Source parameters determination for earthquakes in Kushiro,Japan considering source time function  

作　　者：Lifen Zhang Wulin Liao Guichun Wei Jinggang Li Qiuliang Wang 

机构地区：[1]Institute of Seismology,China Earthquake Administration,Wuhan 430071,China [2]Institute of Geophysics,China Earthquake Administration,Beijing 100081,China

出　　处：《Earthquake Science》2012年第2期137-142,共6页地震学报（英文版）

基　　金：supported by the National Natural Science Foundation of China (Nos.41004020 and IS201102643)

摘　　要：This paper applies a new formulation to do moment tensor inversion for earthquakes in the Kushiro area of Japan. Comparing with conventional moment tensor inversion method, the new one takes the effect of source time function into consideration. For the inversion, best solution is obtained by minimizing the difference between the observed seismograms and the synthetic ones. And the best-fitting focal depth is determined from the variance reduction. The results indicate that half duration of source time function is proportional to the magnitude of earthquakes. Large earthquakes have long half duration, whereas that of moderate-small earthquakes is comparatively shorter. The focal mechanisms of all three earthquakes are of thrust fault type, which is mainly ascribed to the collision of the North American plate with the Eurasia plate in the late Cretaceous or Paleogene.This paper applies a new formulation to do moment tensor inversion for earthquakes in the Kushiro area of Japan. Comparing with conventional moment tensor inversion method, the new one takes the effect of source time function into consideration. For the inversion, best solution is obtained by minimizing the difference between the observed seismograms and the synthetic ones. And the best-fitting focal depth is determined from the variance reduction. The results indicate that half duration of source time function is proportional to the magnitude of earthquakes. Large earthquakes have long half duration, whereas that of moderate-small earthquakes is comparatively shorter. The focal mechanisms of all three earthquakes are of thrust fault type, which is mainly ascribed to the collision of the North American plate with the Eurasia plate in the late Cretaceous or Paleogene.

关 键 词：moment tensor inversion half duration source time function Kushiro 

分 类 号：P315.3[天文地球—地震学]