Statistics of major Chilean earthquakes recurrence

Abstract

In this work, we consider historical earthquakes registered in Chile (from 1900 up to 2010) with epicenters located between 19 and 40°S latitude, in order to evaluate the probabilities of the occurrence of strong earthquakes along Chile in the near future. Applying Gumbel's technique of first asymptotic distribution, Wemelsfelder's theory and Gutenberg-Richter relationship, we estimate that during the next decade strong earthquakes with Richter magnitudes larger than 8. 7-8. 9 could occur along Chile. According to our analysis, probabilities for the occurrence of such a strong earthquake range between 64 and 46% respectively. Particularly in the very well known "seismic gap" of Arica, a convergence motion between Nazca and South American plates of 77-78 mm/year represents more than 10 m of displacement accumulated since the last big interplate subduction earthquake in this area over 134 years ago. Therefore, this area already has the potential for an earthquake of magnitude >8.