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EARTH SCIENCE > Cryosphere > Glaciers/Ice Sheets > Glacier Motion/Ice Sheet Motion

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  • The data set contains values of basal slipperiness (C) and the rate factor (A) for the whole of the Antarctic Ice Sheet. The slipperiness was estimated through model inversion from measurements of surface velocities (1) and ice thickness (2) using the ice-flow model Ua (3). The ice was assumed to deform according to Glen''s flow law with a stress exponent n=3. Basal sliding was assumed to follow Weertman sliding law with m=3, with u_b = C tau^m, where u_b is the basal sliding velocity and tau the (tangential) basal traction.

  • The datasets are ice tilt time series from strings of accelerometers, each located at a discrete depth within one of three boreholes into Khumbu Glacier, Nepal. Ice deformation can be derived from this tilt data, but has not yet been calculated. Boreholes were drilled in May 2017 and 2018 to investigate the internal properties of Khumbu Glacier, specifically ice thickness, temperature, deformation and structure, as part of the NERC-funded ''EverDrill'' research project. Supporting borehole information is provided as a related dataset. Funding was provided by the NERC grant NE/P00265X/1 and NE/P002021/1. ***** PLEASE BE ADVISED TO USE VERSION 2.0 DATA ***** The VERSION 2.0 data set (see ''Related Data Set Metadata'' link below) which contains an additional 11 months of measurements.

  • From May 2009 to May 2013, seven dual-frequency GPS receivers were deployed along a 120 km-long transect in the south-west of the Greenland Ice Sheet. Two additional dual-frequency GPS receivers were deployed perpendicular to longitudinal ice flow at ~14 km inland: one 5 km distant from June 2011 to May 2013, and another 2.5 km distance from May 2012 to May 2013. Each receiver recorded position observations every 10 seconds or 30 seconds (depending on configuration), enabling resolution of horizontal and vertical ice motion. Sites were powered by solar panels and operated 24 hours a day during summer but shut down in the autumn. Absolute ice displacements at each site were obtained for each summer and winter period in the absence of continuous measurements. Position measurements were kinematically corrected relative to an off-ice base station using TRACK (Chen, 1999). Daily velocities were then obtained by differencing across 24-hour periods, whilst continuous velocities were obtained through application of a sliding 6-hour differencing window. At each GPS site we also measured (1) the near-surface air temperature every 15 minutes year-round, (2) net seasonal ablation using ablation stakes, and (3) at several selected sites melt rates using sonic ranging sensors. This version 2 of the dataset updates the previously 2-day temporal resolution of the ice motion records to 1-day resolution. In other respects the dataset has not changed. Funded by NERC, the Carnegie Trust for the Universities of Scotland and The University of Edinburgh. Relevant grants: NE/F021399/1, NE/H024964/1 Studentships: NE/I52830X/1, NE/J500021/1, NE/H526794/1

  • From May 2009 to May 2013, seven dual-frequency GPS receivers were deployed along a 120 km-long transect in the south-west of the Greenland Ice Sheet. Two additional dual-frequency GPS receivers were deployed perpendicular to longitudinal ice flow at ~14 km inland: one 5 km distant from June 2011 to May 2013, and another 2.5 km distance from May 2012 to May 2013. Each receiver recorded position observations every 10 seconds or 30 seconds (depending on configuration), enabling resolution of horizontal and vertical ice motion. Sites were powered by solar panels and operated 24 hours a day during summer but shut down in the autumn. Absolute ice displacements at each site were obtained for each summer and winter period in the absence of continuous measurements. Position measurements were kinematically corrected relative to an off-ice base station using TRACK (Chen, 1999). Daily velocities were then obtained by differencing across 24-hour periods, whilst continuous velocities were obtained through application of a sliding 6-hour differencing window. At each GPS site we also measured (1) the near-surface air temperature every 15 minutes year-round, (2) net seasonal ablation using ablation stakes, and (3) at several selected sites melt rates using sonic ranging sensors. Funded by NERC, the Carnegie Trust for the Universities of Scotland and The University of Edinburgh. Relevant grants: NE/F021399/1, NE/H024964/1 Studentships: NE/I52830X/1, NE/J500021/1, NE/H526794/1

  • Ice front positions for Kangerdlugssuaq Glacier, Greenland, based on digitisation of satellite images between 1985 to 2018. Funding: The data have been collected over many years. Most recent project funding is NERC project CALISMO NE/P011365/1.

  • Surface speeds for a point close to the front of Kangerdlugssuaq Glacier based on satellite image feature tracking from 1985 to 2018. Funding: The data have been collected over many years. Most recent project funding is NERC project CALISMO NE/P011365/1.

  • The data consists of observed terminus position and modelled ocean temperature, air temperature and runoff for 10 tidewater glaciers in east Greenland, 1990-2015. The glaciers are (listed from south to north) Mogens 3, Tingmjarmiut 1, AP Bernstorffs Glacier, Helheim Glacier, Kangerdlugssuaq Glacier, Borggraven, Vestfjord Glacier, Daugaard-Jensen Glacier, Waltershausen Glacier, Heinkel Glacier. Values are given as annual means. Glacier terminus positions are derived directly from remote sensing observations. Ocean temperature is based on the mean 200-400m temperature from GLORYS2V3 1/4 deg ocean reanalysis, obtained from the nearest cell of sufficient depth and adjusted to better agree with available in situ observations. Air temperature is based on the May-September mean of monthly temperatures from European Reanalysis (ERA)-Interim global atmospheric reanalysis, while Q is obtained from a 1-km surface melting, retention, and runoff model forced using ERA-Interim reanalysis. These data were compiled to study the relationship between environmental forcings and tidewater glacier retreat in east Greenland, as published by Cowton et al (2018). Funding was provided by the NERC grants NE/K015249/1 and NE/K014609/1.

  • A distributed acoustic sensing (DAS) experiment was undertaken at SkyTrain Ice Rise in the Weddell Sea Sector of West Antarctica. The aim was to evaluate the use of DAS technology using existing infrastructure and for delineating the englacial fabric to improve our understanding of ice sheet history in the region. Three walkaway profiles were acquired at 45 degree intervals using a hammer and plate source. Both direct and reflected P- and S-wave energy, as well as surface wave energy, are observed using a range of source offsets recorded using fibre optic cable. Significant noise results from the cable hanging untethered in the borehole. At greater depth, where drilling fluid is present, signal strength is sufficient to measure seismic interval velocities and attenuation. Fieldwork was part of the BEAMISH Project (NERC AFI award numbers NE/G014159/1 and NE/G013187/1). John Michael Kendall was supported by additional funding from NERC award No. CASS-166. The Skytrain borehole and fibre optic cable are part of the University of Cambridge WACSWAIN Project (EU Horizon 2020 agreement No. 742224).

  • The datasets are ice tilt time series from strings of accelerometers, each located at a discrete depth within one of three boreholes into Khumbu Glacier, Nepal. Ice deformation can be derived from this tilt data, but has not yet been calculated. Boreholes were drilled in May 2017 and 2018 to investigate the internal properties of Khumbu Glacier, specifically ice thickness, temperature, deformation and structure, as part of the NERC-funded ''EverDrill'' research project. Supporting borehole information is provided as a related dataset. Funding was provided by the NERC grant NE/P00265X/1 and NE/P002021/1.

  • The radar data collected in 2013-2014 at Dome C, East Antarctica, aims to understand bulk preferred crystal orientation fabric near a dome. We measure changes in englacial birefringence and anisotropic scattering in 21 sites along a 36 km long profile across Dome C. These optical properties are obtained by analysing radar returns for different antenna orientations. More details can be found in Ershadi et al, 2021. Funding was provided by BAS National Capability and IPEV core funding.