Terrain analyses and surface velocity measurements of the Hiorthfjellet rock glacier, Svalbard

The morphology and dynamics of the Hiorthfjellet rock glacier, Svalbard, are investigated based on analyses of (1) a digital terrain model and (2) surface velocity measurements during the time period 1994 to 2002. The Hiorthfjellet rock glacier is particularly suited for the interpretation of rock-glacier dynamics from surface morphology since the surface is smooth with homogenous rock size minimally influenced by debris flows. Surface velocity measurements give good evidence of surface strain rate on the order of 4×10−5 year−1 to 8×10−5 year−1. The upper and frontal zones of the rock glacier have extending flow, the central zone compressive flow. There are small deviations between the gradient of the surface velocity vector and the surface gradient of the rock glacier. Observed surface velocity vectors are within the range of 9.5 cm year−1 to 10.8 cm year−1. The DTM analyses clearly show a small-scale ridge-and-furrow surface, most likely attributed to active-layer processes. Copyright © 2003 John Wiley & Sons, Ltd.