Abstract: The evolution of Antarctic subglacial lakes is closely related to global climate change. Active subglacial lakes undergo significant changes in area and volume with the processes of storage and drainage. It is necessary to track and accurately extract outlines of Antarctic subglacial lakes for an in-depth understanding of subglacial hydrological processes and the mass balance of ice sheets. In this paper, we use ATL11 data from the ICESat-2 laser altimeter to extract the active subglacial lake outlines of the Byrd Glacier and Whillans ice flows in the Ross Ice Shelf, Antarctica. Then, we analyze the lake water potential hydrology using the DBSCAN cluster, Graham, and AlphaShape algorithms. The results show that the extracted subglacial lake outlines conform to the hydrological law, and the outlines of Byrd S10, Whillans 6, and other lakes are similar to those described in the latest report from 2022. There is a large amount of water at the intersection and classification of ice flows to promote the formation and expansion of lakes, and this phenomenon has obvious spatiotemporal characteristics. The outline extraction algorithm described in this paper is suitable for various shapes of subglacial lake point clouds and offers increased accuracy.

Key words: ICESat-2 altimetry data,  DBSCAN cluster algorithm,  Graham algorithm,  AlphaShape algorithm,  water potential equation,  Antarctic subglacial lake outlines