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Broknes Peninsula (the area of the Progress station, Larsemann Hills, Princess Elisabeth Land, East Antarctica) is characterized by the presence of well developed hydrographic network consisting of reservoirs located not only in the bedrock, but also inside the glacier thickness and on its surface. As a rule, most of them are dammed by natural snowice weirs, which are often destroyed during the Antarctic summer. As a result of this process, glacial water outburst may occur. In the course of the summer season of the 63‑th Russian  Antarctic Expedition (RAE) intensive hydrological field observations were carried out for identification and comprehensive investigation of potentially outburstprone reservoirs located in close proximity to Russian and foreign stations and field bases (area of the  Progress station and the field base Law-Racovita). The works included: the organization of temporary pile and depth-stick water gauge stations, mapping positions of the shoreline of lakes (reservoirs), bathymetric surveys of them, as well as field hydro-chemical express analyses. Based on the results of the level measurement, it was found that most of the lakes of the oasis are characterized by a sharp drop in the height of the water surface level associated with the breakthroughs. In particular, the authors witnessed the breakthrough of the Discussion Lake, which occurred on January 22, 2018. This resulted in decrease of the water level by 0.95 m. Based on the data of the bathymetric surveys, the morphometric (hydrometric) characteristics of the lakes were calculated and detailed grids (regular net of rectangular matrices, in the nodes of which some effective values of the mapped values are located) were formed for the following numerical modeling of hypothetical and real breakthroughs of water bodies and construction of estimated hydrographs.

The destruction of ground dams, of natural and artificial origin, is caused by certain critical conditions. The main reasons for this are the overflow of water over the crest of a dam, the filtration of water through its body, or mechanical destruction. The processes of destruction of ground dams of moraine lakes are very frequent phenomena for mountain regions and can often occur there. In addition, the outburst of ground dams can take place under the thickness of the cover and mountain glaciers that leads to the formation of the subglacial hydrographic drainage system. Because of the dam destruction, outburst floods, which are accompanied by significant destruction and even human losses, are formed. Considering that, it is extremely difficult and unsafe to investigate the outburst process directly at the time of its natural occurrence, the researchers turn to alternative methods, like physical modeling. In this paper, the results of physical modeling of the outburst of the moraine model reservoir are presented. The experiment was carried out near the coastline of the outburst glacier lake Bashkara (Central Caucasus, Elbrus Region, Russia). Therefore, the artificial dam, consisting of material of moraines surrounding the lake, was created. This leads to a possibility to recreate the experimental conditions closest to natural. During the research photography and video filming of the outburst of the model reservoir were carried out. The results of physical modeling are in complete agreement with previously published data of outburst of ground dams and do not contradict with the physical essence of the process.

The study aims to identify formation factors of water inflow to the Antarctic lakes of the Larsemann Hills oasis (East Antarctica). The objects of study are 11 lakes of the oasis. The analysis was performed based on the expeditionary data of the Russian Antarctic Expedition (RAE): 63rd season (23 December 2017 – 3 February 2018), 64th season (12 January 2019 – 27 February 2019), 65th season (2 November 2019 – 24 March 2020). Data of lakes water level observations, aerial photography of the unmanned aerial vehicle (UAV) and route surveys are given, the results of identifying the boundaries of the lakes catchments are presented. The factors that determine the formation of water inflow to the lakes in this region were identified based on the analysis of the materials. The most significant are the meteorological conditions, the presence of perennial snowfields and glacial areas in the catchments, and the presence of lakes that can cause outburst flood. The seasonally thawed layer also has an impact on the formation of the inflow to the lakes. The vegetation cover is not so important for inflow formation in this region due to the physical and geographical conditions. As for anthropogenic activity, it mainly affects the environmental situation of the catchments and water quality, while the anthropogenic influence on the formation of water inflow to the lakes in the oasis is limited to the territories of polar stations. The factors identified should be taken into account in the further study of hydrological processes, the creation of models that describe them, and the organization of field observations.

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