Quantitative reconstructions of the last glaciation of the Barents Sea: a review of ice-sheet modelling problems

Abstract

Reconstructions of the Late Weichselian ice sheet within the Barents Sea have varied from complete coverage of a large (3 km thick) grounded ice mass, to a situation in which glacier extent was restricted to the Svalbard coast. Recently obtained geological data indicate that 1) glaciation of the Barents Sea occurred after 25 000 years ago; 2) the ice sheet was at its maximum extent at around 20 000 years ago; 3) the maximum-sized ice sheet covered the entire Barents Shelf; and 4) ice-sheet decay began at about 16 500 years ago. The ice sheet was, consequently, one of the last to grow and first to decay during the last glacial. However, this recently derived chronology of glacial events has reintroduced problems concerning the thickness distribution of the maximum- sized ice sheet, and the glaciological processes by which rapid glaciation and ice decay happened. In particular, the situation in which regional glaciation of Bjomoya occurred at the same time as grounded ice (and ice-stream activity) within the relatively deep Bjørnøyrenna is yet to be understood fully. This article provides a review of reconstructions of the last Barents ice mass, and compares these models with geological and palaeoceanographic information from the area in order to provide a summary of what is presently known, and to indicate explicitly what is not known, about the Late Weichselian Barents Sea ice sheet.