FORMATION AND EVOLUTION OF MORAINE-DAMMED (PERIGLACIAL) LAKE NURGAN, NORTHWESTERN MONGOLIA
G.V. Pryakhina1, M.P. Kashkevich1, S.V. Popov2,3, V.A. Rasputina1, A.S. Boronina4,3, D.A. Ganyushkin1, A.R. Agatova5, R.K. Nepop5
1St. Petersburg State University, St. Petersburg, Russia
2Polar Marine Geosurvey Expedition, St. Petersburg, Russia
3St. Petersburg State University
4State Hydrological Institute, St. Petersburg, Russia
5Sobolev Institute of Geology and Mineralogy, SB RAS, Novosibirsk,Russia
Keywords: moraine-dammed lakes, periglacial lakes, formation of periglacial lakes, moraine-dammed lakes outbursts
Abstract
The shrinking in mountain ranges caused by climate change worldwide today leads to periglacial lakes formation in the areas of degrading glaciation. The lifetime of moraine-dammed lakes is ephemeral on the geological time scale. They are characterized by dynamic instability and are prone to outbursts. Degradation of moraine dams often results in catastrophic outbursts. Generally, these floods are followed by mudflows. Thus, glacial outburst floods and mud floods cause significant damage to the infrastructure and populated localities in the mountain foothills. In this study, we present the stages of formation and evolution of a periglacial water body on the example of Lake Nurgan (Tsambagarav, northwestern Mongolia). Based on the results of the comprehensive field research, we have described the transgressive, regressive and post-regressive phases of the periglacial reservoir evolution.
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