Earth’s Cryosphere, 2020, vol. XXIV, No. 4, pp. 50-59
10.21782/EC2541-9994-2020-4(50-59)
CATASTROPHIC OUTBURST-FLOOD OF THE SPARTAKOVSKOYE GLACIER-DAMMED LAKE ON THE BOLSHEVIK ISLAND (SEVERNAYA ZEMLYA)
R.A. Chernov, A.Ya. Muraviev
Institute of Geography, RAS, 29, Staromonetniy per., Moscow, 119017, Russia; rob31@mail.ru
The changes in the level of the Spartakovskoye glacier-dammed lake during the period of 2016 to 2019 have been studied. In the summer of 2016, the lake level reached its maximum, and during the period from August 16 to August 25, a catastrophic outburst-flood occurred due to the floating-up of a glacier dam formed by the outlet glacier of the Semenov-Tyan-Shansky dome. Estimation of the lake area has been obtained as a result of interpretation of satellite images. The volume of the lake and the height of the glacier dam have been determined according to the data of processing of the multi-temporal digital relief models. The maximum water level in Spartakovskoye Lake was 122.9 m, while its area and volume were (6.63 ± 0.42) km2 and (404.3 ± 21.9) million m3, respectively. The minimum height of the iceshed of the dam before the lake drainage was about 137 m, which ensured its ascent with an average ice density of 0.875 g/cm3. The calculations based on the data of snow surveys and the amount of summer melting have revealed that the melting of seasonal snow cover, perennial snowfields and ice on the surface of glaciers in the catchment area of the lake gives a runoff value of 37.1 to 48.2 million m3 of water annually depending on average summer temperatures and precipitation. The lake basin is completely filled in about 10 years. The previous outburst-flood of the lake had occurred in the summer of 2006, and until 2016 the level of the lake was continuously raising. At the end of August 2019, the lake’s level reached 80 m, which was consistent with the calculations of runoff into the lake. While maintaining the pace of the lake’s filling, its next outburst-flood may occur in 2024–2025.
Key words: glacier-dammed lake, outlet glacier, snow cover, melting, maximum level, flood-outburst of lake, Severnaya Zemlya
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