EGU22-3912
https://doi.org/10.5194/egusphere-egu22-3912
EGU General Assembly 2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Performance and limits of a shallow model for landslide generated tsunamis: from lab experiments to simulations of flank collapses at La Montagne Pelée (Martinique)

Pablo Poulain1, Anne Le Friant1, Anne Mangeney1, Sylvain Viroulet1,2, Enrique Fernandez-Nieto3, Manuel Castro Diaz4, Marc Peruzzetto1,5, Gilles Grandjean5, François Bouchut6, Rodrigo Pedreros5, and Jean-Christophe Komorowski1
Pablo Poulain et al.
  • 1Université de Paris, Institut de Physique du Globe de Paris, CNRS, F-75005, Paris, France (poulain@ipgp.fr)
  • 2Institut de Mécanique des Fluides de Toulouse (IMFT) - Université de Toulouse, CNRS, 31400; Toulouse, France
  • 3Dpto. Matematica Aplicada I, ETS Arquitectura - Universidad de Sevilla, Avda. Reina Mercedes S/N, 41012 Sevilla, Spain
  • 4Departamento de Analisis Matematico, Estadística e Investigación Operativa y Matemática Aplicada. Universidad de Malaga, Facultad de Ciencias, Campus Teatinos S/N, 29081 Málaga. Spain.
  • 5BRGM (French Geological Survey), Orléans, France
  • 6Laboratoire d’Analyse et de Mathématiques Appliquées (UMR 8050), CNRS, Univ. Gustave Eiffel, UPEC, F-77454, Marne-la-Vallée, France

We investigate the dynamics and deposits of granular flows and the amplitude of the generated water waves using the depth-averaged shallow numerical model HySEA, both at the lab- and field scales. We investigate the different sources of errors by quantitatively comparing the simulations with (i) six new laboratory experiments of granular collapses in different conditions (dry, immersed, dry flow entering water) and slope angles, and (ii) numerical simulations made with the code SHALTOP that describes topography effects better than most landslide-tsunami models. In the laboratory configurations, at the limit of the shallow-approximation in such models, we show that topography and non-hydrostatic effects are crucial. However, when empirically accounting for topography effects by artificially increasing the friction coefficient and performing non-hydrostatic simulations, the model is able to reproduce the granular mass deposit and the waves recorded at gauges located at a distance of more than 2-3 times the characteristic dimension of the slide, with an error ranging from 1 % to 25 % depending on the scenario, without any further calibration. Taking into account this error estimation, we simulate landslides that occurred on Montagne Pelée volcano, Martinique, Petites Antilles as well as the generated waves. Results support the hypothesis that large flank collapse events in Montagne Pelée likely occurred in several successive sub-events. This result has a strong impact on the amplitude of the generated waves, and thus on the associated hazards. In the context of the on-going seismic volcanic unrest at Montagne Pelée volcano, we calculate the debris avalanche and associated tsunami for two potential flank-collapse scenarios.

How to cite: Poulain, P., Le Friant, A., Mangeney, A., Viroulet, S., Fernandez-Nieto, E., Castro Diaz, M., Peruzzetto, M., Grandjean, G., Bouchut, F., Pedreros, R., and Komorowski, J.-C.: Performance and limits of a shallow model for landslide generated tsunamis: from lab experiments to simulations of flank collapses at La Montagne Pelée (Martinique), EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-3912, https://doi.org/10.5194/egusphere-egu22-3912, 2022.

Display materials

Display file

Comments on the display material

to access the discussion