Multilayer-HySEA model validation for landslide generated tsunamis. Part I Rigid slides

Abstract. The present work is devoted to the benchmarking of the Multilayer-HySEA model using laboratory experiment data for landslide generated tsunamis. This first part of the work deals with rigid slides and the second part, in a companion paper, with granular slides. The US National Tsunami Hazard and Mitigation Program (NTHMP) has proposed the experimental data used and established for the NTHMP Landslide Benchmark Workshop, held in January 2017 at Galveston. The first three benchmark problems proposed in this workshop dealt with rigid slides, simulated as a moving bottom topography, that must be imposed as a prescribed boundary condition. These three benchmarks are used here to validate the Multilayer-HySEA model. This new model of the HySEA family consists of an efficient hybrid finite volume/finite difference implementation on GPU architectures of a non-hydrostatic multilayer model. A brief description of model equations, its dispersive properties, and the numerical scheme is included. The benchmarks are described and the numerical results compared against the lab measured data for each of them. The specific aim of the present work is to validate this new code for tsunamis generated by rigid slides. Nevertheless, the overall objective of the current benchmarking effort is to produce a ready-to-use numerical tool for real world landslide generated tsunami hazard assessment. This tool has already been used to reproduce the Port Valdez Alaska 1969 event.