We use polarimetric radar sounding to investigate variation in ice crystal orientation fabric within the near-surface (top 40-300 m) of Rutford Ice Stream, West Antarctica. To assess the influence of the fabric on ice flow, we use an analytical model to derive anisotropic enhancements of the flow law from the fabric measurements. In the shallowest ice (40-100 m) the azimuthal fabric orientation is consistent with flow-induced development and correlates with the surface strain field. Notably, toward the ice-stream margins, both the horizontal compression angle and fabric orientation tend toward 45 degrees relative to ice flow. This result is consistent with theoretical predictions of flow-induced fabric under simple shear, but to our knowledge has never been observed. The fabric orientation in deeper ice (100-300 m) is significantly misaligned with shallower ice in some locations, and therefore inconsistent with the local surface strain field. This result represents a new challenge for ice flow models which typically infer basal properties from the surface conditions assuming simplified vertical variation of ice flow. Our technique retrieves azimuthal variations in fabric but is insensitive to vertical variation, and we therefore constrain the fabric and rheology within two end-members: a vertical girdle or a horizontal pole. Our hypotheses are that fabric near the center of the ice-stream tends to a vertical girdle that enhances horizontal compression, and near the ice-stream margins tends to a horizontal pole that enhances lateral shear. ApRES radar data were collected as part of the BEAMISH Project (NERC AFI award numbers NE/G014159/1 and NE/G013187/1). Tom Jordan would like to acknowledge support from EU Horizon 2020 grant 747336-BRISRES-H2020-MSCA-IF-2016.

Polarimetric phase-sensitive radar measurements were collected at the Western Antarctic Ice Sheet (WAIS) Divide on the 25th and 26th December 2019. The measurements were conducted at 10 sites along a 6 km-long transect ~5-10 km northeast of the location of the WAIS Divide Deep Ice Core. At each site, a suite of four quadrature (quad-) polarimetric measurements were collected using an autonomous phase-sensitive radio echo sounder (ApRES) in a single-input single-output (SISO) configuration. The study is part of the Thwaites Interdisciplinary Margin Evolution (TIME) project of the International Thwaites Glacier Collaboration (ITGC), and is a collaboration between the United States National Science Foundation (NSF) and the United Kingdom Natural Environment Research Council (NERC). It was funded by UK Natural Environment Research Council (NERC) research grant NE/S006788/1 and USA National Science Foundation (NSF) research grant 1739027.

This dataset contains the position and depth of four spatially-extensive Internal Reflecting Horizons (or IRHs) traced on the British Antarctic Survey''s PASIN system and NASA Operation IceBridge''s MCoRDS2 system across the Pine Island Glacier catchment. Using the WAIS Divide ice-core chronology and a 1-D steady-state model, we assign ages to our four IRHs: (R1) 2.31-2.92 ka, (R2) 4.72 +/- 0.28 ka, (R3) 6.94 +/- 0.31 ka, and (R4) 16.50 +/- 0.79 ka. This project was funded by the UK Natural Environment Research Council Grant NE/L002558/1

We present here the Bedmap3 ice thickness, bed and surface elevation aggregated points and survey lines. The aggregated points consist of statistically-summarised shapefile points (centred on a continent-wide 500 m x 500 m grid) that reports the average values of Antarctic ice thickness, bed and surface elevation from the full-resolution survey data and information on their distribution. The points presented here correspond to the added points since the last release of Bedmap2. The data comes from 14 different data providers and 75 individual surveys. They are available as geopackages and shapefiles. The associated Bedmap datasets are listed here: https://www.bas.ac.uk/project/bedmap/#data This work is supported by the SCAR Bedmap project and the British Antarctic Survey''s core programme: National Capability - Polar Expertise Supporting UK Research

Three separate airborne radar surveys were flown during the austral summer of 2016/17 over the Filchner Ice Shelf and Halley Ice Shelf (West Antarctica), and over the outlet glacier flows of the English Coast (western Palmer Land, Antarctic Peninsula) during the Filchner Ice Shelf System (FISS) project. This project was a NERC-funded (grant reference number: NE/L013770/1) collaborative initiative between the British Antarctic Survey, the National Oceanography Centre, the Met Office Hadley Centre, University College London, the University of Exeter, Oxford University, and the Alfred Wenger Institute to investigate how the Filchner Ice Shelf might respond to a warmer world, and what the impact of sea-level rise could be by the middle of this century. The 2016/17 aerogeophysics surveys acquired a total of ~26,000 line km of aerogeophysical data. The FISS survey consisted of 17 survey flights totalling ~16,000 km of radar data over the Support Force, Recovery, Slessor, and Bailey ice streams of the Filchner Ice Shelf. The Halley Ice Shelf survey consisted of ~4,600 km spread over 5 flights and covering the area around the BAS Halley 6 station and the Brunt Ice Shelf. The English Coast survey consisted of ~5,000 km spread over 7 flights departing from the Sky Blu basecamp and linking several outlet glacier flows and the grounding line of the western Palmer Land, including the ENVISAT, CRYOSAT, GRACE, Landsat, Sentinel, ERS, Hall, Nikitin and Lidke ice streams. Our Twin Otter aircraft was equipped with dual-frequency carrier-phase GPS for navigation, radar altimeter for surface mapping, wing-tip magnetometers, an iMAR strapdown gravity system, and a new ice-sounding radar system (PASIN-2). We present here the full radar dataset consisting of the deep-sounding chirp and shallow-sounding pulse-acquired data in their processed form, as well as the navigational information of each trace, the surface and bed elevation picks, ice thickness, and calculated absolute surface and bed elevations. This dataset comes primarily in the form of NetCDF and georeferenced SEGY files. To interactively engage with this newly-published dataset, we also created segmented quicklook PDF files of the radar data. This is Version 2 of the dataset. This version differs from Version 1, as follows: 1. The variables "fast_time" has been updated due to errors found. The error in the variable related to an error in the sampling frequency of the system, which should have been 24 MHz instead of 22MHz. This has been updated. 2. The units in the "surface_pick_layerData" and the "bed_pick_layerData" variables should have been "samples relative to the BAS radar system", instead of "microseconds". This has been corrected. 3. The metadata in this DMS entry and in the NetCDF files has also been updated. Mainly, the sampling frequency has been modified from 22 MHz to 24 MHz to reflect the radar system characteristics. This also affected the value provided for the radar system resolution and sampling interval, which have both been updated in the metadata. 4. The SEGY sampling interval value (byte numbers: 117-118 (SI)) has also been updated to reflect the change in sampling frequency mentioned above. All other variables remain unchanged. Note that these changes do not affect the radar data or the associated radar-derived data in the files.

This dataset includes double-difference interferograms derived from TerraSAR-X synthetic aperture radar data acquired at the grounding line downstream of Engelhardt Subglacial Lake on the Gould Coast, Antarctica, in September 2012, April 2016, July 2023 and October 2023. The September 2012, July 2023 and October 2023 interferograms were generated by Oliver J. Marsh (British Antarctic Survey) using the Gamma Remote Sensing software and geocoded with the Bedmap2 DEM. The April 2016 interferogram was generated by Dana Floricioiu (DLR, German Aerospace Center) using DLR''s Integrated Wide Area Processor (IWAP; Rodriguez et al, 2013). The image processing information, acquisition time and coincident modelled tide heights for all data used to derive the TerraSAR-X interferograms are provided in the lineage section. For each interferogram (September 2012, April 2016, July 2023 and October 2023) we provide a shapefile of the derived grounding line, which was manually traced along the landward boundary of the dense fringe belt associated with the vertical tidal motion of the ice (Point F). This dataset was produced as part of the study: Freer et al. (2024) Synchronous lake drainage and grounding line retreat at Engelhardt Subglacial Lake, West Antarctica. Journal of Geophysical Research: Earth Surface. Funding: Bryony I. D. Freer (project lead) was supported by Natural Environment Research Council (NERC) Satellite Data in Environmental Science (SENSE) Centre for Doctoral Training (grant no. NE/T00939X/1). Dana Floricioiu (dataset creator) was supported by DLR''s Polar Monitor II and Antarctic Ice Sheet CCI projects (ESA/Contract No. 4000126813/18/I-NB). Images were acquired under DLR TerraSAR-X science data proposal HYD3673 (PI Dana Floricioiu).

An airborne radar survey was flown during the austral summer of 2015/16 over the Foundation Ice Stream, Bungenstock Ice Rise, and the Filchner ice shelf as part of the 5-year Filchner Ice Shelf System (FISS) project. This project was a NERC-funded (grant reference number: NE/L013770/1) collaborative initiative between the British Antarctic Survey, the National Oceanography Centre, the Met Office Hadley Centre, University College London, the University of Exeter, Oxford University, and the Alfred Wenger Institute to investigate how the Filchner Ice Shelf might respond to a warmer world, and what the impact of sea-level rise could be by the middle of this century. The 2015/16 aerogeophysics survey acquired ~7,000 line km of aerogeophysical data with a particular focus on the Foundation Ice Stream. Our Twin Otter aircraft was equipped with dual-frequency carrier-phase GPS for navigation, radar altimeter for surface mapping, wing-tip magnetometers, and a new ice-sounding radar system (PASIN-2). We present here the full radar dataset consisting of the deep-sounding chirp and shallow-sounding pulse-acquired data in their processed form, as well as the navigational information of each trace, the surface and bed elevation picks, ice thickness, and calculated absolute surface and bed elevations. This dataset comes primarily in the form of NetCDF and georeferenced SEGY files. To interactively engage with this newly-published dataset, we also created segmented quicklook PDF files of the radar data. This is Version 2 of the dataset. This version differs from Version 1, as follows: 1. The variables "fast_time" has been updated due to errors found. The error in the variable related to an error in the sampling frequency of the system, which should have been 24 MHz instead of 22MHz. This has been updated. 2. The units in the "surface_pick_layerData" and the "bed_pick_layerData" variables should have been "samples relative to the BAS radar system", instead of "microseconds". This has been corrected. 3. The metadata in this DMS entry and in the NetCDF files has also been updated. Mainly, the sampling frequency has been modified from 22 MHz to 24 MHz to reflect the radar system characteristics. This also affected the value provided for the radar system resolution and sampling interval, which have both been updated in the metadata. 4. The SEGY sampling interval value (byte numbers: 117-118 (SI)) has also been updated to reflect the change in sampling frequency mentioned above. All other variables remain unchanged. Note that these changes do not affect the radar data or the associated radar-derived data in the files.

This dataset contains data from three ground-penetrating radar surveys undertaken to image ice thickness and englacial stratigraphy during the 2019-20 Antarctic field season, as part of the International Thwaites Glacier Collaboration (funded by NERC and NSF). The ground-penetrating radar data are presented as SEG-Y, along with the GPS tracks of the surveys, presented as GPS Exchange Format (GPX). The subglacial extensions of ridges of three nunataks close to Pine Island and Larter Glaciers in the Hudson Mountains region were surveyed, with the aim of determining their suitability as subglacial bedrock drill sites. Those nunataks are Winkie Nunatak (74 degrees 51'' 41.0" S/99 degrees 46'' 49.4" W), Evans Knoll (74 degrees 51'' 00.0" S/100 degrees 25'' 00.0" W), and Webber Nunatak (74 degrees 47'' 00.0" S/99 degrees 50'' 00.0" W). This work was funded by NERC grants NE/S00663X/1 and NE/S006710/1.

We present here a suite of ground-penetrating radar (GPR) data collected on Larsen C Ice Shelf, Antarctic Peninsula, in November and December 2022 as part of the NERC-funded RiPIce (Rift Propagation for Ice sheet models) research project. All data were acquired with a Sensors&Software pulsEKKO PRO GPR system, fitted with antennas of 50 MHz centre-frequency. The system was towed behind a snowmobile, with distances recorded with GPS. This project is funded by a NERC standard grant NE-T008016-1.

The EISCAT (European Incoherent Scatter ) data is from either the Ultra High Frequency (UHF) or Very High Frequency (VHF) radar observations of Polar Mesospheric Summer Echoes/Winter Echoes (PMSE/PMWE). The data archive contains EISCAT UHF or VHF radar data, processed with GUISDAP (Grand Unified Incoherent Scatter Design and Analysis Package) analysis software, of electron density, ion temperature, electron temperature or ion velocity as a function of altitude along with estimates of their uncertainty. The time and range resolution is variable depending on the analysis settings. Data was collected in July 2012, June-July 2013, June-July 2014 and November 2014.