Tsangbu Ri slope failure triggers massive flash flood across the Himalaya and shakes the globe – the seismic observations

Authors

  • Lok Bijaya Adhikari National Earthquake Monitoring and Research Centre, Department of Mines and Geology, Kathmandu, Nepal
  • Shiba Subedi Seismology at School in Nepal, Pokhara, Nepal https://orcid.org/0000-0002-7009-7333
  • György Hetényi Institute of Earth Sciences, University of Lausanne, Switzerland https://orcid.org/0000-0001-9036-4761
  • Laurent Bollinger CEA, DAM, DIF, F-91297 Arpajon, France https://orcid.org/0000-0002-5116-860X
  • Li Li Institute of Geophysics, China Earthquake Administration, Beijing, China
  • Stephen P. Hicks Department of Earth Sciences, University College London, United Kingdom https://orcid.org/0000-0002-7476-3284
  • Marianne S. Karplus Department of Earth, Environmental, and Resource Sciences, University of Texas at El Paso, El Paso, USA https://orcid.org/0000-0001-6007-5790
  • Jordi Diaz GEO3BCN‐CSIC, Barcelona, Spain https://orcid.org/0000-0003-1801-0541
  • Hari Ram Thapa Department of Environment, Earth and Geospatial Science, North Carolina Central University, Durham, USA https://orcid.org/0000-0002-6227-2381
  • Tara Pokharel National Earthquake Monitoring and Research Centre, Department of Mines and Geology, Kathmandu, Nepal https://orcid.org/0009-0005-5606-7508
  • Chintan Timsina National Earthquake Monitoring and Research Centre, Department of Mines and Geology, Kathmandu, Nepal https://orcid.org/0000-0003-2222-3806
  • Aastha Poudel Central Department of Geology, Tribhuvan University, Kathmandu, Nepal https://orcid.org/0009-0009-4650-219X
  • Kushal Pokhrel Central Department of Physics, Tribhuvan University, Kathmandu, Nepal https://orcid.org/0009-0003-7879-2618
  • Shila Bhattarai National Earthquake Monitoring and Research Centre, Department of Mines and Geology, Kathmandu, Nepal
  • Elise Weiskopf National Earthquake Monitoring and Research Centre, Department of Mines and Geology, Kathmandu, Nepal
  • Rajesh Sharma National Earthquake Monitoring and Research Centre, Department of Mines and Geology, Kathmandu, Nepal
  • Mukunda Bhattarai National Earthquake Monitoring and Research Centre, Department of Mines and Geology, Kathmandu, Nepal

DOI:

https://doi.org/10.26443/seismica.v5i2.3433

Abstract

On 26 August 2026, a massive slope failure in the Himalaya caused a destructive flash-flood all along the Trishuli River. Here we report the first complete set of related seismic observations from Nepal and China. Using first-arrivals of high-frequency waveforms, we localize the main mass-movement and a nearby M2.5 seismic event shortly preceding it. The flash-flood increased seismic noise levels, persisting for hours. We report global seismic detections of the main event. Ultimately, we argue that a regional seismic monitoring network coupled with a signal detection and classification system would provide an early warning tool for future high-risk events.

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Published

2026-10-02

How to Cite

Adhikari, L. B., Subedi, S., Hetényi , G., Bollinger, L., Li, L., Hicks, S. P., Karplus, M. S., Diaz, J., Thapa, H. R., Pokharel, T., Timsina , C., Poudel, A., Pokhrel, K., Bhattarai, S., Weiskopf, E., Sharma, R., & Bhattarai, M. (2026). Tsangbu Ri slope failure triggers massive flash flood across the Himalaya and shakes the globe – the seismic observations. Seismica, 5(2). https://doi.org/10.26443/seismica.v5i2.3433

Issue

Vol. 5 No. 2 (2026)

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Fast Reports

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Copyright (c) 2026 Lok Bijaya Adhikari, Shiba Subedi, György Hetényi , Laurent Bollinger, Li Li, Stephen P. Hicks, Marianne S. Karplus, Jordi Diaz, Hari Ram Thapa, Tara Pokharel, Chintan Timsina , Aastha Poudel, Kushal Pokhrel, Shila Bhattarai, Elise Weiskopf, Rajesh Sharma, Mukunda Bhattarai

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This work is licensed under a Creative Commons Attribution 4.0 International License.