1 November 2021

A large landslide or glacial lake outburst in the headwaters of the Kameng River in Northern India?

Posted by Dave Petley

A large landslide or glacial lake outburst in the headwaters of the Kameng River in Northern India?

Loyal reader Robert Wasson has very kindly highlighted an interesting article in the Discovering Arunachal blog, posted on Saturday.  This article observes that at about 10:30 am on 29 October 2021 the Kameng River in East Kameng district in Arunachal Pradesh in northern India became extremely muddy.  News reports indicate that the measured dissolved solids increased by about five fold and there was a mass die off of the fish population in the river.

Chintan Sheth, the author of the Discovering Arunachal blog, has used satellite images to try to discover what caused this unexpected event.  The upstream area, along the banks of the Warriyang Bung river, is almost permanently covered in cloud at this time of the year, but on 29 October 2021 Planet Labs captured an image of part of the Warriyang Bung river catchment, from which Chintan Seth has created an image of the impact of the event:-

A composite set of Planet Labs images showing the change in the visible section of channel on the Warriyang Bung river in northern India.

A composite set of Planet Labs images showing the change in the visible section of channel on the Warriyang Bung river in northern India. Image compiled by Chintan Sheth and published on the Discovering Arunachal blog.

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The location of the site is 27.877, 92.702.  The images appear to show that there has been heavy erosion and deposition along the river.  Unfortunately the source of this event is under thick cloud.

Back on 1 October 2021 Planet Labs captured a beautiful image of the catchment:

The catchment of the Kameng River that was the source of the event of 29 October 2021

The catchment of the Kameng River that was the source of the event of 29 October 2021. Image copyright Planet Labs, used with permission, captured on 1 October 2021.

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This is a complex catchment, with small glaciers and steep slopes.  I cannot see any obvious glacial lakes, but these could be obscured by clouds.  The most three obvious candidates for this event are the collapse of a glacial lake, a the collapse of a glacier or a rock slope collapse.  The latter seems more likely, but we may not know until a cloud free image with low levels of snow becomes available.  That might not be the case until the spring.

Imagery of the channel downstream shows erosion and deposition along the channel, suggesting that this was a significant event.

The upper catchment of the Kameng River showing changes to the channel following the event of 29 October 2021.

The upper catchment of the Kameng River showing changes to the channel following the event of 29 October 2021. Image copyright Planet Labs, used with permission, captured on 29 October 2021.

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Reference

Planet Team (2021). Planet Application Program Interface: In Space for Life on Earth. San Francisco, CA. https://www.planet.com/