Palaeoceanography on the European arctic margin during the last deglaciation

Abstract

Abstract To reveal the palaeoceanographic and palaeoclimatic evolution related to the disintegration of the Barents Sea and Fennoscandian ice sheets, high-resolution sediment cores from the continental margin off western Svalbard, western Barents Sea and northern Norway were investigated. The location of these cores is below the axis of the Norwegian Current and beyond, but close to, glaciated continental areas. Hence they should sensitively reflect the palaeoceanography of the northernmost Norwegian Sea. Between, 14.5–19.5 and 22.5–29 14 C ka, a high abundance of planktonic foraminifera and a small content of subpolar species indicate seasonally ice-free and slightly warmed surface water. This phenomenon is related to the advection of surface water of North Atlantic origin. The onset of the deglaciation is characterized by a marked low oxygen event dated to between 15 and 13 ka, interpreted to reflect a surface water freshening produced by meltwater and reduced oceanic mixing. After the onset of deglaciation, the surface ocean warmed in three rapid steps: (1) around 12.5 ka, indicated by increased abundances of planktonic foraminifera; (2) at 10.2 ka and at (3) 10–9.6 ka. The two latter steps are reflected by the increased abundance of subpolar planktonic foraminifera.