Analysis of Long-Term Dynamic Changes of Subglacial Lakes in the Recovery Ice Stream, Antarctica

Abstract. The dynamic activity of subglacial lakes plays a crucial role in modulating glacial dynamic processes and influencing the mass balance of the Antarctic ice sheet. The Recovery Ice Stream (RIS), projected to experience significant mass loss in East Antarctica during coming centuries, requires continued investigation of its subglacial hydrological activity. Prior to 2012, nine active subglacial lakes and their dynamics in the RIS were identified through combined analysis of ICESat satellite altimetry and IceBridge airborne altimetry data. However, recent subglacial hydrological dynamics require further investigation. In this study, we investigate recent activity of nine subglacial lakes in the inventory of the RIS region using newly available ICESat-2 altimetry data, updating their outlines based on observed activity during the ICESat-2 mission period. Furthermore, we identify 14 newly active subglacial lakes designated as RecN1-RecN14. By synthesizing multi-source altimetry data (ICESat, IceBridge, ICESat-2), we establish a 21-year (2003–2023) elevation change time series for subglacial lakes in the RIS region. Through crossover analysis, we precisely identify elevation changes within subglacial lakes and elucidate spatiotemporal patterns across distinct lake sectors, revealing significant disparities between lake centers and their peripheries with a maximum difference of 4 m (e.g., lake Rec6-1). Finally, quantitative analysis of volume changes within primary drainage networks, based on constructed subglacial hydrological networks, confirms effective hydraulic connectivity between subglacial lake clusters in the RIS region. This study elucidates the hydrological dynamics of subglacial lakes in the RIS region, providing scientific basis for a deeper understanding of the evolutionary processes of Antarctic subglacial hydrological systems.