Formation and Outburst of the Toguz-Bulak Glacial Lake in the Northern Teskey Range, Tien Shan, Kyrgyzstan
In Kyrgyzstan, outburst flood disasters from glacial lakes are increasing. An example is the sudden drainage on 8 August 2019 of the Toguz-Bulak glacial lake in the Tosor river basin of the northern Tien Shan region. In this study, we used remote sensing and field surveys to examine the reasons for...
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MDPI AG
2020-11-01
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| Series: | Geosciences |
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| Online Access: | https://www.mdpi.com/2076-3263/10/11/468 |
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| author | Mirlan Daiyrov Chiyuki Narama Andreas Kääb Takeo Tadono |
| author_facet | Mirlan Daiyrov Chiyuki Narama Andreas Kääb Takeo Tadono |
| author_sort | Mirlan Daiyrov |
| collection | DOAJ |
| description | In Kyrgyzstan, outburst flood disasters from glacial lakes are increasing. An example is the sudden drainage on 8 August 2019 of the Toguz-Bulak glacial lake in the Tosor river basin of the northern Tien Shan region. In this study, we used remote sensing and field surveys to examine the reasons for the outburst. We found that the lake area changed from 0.021 km² to 0.002 km<sup>2</sup> due to the outburst, in which most of the initial 130,000 m<sup>3</sup> of water discharged within four hours. In examining the longer-term behavior of this lake, we found that from 2010 through 2019, it appears in June and disappears in September every year. Its maximum area occurs in late July and early August. With the expansion of the lake basin between 2010 and 2019, the lake also increased greatly in size, particularly so in the three years before the outburst, linked to high summer temperatures and the resulting higher inflow of glacier meltwater, finally leading to the sudden drainage in 2019. Before this outburst, a 2-m high moraine dam retained the lake. Continuously inflowing meltwater and the related increasing pressure by the lake water mass eventually broke the moraine dam. Satellite radar interferometry revealed active displacement fringes in the lake basin and moraine dam due to the melting and subsidence of buried ice. An analysis using digital elevation models from 1964 and 2010 also confirms the surface lowering in the lake basin by up to 8.5 m and on the moraine dam by 2 m. Such lowering of the proglacial moraine complex destabilized the moraine dam. |
| first_indexed | 2024-03-10T14:44:23Z |
| format | Article |
| id | doaj.art-f0e2afb9c1e54fea9053fbd3d01f8795 |
| institution | Directory Open Access Journal |
| issn | 2076-3263 |
| language | English |
| last_indexed | 2024-03-10T14:44:23Z |
| publishDate | 2020-11-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Geosciences |
| spelling | doaj.art-f0e2afb9c1e54fea9053fbd3d01f87952023-11-20T21:32:11ZengMDPI AGGeosciences2076-32632020-11-01101146810.3390/geosciences10110468Formation and Outburst of the Toguz-Bulak Glacial Lake in the Northern Teskey Range, Tien Shan, KyrgyzstanMirlan Daiyrov0Chiyuki Narama1Andreas Kääb2Takeo Tadono3Central-Asian Institute for Applied Geosciences (CAIAG), Bishkek 720027, KyrgyzstanProgram of Field Research in the Environmental Sciences, Niigata University, Niigata 950-2181, JapanDepartment of Geosciences, University of Oslo, 0316 Oslo, NorwayJapan Aerospace Exploration Agency (JAXA), Tsukuba 305-8505, JapanIn Kyrgyzstan, outburst flood disasters from glacial lakes are increasing. An example is the sudden drainage on 8 August 2019 of the Toguz-Bulak glacial lake in the Tosor river basin of the northern Tien Shan region. In this study, we used remote sensing and field surveys to examine the reasons for the outburst. We found that the lake area changed from 0.021 km² to 0.002 km<sup>2</sup> due to the outburst, in which most of the initial 130,000 m<sup>3</sup> of water discharged within four hours. In examining the longer-term behavior of this lake, we found that from 2010 through 2019, it appears in June and disappears in September every year. Its maximum area occurs in late July and early August. With the expansion of the lake basin between 2010 and 2019, the lake also increased greatly in size, particularly so in the three years before the outburst, linked to high summer temperatures and the resulting higher inflow of glacier meltwater, finally leading to the sudden drainage in 2019. Before this outburst, a 2-m high moraine dam retained the lake. Continuously inflowing meltwater and the related increasing pressure by the lake water mass eventually broke the moraine dam. Satellite radar interferometry revealed active displacement fringes in the lake basin and moraine dam due to the melting and subsidence of buried ice. An analysis using digital elevation models from 1964 and 2010 also confirms the surface lowering in the lake basin by up to 8.5 m and on the moraine dam by 2 m. Such lowering of the proglacial moraine complex destabilized the moraine dam.https://www.mdpi.com/2076-3263/10/11/468glacial lakeGLOFlake basinmoraine-dammed lakemoraine complexTien Shan |
| spellingShingle | Mirlan Daiyrov Chiyuki Narama Andreas Kääb Takeo Tadono Formation and Outburst of the Toguz-Bulak Glacial Lake in the Northern Teskey Range, Tien Shan, Kyrgyzstan Geosciences glacial lake GLOF lake basin moraine-dammed lake moraine complex Tien Shan |
| title | Formation and Outburst of the Toguz-Bulak Glacial Lake in the Northern Teskey Range, Tien Shan, Kyrgyzstan |
| title_full | Formation and Outburst of the Toguz-Bulak Glacial Lake in the Northern Teskey Range, Tien Shan, Kyrgyzstan |
| title_fullStr | Formation and Outburst of the Toguz-Bulak Glacial Lake in the Northern Teskey Range, Tien Shan, Kyrgyzstan |
| title_full_unstemmed | Formation and Outburst of the Toguz-Bulak Glacial Lake in the Northern Teskey Range, Tien Shan, Kyrgyzstan |
| title_short | Formation and Outburst of the Toguz-Bulak Glacial Lake in the Northern Teskey Range, Tien Shan, Kyrgyzstan |
| title_sort | formation and outburst of the toguz bulak glacial lake in the northern teskey range tien shan kyrgyzstan |
| topic | glacial lake GLOF lake basin moraine-dammed lake moraine complex Tien Shan |
| url | https://www.mdpi.com/2076-3263/10/11/468 |
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