Identification and Activity of Subglacial Lakes Beneath the Mercer and Whillans Ice Streams and Slessor Glacier

The identification and activity monitoring of Antarctic subglacial lakes contribute to the analysis of the mass balance and sea level change. Remote sensing techniques, especially satellite altimetry, are ideal ways for identifying active subglacial lakes and indirectly monitoring their hydrological activity. Based on ICESat-2 altimetry data, we propose two methods to generate the rates of ice surface elevation changes for identifying active subglacial lakes in Antarctica. We identify 15 new active subglacial lakes and provide denser and more precise outline detail for known subglacial lakes in the Mercer and Whillans Ice Streams and Slessor Glacier regions. Then, we use ICESat-2 and earlier CryoSat-2 data to get the time series of ice surface elevation changes for subglacial lakes to further understand their hydrological processes. Results show that subglacial lakes have exhibited periodic activity and at least two fill-drain cycles in the Mercer and Whillans Ice Streams region. Owing to data limitations, the time series shows less periodic lake activity in the Slessor Glacier region. However, subglacial water movements are similarly active and have various activity patterns.