地震学报（英文版）2003，Vol.16Issue(4)：371-381,11.
Changes in source parameters of foreshocks and aftershocks of the 2001 MS=6.0 Yajiang, Sichuan, earthquake
Changes in source parameters of foreshocks and aftershocks of the 2001 MS=6.0 Yajiang, Sichuan, earthquake
摘要
Abstract
In this paper changes in focal mechanisms, parameters of wave spectra, and stress drops for the MS=5.0 foreshock and MS=6.0 mainshock in February 2001 in Yajiang County, Sichuan, and seismicity in epicentral region are studied. Comparison of focal mechanisms for the Yajiang earthquakes with distribution patterns of aftershocks, the nodal plane I, striking in the direction of NEN, of the Yajiang M=5.0 event is chosen as the faulting plane; the nodal plane II, striking in the direction of WNW, of the M=6.0 event as the faulting plane. The strikes of the two faulting planes are nearly perpendicular to each other. The level of stress drops in the epicentral region before the occurrence of the M=6.0 earthquake increases, which is consistent with increase of seismicity in the epicentral region. The rate decay of the Yajiang earthquake sequence, changes in wave spectra for foreshocks and aftershocks, and focal mechanisms are complex.关键词
Yajiang earthquake/sequence characteristics/source parametersKey words
Yajiang earthquake/sequence characteristics/source parameters分类
天文与地球科学引用本文复制引用
程万正,陈天长,魏娅玲,朱航..Changes in source parameters of foreshocks and aftershocks of the 2001 MS=6.0 Yajiang, Sichuan, earthquake[J].地震学报（英文版）,2003,16(4):371-381,11.基金项目
State Key Basic Development and Programming Project "Mechanism and Prediction of Continental Strong Earthquakes" (95130505). （95130505）
