Tsunami Scenarios in Northern Chile after the 2014 Iquique Earthquake using non-uniform slip distributions.

Wednesday, 17 December 2014
Sebastian Riquelme1, Javier A Ruiz1, Mauricio Antonio Fuentes2, Yoshiki Yamazaki3 and Jaime A Campos4, (1)University of Chile, Santiago, Chile, (2)Departamento de Geofísica, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Santiago, Chile, (3)University of Hawaii at Manoa, Honolulu, HI, United States, (4)Universidad de Chile, Santiago, Chile
The recent Iquique Earthquake 2014 did not break as it was expected, many authors proposed a large seismic gap in northern Chile, which potentially could break as a Mw 9.0 - 9.1. The 2014 Iquique earthquake broke the middle segment of the mega-thrust zone, from 30 to 55 km along dip, reaching a magnitude Mw 8.1-8.2. The northern and southern segments are still unbroken. Thus, there still is a large area that could break Mw 8.8-8.9 with its potential tsunami. To improve tsunami hazard mapping in the near-field region, we characterize size for the largest expected seismic event, and incorporate a good description of the source parameters that controls seafloor co-seismic displacement during an earthquake. Considering this background, we generate stochastic finite fault models taking into account the geometry of the slab. We construct a set of possible earthquakes with its respective tsunamis, including the effect of the recent 2014 Iquique earthquake to study the potential impact of a tsunami in northern Chile, assuming there still is enough energy to generate a Mw 9.0 earthquake. We model our preferred earthquake sources. The results show a maximum run-up of ~25 mt. The minimum run–up, coincides with a seismic source with uniform slip. This underestimates run-up by a factor of 6 at some places along the coast, showing agreement with near field run-ups calculated by Geist (2002) using a similar methodology. The tectonic setting and subsidence produced by subduction type earthquakes make Arica prone to have higher run-up in numerous scenarios.