Monitoring Temperate Glacier Displacement by Multi-Temporal TerraSAR-X Images and Continuous GPS Measurements

Abstract

International audienceA new generation of space-borne SAR sensors were launched in 2006-2007 with ALOS, TerraSAR-X, COSMO-Sky-Med and RadarSat-2 satellites. The data available in different bands (L, C and X bands), with High Resolution (HR) or multi-polarization modes offer new possibilities to monitor glacier displacement and surface evolution by SAR remote sensing. In this paper, the first results obtained with TerraSAR-X HR SAR image time series acquired over the temperate glaciers of the Chamonix Mont-Blanc test site are presented. This area involves well-known temperate glaciers which have been monitored and instrumented i.e. stakes for annual displacement/ablation, GPS for surface displacement and cavitometer for basal displacement, for more than 50 years. The potential of 11-day repeated X-band HR SAR data for Alpine glacier monitoring is investigated by a combined use of in situ measurements and multi-temporal images. Interpretations of HR images, analysis of interferometric pairs and performance assessments of target/texture tracking methods for glacier motion estimation are presented. The results obtained with four time series covering the Chamonix Mont-Blanc glaciers over one year show that the phase information is rarely preserved after 11 days on such glaciers, whereas the high resolution intensity information allows the main glacier features to be observed and displacement fields on the textured areas to be derived

Geochemical Processes Leading to the Precipitation of Subglacial Carbonate Crusts at Bossons Glacier, Mont Blanc Massif (French Alps)

“…The distribution of the basal ice temperature of the Bossons glacier is complex and a minimum elevation of 3,300 m has been suggested as the boundary between cold and temperate (at the melting point) basal ice (Le Meur and Vincent, 2006). The Bossons glacier is an exceptionally steep glacier with a mean slope of ∼28 • , which drives ice flows speeds at more than 1 m/day in the summer (data from an altitude of 2,300 m; Fallourd et al, 2011). The glacier topography is typically disrupted by crevasses and seracs, but a remarkably smooth surface is observed at an altitude of 1,700−1,850 m; this zone is characterized by a flattening of the slope ("Pyramids plateau").…”

Taking Advantage of the ESA G-POD Service to Study Ground Deformation Processes in High Mountain Areas: A Valle d’Aosta Case Study, Northern Italy

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