Mapping and interpreting glacier changes in Severnaya Zemlya with the aid of differential interferometry and altimetry

Abstract

The combination of satellite differential radar interferometry (DINSAR) and altimetry was successfully applied to the overall geometric modelling of glacier elevation changes in Severnaya Zemlya in the period from the 1980s to the 2000s. The 2-pass DINSAR orthomosaic composed of 12 ascending ERS-1/2 tandem SAR interferograms covering the entire archipelago was calibrated and de-ramped using the change signal obtained by differencing ICESat altimetric profiles taken in the 2000s and the reference elevation model representing the glacier state as of the 1980s. The glacier-wide change signal was derived from the calibrated differential phase and mapped at 1:500,000 scale. An integral assessment of glacier changes was carried out. High spatial correlation (> +0.91) between glacier accumulation, sea ice concentration and the magnitude of the geopotential was determined and the spatial asymmetry in the distribution of glacier changes and ice flow pattern was explained.