Stochastic Strong-Motion Simulation of Valparaiso 1985 Mw 8.0 Chile Earthquake

In recent years, several historical earthquakes have been studied in Chile to understand the seismotectonic context and anticipate the ground motion of these natural phenomena. One of the first great earthquakes documented by the Global Digital Seismographic Network (GDSN) occurred on March 3, 1985, off the coast of Valparaiso, with a moment magnitude (Mw) 8.0.

Several researchers have modeled the slip distribution at the seismic source, obtaining satisfactory results and fits, mainly at low frequencies and in far field. However, a discrepancy has been observed between the areas of maximum slip and the accelerations recorded in the near field.

In this study, the code proposed by Ruiz and Otarola (2016) was employed to stochastically generate synthetic accelerograms capable of accurately replicating the accelerations observed during near-field ground motion. This approach provides a realistic simulation of earthquake characteristics, source, path, and site.

The importance of generating synthetic accelerograms extends to critical sectors such as civil engineering, geophysics, construction, and urban planning. These simulations play a critical role in understanding ground behavior, predicting large seismic movements, and improving the development of earthquake-resistant structures. Furthermore, in the fields of construction and urban planning, synthetic accelerograms are essential for assessing the vulnerability of specific areas, diversifying applications in industry, and facilitating a more resilient design approach for future seismic events.

The results obtained by generating synthetic accelerograms can replicate the spectral and temporal shape, in agreement with the records provided by the National Seismological Center (CSN) network. Stochastic simulations have been run both in rocky environments and in areas with site effects.