENCE > Solid Earth > Seismology > Seismic Profile 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 Larsen anisotropy calving ice shelf seismic refraction theme Larsen C Ice Shelf, Antarctic Peninsula Antarctica place Elevation Meteorological geographical features Geology 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 This data is governed by the NERC data policy and supplied under Open Government Licence v.3 otherRestrictions No restrictions apply. url url crossReference url url crossReference textTable eng utf8 climatologyMeteorologyAtmosphere environment geoscientificInformation -62.56892 -61.82509 -68.0041 -67.79944 2017-11-22 2017-11-29 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/plain application/pdf application/octet-stream bytes 1610612736 https://ramadda.data.bas.ac.uk/repository/entry/show?entryid=147baf64-b9af-4a97-8091-26aec0d3c0bb WWW:LINK-1.0-http--link Get Data Download data download bytes 1610612736 https://ramadda.data.bas.ac.uk/repository/entry/show?entryid=147baf64-b9af-4a97-8091-26aec0d3c0bb WWW:LINK-1.0-http--link Get Data Download data download bytes 1610612736 https://ramadda.data.bas.ac.uk/repository/entry/show?entryid=147baf64-b9af-4a97-8091-26aec0d3c0bb WWW:LINK-1.0-http--link Get Data Download data download dataset Methodology: Seismic data were recorded using Geometrics GEODE instrumentation, deploying 24 10 Hz geophones at 10 m intervals. Each record is 1 s long, sampled at 62.5 us. A hammer-and-plate seismic source was deployed, with offsets from the first geophone extending to ±200 m, typically recording 5 shots at each location. The line was sequentially rotated about a common midpoint, relative to the dominant ~easterly flow direction. As the acquisition azimuth varies, variations in the travel-time of either first-breaks or reflections can be used to infer any trends in anisotropy and therefore stress condition. The acquisition is fully documented within the Observer's Logs which accompany these data. Data collection: Instrumentation: Geometrics GEODE seismic system. 24x10 Hz geophones. Data quality: Data from S2, acquired on 22/11/2017, are generally of good quality, with clear first breaks and visible bed reflections after minimal processing; the reflection from the underlying sea-bed is also typically visible, even in unstacked data. Data are supplied in raw format here, but an Ormsby bandpass filter with corner frequencies at 75-150-300-600 Hz, plus a 100 ms AGC window, provides good improvement to the visibility of arrivals. The good quality of these data is attributed to simple structure at the site, plus calm weather conditions at the time of acquisition (22/11/2017). Note that the time was incorrectly recorded until shot record 150. A 2 hour shift is needed, then a one hour shift after note. Data from S1 are rather noisier, likely a result of windy weather at the time of acquisition (28/11/2017). The same processing parameters reveal base-ice reflections, but these are typically less coherent than the equivalents at S2. On stacking, base-ice reflections are improved but the data would benefit from ground-roll suppression. S1 central location: 67.79944383°S, 61.825091°W S2 central location: 68.00410°S, 62.568916°W The acquisition is fully documented within the Observer's Logs which accompany these data. asNeeded completed