These are vertical density profiles of snow, firn and ice reconstructed from the vertical luminosity trace of digital optical televiewer (OPTV) logs of five boreholes drilled by hot water to ~100 m depth in Larsen C Ice Shelf, Antarctica. Boreholes were drilled in austral summers of 2014 and 2015 in order to investigate the internal properties of the ice shelf, and specifically the influence of surface melting and melt pond formation on those properties. These data are part of the NERC-funded MIDAS (''Impact of surface melt and ponding on ice shelf dynamics and stability'') research project, with grant references NE/L006707/1 and NE/L005409/1. The associated borehole OPTV logs and temperature profiles are also available, as are other MIDAS datasets.
Ice cores were drilled at four sites on the Antarctic Peninsula during the 2004-2005 austral summer. Loggers designed to measure the compaction of snow were installed in boreholes, these sensors took a measurement every hour and were sensitive to downward movements of less than a millimetre. Automatic Weather Stations (AWS), sonic snow rangers and thermistor strings were also installed at each site, measuring the snow arriving at hourly intervals. A network of stakes was surveyed by GPS to provide horizontal strain rates, of the glacier, at each location. The flow away from the sites was compared with the snowfall from the ice cores to show up any imbalance. This work was carried out as part of the CVaCS-DECAP project (Correction, Verification and Context, of Satellite-Derived Elevation Changes on the Antarctic Peninsula). The aim of the project was to measure the various factors that affect altitude of snow surfaces in Antarctica, in order to validate data from satellite altimeters. In particular, it aimed for a better understanding of the factors affecting snowpack compaction rates, by accurate measurement of compaction over a period of several years.