Probabilistic tsunami hazard analysis of the southern Pacific coast of Mexico

We present a Probabilistic Tsunami Hazard Analysis (PTHA) of the Mexican Subduction Zone (MSZ) and report inundation hazard curves and tsunami amplitude maps along coastlines. This is particularly important, keeping in mind the events of September 2017 which produced a small tsunami, and the high seismic activity in a country with a history of significant earthquake-related inundations. Our analysis uses deterministic tsunami simulations based on kinematic seafloor displacement models. Rupture models follow the work of Melgar et al. (2016) and include both heterogeneous slip distributions and stochastic source locations. We obtain our deformation models using the finite element toolchain Hercules and employ a 3D velocity model. We then carry out our numerical tsunami simulations using the tsunami propagation code, GeoClaw, and a nested bathymetry, providing added resolution near select coastal locations. According to the magnitude-frequency distribution (b-value segmentation for the MSZ) given by Rodríguez-Pérez and Zuñiga (2018), only tsunamigenic seismic sources are considered for PTHA. As part of the preliminary validation of the PTHA methodology, we show that our deterministic approach honors the observations of the Tehuantepec's tsunami (buoys and inundation measurements). We then discuss some issues not considered, such as distant sources and slip heterogeneities, that are left for future computations.