Dynamics of Arctic glacier surges measured by ERS SAR interferometry and feature tracking
Adrian Luckman(1) and Rob Fatland(2)
University of Wales Swansea,
(2) Vexcel, 4909 Nautilus Court N., Boulder, CO 80301, United States
Glacier surges are profound, short-term increases in flow rate and occur in a small but significant proportion of glaciers. The relatively small associated change in driving stress suggests the occurrance of a fundamental switch in basal processes between surge and quiescence. This makes surges of particular interest in understanding the response of ice masses to present and future climate change. Before ERS, monitoring glacier velocities was restricted to a few easily-accessible glaciers. Since 1991, the availability of SAR data from ERS1 and ERS2, and the development of Satellite Radar Interferometry (SRI) and feature tracking by patch correlation, have made longer-term retrospective analyses of surge glacier dynamics much more feasible.
This study looks at the surges of four glaciers which have occurred during the period of archived ERS SAR data: Monacobreen and Fridtjovbreen in Svalbard, Sortebrae in Greenland, and Bering Glacier in Alaska. SRI yields high spatial resolution velocity fields for 1-day and 3-day repeat images of Monacobreen and Fridtjovbreen, while feature tracking yields lower spatial resolution velocity fields for longer periods of the available archive for Monacobreen, Sortebrae and Bering Glacier. Many lessons have been learned regarding the selection and processing of ERS data for these techniques. It is emerging that a single model of surge behaviour is unlikely to describe all glacier surges.
Keywords: ESA European
Space Agency - Agence spatiale europeenne,
observation de la terre, earth observation,
satellite remote sensing,
teledetection, geophysique, altimetrie, radar,
chimique atmospherique, geophysics, altimetry, radar,