ApRES_Data_Overview

We present a 1000 km transect of Autonomous phase-sensitive Radio Echo Sounding (ApRES) measurements of ice thickness, basal reflection strength, basal melting, and ice-column deformation across the Ross Ice Shelf (RIS). Measurements were gathered over five seasons (2015-2020), two seasons along the full transect connecting the grounding line with the distant ice shelf front. ApRES identifies regions with varying basal reflection strength showcasing a variety of basal conditions influenced by upstream glacial processes and the interaction of different water masses. The mean basal melt rate was 0.099 ± 0.013 m a^-1; the central RIS experienced negligible melt, with weak basal reflections, likely driven by basal debris and marine ice. Strong reflections in the northern and southern regions correlate with higher basal melt, rising to 0.285 ± 0.034 m a^-1 in the vicinity of the south western grounding lines, and to 0.468 ± 0.020 m a^-1 towards the calving front. Basal melt rates on the Siple Coast are low between 0.002 ± 0.011 m a^-1 and 0.040 ± 0.003 m a^-1 but increase to 0.145 ± 0.011 m a^-1 within 8 km of the Kamb Ice Stream grounding line.