Northern Margin of the Barents Sea Shelf after the Little Ice Age: Variability of the Drift Ice Edge and Sedimentation Dynamics

This paper presents results of a study of bottom sediments of the northern margin of the Barents Sea shelf. The study was carried out within the framework of the Transarctic 2019 expedition. The exposed bottom sediments with a thickness of 11 to 18 cm began to form approximately 300–400 years ago. The sedimentary strata are composed of pelite and siltstone fractions with local periodic inclusions of coarse-grained particles. After the Little Ice Age (LIA), sedimentation rates in the area of the northern margin of the Barents Sea shelf varied in time and space from 0.04 to 0.19 cm/year, with average values of 0.04–0.1 cm/year. The main factor of sedimentation north of the strait between Spitsbergen and Franz Josef Land is ice and iceberg spread of terrigenous sediments. Chronostratigraphic studies indicate a significant impact of global climate change on the sedimentation regime in the northern Barents Sea shelf after the end of the LIA from the late 18th to early 19th centuries. The periodicity of changes is close to climatic periods of 50–60 years. However, in the direction from southwest to northeast, there is a lag of peaks of approximately 20 years (according to our observations of the structure of the sedimentary cover and the intensity of sedimentation). Due to local changes in the sedimentation regime after the LIA, three areas that differ in the response of sedimentogenesis to climate change have been identified: (1) the high response area—the northeast of the Spitsbergen archipelago; (2) the moderate response area—the northern shelf of the Franz Josef Land archipelago; and (3) the low response zone—the Franz Victoria Trough area.