Detection of Antarctic Subglacial Lakes Activities Using ICESat Altimetry Data

Antarctic subglacial lakes form an important component of the subglacial hydrological system. The movements of some subglacial lakes have great impacts on subglacial hydrology, ice-flow velocity, mass balance of ice sheet and sea level changes. According to the deformation of the ice-sheet above the subglacial lakes, the repeat-track algorithm based on ICESat altimetry data was introduced to detect the height changes of subglacial lakes. Then simulative models were established to analyze the ice-sheet deformation caused by the different patterns of active subglacial lakes. Finally, the Aca-demy₁₂ and Cook_E2 subglacial lakes were selected to analyze the actual application of the algorithm. The results show that the ice-sheet above the Academy₁₂ and Cook_E2 subglacial lakes went up 6 m and went down 70 m respectively. All the altimetry data applied in the repeat-track algorithm is capable of detecting the right height changes when the height change patterns are steady. However, when there exists high variability of the height change patterns, the proper altimetry data should be adopted to calculate the topography in order to get the right height changes.