Variability of Sedimentation Processes in Northern Part of East Novaya Zemlya Trough in the Anthropocene

Abstract

The lithological and mineralogical characteristics of sea surface sediments, composition of microfossils, contribution of organic matter, and element composition have been studied in a core from the northern part of East Novaya Zemlya Trough. Sedimentation rates were calculated based on the radioisotopes 210Pb and 137Cs. Lithological, biogeochemical, and geochemical studies showed a low variability of the sedimentation conditions over the last 250 years. However, even small changes in microfossils, as well as lithological and geochemical parameters, make it possible to trace some short-term climate changes in this area, probably controlled by atmospheric circulation. The core shows a clear binomial structure, reflecting changes in sedimentation at the end of the Little Ice Age (LIA) and afterward. For the northern part of the East Novaya Zemlya Trough, low sea surface temperatures and an increase in the duration of ice cover at the end of the LIA in the 1780s−1810s have been reconstructed. Since the 1810s, the hydrodynamic activity of water masses intensified sharply due to glacier melting (especially after the 1840s). In addition, an increase in sea surface temperatures can be assumed, except for the cooling of the 1910s. Later, circulation of water masses increased, contributing to the supply of terrigenous material to the deep parts of the trough.