19 July 2018
Ishkoman, Pakistan: a valley blocking glacial debris flow this week (updated with satellite imagery)
Posted by Dave Petley
Ishkoman, Pakistan: a valley blocking glacial debris flow this week (updated with satellite imagery)
The Pamir Times has a report that earlier this week a significant valley blocking event occurred at Ishkoman, high up in the mountains of Gilgit in northern Pakistan. This has also been reported in the mainstream media in Pakistan. For example, Dawn reports that:-
“A small glacier melt has swollen Barsuwat Nullah in the Ishkoman valley of Ghizer district, Gilgit-Baltistan, creating an artificial lake and blocking the flow of the Immit River. The water has submerged more than 30 houses, cultivated land, a link road and cattle farms and washed away over a dozen vehicles and hundreds of cattle head in the upstream areas.”
They also provide some more detail about the event itself:
“Deputy Commissioner of Ghizer Shuja Alam said that the Barsuwat glacier started melting on Tuesday at about 7pm. Water from the melting glacier, containing mud and stones, fell into Barsuwat Nullah and caused flooding. The nullah ultimately falls into the Immit River whose flow has been blocked and the stagnant water has created an artificial lake similar to Attabad Hunza lake, disconnecting upstream villages from other areas.”
The Pamir Times has tweeted this image of the aftermath of the event:-
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This is clearly a significant event, and it appears that a substantial volume of water has been impounded. There are some suggestions that it might have started to drain however, but this is unclear. It is very unlikely that the blockage will create a problem on the scale of the 2010 Attabad landslide given the low height of the debris pile.
(updated) This satellite image, via Planet Labs, shows the aftermath of the event (the lake has started developing; it appears to me that water flow around the distal side of the debris has started to develop at the time the image was collected). It is a Planetscope image with 3 m resolution, collected at 05:16 UTC on 18th July (thanks to Jakob Steiner for finding it):-
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Reference
Planet Team (2018). Planet Application Program Interface: In Space for Life on Earth. San Francisco, CA. https://api.planet.com