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.

This dataset contains detailed records of snowpack characteristics near Ny-Alesund, Svalbard, between 21st and 31st March 2023. They were recorded in ten snow pits before in-situ tracer percolation experiments, and the records include location and overview photos of each pit, snow height, snow temperature, snow density, detailed snow stratigraphy observations, and stable water isotope signatures from the snow surface to the ground. The records were obtained by Dorothea Moser as part of an experimental field project ("Wet Fingerprints") to contextualise the results of the subsequently conducted tracer percolation experiments. The project was supported by an Arctic Field Grant through the Norwegian Research Council (Project No. 342165, Research in Svalbard RiS ID 12132). Dorothea Elisabeth Moser was supported by BAS Cambridge and the NERC C-CLEAR Doctoral Training Programme (grant no. NE/S007164/1).