Abstract: The article presents preliminary results of field studies of the outcrops of the eastern coast of the Chukchi Peninsula, containing massive ice beds. The expeditions were conducted in 2014–2018. Descriptions and photographs of ice and enclosing sediments are given. Four outcrops of ice up to 4.7 m thick and up to 45 m long are described within the Saint Lawrence Bay and Mechigmensky Bay. The morphology of the massive ice bodies, a variety of ice structures and host sediments allow suggesting their polygenetic origin. The results of long-term active layer thickness monitoring indicated that the intensification of thaw slump events in the past four years is associated with the increase in the depth of thawing, which in 2018 reached highest values in over two decades. The formation of thaw slumps and associated thermocirques is cyclic. As the active layer thickness increases, their number increases, forming nested thermocirques, and as the thaw depth decreases, cryogenic creep slows down.

Abstract: The article contains the results of field investigations of cryospheric objects – land-based glaciers and permafrost rocks in the area of the Lavrenty Bay, Eastern Chukotka. Glaciers of the Laurentian group were described in the mid-1970s by Rudolf Sedov, later they were studied with the help of space imagery by one of the authors. Since glaciers are of small size, and satellite images can give errors in this case, it was necessary to check in situ their condition. Field studies have made it possible to ascertain the severe degradation of small glaciers of the Chukchi Highlands. Also field studies of the permafrost seasonal thawing, carried out by the authors in the season of 2017, revealed that the difference in thickness of the seasonally thawed layer in the study area at the end of August was, in comparison with the previous year, -0.5 .. + 4.3 cm, depending on local natural conditions. 

Abstract: The paper contains the results of active layer studies in Lorino monitoring site (Eastern Chukotka, Russia), conducted in framework of the Circumpolar Active Layer Monitoring (CALM) program during 2010-2015. The study site includes tundra landscapes of Eastern Chukotka coastal lowlands. The main purpose of the paper is to obtain spatial and temporal patterns of seasonal melting distribution and reveal the main natural factors defining active layer depth within study site. The author demonstrates the predominance of thermal forcing in active layer development, which was strongly complicated by local (microrelief, vegetation, soil moisture, etc.) conditions. These factors determined high spatial and temporal variability of active layer thickness within single grid (100×100 m). The study also reveals the lack of statistical data on natural characteristics and the need for further detailed studies of seasonal melting process.