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Satellite Remote Sensing Investigations into Changing Ice-shelf Extents in the Eastern Weddell Sea Sector of Antarctica



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Homer, Nicholas 


Satellite observations of ice-shelf collapse and related ice-mass drawdown from the Antarctic Peninsula over the past > 3 decades have been unambiguously linked to changes in atmospheric and oceanic processes as a result of anthropogenic climate change. Therefore, contemporary glaciological research is increasingly focussed on the long-term future stability of the vast West and East Antarctic Ice Sheets under different climate change scenarios, where similar changes to atmospheric and oceanic processes to those found in the Antarctic Peninsula are forecast. The floating ice shelves which extend from the ice sheet in these regions are of particular research interest because, by their very nature, they exert considerable control over the flow of the inland ice-sheet as well as respond relatively rapidly to external forcing mechanisms.

Here, new ice-shelf extent mapping is undertaken by mapping the calving front locations in the eastern Weddell Sea Sector of the East Antarctic Ice Sheet, where four of Antarctica’s ten largest ice shelves are located. Calving fronts and other lengths of coastline were mapped using an adapted edge-extraction coastline delineation method, entirely within a GIS computing environment, from a variety of remotely-sensed satellite optical and radar imagery. Combined with pre-existing coastline products form the region a timeseries of ice-shelf areas is presented and discussed in the context of known and theorised ice-ocean-atmosphere interactions occurring in the region. In contrast to what is occurring in other regions of the Antarctic Ice Sheet, ice shelves are broadly found to have been synchronously advancing since the 1960s, with only the occasional detachment of large, tabular icebergs causing ice-shelf retreat on sub-decadal timescales. Most recently, total ice-shelf area along the eastern Weddell Sea coastline from Filchner to Fimbul ice shelves, inclusive, has been increasing by c. 550 km2 yr-1 between 2009 and 2019.

Analysis of meteorological and sea-ice data suggests that increasing north to south surface wind-speed anomalies along the eastern Weddell Sea coastline are facilitating increased sea-ice concentrations at the margins of the ice shelves and it is argued that this may be increasing the ice-shelves’ structural integrity, limiting iceberg calving activity. However, ultimately the ice shelves in this region are still primarily governed by bed-geometry and internal ice dynamical properties. Although this evidence is indicative of a region of the ice sheet in relative mass balance, the continuation of an identified surface air warming trend here will increase the likelihood of increased iceberg calving, or indeed ice-shelf retreat or collapse, as observed at the Anatectic Peninsula. However, further research is needed into the what affect warming might have on the large-scale atmospheric processes governing changes to the surface winds and related sea-ice concentration anomalies, so that better predictions as to the future of these ice shelves may be made.




Dowdeswell, Julian


Satellite remote sensing, Ice shelves, Weddell Sea Sector, East Antarctica



Awarding Institution

University of Cambridge