DYNAMICS OF PERMAFROST IN THE COASTAL ZONE OF EASTERN-ASIAN SECTOR OF THE ARCTIC

Anatoly V Gavrilov,Elena I Pizhankova

doi:10.24057/2071-9388-2018-11-1-20-37

Abstract

The study summarizes results on the cryogenic dynamics in the coastal zone. The paper shows that ongoing climate warming and shrinking of ice extent of the Arctic seas triggers both thermogenic and cryogenic processes at the same time. The first group includes thermal abrasion, thermal denudation, degradation of submarine permafrost, and the second one is the syncriogenesis of the new-formed coastal-marine sediments. The first group results in an increase of the retreat rate of coasts, the second results in the islands formation on banks and shallows where the domination of bottom thermal abrasion and deepening of the sea bottom has been taken place previously. Arguments for stamukhas and cryogenesis role in islands formation are presented.

Highlights

Studies of coastal dynamics in cryolithozone are often conducted disregarding the processes along the submarine near shore zone
The coastal zone of the East Asian sector of the Arctic is the area with highly dynamic permafrost environment
Here the onshore permafrost is transformed into degrading offshore permafrost, and, on the other hand, modern submarine and subaerial syncryogenic permafrost are under formation

Summary

Introduction

Studies of coastal dynamics in cryolithozone are often conducted disregarding the processes along the submarine near shore zone. In the cold period of the Late Pleistocene, syncryogenic deposits of the Ice Complex (IC) were formed at the drained shelf and the coastal lowlands of the Eastern sector of the Eurasian Arctic. The vulnerability of icy deposits towards the thermal influence causes the shores retreat as a result of thermal abrasion and thermal denudation, and the degradation of offshore permafrost These processes determine the environmental conditions at the coastal zone of the East-Arctic seas. The coastal zone is the particular place on the Eastern sector of Eurasian Arctic shelf where there are widely spread multidirectional cryogenic processes under natural conditions Their characteristics in connection the sea ice coverage and climate changes in the second part of the 20th Century and the beginning of the 21th Century is the matter of consider in this paper

MATERIALS AND METHODS

CONCLUSIONS