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Pure Appl. Geophys. 172 (2015), 16791698 2014 Springer Basel
DOI 10.1007/s00024-014-0988-3 Pure and Applied Geophysics
Advanced Tsunami Numerical Simulations and Energy Considerations by use of 3D2D Coupled Models: The October 11, 1918, Mona Passage Tsunami
ALBERTO M. LPEZ-VENEGAS,1 JUAN HORRILLO,2 ALYSSA PAMPELL-MANIS,2
VICTOR HURFANO,1 and AURELIO MERCADO3
AbstractThe most recent tsunami observed along the coast of the island of Puerto Rico occurred on October 11, 1918, after a magnitude 7.2 earthquake in the Mona Passage. The earthquake was responsible for initiating a tsunami that mostly affected the northwestern coast of the island. Runup values from a post-tsunami survey indicated the waves reached up to 6 m. A controversy regarding the source of the tsunami has 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 initiated by the earthquake. Improvements on our previous study include: (1) higher-resolution bathymetry; (2) a 3D2D coupled numerical model specically developed for the tsunami; (3) use of the nonhydrostatic numerical model NEOWAVE (non-hydrostatic evolution of ocean WAVE) featuring two-way nesting capabilities; and(4) comprehensive energy analysis to determine the time of full tsunami wave development. The three-dimensional NavierStokes model tsunami solution using the NavierStokes algorithm with multiple interfaces for two uids (water and landslide) was used to determine the initial wave characteristic generated by the submarine landslide. Use of NEOWAVE enabled us to solve for coastal inundation, wave propagation, and detailed runup. Our results were in agreement with previous work in which a submarine landslide is favored as the most probable source of the tsunami, and improvement in the resolution of the bathymetry yielded inundation of the coastal areas that compare well with values from a post-tsunami survey. Our unique energy analysis indicates that most of the wave energy is isolated in the wave generation region, particularly at depths near the landslide, and once the initial wave propagates from the generation region its energy begins to stabilize.
Key words: 1918 Mona, tsunami, submarine landslide, volume of uid, three-dimensional model, non-hydrostatic model, tsunami energy.
1. Introduction
The most recent tsunami affecting the island of Puerto Rico in the...