Glacier dynamics at Skalafellsjökull, Iceland

Abstract

GPR and GPS were used to: 1) Identify the glacier base, and combined with measured borehole depths, map the glacier depth (0-190m) and calculate the radar velocity through ice (0.179m ns-1). 2) Identify three styles of subglacial glaciotectonic compressive deformation from the radargrams: a) subglacial thrust sheets (2.7-5m thick sheets moving at approximately 3m per year); b) an elongated hill, oriented parallel with the ice direction (elongation ratio 1.4:1; 20m high, 142m long, with a step proximal side and a shallow distal side), composed of till thrust sheets (4-5m thick)(drumlinoid); c) a series of till ridges perpendicular to ice direction (6m high, 50-110m in length) also comprising till thrust sheets (ribbed moraine), 3) Calculate spatial and temporal changes in the glacier velocity.