This data set contains bed and surface elevation picks derived from airborne radar collected during the WISE/ISODYN project. This collaborative UK/Italian project collected ~ 61000 line km of new aerogeophysical data during the 2005/2006 austral summer, over the previously poorly surveyed Wilkes subglacial basin, Dome C, George V Land and Northern Victoria Land.
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.
This dataset includes ~3,000 line km of radio-echo sounding data along the English Coast of western Palmer Land in the Antarctic Peninsula. Data was acquired by the British Antarctic Survey Polarimetric-radar Airborne Science Instrument (PASIN2) ice sounding radar system in the austral summer of 2016/2017. Radar lines collected at ~3-5 km line spacing transect a number of outlet glacier flows, close to the grounding line, where continental ice begins to float. Data were funded by a BAS National Capability grant.
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.