[关键词]
[摘要]
利用精河MW6.3地震有限断层破裂模型,计算了精河地震产生的位移场、应力场、周围主要断层上的静态库仑应力变化以及主震对余震的触发作用。结果表明:①精河地震产生的地表隆升最大值约为6.6cm,沉降最大值约为1.8cm;水平位移方向呈现震中南北侧向震中汇聚、震中东西侧向外“流出”的特点。②精河地震产生的水平面应力场展布南北侧物质主要受到指向震中的拉张力作用,东西两侧物质主要受到因震中过剩物质东西向排出而导致的东西向挤压力作用。③震中西侧距震中约20km的库松木契克山前断裂中段和震中东北部距震中约50km的四棵树-古尔图南断裂西段的库仑应力加载均大于0.01MPa,即2处为地震危险区。④在震源深度为8~12km的余震事件中,约有85.5%处于库仑应力加载区,即受到主震的的触发作用;在深度为4~8km的余震事件中,约有87%受到主震的应力触发作用。
[Key word]
[Abstract]
We used the finite fault-rupture model of the MW6.3 Jinghe earthquake to estimate the displacement field, the stress field, the static coulomb stress changes on the main faults around the seismic area and study the static stress triggering effect on aftershocks. The result indicates that:(1)Generated by the Jinghe earthquake, the maximum surface uprising is about 6.6cm, while the maximum surface subsidence is about 1.8cm. Study shows that the horizontal displacement in south and north gathers in the epicenter, while in east and west the displacement direction is toward each side separately. (2)The stress field on the horizontal plane indicates that the substance located on the south and north sides of the epicenter is in extension, yet on the east and west sides it is extruded in the east-west direction by the surplus substance in the epicenter being discharged to east and west sides. (3)The Jinghe earthquake has a stress triggering influence on the middle part of the Kusongmuxieke piedmont fault near 20km from the epicenter and the west part of the Four trees-Gurt fault near 50km from the epicenter. The coulomb static stress changes of these two faults have increased over 0.01MPa, so that these two have high seismic risk. (4)About 85.5% of the aftershocks distributed in the depth of 8km to 12km are located in the Coulomb stress loading zone, so that they are triggered by this earthquake. Nearly 87% of the aftershocks in the depth of 4km to 8km are triggered by this earthquake.
[中图分类号]
P315
[基金项目]
国家自然科学基金(41674055)、河北省地震局地震科技星火计划项目(DZ20170109001)共同资助