Grounding-zone wedges and mega-scale glacial lineations in Kveithola Trough, Barents Sea

Abstract

Multibeam-bathymetric data from Kveithola Trough show a seafloor characterized by east–west-trending mega-scale glacial lineations (MSGLs) overprinted by transverse grounding-zone wedges (GZWs). GZWs are thought to form by deposition of subglacial till at temporarily stable ice-sheet marine termini between successive episodic retreats (Batchelor & Dowdeswell 2015). Sub-bottom profiles show that the present-day morphology of Kveithola Trough is largely inherited from the palaeo-seafloor topography of the GZWs, which is now draped by deglacial to early Holocene glacimarine sediment about 15 m thick. The ice stream that produced such subglacial morphology was flowing from east to west towards the shelf edge in Kveithola Trough during the Last Glacial Maximum (LGM). Its rapid retreat was probably associated with progressive lift-off and successive rapid melting of grounded ice induced by eustatic sea-level rise