Preliminary re-evaluation of probabilistic seismic hazard assessment in Chile: from Arica to Taitao Peninsula

Abstract

Abstract.Chile is one of the most seismically active countries in the world; indeed, having witnessed very large earthquakes associated with high horizontal peak ground accelerations, the use of probabilistic hazard assessment is an important tool in any decision-making. In the present study, we review all the available information to improve the estimation of the probabilistic seismic hazard caused by two main sources: shallow interplate, thrust earthquakes and intermediate depth, intraplate earthquakes. Using previously defined seismic zones, we compute Gutenberg-Richter laws and, along with appropriate attenuation laws, revaluate the probabilistic seismic hazard assessments in Chile. We obtain expected horizontal peak ground acceleration with a 10% of probability of being exceeded in 50 years, reaching from 0.6 g up 1.0 g in the coast and between 0.4 g and 0.6 g towards the Andes Mountains, with larger values in Northern part of the country. The present study improves our knowledge of geological hazards in Chile, enabling the mitigation of important human and material losses due to large earthquakes in the future.

Magnitude Scaling of Early-Warning Parameters for the Mw 7.8 Tocopilla, Chile, Earthquake and Its Aftershocks

“…The retrieved b coefficient is equal to 0:58 0:30. This value is in good accordance with that calculated by Leyton, Ruiz, and Sepulveda (2009) for northern Chile. However, in most other studies, b is typically close to 1.…”

“…Each bin has a size of 0.3 and represents the number of events with magnitude greater or equal to the magnitude value corresponding to the bin. The black line is the Gutenberg-Richter law evaluated on the retrieved dataset; the dashed line is the Gutenberg-Richter law retrieved by Leyton, Ruiz, and Sepulveda (2009) from the historical catalog for northern Chile. Because the number of events with 3 < M w < 3:3 is smaller than the number of events with 3:3 < M w < 3:6, it is then clear that we missed several events belonging to the first magnitude bin.…”

Risk-informed optimization of the tuned mass-damper-inerter (TMDI) for the seismic protection of multi-storey building structures

“…. The regional seismicity factors bM and aM are chosen by averaging the values for the seismic zones close to Santiago based on the recommendations in [47]. This results to bM=0.8loge (10) and aM=5.65loge (10).…”

Earthquake risk assessment of buildings accounting for human evacuation

“…The Gutenberg‐Richter law implies that the PDF of the magnitude M of earthquakes with M min ≤ M ≤ M max is: The seismic sources used to carry out this work are taken from reference , which subdivides the converging margin between the subducting Nazca and overriding South‐American plate into coastal and interior planar faults with different geometric and G‐R parameters as a function of latitude. More recent Chilean seismic recurrence models have also been presented, for example, .…”

“…The seismic sources used to carry out this work are taken from reference [23], which subdivides the converging margin between the subducting Nazca and overriding South-American plate into coastal and interior planar faults with different geometric and G-R parameters as a function of latitude. More recent Chilean seismic recurrence models have also been presented, for example, [24]. The mean annual frequency of intensity measure IM exceeding values im at a specific site is known as the hazard curve, and is obtained by adding the contribution of all independent seismic sources in the region, N s , and conditioning to the different magnitudes M i and source-to-site distances R i , that is,…”