Phase-sensitive Radio Echo Sounding (pRES) to estimate basal melt rates

Basal melting under the glacier tongue is assumed to be a major factor in the destabilization of the glacier and the feeding ice stream. An important aspect of GROCE is the determination of basal melt rates under the floating ice tongue of the 79NG. These melt rates can be derived from repeated measurements of the ice thickness at the same surface point. The accuracy of the ice thickness estimation can be increased by considering the phase information. Such a system is called phase-sensitive radio echo sounder (pRES). To estimate the basal melting, phase-sensitive radar stations were installed on the floating part of the glacier, which continuously measure the basal melting over the course of a year. For a better spatial distribution of mean annual melt rates, these time series have been supplemented by comprehensive radar measurements and will be completed by re-measurements in 2018.