A Discussion on Some Problems Related to the 1303 Hongtong ,Shanxi, Strong Earthquake M 8

From the regularity of of earthquake on bottom fault following the occurrence of earthquake on perpendicular fault, the relation between the 1303 Hongtong ,Shanxi, strong earthquake and 1695 Linfen ,Shanxi, strong earthquake is discussed. It is pointed out that the majority of temporal intervals between the 1303 strong earthquake and other large earthquakes in the North China are multiple of 25 years. The geodynamic and tectonic conditions on occurrence of the 1303 large earthquake are edge of the stable ordos block and near to the 35° latitude belt. Finally, the difficulties of alternately occurring earthquake along conjugate faults are also pointed out.