Vestnik MGTU (Mar 2021)
Lithological characteristics of modern sediments in the southwestern part of the Kara Sea shelf
Abstract
In August – September 2020, during cruise 49 of the R/V Akademik Nikolay Strakhov, comprehensive geological, geophysical, hydroacoustic, geomorphological and hydrophysical research studies of the western segment of the Arctic zone within the Pechora and Kara Seas began in 2018–2019 were continued. As previously, the work was aimed at mapping the relief and modern sediments in order to assess the possible negative consequences of changes in natural conditions on the Arctic coast of the Russian Federation. The main purpose of the research was to assess the evolution of natural environments within the southwestern part of the Kara Sea shelf in connection with the observed global climate change in the Arctic, as well as with the expected increase in anthropogenic load on the Arctic shelf due to the development of oil and combustible natural gas fields. Bottom grab and a shock ground tube were used to obtain samples of recent sediments of the Kara Sea. The sampling sites were determined based on the analysis of data from bathymetric bottom survey and continuous seismic profiling. During the research, the boundaries of the distribution of various facies of bottom sediments within the southwestern part of the Kara Sea shelf have been clarified. The main feature of the modern bottom sediments in the southwestern part of the Kara Sea shelf is a wide areal distribution of thin facies – pelitic muds. Along the eastern and southern coasts of the Archipelago Novaya Zemlya, a distribution zone of iceberg sediments with a width of at least 150 km has been established. The formation of icebergs should be associated with the movement of the Novaya Zemlya cover glacier, formed 30–20 thousand years ago during the Sartan Ice Age. As the studies have shown, the general Holocene transgression in the Kara Sea was periodically replaced by short regressions, at least in the southwestern part of the basin.
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