First access to the ocean beneath Ekströmisen, Antarctica, by means of hot-water drilling

A hot-water drill developed during the past 2 years at Alfred-Wegener-Institut was used to penetrate Ekstromisen several times near the German wintering-over base, Neumayer (70°39' S, 08°15' W). The drilling operation was very successful and the initial large diameter (≥ 35 cm) allowed easy access to the ocean. One hole was used to install an ultrasonic echo-sounder which recorded the ablation at the ice-shelf bottom continuously. Another hole was destined for emplacement of a thermistor string throughout the 237 m thick ice shelf for ice-temperature measurements. Several CTD profiles in the 175 m deep water column and the analysis of water samples provided valuable data for the understanding of ice-shelf-ocean interactions.