Multiparametric Cartographic Visualisation of Glacier Rheology

Abstract

In cooperation between remote sensing experts and cartographers interested in glaciology, new types of maps showing the glacier dynamics have been developed. The maps make use of the original phase gradient approach to glacier rheology modelling based on repeat-pass ERTS SAR interferograms. Careful map design and, in particular, colour assignment allow the visualisation of the glacier dynamics in its locally changing velocity with an estimated accuracy of approximately 2.0 cm per day. Two map derivates – a differential interferogram showing the glacier velocity and another product displaying the glacier strain rate – have been designed. Moreover, maps displaying the glacier marginal changes within the space of four years have been generated. The strain rate maps evidence that spots with high values frequently correspond with crevasse-prone areas which are even detectable under thick layers of snow. In this sense, the latter visualisations can be seen as maps of crevasse danger zones. The Svartisen in Norway and the Hintereis Glacier in Austria served as testbeds for the development of these different types of maps which are at the scales of 1:25 000, 1:50 000 and 1:100 000.