Re-evaluation of probabilistic seismic hazard in central Chile

• Felipe Leyton ^[1] ; Sergio Ruiz ^[2] ; Sergio A. Sepúlveda ^[2]
  1. [1] Universidad Diego Portales

     Universidad Diego Portales

     Santiago, Chile

     
  2. [2] Universidad de Chile

     Universidad de Chile

     Santiago, Chile

     
• Localización: Andean geology: Formerly Revista geológica de Chile, ISSN-e 0718-7106, ISSN 0718-7092, Vol. 37, Nº. 2, 2010, págs. 455-472
• Idioma: inglés
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• Resumen

  • Chile is one of the most seismically active countries in the world, having witnessed several large earthquakes that produced human and material losses; seismic hazard estimation is one of the most used tools to prevent such losses. The present study reviews the state-of-the-art of the probabilistic seismíc hazard, comparing 3 different approaches and adapting them to central Chile. We include a series ofnew findings, such as the definition ofthe main seismogenic sources (interplate, interrnediate-depth intraplate, and crustal earthquakes ), new estimations of Gutenberg-Richter laws, and the use of specific attenuation laws for each one of them. Considering this information, we compute maps showing the expected peak ground horizontal acceleration (PGA), given a certain probabi1ity and time period where is observed not only the influence of interplate earthquakes, but also the effect of intermediate-depth intraplate and crustal earthquakes. For the Santiago Metropolitan area we obtain values for PGA of 55% g for a retum period of 475 years and 72% g for a retum period of 1950 years; only 13% lower than those observed on the coast (63% g and 83% g, respectively).