Changes in the flow of Atlantic water into the Arctic Ocean since the last deglaciation: Evidence from the northern Svalbard continental margin, 80°N

Abstract

The Svalbard archipelago is located in the high Arctic (76°–80°N) within the northernmost reach of the West Spitsbergen Current, which is the continuation of the North Atlantic Current. In this specific setting close to the Polar Front, even small variations in the current system are expected to give large and distinct signals in paleoceanographic parameters. Thus the Svalbard area is ideal for monitoring the past history of the inflow of Atlantic water to the Arctic Ocean. We have studied sediment core NP94‐51 taken outside the mouth of the Hinlopen Strait on the northern Svalbard shelf. The paleoceanographic development of the last deglaciation and the Holocene has been reconstructed using benthic and planktonic foraminifera, oxygen isotopes, and ice‐rafted detritus. The results show that the first strong subsurface inflow of Atlantic water to the Arctic Ocean after the Last Glacial Maximum commenced at 12.6 14C kyr B.P. (circa 15,000 calendar (cal) years B.P.) during the Bølling‐Allerød interstadial. During the Younger Dryas, polar conditions prevailed at the surface with extensive sea ice cover, and the inflow of Atlantic‐derived water was generally diminished. The inflow of more saline, but still cold Atlantic water was relatively strong during the early Holocene and caused intensified seasonal biological productivity. The Atlantic water inflow declined gradually during the mid‐Holocene. Between 4500 and 1100 cal years B.P. the inflow was very weak, and the bottom waters over the northern Svalbard margin were cold and of lower salinity. During the last ∼1000 years, climatic conditions improved such that the subsurface inflow of Atlantic‐derived water increased. However, the surface waters were still cold.