Earth’s Cryosphere, 2017, Vol. XXI, No. 6, p. 73-83

EROSION OF PERMAFROST COASTS OF KARA SEA NEAR KHARASAVEY CAPE, WESTERN YAMAL

N.G. Belova, N.N. Shabanova, S.A. Ogorodov, A.M. Kamalov, D.E. Kuznetsov, A.V. Baranskaya, A.V. Novikova

Lomonosov Moscow State University, Faculty of Geography, Laboratory of Geoecology of the North, 1, Leninskie Gory, Moscow, 119991, Russia; nataliya-belova@ya.ru

Analysis of multi-temporal satellite imagery and results of long-term field monitoring of coastal dynamics allowed to determine retreat rates of a 7-km coastal section between Kharasavey settlement and Cape Kharasavey, Western Yamal. Its bluffs, 7–12 m in height, are composed of permafrost and retreat at an average annual rate of 1.1 m per year (over a 52-year period). The highest mean annual retreat rates (>2 m per year) are typical for coasts composed by ice-rich fine silty clays, their cryogenic structure being the main factor of such fast retreat. In 2006–2016, average retreat rates increased to 1.2 m/year compared with the 1.0 m/year rate in 1964–2006, primarily due to the accelerated erosion rates of ice-rich silty clays in the coastal bluffs. The impact of hydrometeorological forcing on Kharasavey coastal area increased in the late XX–early XXI centuries, causing faster coastal retreat.

Western Yamal, permafrost, coastal dynamics, thermal abrasion, thermal denudation, ground ice, hydrometeorological forcing