Subglacial lake detection in Dronning Maud Land, East Antarctica using ICESat-2

Subglacial lakes beneath the Antarctic Ice Sheet are known to influence ice-sheet dynamics and form part of an extensive active hydrological network. Ice surface elevation anomalies from repeat-track altimetry can be useful for detecting subglacial lakes and the evolution of subglacial water transport towards sub-ice-shelf cavities. Here, we analyse a 5-year time series of laser altimetry data from the ICESat-2 satellite to investigate potential subglacial lake activity in the coastal Dronning Maud Land region of East Antarctica. Our results reveal ice surface uplift and subsidence events which we interpret to reflect the active draining and filling of subglacial lakes over annual timescales. We find lake locations to be topographically-controlled and coincide spatially with predicted subglacial water routing pathways. Our results highlight subglacial lake activity as close as 10 km from the grounding line in a region of East Antarctica where no subglacial water has been observed in the coastal zone previously. These findings bring knowledge of the dynamics and evolution of subglacial meltwater in this region and provide new observational data to refine subglacial hydrological model estimates of water flux towards ice-shelf grounding zones.