AN EXPERIMENTAL STUDY OF THE SHAPE OF ISOSEIS- MAL LINES OF THE HUAXIAN GREAT EARTHQUAKE OF 1556

Using the method of model seismology, the Huaxian great earthquake which occurred in 1556 is studied. The results show that the intensity distribution of the earthquake has the shape of a new moon because of the special layer structures of the media of the Tertiary Period and the Quaternary Period overlying the source region and the effect of convergence and amplification on seismic waves, the wave reflection on the fault plane of the great fault on the north side of the Qinling Mountains and the special fracture styles of the fault.