Seismology-based hybrid ground motion prediction models of PGA in Sichuan, China

Regional Finite-Fault Source Model for Development of Ground Motion Attenuation Relationship in Sichuan, China

“…Based on the statistical analysis of the slip distribution data of the 2002-2009 Sumbawa (Indonesia) earthquakes, the roughness parameters are extracted and the scaling law of local source parameters is established. Jiang et al [15] proposed the k -2 model for the randomness of the slip distribution on the fracture surface. Ruiz et al [16] studied the method of generating the physical slip velocity function in the kinematic k −2 source model.…”

“…Using the moment tensors in CMT catalogue, the focal mechanism solutions of 99 major earthquakes [22,23] with M S ≥ 5.0 in Sichuan from 1850 to 2019 are collected. According to the distribution direction of aftershocks and the occurrence of regional seism-tectonics, the rupture planes are selected from the two nodes of the mechanism solutions to determine the dip angle; the rupture types of each earthquake are determined according to the classification standard in Table 2 [8], and the ones of the main rupture areas and comparative analysis of inclination range. In order to deeply analyze the rupture types and change rules of dip angle, the relationship between dip angle and magnitude of two rupture types in Sichuan is drawn as shown in Fig.…”

“…The thickness of the weak sedimentary cover on the crustal surface in Sichuan is about several kilometers, and earthquakes rarely occur. The crystalline basement under the cover is mainly composed of hard and brittle rocks [8]. In the process of plate movement, it is easy to accumulate energy and generate strong earthquakes.…”

“…(3) By substituting each random number into Eq. (3), 30 sets of source parameters of corresponding magnitude can be calculated [8].…”

“…According to the characteristics of two attenuation relations in seismology, a new weighted scheme is put forward, which represents the applicable range of point source and finite fault source, respectively. It emphasizes the important consensus that "point source model is suitable for medium and small earthquakes as well as far-field ground motion estimation, while the finite fault model is suitable for predicting near-field strong ground motion" [8], and a regional hybrid attenuation relation is established. The point source model used in this study has carried out a lot of relevant researches on the attenuation relationship of regional small and medium-sized earthquakes, which lays the foundation of mixed attenuation relationship [9].…”