Shoreline Dynamics of the Islands of the Northern Part of Ushakov Island

The analysis of a large amount of data–satellite images, UAV surveys, meteorological observations of polar stations, and archival data made it possible to establish the shoreline retreat rates of Ushakov Island. The island is entirely covered by a glacial dome formed above Late Cretaceous and Quaternary rock formations. The ice/rock interface is partially located below sea level. Ushakov Island is located in the northern part of the Central Kara Upland; it was discovered in 1935 by a Soviet sea expedition and visited by scientific expeditions extremely rarely. For a long time, Ushakov Island was maintained under a slightly negative (up to 1% volume annually) ice balance, a short ice-free period, and protected from storm waves by fast ice. At the beginning of the twenty-first century, the situation changed—the air temperature increased noticeably, the area of sea ice shrunk, and the wave activity increased during the warm season. The edges of the Ushakov ice dome began to break off and float into the sea as icebergs evenly around the perimeter with an increasing rate: from 10.9 m/year in 1954–2011, up to 27.8 m/year in 2011–2019. The area of the island decreased in 2002–2019 by 230.8 ha/year, and in 2015–2019, up to 294 ha/year. The glacier surface around the polar station has decreased by 15 m in 65 years. A monument of science and technology, the polar station (built in 1954, 800 m from the edge of the glacier) was washed away into the sea in 2018. The subtype of ice shores has changed from ice barriers up to 3 m high (low cliffs of floating ice) to ice walls up to 45 m and more.