Global warming and ocean circulation changes have posed substantial threat to Greenland and Antarctic glaciers, which are melting rapidly and have triggered 14 mm sea level rise from 2003 to 2019. Antarctic glaciers are losing ice to the ocean primarily through two processes: iceberg calving and basal melting of ice shelves/tongues. To better predicate future sea level rise, it is urgent to monitor the three-dimensional changes and reveal the calving and basal melting mechanism of Antarctic glaciers. In this presentation, Mertz and Drygalski Ice Tongues are taken as example to study the iceberg calving and how ocean melting ice tongue in East Antarctica. Remote sensing and satellite altimetry were used to detect Mertz Ice Tongue changes before and after calving event. A calving cycle of approximately 70 years caused by seafloor shore, Mertz Bank has been revealed. The glacier-ocean interaction was conducted around Drygalski Ice Tongue. Measurement from Autonomous Phase-sensitive Radio-Echo-Sounder (ApRES), oceanographic mooring and computer modeling were used to study the basal melting of Drygalski Ice Tongue. Rapid basal melting close to the tongue front was detected in austral summer, which was likely triggered by intrusion of Antarctica Surface Water in austral summer. Glacier-ocean interactions, such as glacier calving or basal melting, can be reflected from spaceborne, terrestrial and oceanic observations and are important processes to predict sea level changes. To better understand the driving forces of glacier changes, multi-disciplinary observation and modeling from remote sensing, computer science, glaciology, oceanography and atmosphere science are required.

Speaker

 A/Prof. Xianwei Wang

 School of  Oceanography, SJTU

Time

        2024.3.13 12:00-13:30