Estimation of the seismic source for the 1868 Arica earthquake and tsunami

Abstract

The purpose of this work is to estimate the seismic source parameters which result in the Arica's earthquake in 1868 (9.0 Mw) and to simulate the coseismic efects. Seismicity, seismic gaps are assessed to identify borders which not allow the earthquakes propagation (10° - 25° S y 62° - 84° W). Besides, the deformation is calculated by Okada deformation in the same region to determine  the uplift and subsidence produced by the earthquake at the tsunami generation stage. The TUNAMI-F1 model is used  which use the shallow water equations that describe the tsunami propagation. It is important to gather and review some reports, which give in very detail the severe damages in Arica (south of Peru and north of Chile), and New Zealand and Antarctica to correlate what was simulated and reported. As a result, it is obtained that the seismic source had a 12.5 m of slip, 570 km of length and 140 km of wide with angles of rake (90°), strike (309°) and dip (16°); these parametres are introduced in TUNAMI-F1 model which reproduce the tsunami in Arica with the maximun height of wave (16 m) that destroyed the Arica port and its propagation in the Pacific with direction of New Zealand and Antarctica.