1303年洪洞8级地震震源过程研究

ANALYSIS OF HONGTONG 1303 M8 EARTHQUAKE PKOCESSES

运用霍山断裂滑动速率和１３０３年洪洞８级地震错距的资料，将霍山断裂面取作位错面，使用粘弹介质中位错模型的有限单元公式￣［１］，计算震前断层蠕滑动和震时断层错动对应的临汾盆地应力和应变能密度年速率分布，由此得出：（１）１３０３年洪洞地震前，在临汾盆地以霍山断裂中段和南段应力和应变能密度年速率正值最高，为积累过程，而震时（含震后），年速率负值最高，为释放过程；（２）１３０３年洪洞地震加速了１６９５年临汾地震应力和应变能积累；（３）用有限单元分析方法中的劈节点技术离散位错面，可以符合位错概念。

Available are a lot of data about the slip rate for the Huoshan fault and the dislocations associated with Hong tong 1303 M8 earthquake and the Cenozoic activities are investigated for the Linfin basin. In this paper，Huoshan fauIt plane is taken as dislocation plane。The stress rates and strain energy rates corresponding to the fauIt creep in pre-seismic period and the fault dislocation in co-seismic period have been calculated by means of the finite element formula of dislocation model in viscoelastic medium. Three results have been obtained ：（1）Prior to Hongtong 1303 earthquake，he stress and strain energy rates are the highest for the southern section of the Huoshan fault in the Linfin basin，suggesting aaccumulating process．However，the minus rates are the highest in co-seismic period，suggesting a relieving process。（2）Hongtong 1303 earthquake speeded up the accumulation of strain energy for Linfin 1695 earthquake.（3）Application of split node technique in fimite element analysis to discreteness of the dislocation planes is in agreement with the dislocation concept.