Analysis on the parameters of seismogenic fault of the earthquake more than 6.5 in North China

Based on the data of historical earthquakes and seismotectonic we analysised the parameters of seismogenic fault of the earthquakes more then MS 6.5 occurred in North of China since 1300 A.D..Using the earthquake parameters of Longyao,Haicheng,Bohai Sea and Tangshan earthquakes since 1968 A.D.We studied and developed the regression equations between the length of long axis of Ⅷ isoseismal curve and long axis of aftershork series as well as earthquake magnitude and the long axis of aftershork series.Using the long axis of aftershork series instead of the length of seismogenic fault,we gave the length of seismogenic fault of earthquake occurred in Huabei of China since 1300 A.D..On studying the data of explosion seismic sounding profile of crustal structure and tectonic,focal distribution of aftershork series,low velocity belts in the crust and tectonic of upcrust,basin's tectonic and distribution of Curie surface and distribution of known earthquake focal we implied the rupture width of seismogenic fault.Under some reasonable hypothesis we calculated the displacement of the seismogenic fault and the rakeangle on the fault plane.