【摘要】 20 0 1年雅江地震序列 (主要地震是 2月 14日的MS5 1和 2月 2 3日的MS6 0地震 )是四川地区近 13年来的重要地震。选择 2 0 0 1年 1月 1日～ 6月 30日期间 ,四川地震台网至少 5个清晰的初动到时所记录的雅江地震序列中 88次地震 ,并对其作了重新定位 ,对其中较大的 13次地震用四川地区地震台网P波初动资料作了震源机制解。 88次地震震源深度分布在 2～16km ,优势深度为 9～ 11km。前震、5 1级地震及其余震、6 0级地震及余震都紧邻孜河断裂分布 ,且按时段划分的震中优势分布方位与孜河断裂走向都是北西向。根据雅江地区近期大地形变场物质运移方向 ,选定了震源机制解的破裂面。 13次较大地震震源机制解的主压应力P轴具有较大的垂向分量 ,水平投影方向为南东 ;地震类型都是左旋、走滑 -正断型或正断 -走滑型 ;大部分地震破裂面走向为北西 -南东 ,倾向南西。根据前震、5 1级地震及其余震、6 0级地震及其余震震中优势分布方位 ,以及大多数较大地震破裂面走向和倾向 ,认为穿过震区的走向北西、倾向南西的孜河断裂是这次雅江地震序列的发震断裂。更多还原

【Abstract】 The Yajiang earthquake sequence with M S6.0 in 2001 is the most important earthquakes in the Sichuan region since 1989 Batang M S6.7 and Xiaojin M S6.6 earthquakes. 88 earthquakes of the Yajiang sequence are repositioned with the onset parameters recorded by the Sichuan Seismological Network during 2001-01-01～2001-06-30. There are 5 clean onset directions of every one of 88 events at least. The focal mechanism of 13 large earthquake of the Yajiang sequence have been given. The focal depths of 88 events distributed in 2～16km,the superior depth is 9～11km.The foreshocks,M S5.1 event and its aftershocks,M S6.0 event and its aftershocks are colsely located along the Zihe fault,and the superior orientations of focal distributions in 3-time interval are identical with the Zihe fault strike separately.These orientations are in northwest direction.The fracture surfaces of the focal mechanisms are selected according to the mass moving orientation of earth deformation field in the Yajiang region in recent period.The main pressure P axes of focal mechanisms of 13 large earthquakes have bigger vertical components,and its horizontal project orientation components are in all southeast direction;these earthquakes are all left-lateral,strike slip-normal or normal-strike slip types.The fracture surface strikes of 13 events are most in northwest-southeast direction,dip is southwest.The Zihe fault is considered as the seismogenic fault of the Yajiang sequence according to the supperior distribution orientation of the foreshocks,M S5.1 and M S6.0 earthquakes and its aftershocks,the strikes and dips of fracture surfaces of most bigger earthquakes of the Yajiang sequence.更多还原