On the Kamchatka Peninsula, a number of glaciers are covered by thick volcanic debris, which makes their margins difficult to delineate from satellite imagery. Fortunately, high resolution, multi-temporal digital surface models (DSMs) covering the entire peninsula have recently become freely available (i.e., ArcticDEM). We use these DSMs to analyse the dimensions and dynamics of debris-covered glaciers in the northern Kluchevskoy Volcanic Group, central Kamchatka. This approach demonstrates that between 2012 and 2016, some of the region’s glaciers advanced despite regional and local climate warming. These glacial advances are part of a long-term trend, presumed to reflect the role of extensive supraglacial debris in limiting ice ablation, though there is also evidence for local ice melt due to supraglacial lava/debris flows. Glacier surface velocities during the period 2012–2015 were typically 5–140 m yr⁻¹. Velocities for the major outlets of the region’s central icefield were typically higher than for other extensively debris-covered glaciers globally, likely reflecting the influence of ice supply from the high altitude Ushkovsky caldera. In all, we find ArcticDEM useful for analysing debris-covered glaciers in Kamchatka, providing important information on flow dynamics and terminus change that is difficult to derive from satellite imagery.

На основе дешифрирования аэрофотоснимков и космических снимков приводятся данные о количестве и динамике озёр у ледника Малый Азау за 1957–2015 гг. Наибольшая площадь озера (25,5 тыс. м2) зафиксирована на космоснимке 22.08.2011 г. незадолго до прорыва. Прорывы озёр происходили в 1978 и 2011 гг. и имели разные причины. Первый прорыв связан с оползневыми деформациями моренного массива, слагающего часть озёрной котловины, второй – с деградацией ледяной плотины озера и переливом воды поверх неё. Установлен также факт значительного падения уровня воды в озёрах в зимний период.

The data of interpretation of aerial photographs and satellite images over 1957–2020, as well as field studies and helicopter observations were used to determine specific features of the evolution of lakes at Dzhikiugankez glacier and the mechanisms of their outburst, including those through subsurface channels. Data on lakes Podkova, Severnoe Chungurchat, and Balyk Yuzhnoe were used to show that the formation of subsurface runoff channels does not necessarily imply descent of debris flows; however, even small lakes can become sources of considerable debris flows.

По данным дешифрирования аэрофотоснимков и космических снимков за 1957-2020 гг., а также полевых наблюдений и вертолётных облётов определены особенности эволюции озёр у ледника Джикиуганкез и механизмы их прорыва, в том числе по подземным каналам. На примере озёр Подкова, Северное Чунгурчат и Балык Южное показано, что формирование подземных каналов стока не обязательно приводит к сходу селевых потоков, однако даже небольшие озёра могут быть очагами значительных селей.

As a result of climate change there have been high rates of degradation of mountain glaciers in recent years. During deglaciation in the territories previously occupied by glaciers, moraines of various morphogenetic types remain deposited by them, connected with massifs of glacial-colluvial and other deposits. The most actively involved in debris flow processes are massifs of terminal moraines with extended steep ledges, on which debris flow cuts and furrows develop. Much less often, debris flow original sites are formed on lateral moraines, but debris flows can reach catastrophic proportions. The analysis of publications and of multi-time satellite images revealed data on the formation of debris flow original sites of various types in the areas of lateral moraines of mountain glaciers, pockets of lateral moraines filled with slope and glacial deposits, as well as lakes and streams inside them. Similar debris flow original sites have been characterized for the Central Caucasus, the Andes, the Hindu Kush, the Himalayas and Tibet. The largest debris flow disasters with original sites in areas of lateral moraines were outbursts of Palcacocha lakes in Peru in 1941 and Chorabari in India in 2013 with a death toll of up to 6054, as well as the outburst of South Lhonak Lake in Sikkim (India) in 2023. In areas of lateral moraines of valley glaciers connected with moraine pedestals of former tributary glaciers, the volume of mass transport of debris flows can reach 6.5 million m3 (lateral moraine of the Gangotri glacier in the Himalayas in 2017). The progress of debris flow processes on lateral moraines of mountain glaciers must be taken into account when developing mountain territories both in areas near lateral moraines and at a considerable distance from them.