A STUDY OF FRACTURE PROCESS OF EARTHQUAKES WITH MAGNITUDES,M_s = 5-6 BY THE GENERALIZED DIRECTIVITY FUNCTION OF RAYLEIGH WAVES

In this paper, the directions and the total length of the earthquake rupture as well as the velocity of rupture have been determined for the Jiexiu earthquake (Ms = 5.1), Shansi Province of June 19,1979 and the Li Yian earthquake (Ms = 6.0) Jiangsu Province of July 9,1979 by using directly the relation between the station azimuth relative to the rupture direction and the minimum period of the generalized directivity function of Eayleigh waves.The results show that both earthquakes are mainly strike-slip in character. The direction of rupture of the .Jie Xiu earthquake is south-southeast at a velocity of 1.1 km/sec, and total length, 11km, while the direction of rupture of the Liyian earthquake is southeast at a velocity of 2.5 km/sec, and total length, 15 km. This result agrees rather well with that of fault-plane solutions.