79c8eb39-5c19-440e-804f-816cd0b8e4bd 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 2024-07-22 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 Geomorphological measurements and lithological classifications of 90 erratic cobbles from the Hudson Mountains, West Antarctica 2024-07-22 creation 2024-07-22 revision 2024-07-22 publication 2024-07-22 released 1.0 https://doi.org/10.5285/79c8eb39-5c19-440e-804f-816cd0b8e4bd doi GB/NERC/BAS/PDC/01867 https://data.bas.ac.uk/ NE/S006710/1 award Please cite this item as: Johnson, J., & Smith, J. (2024). Geomorphological measurements and lithological classifications of 90 erratic cobbles from the Hudson Mountains, West Antarctica (Version 1.0) [Data set]. NERC EDS UK Polar Data Centre. https://doi.org/10.5285/79c8eb39-5c19-440e-804f-816cd0b8e4bd This dataset contains geomorphological data (measurements of size, shape, long axis orientation and weathering characteristics) on 90 erratic cobbles collected from the Hudson Mountains in West Antarctica. These were collected during three field campaigns, as follows: 1) 75 erratic cobbles collected by Joanne S Johnson during a British Antarctic Survey-supported geological field campaign undertaken in November-December 2019, as part of the International Thwaites Glacier Collaboration (funded by NERC and NSF). 2) 13 cobbles collected by James A Smith (British Antarctic Survey) in February and March 2010 during RV Polarstern cruise ANT XXVI/3, and 3) a further two cobbles collected in March 2006 by Johnson during RV Polarstern cruise ANT XXIII/4. These cobbles were all collected for surface exposure dating. Funding: NERC grant: NE/S006710/1 No credit. completed Johnson, Joanne British Antarctic Survey Researcher author Smith, James British Antarctic Survey 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 > Glaciers EARTH SCIENCE > Land Surface > Geomorphology > Glacial Landforms/Processes 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 Hudson Mountains Pine Island Glacier West Antarctica erratic granite theme Hudson Mountains Antarctica place Elevation Land cover 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 url url largerWorkCitation url url crossReference textTable eng utf8 geoscientificInformation -100.415 -98.3271 -74.9052 -74.4591 2006-03-13 2006-03-13 173.0 830.0 urn:ogc:def:crs:EPSG::5714 MSL height Not specific to any location or epoch. Hydrography. 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 bytes 17203 http://ramadda.data.bas.ac.uk/repository/entry/show?entryid=79c8eb39-5c19-440e-804f-816cd0b8e4bd WWW:LINK-1.0-http--link Get Data Download data download dataset Methodology: The erratics described in the dataset were originally collected for cosmogenic nuclide surface exposure dating, during 3 different field campaigns: in 2006 on a geological campaign undertaken during cruise ANT XXIII/4 of RV Polarstern for the BAS GRADES-QWAD project, in 2010 on a geological campaign undertaken during cruise ANT XXVI/3 of RV Polarstern, and in 2019-20 on a geological campaign supported by British Antarctic survey logistics as part of the Geological History Constraints project (one of the component projects of the International Thwaites Glacier Collaboration). The data here pertain to their location, size, shape, orientation, degree of weathering and lithology. Locations (latitude, longitude and altitude, m above sea level) were measured using GPS (details for each season are provided in point 7 below). The size of each erratic was measured in the field using a standard ruler. Three axes were measured: short, intermediate and long, and their lengths recorded in centimetres. The shape (degree of roundness) of each erratic was determined by a visual assessment and comparison with the Powers roundness scale (Powers, 1953). Long axis orientations were measured as magnetic bearings and corrected to true bearings using the magnetic declination of 46&deg; E. The degree of weathering was assessed by visual comparison with a weathering index simplified from existing schemes published by Owen et al. (2009), Moriwaki et al. (1994) and White et al. (2009), as follows: Weathering classification W1: Heavily weathered surface, surrounded by spallation products; no iron staining or pitting on upper surface W2: Moderately weathered surface, iron stained, with some spalling/pitting of upper surface W3: Intact slightly weathered surface, unspalled W4: Fresh surface, unweathered, unspalled After sampling, the lithology of each cobble was classified using visual estimation of the modal proportions of constituent minerals (specifically quartz, alkali feldspar and plagioclase feldspar) plotted on a QAPF diagram (Streickheisen, 1976). Data collection: Data collected in 2019-20 season: Position (latitude and longitude, in decimal degrees) and altitude (metres above ellipsoid) were measured for each erratic using a Javad Triumph II GPS receiver. Files were processed on return to the UK. The heights above ellipsoid were corrected to orthometric heights (height above geoid EGM08 in metres above sea level) using Precise Point Positioning software [version 2]. As a back-up, satellite GPS measurements from a handheld Garmin 60CSx GPS unit were recorded at each sample location. Positional accuracy of the Javad Triumph II receiver is 0.010 m (horizontal) and 0.015 m (vertical). No other instrumentation or software was used. Data collected in 2009-10 season: Position (latitude and longitude, in decimal degrees) and altitude (metres above sea level) using a hand-held Garmin GPS Map 60CSx and helicopter altimeter and calibrated to known elevations. Positional accuracy is <5 m (horizontal) and <5 m (vertical). No other instrumentation or software was used. Data collected in 2005-06 season: Position (latitude and longitude, in decimal degrees) and altitude (metres above sea level) were measured for each erratic using a hand-held Garmin E-Trex Summit GPS. Positional accuracy is <5 m (horizontal) and <5 m (vertical). No other instrumentation or software was used. Data quality: For erratics that are equant in shape, no long axis orientation can be measured and the corresponding values cells in the data table are left blank. Where no long axis orientation was measured in the field and it was not possible to reconstruct it from photographs, the cells are filled with'n.d' for 'not determined''. asNeeded completed