Probabilistic Seismic Hazard Analysis for Chile

Abstract eng:
A probabilistic seismic hazard analysis (PSHA) of Chile is presented, based on a newly assembled homogeneous and complete catalog of unique and independent (Poissonian) seismic events affecting Chile. All seismogenic zones present in Chile are included in the model: subduction, shallow, intermediate, deep, and outer-rise seismicity, and the main Quaternary faults located within the country or in close proximity to its borders (in Argentina, Bolivia, and Peru). The effect of the Chile triple junction at the Taitao Peninsula is considered, and consequently is reflected in the results obtained. The PSHA included: (a) Gutenberg-Richter rate of exceedance models developed for all the seismogenic zones considered; (b) the most up-to-date ground-motion prediction models available for the seismogenic zones considered; and (c) both, a rupture model and the three-dimensional geometry of the subduction slab. Several features of the model were verified with three recent events: (1) 2005 Tarapacá, Mw=7.9; (2) 2010 Maule, Mw=8.8; and (3) 2014 Iquique, Mw=8.2. The results show good agreement with the data observed. Disaggregation of the probabilities of exceedance show that most of the risk is due to magnitude 7.8 or greater subduction events, located at approximately 40 km from the considered sites. The hazard is finally expressed in terms of peak ground acceleration and spectral acceleration maps at 10% and 2% probability of exceedance in 50 years for Continental and Insular Chile, suitable for seismic code applications. These maps include Eastern and Salas y Gómez Islands, Desventuradas Archipelago (San Ambrosio and San Félix Islands), Juan Fernández Archipelago, the southern tip of Peru, southwestern Bolivia, and western Argentina.

• Export as: BibTeX | MARC | MARCXML | DC | EndNote | NLM | RefWorks
• Add to your basket