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 processes and 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 dynamics. In this study, we re-examine and update the outlines of nine active subglacial lakes identified before 2012 and identify 14 additional new active lakes (RecN1-RecN14) using ICESat-2 data. By synthesizing multi-source altimetry data (ICESat, IceBridge, ICESat-2), we establish a 21-year (2003–2023) elevation change time series for lakes in the RIS. This extended observational record reveals that the drainage regime in RIS is characterized by long-term, sustained water transport. Through crossover analysis, we precisely identify elevation changes and elucidate internal spatiotemporal patterns across distinct lake sectors, revealing significant disparities between lake centers and their peripheries. We demonstrate that the original lake Rec1 comprises two distinct lakes and analyze their hydrological connection, supporting the previously proposed hypothesis of two subglacial drainage outflows in the RIS. Furthermore, quantitative volume change analysis along the constructed subglacial hydrological networks reveals clustered filling-draining patterns. Specifically, we identify for the first time a cascading drainage event involving ten lakes and spanning over approximately 1000 km, revealing a highly connected subglacial hydrological system in this region. This study advances the understanding of subglacial lake hydrological dynamics in the RIS, thereby informing the evolution of the Antarctic subglacial system.