Abstract:

Totten Glacier is in the region that has undergone the most dramatic thinning in the East Antarctic ice sheet in recent years. The mass balance of this region may be affected by the hydrological activity of Totten₂—an active subglacial lake in the upstream catchment of the glacier—over a time scale of several decades. This study applied the small baseline subset interferometric synthetic aperture radar (SBAS-InSAR) to 57 Sentinel-1 radar images from April 2022 to March 2024 to monitor changes in the ice surface elevation of Totten₂ at a high spatiotemporal resolution. Results were compared with ICESat-2 ATL11 data. Over the study period, ice sheet elevation decreased continuously, indicating continuous draining of the lake. Close agreement between Sentinel-1 and ICESat-2 data demonstrates that SBAS-InSAR is an effective tool for monitoring subglacial lake activity at small spatiotemporal scales and for studying the hydrological activity of Antarctic subglacial lakes.

Key words: radar image data, SBAS-InSAR, subglacial lake activity, elevation change, hydrological activities