Numerical Modeling of Tsunami in the City of Chorrillos, Lima—Peru

Abstract

Peru is located in a region of tectonic plate interaction, subduction of the Nazca plate underneath the South American plate, originating many earthquakes. Peru has endured the effects of large tsunamis, in some cases very large and destructive (Martínez, Dinámica y modelado numérico de un tsunami en el terminal portuario del Callao y zonas adyacentes, 2014). On October 28, 1746, an earthquake of estimated magnitude 8.8 Mw, generated a large tsunami that affected the central coast of Peru causing destruction in the port of Callao, with waves greater than 20 m and flooding of approximately 5 km, the victims of the earthquake and tsunami reached 4000 people (Silgado, Historia de los sismos más notables ocurridos en el Perú 1513–1974, República de Perú Sector Energía y Minas, Instituto de Geología y Minería, Boletín N°3 Serie C, Geodinámica e Ingeniería Geológica, 1978). In such a scenario, the district of Chorrillos, located in the department of Lima, would be severely affected. This study simulates the most probable scenario, using the homogeneous seismic source model, topographic and bathymetric data with a spatial resolution of 10 m, applying the TUNAMI-N2 algorithm, developed by the Disaster Research and Control Center of Tohoku University. The main results obtained show that the inundation occurs 20 min after the earthquake and reaches 1 km, with heights exceeding 9 m. The hydrodynamic parameters confirm a high level of hazard, because the flood depth is high (>2 m) and the flow velocities exceed 1.5 m/s, signifying high levels of danger to people.