Glacial geomorphic features in the northern Barents Sea: direct evidence for grounded ice and implications for the pattern of deglaciation and late glacial sedimentation

Abstract

Abstract Glacial landforms, in particular flutes and associated transverse ridges, have been identified in an area of roughly 4000 km 2 and between approximately 150 and 340 m water depth in the north-central Barents Sea. The transverse ridges are interpreted to be analogous to De Geer moraines and are observed only in the southern part of the fluted area. The flutes, trending roughly north-south, have a relief of less than one metre, widths on the order of 4–8 m and lengths usually 100–500 m. Although the present data do not allow firm conclusions on the exact genesis of these features, they are compared to analogous terrestrial features. The existence of these glacigenic morphological features has major implications concerning the late glacial history of the Barents Sea. They give the first direct evidence of a grounded ice sheet in the northern Barents Sea. Ice flow directions during the latest phase before final recession were mainly southwards, but a partly topographically influenced flow pattern indicates that the main banks may have acted as local ice centres. The ice sheet was relatively thin and rested on a deformable bed. It retreated rapidly from the fluted area, as evidenced by the lack of sediment masking the low-relief flutes. The general retreat from the region took place in a stepwise manner, apparently without surging and with deposition of locally thicker glacier-proximal deposits during halts in the recession.