La Palma landslide tsunami: computation of the tsunami source with a calibrated multi-fluid Navier–Stokes model and wave impact assessment with propagation models of different types

Abstract

In this paper, we present a new source assessment of the La Palma collapse scenario previously described and studied in Abadie et al. (2012). Three scenarios (i.e., slide volumes of 20, 40 and 80 km 3 ) are considered, from the initiation of the slide to the water waves generation, using THETIS, a 3D Navier-Stokes model. The slide is considered as a Newtonian fluid whose viscosity is adjusted to approximate a granular behavior. After 5 minutes of propagation with THETIS, the generated water wave is transferred into FUNWAVE-TVD for 15 minutes of Boussinesq model simulation. Then, four different depth-averaged 5 codes are used to propagate the wave to the Guadeloupe area, Europe and French coasts. Finally, the wave impact in terms of run-up is evaluated through direct computations in specific areas or using theoretical formulas. Although the wave source appears reduced due to the rheology used compared to former works, the wave impact is still significant for the maximum slide volume considered on surrounding islands and coasts, as well as on remote most exposed coasts such as Guadeloupe. In Europe and in France, the wave impact is moderate (for specific areas in Spain and Portugal) to weak (Atlantic French coast). 10The comparison between the different wave models in overlapping computational regions shows an overall agreement in terms of first wave amplitude and time of arrival, but differences appear in the trailing waves.

Numerical simulation of submarine landslides and generated tsunamis: application to the on-going Mayotte seismo-volcanic crisis

“…To overcome this issue, we propose a framework for coupling two near-field and farfield numerical models as done for example by Grilli et al [2019], each model being efficient to describe a specific part of the physical processes involved. We thus combine the HySEA model [Macías et al, 2017], used to describe the submarine avalanche and initiate the waves, with the widely used Boussinesq FUNWAVE-TVD model [Abadie et al, 2020, Grilli et al, 2019, Le Roy and Legendre, 2017, Rohmer et al, 2017, Shi et al, 2012, used to propagate the wave and compute the flooding on the Mayotte coast. To implement this approach, we: (i) analyze morphological data offshore Mayotte to define scenarios of potential submarine landslides by reconstructing precise topography, (ii) process numerical simulation of the submarine landslide including a detailed description of the sources and of the granular flow, (iii) simulate the waves generated by the landslide, its propagation, and the coast inundation and discuss the pertinence of the combination of models.…”

Landslide Induced Tsunami Hazard at Volcanoes: the Case of Santorini

“…It is long argued that based on geologic evidence, a future eruption of the Cumbre Vieja Volcano on the Island of La Palma may trigger a catastrophic failure of its west flank, dropping 150 to 500 km 3 rock into the sea, resulting in a tsunami in the Atlantic Basin with a speed of 100 m/s and impacting the coasts of Americas with 3-8 m in Newfoundland (Canada) and 10-25 m (Florida, USA) height, respectively (Ward & Day, 2001). Significant wave impact has been modeled in near-and far-field even for reduced source volumes (Abadie et al, 2012(Abadie et al, , 2020, where it is claimed that La Palma, the town of Santa Cruz, would be struck by two simultaneous inundation waves with devastating consequences and important cities in Gran Canaria or Tenerife were identified as subject to high tsunami impact for every considered scenario. It's important to note, however, that another study (Pararas-Carayannis, 2002) rejects such claims.…”

Model development for simulating mudslide and the case study of the failure of the gypsum tailings dam in East Texas in 1966

“…CC BY 4.0 License. computers in the early twentieth century, the 3D Navier-Stokes equations have been used to study mudflow (Dai et al, 2014, Abadie et al, 2019, Wang et al, 2016. Nevertheless, the stratification effect between solid and liquid phase hasn't been invested.…”