Source Rupture Processes of 3 Jiashi Ms6 Events (1998~2003) and Its Correlation with the Aftershock Activity

Abstract

AbstractBy using far field body wave data, the temporal and spatial rupture processes of 3 Ms6 events with different focal mechanisms occurred in Jiashi, Xinjiang autonomous region, China, from 1998 to 2003 were studied. The rupture pattern of Aug. 2, 1998 reveals that the rupture zone is small, the rupture process is simple and lasted about 8 s with the maximum slip 12 cm. The rupture scenario of Aug. 27, 1998 demonstrates a bilateral rupture characteristic, the process finished within 13 s with the maximum slip of 63 cm. The rupture process of Ms6.8 on Feb. 24 2003 is the most complicated among them. Its source time function is composed by 2 rise periods, and totally lasted about 32 s, with the maximum slip displacement of 30 cm. Our study reveals that aftershocks following the corresponding main shock occurred along the edge of the large slip area, or on the area of slip rapidly decreased. Aftershocks following the main shocks within the first 10 days exhibit focal mechanisms coincidental with the direction of the slip vector on the fault plane of the main shock, indicating that the location and mechanisms of aftershocks following the main shock are related with the stress redistribution resulted by the main shock