Chapter 14 - The North Sea and Mid-Norwegian continental margin: glacial landforms during deglaciation, the Bølling–Allerød Interstadial and the Younger Dryas Stadial

Abstract

A reconstruction of the last deglaciation of the Mid-Norwegian continental shelf and the North Sea, based on published mapping of marine glacial landforms (such as end moraines and grounding zone wedges) and available chronological information, is presented. The Fennoscandian Ice Sheet (FIS) and the British–Irish Ice Sheet (BIIS) was at c.20–19ka BP located close to the shelf edge in the north and the Dogger Bank in the southern North Sea. At c.19ka BP the ice streams in the Norwegian Channel and the Trænadjupet–Vestfjorden Trough started to retreat. This was followed by separation of the FIS and BIIS in the North Sea at c.18.7ka BP, and northwards drainage of an ice-dammed lake in the southern North Sea. By 17ka BP the FIS had withdrawn to a position close to the coastline of southern and southwestern Norway. At 16ka BP the FIS ice margin is suggested to have been located in a mid-shelf position at the Mid-Norwegian continental shelf, whereas a marine-extending ice cap existed in the Shetland Icelands region. By 15ka BP the FIS had withdrawn to a coastal position along the Mid-Norwegian continental shelf, that is, about 2kyr later than further south. In southern Norway the ice margin was restricted to inner fjord or inland areas during the Bølling–Allerød, and during the Younger Dryas glacial ice advanced to the outer coast along the west coast and well out into the Oslofjord in the east. Palaeoceanographic data as well as sea level consideration suggest that the North Sea was not a significant moisture source for the Younger Dryas advance in Britain and Scandinavia.