Abstract: Based on several types of data, segmentation and its cause, earthquake ruptures along the Xianshuihe-Anninghe-Zemuhe fault zone in western Sichuan are analyzed from various aspects. The fault zone is divided into 12 rupture-segments for characteristic earthquakes. Along this fault zone, the persistent and non-persistent boundaries of ruptures have almost the same number ratio of 2%. The persistent and important boundaries can be identified by criteria such as geometry, structure and active behavior of faults. They terminate the propagation of earthquake ruptures by partly volume-changing there. The non-persistent boundaries can be identified by criteria such as extension and recurrence behavior of earthquake ruptures, spatial difference of current active behavior of faults, composition of both relatively small-scale geometric barriers and release barriers. Locations of the non-persistent boundaries may vary with time. Relatively small overlap occurs between adjacent ruptures if the time interval between them is shorter, and relatively large overlap appears between adjacent ruptures if the time interval between them is longer.

Key words: Strike-slip fault zone, Earthquake rupture, Segmentation, Segment boundary, Sichuan

摘要： 依据多种资料分层次剖析了川西鲜水河-安宁河-则木河断裂带的地震破裂分段性及其原因,并将该断裂带划分为12个特征地震破裂段。断裂带上持久性和非持久性的破裂边界各占约2%;持久性及重要的破裂边界可依据断裂几何结构及活动习性标志进行判定,它们均以局部体积变化的方式来终止破裂的扩展;非持久性的破裂边界则可依据地震破裂与复发行为、断裂现今活动习性空间差异、松驰障碍体与较小尺度几何障碍的复合体等进行判定,其位置可随时间变化。地震破裂时间间隔短的,相邻破裂的重叠量较小;时间间隔长的,相邻破裂的重叠量则较大。

关键词: 走滑断裂带, 地震破裂, 分段性, 段边界, 四川