ADVANCED TSUNAMI NUMERICAL SIMULATIONS OF THE PUERTO RICO OCTOBER 11, 1918 MONA PASSAGE TSUNAMI

The most recent tsunami observed along the coasts of the island of Puerto Rico occurred in October 11, 1918 after a magnitude 7.2 earthquake in the Mona Passage. The earthquake was responsible for triggering a tsunami that mostly affected the northwestern coast of the island of Puerto Rico. Run-up values from a post-tsunami survey indicated the waves reached up to 6 meters. A controversy regarding the source of the tsunami have resulted in several numerical simulations involving either fault rupture or a submarine landslide as the most probable cause of the tsunami. Here we follow up on previous simulations of the tsunami from a submarine landslide source off the western coast of Puerto Rico as triggered by the earthquake. Improvements from our previous study include: (1) a higher resolution bathymetry, (2) a 3D-2D coupled numerical models specifically developed for the tsunami event, and (3) the use of the non-hydrostatic numerical model NEOWAVE, featuring two-way nesting capabilities. The three-dimensional Navier-Stokes model TSUNAMI3D for two fluids (water and mud) is used to determine the initial wave characteristic generated by the submarine landslide. Employing NEOWAVE allows us to solve for coastal inundation, wave propagation and detailed runup. Our results are in agreement with previous works in which a submarine landslide is favored as the most probable source of the tsunami, and the improvement in the resolution of the bathymetry yield inundation of the coastal areas that compare to the values from a post-tsunami survey.