Modification of fault slip models of the M_w 9.0 Tohoku Earthquake by far field GPS observations

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• 作者：Wuxing Wang^a ; ^{bkwwx@seis.ac.cn" class="auth_mail} ; ^{wwxyyz@sina.com" class="auth_mail} ; Wenke Sun^a ; ^b ; Yanqiang Wu^a ; Guohua Gu^a
• 关键词：The Mw 9.0 Tohoku Earthquake ; Far field GPS observation ; Spherical Earth dislocation model ; Fault slip model ; Modification
• 刊名：Journal of Geodynamics
• 出版年：April, 2014
• 年：2014
• 卷：75
• 期：Complete
• 页码：22-33
• 全文大小：6256 K

文摘

GPS data from Crustal Movement Observation Network of China (CMONOC) are used to derive far-field co-seismic displacements induced by the M_w 9.0 Tohoku Earthquake. Significant horizontal displacements about 30 mm, 10 mm, and 20 mm were caused by this large event in northeast China, north China, and on the Korean peninsula respectively. Vectors of relatively large horizontal displacements with dominant east components pointed to the epicenter of this earthquake. The east components show an exponential decay with the longitude, which is characteristic of the decay of the co-seismic horizontal displacements associated with earthquakes of thrust rupture. The exponential fit of the east components shows that the influence of the co-seismic displacements can be detected by GPS at a distance of about 3200 km from the epicenter of the earthquake. By considering the capability of the far field displacements for constraining the inversion of the fault slip model of the earthquake, we use spherically stratified Earth models to simulate the co-seismic displacements induced by this event. Using computations and comparisons, we discuss the effects of parameters of layered Earth models on the results of dislocation modeling. Comparisons of the modeled and observed displacements show that far field GPS observations are effective for constraining the fault slip model. The far field horizontal displacements observed by GPS are used to modify the slips and seismic moments of fault slip models. The result of this work is applicable as a reference for other researchers to study seismic source rupture and crustal deformation.