Longterm monitoring of the glaciers in Wordie Bay, Antarctic Peninsula, using multi-mission SAR time series

Abstract

The Antarctic Peninsula is one of the world`s most affected regions by Climate Change. Dense and long time series of multi-mission SAR data enable detailed studies of the rapid glaciological changes in this area. We present results of a case study at the former Wordie Ice Shelf, located at the south-western side of the Antarctic Peninsula. Since the ice shelf disintegrated in a series of events starting in the 1970s, only disconnected tidewater glaciers have remained today. Due to the loss of the buttressing force of the ice shelf, the former tributary glaciers reacted with an acceleration of their flow speeds in order to adapt to the new boundary conditions. While the loss of the ice shelf itself does not affect sea level, the increased outflow of the glaciers and the associated mass loss contribute to global sea level rise. All former studies conducted at Wordie Bay so far covered only relatively short investigation periods. Hence it was not well known how long the process of adaption to the changing boundary conditions exactly lasts and how it is characterized in detail. We provide completest possible time series of glaciological parameters for the glaciers in Wordie Bay obtained from multi-mission SAR remote sensing data. For this purpose large datasets of previously active (e.g. ERS, Envisat, ALOS PALSAR, Radarsat-1) as well as currently recording SAR sensors (e.g. Sentinel-1, TerraSAR-X, TanDEM-X) were processed in an hpc environment and combined with data from other sources (e.g. optical images, airborne laser altimeter and ground penetrating radar data). The usage of large multi-mission SAR datasets allows us to obtain more dense time series of glacier monitoring measurements, which lead to a better understanding of the climate- and ocean-triggered glaciological processes in Wordie Bay. The high temporal resolution of our data reveals new insights into the glacier`s behavior after the disintegration of the former ice shelf. Therefore we are able to show that changes and adaption processes at Wordie Bay still go on. This is in contrast to the assumption of earlier publications which proposed that some of the glaciers in Wordie Bay may be approaching a new equilibrium.