EGU General Assembly 2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Anatomy of a cascading hazard: the flood part of the 7 February Uttarakhand event

Michael Dietze1, Himangshu Paul2, Anand Kumar Pandey2, Rajesh Rekapalli2, Puranchand Rao2, Srinagesh D.2, Kirsten L. Cook1, Marco Pilz1, Niels Hovius1,3, and Virendra Mani Tiwari2
Michael Dietze et al.
  • 1Helmholtz Centre Potsdam GFZ German Research Centre for Geosciences, Telegrafenberg, 14476 Potsdam, Germany
  • 2CSIR National Geophysical Research Institute, Uppal Road, Hyderabad, India
  • 3University of Potsdam, Institute for Geosciences, Karl-Liebknecht-Str. 24-25, 14476 Potsdam, Germany

The 7 February Chamoli, Uttarakhand singularity imposed a severe geomorphic crisis. While remote sensing imagery quickly identified a major rock avalanche as its origin, there is a fundamental lack in high precision temporal information on the kinetics of this event about when, how, and why it evolved from a slope failure into a channel-confined mass wasting process, and ultimately into a debris laden flood. Furthermore, while the initial rock slide could be detected and located by global seismic networks, it was the flood which caused most of the destruction and fatalities. Yet, that part of the process cascade remained elusive in global seismic data sets.

Here, we present a detailed anatomy of the hazard cascade, with emphasis on the flood part. Using information from a dense seismic network, we explore the limits of detection and constrain its propagation velocity. By jointly inverting two physical models that predict spectral signal properties of floods, we estimate important hydraulic and sediment transport metrics. These information are key for designing any future early warning infrastructure.

How to cite: Dietze, M., Paul, H., Pandey, A. K., Rekapalli, R., Rao, P., D., S., Cook, K. L., Pilz, M., Hovius, N., and Tiwari, V. M.: Anatomy of a cascading hazard: the flood part of the 7 February Uttarakhand event, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-16593,, 2021.

Corresponding presentation materials formerly uploaded have been withdrawn.