Comparison of landslide tsunami models and exploration of fields of application
After earthquakes, landslides are the second cause of tsunami generation. A proper understanding is required to prevent future disasters or to develop early warnings. This can be achieved through physical models in laboratory or numerical models. In the last category, several models exist and can provide very similar results for a case study. Among them, depth-averaged models using for example shallow water or Boussinesq equations can be opposed to Navier-Stokes models. The main objective of this work is to compare these two modeling strategies with two specific models, a depth-averaged model, AVALANCHE, and a Navier-Stokes model, OpenFOAM. First, two benchmarks (a subaerial and a submerged one) are used to calibrate the models. This highlighted that both models could reproduce the experimental data and that several combinations of parameters led to similar results. Second, sensitivity studies are carried out to evaluate the influence of the initial landslide position and the slope angle and to observe the behavior of the different equations (shallow water, Boussinesq, or Navier-Stokes) during the wave generation and propagation phases. Finally, both models are applied to two real cases, the June 17, 2017, Karrat Fjord, Greenland, landslide and tsunami, and the December 22, 2018, Anak Krakatau, Indonesia, collapse and tsunami, and are intercompared.
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