Synthetic Ground-Motion Simulation Using a Spatial Stochastic Model with Slip Self-Similarity: Toward Near-Source Ground-Motion Validation

Abstract

Near-fault ground motion is a key to understanding the seismic hazard along a fault and is challenged by the ground motion prediction equation approach. This paper presents a developed stochastic-slip-scaling source model, a spatial stochastic model with slipped area scaling toward the ground motion simulation. We considered the near-fault ground motion of the 1999 Chi-Chi earthquake in Taiwan, the most massive near-fault disastrous earthquake, proposed by Ma et al. (2001) as a reference for validation. Three scenario source models including the developed stochastic-slip-scaling source model, meanslip model and characteristic-asperity model were used for the near-fault ground motion examination. We simulated synthetic ground motion through 3D waveforms and validated these simulations using observed data and the ground-motion prediction equation (GMPE) for Taiwan earthquakes. The mean slip and characteristic asperity scenario source models over-predicted the near-fault ground motion. The stochastic-slip-scaling model proposed in this paper is more accurately approximated to the near-fault motion compared with the GMPE and observations. This is the first study to incorporate slipped-area scaling in a stochastic slip model. The proposed model can generate scenario earthquakes for predicting ground motion.

1909 Taipei Earthquake Ground Motion Simulation

“…We also assessed two epicenters, namely the location of the 1909 Taipei earthquake and the location of the selected small event, in this study. However, to examine the possible influence in the slip distribution heterogeneity on the fault to the ground motion at surface, we considered an additional case as an asperity model, having an asperity with 1.5 times the average slip and 20% of the fault area (Lee et al 2016) in the upper portion of the fault. We, thus, compare the difference from this model to others as a reference in section 4.2.…”

Investigation and hazard implication of 1604 Quanzhou earthquake using modern simulation with literature intensity

“…We consider the area with a slip (D a ) twice the average slip as asperity, and following Somerville et al (1999) and Lee et al (2016) the asperity area Sa is 22% of the total area (S) based on observations from earthquakes from California and Taiwan. Although there can be multiple asperities distributed within the fault plane, for simplification due to many uncertainties from this 400-year-old historical earthquake, we consider only a single asperity for our heterogeneous model.…”