Brief communication: Rapid ∼  335  ×  10<sup>6</sup> m<sup>3</sup> bed erosion after detachment of the Sedongpu Glacier (Tibet)
<p>Following the 130 <span class="inline-formula">±</span> 5 <span class="inline-formula">×</span> 10<span class="inline-formula"><sup>6</sup></span> m<span class="inline-formula"><sup>3</sup...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2023-06-01
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| Series: | The Cryosphere |
| Online Access: | https://tc.copernicus.org/articles/17/2533/2023/tc-17-2533-2023.pdf |
| Summary: | <p>Following the 130 <span class="inline-formula">±</span> 5 <span class="inline-formula">×</span> 10<span class="inline-formula"><sup>6</sup></span> m<span class="inline-formula"><sup>3</sup></span> detachment of
the Sedongpu Glacier, south-eastern Tibet, in October 2018, the Sedongpu
Valley, which drains into the Yarlung Tsangpo (Brahmaputra) River, underwent
rapid large-volume landscape changes. Between December 2018 and 2022 and in
particular during summer 2021, an enormous volume of in total
<span class="inline-formula">∼</span> 335 <span class="inline-formula">±</span> 5 <span class="inline-formula">×</span> 10<span class="inline-formula"><sup>6</sup></span> m<span class="inline-formula"><sup>3</sup></span> was eroded from the former
glacier bed, forming a new canyon of up to 300 m depth, 1 km width, and
almost 4 km length. The 2021 erosion peak happened through massive but still
gradual retrogressive erosion into the former glacier bed. Several rock–ice
avalanches of in total <span class="inline-formula">∼</span> 150 <span class="inline-formula">±</span> 5 <span class="inline-formula">×</span> 10<span class="inline-formula"><sup>6</sup></span> m<span class="inline-formula"><sup>3</sup></span> added
to the total rock, sediment, and ice volume of over 600 <span class="inline-formula">×</span> 10<span class="inline-formula"><sup>6</sup></span> m<span class="inline-formula"><sup>3</sup></span> (0.6 km<span class="inline-formula"><sup>3</sup>)</span> that has been exported from the basin since around 2017. The recent
erosion volumes at Sedongpu are by order of magnitude equivalent to the
average annual denudation volume of the entire Brahmaputra basin upstream of
the location where the river leaves the Himalayas. This high-magnitude
low-frequency event illustrates the potential for rapid post-glacial landscape
evolution and associated hazards that has rarely been observed and
considered at such high intensity so far.</p> |
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| ISSN: | 1994-0416 1994-0424 |