Abstract
Surface meltwater accumulating on Antarctic ice shelves can drive
fractures through to the ocean and potentially cause their collapse,
leading to increased ice discharge from the continent. Implications of
increasing surface melt for future ice shelf stability are inadequately
understood. The southern Amery Ice Shelf has an extensive surface
hydrological system, and we present data from satellite imagery and
ICESat-2 showing a rapid surface disruption there in winter 2019,
covering ~60 km2. We interpret this as an ice-covered
lake draining through the ice shelf, forming an ice doline with a
central depression reaching 80 m depth, amidst uplift reaching 36 m.
Flexural rebound modelling suggests 0.75 km3 of water was lost. We
observed transient refilling of the doline the following summer with
rapid incision of a narrow meltwater channel (20 m wide and 3 m deep).
This study demonstrates how high-resolution geodetic measurements can
explore critical fine-scale ice shelf processes.