HR: 0800h
AN: S41A-0937    [Abstracts]
TI: Study Of Triggering Action Of Great Earthquakes In Qinghai-Tibet Plate And Their Dynamic Effect
AU: * Bing, C
EM: chbbbc@sina.com
AF: The second monitoring center,China seismological Bureau, No.316 Xiying road, Xian, sha 710054 China
AU: Guizhi, Z
EM: zhuguizhi@163.com
AF: The second monitoring center,China seismological Bureau, No.316 Xiying road, Xian, sha 710054 China
AU: Xiaoliang, Z
EM: miyuedao@163.net
AF: The second monitoring center,China seismological Bureau, No.316 Xiying road, Xian, sha 710054 China
AB: In the early 60s of 20th century, The stress triggering effect problems was contributed in by some scholars. Specially in recent years, The problem attracts peoples­_ great interesting again. Okada(1992) get the Internal deformation field strain field formula due to tectengular dislocation in a half-space. According to it, we get the stress component on any position of half-space and coulomb stress formula on any fault. And research the stress trigging action of Mani(Ms7.9, Nov. 1997) earthquake to Kunlun(Ms8.1, Nov. 2001) earthquake. Results show that , 10-3MPa Coulomb stress due to Mani earthquake is added to the fracture fault of Kunlun earthquake, and this may shift the broken date of latter to earlier about 10 years, Kunlun earthquake is the only great event which is larger than Ms8 in the past 50 years in China. The dynamic effect to block movement and load situation of fractures around epicenter is obvious. The long level sections data across Qilian fracture zone and cross-fault short level data all reflect that, in above area, fault movement are more active than that before Kunlun quake. GPS data mirrors an opposite direction motion after event at northern area of Qinghai-Tebit plate. This produces a relative relaxed stress region between Kunlun fracture zone and Qilian fracture zone in short time. It is advantageous to potential failures to happen. This is proved by three medium earthquakes, which are Yumen earthquake (Ms5.9, Dec.,14, 2002), Delingha earthquake(Ms6.6, Apr.,17, 2003) and Minle earthquake(Ms6.1, Oct.,25.2003) occurred in above area. All of these show that, a large broken event may produce obvious influence on block motion, fracture activity and their stress situation.
DE: 8155 Plate motions--general
DE: 7205 Continental crust (1242)
DE: 1206 Crustal movements--interplate (8155)
DE: 1242 Seismic deformations (7205)
SC: Seismology [S]
MN: 2004 AGU Fall Meeting