Spatiotemporal variability of active subglacial lakes in Antarctica from
2018-2021 using ICESat-2 laser altimetry
Abstract
To understand the movement of subglacial water in Antarctica, we present
an updated inventory of active subglacial lakes using ICESat-2 laser
altimetry data. The ICESat-2/ATLAS instrument’s six-beam laser array
captures denser point measurements than the previous generation ICESat
and Cryosat-2 satellites, allowing us to examine the spatial and
temporal variability of active subglacial lakes with unprecedented
detail. Active subglacial lakes are classified directly from the high
density ATL11 land ice time-series (60 m along track spatial resolution)
point cloud data using an unsupervised density-based clustering
algorithm. The key finding we show is how subglacial lake shorelines can
migrate spatially over time through fill-drain cycles. In addition, we
examine subglacial water connectivity from coupled fill-drain cycles
over lakes at the Whillans Ice Stream on the Siple Coast. This study
yields new insights into the dynamic nature of the subglacial water
system in Antarctica, and will be of interest to biologists quantifying
biogeochemical cycle processes and glaciologists studying the influence
of subglacial hydrology on ice dynamics.