The Changing Surface Hydrology of the Nivlisen Ice Shelf, Dronning Maud Land, East Antarctica

The collapse of four major Antarctic Peninsula ice shelves since the 1950s, and most notably the catastrophic collapse of the Larsen B Ice Shelf in 2002, has highlighted the need for a greater understanding of the drivers of ice shelf instability under current climate warming trends. In particular, surface and basal melting, firn densification, ponding, vertical hydrofracturing, horizontal fracture propagation, and ice shelf edge retreat have all been identified as factors that may have contributed to past ice shelf collapse events. We are using remotely sensed data from several Antarctic ice shelves in order to further investigate the potential precursors to ice shelf instability. Here, we focus on the Nivlisen Ice Shelf, which is characterised by extensive surface water features, analysing optical imagery from Sentinel-2 and Landsat. We are developing semi-automated methods for tracking spatial and temporal changes in the development and demise of surface meltwater features, based on similar algorithms that have been used to identify lake drainage events on the Greenland Ice Sheet. Preliminary results from surface meltwater analysis on the Nivlisen Ice Shelf reveal marked inter- and intra- annual variations between 2013 and 2017. The area of surface melt increases throughout each melt season, and often propagates across the ice shelf through a series of defined melt water channels.