【摘要】 2008年3月21日新疆于田发生7.3级地震,打破了中国大陆6年多的7级地震平静,成为我国近期较为显著的一次地震事件。综合分析MS≥4.0余震分布、震区断裂性质以及等震线长轴方向等资料,认为郭扎错断裂是这次地震的发震构造;据Harvard震源机制解分析,这次地震是在近NS向力的作用下,郭扎错断裂发生略带走滑分量的拉张破裂所致。通过地震前震区附近地震活动特征分析发现,于田地震发生在1996年以来新疆南部及邻区7级地震有序分布的空段;震前震区附近有4级地震空区形成,空区持续91个月后发生了2006年9月12日皮山5.8级"信号震",其后1.5年发生于田7.3级地震。更多还原

【Abstract】 The Yutian M7.3 earthquake on March 21, 2008, Xinjiang broke the quiescence of more than six years for M7.0 earthquake in Chinese Mainland. The analysis of the aftershocks with M_S≥4.0, fault strike direction in seismic region and the long axis of isoseismal shows Gozhaco fault is the seismogenic structure. According to the Harvard focal mechanism, the normal break of Gozhaco fault leads to the Yutian earthquake under the NS direction regional stress. The analysis of the seismic activity before Yutian earthquake shows that the earthquake occurred in the empty area between the belt of M7.0 earthquakes in the southern region of Xinjiang and its adjacent region; there is M_S4.0 seismic gap, and it lasts 91 months. After that, the "signal earthquake" occurred on September 12, 2006 in the seismic gap, 1.5 years prior to the Yutian earthquake.更多还原