Late glacial air temperature, oceanographic and ice sheet interactions in the southern Barents Sea region

Abstract

Abstract Stratigraphic records from three areas (the Andøya area, the continental slope and the continental shelf of the southern Barents Sea) are used to evaluate the history of the late glacial Barents Sea Ice Sheet and the northern Fennoscandian Ice Sheet. Two late glacial maxima are indicated: one before 22 ka BP (LGM I) and the younger after 19 ka BP (LGM II). A major deglaciation phase was initiated during a warm spell between 16 and 15 ka BP . During a drawdown of marine based ice sheets about 14.5 ka BP large parts of the southern Barents Sea Ice Sheet decayed. This deglaciation was retarded between 13.7 and 13 ka BP . Most of the eastern and northern Barents Sea was deglaciated during the Bølling-Allerød interstadial complex. During the LGM II there was an ice stream in the Bear Island Trough with an estimated velocity at the front of about 2.5 km/year. An average accumulation rate of 0.3–0.4 m/year is estimated for the drainage area of the Bear Island Trough Ice Stream. A close interrelation exists between summer air temperatures and the waxing and waning phases of the northern Fennoscandian and southern Barents Sea ice sheets. It is suggested that most of the ice sheet decay was due to climatic warming, which caused thinning of the ice sheets, making them susceptible to decoupling from the sea bed and increased calving. The subsequent halts/readvances were due to climatic deteriorations caused by huge inputs of icebergs to the Norwegian Sea which cooled the surface water and in turn promoted sea ice preservation through the summer season and thereby increased the albedo.