flash flood

First scientific article on the 26 August catastrophe in the Himalaya

György Hetényi News , , , , , , , , , ,

Following a rapid, joint effort, and a fast review process, our freshly published paper is the first peer-reviewed study reconstructing and characterizing the cascading catastrophes that have hit the Himalaya on August 26th, 2026. The main event was a rock (and some ice) fall on the north flank of Tsangbu Ri mountain, of about 100 million m3 volume, which triggered an extreme flash flood along the Trishuli River. Seismometers at 100 km distance from the river vibrated for hours, and the event was detected all around the globe. Full details are in our paper published in Seismica today by Adhikari, Subedi et al.

A related radio interview in the CQFD emission on RTS is available here (in French). (08.10.2026)

A summary in non-technical language is available in this article on Inside Climate News. (14.10.2026)

Newspaper article in Le Temps on the event and the urgent need for an early warning system: in English, in French. (22.10.2026)

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The estimated volume fits the amount of rock and ice seen on a July 1st satellite photo, and the scarp of the August 26th mass movement (in red). Background image source: Airbus, CNES, GoogleEarth.

Devastating earthquake-triggered flood in the Himalaya

György Hetényi News , , , ,

A devastating flash flood has hit Nepal and Tibet this morning. Hundreds are missing and rescue teams are challenged both in Rasuwa and further downstream in Nepal, and in Gyirong, Tibet. The flash flood was first reported to have been triggered by a nearby magnitude 4.4 earthquake — this is a usual, moderate size event for the region. Later reports from USGS indicate that a major landslide or glacier collapse was the cause of the first signal, with a magnitude equivalent to M5.2. In any case, the impact of the flash flood can be assessed on the records of the seismometer tens of kilometres away: after the short initial signal, the ground was vibrating for over two hours due to the flash flood. Credits: Shiba Subedi, NAST.

rasuwa flood2
Seismic signal of the initial event followed by that of the flash flood in the Nepal Himalaya / S. Subedi