实验场30年地震危险性概率预测

2019-05-05
地球所

  SichuanYunnan are among the areas with most severe seismic hazard in China, thus hazard estimation is significant to earthquake preventiondisaster reduction. Probabilistic seismic hazard analysis is an effective tool for quantifying seismic hazard, which requires the “best available science” to calculate the mean rate of earthquakes. Compared with data in California, the data in SichuanYunnan is somehow limited, which is insufficient to build a counterpart of the currently used third version of Uniform California Earthquake Rupture Forecast model (UCERF3). However, it is adequate to carry out a multidisciplinary approach. By gathering geologic, geodeticseismologic data in the area, we calculated the magnitude-frequency distribution. By applying PoissonNon-Poisson model, we obtained the patterns of peak ground acceleration (PGA) exceeding rate. The result show that, when the target PGA is low, the main boundaries of SichuanYunnan Diamond Zone all have high exceeding rate, such as Xianshuihe Fault Zone, Anninghe Fault Zone, Zemuhe Fault Zone, Xiaojiang Fault Zone, Honghe Fault ZoneXiaojinhe Fault Zone; when the target PGA is high, Xianshuihe Fault Zone, NorthernSouthern sections of Xiaojiang Fault ZoneLianfeng-Zhaotong Fault Zone in the eastern boundary of SichuanYunnan Diamond Zone still have moderate to high exceeding rate, but the rates in Anninghe Fault Zone, Zemuhe Fault Zonecentral section of Xiaojiang Fault Zone are relatively low. Finally, we compared the result of our research with that of predecessors,discussed the possible reasons of differencessimilarities between the results.

  11160512wkoj 11160516xqzr 11160524r2zf