摘要
首先利用新疆地区自1900年以来的828个MS≥3.0地震的震源机制解,采用区域应力张量阻尼反演方法获得新疆地区区域应力场特征,结果显示新疆地区区域应力状态大多数地震为逆断和走滑性质,最大水平主压应力优势方位近SN向,伴有局部地区的拉张和剪切作用。然后根据区域应力场特征及区内强震空间分布特征,划分为天山地区、喀什—乌恰地区以及昆仑—阿尔金三个地区,并对区内强震间的库仑应力变化进行计算。得出天山地区强震对后续地震的发生几乎影响不大,个别地震存在延缓发生的现象;喀什—乌恰交汇区是强震多发区,且震中位置分布较密集,地震之间触发或延迟作用明显;昆仑—阿尔金地区除2008年于田地震对2014年于田地震的发生有一定的触发作用外,其他地震之间的影响作用不大。最后,计算强震对周边断层的库仑应力变化,结果发现博罗科努断裂西侧中段、卡兹克阿尔特断裂西段、木吉断裂西段以及和田断裂西段不同程度的库仑应力增加,具有一定的地震危险性。
Based on the focal mechanisms of 828 MS≥3.0 earthquakes occurring in the Xinjiang area since 1900,we adopted the method of damped regional-scale stress inversion to obtain the characteristics of regional stress field in Xinjiang.The results revealed that the main types of focal mechanisms in Xinjiang are thrust and strike-slip,and the maximum horizontal principal compressive stress is in nearly SN direction along with local tension and shear.Then,according to the characteristics of regional stress field and spatial distribution of strong earthquakes in the region,we calculated the Coulomb stress changes among strong earthquakes in Tianshan,Kashi-Wuqia,and Kunlun-Altun areas.It is concluded that the strong earthquakes in Tianshan area has little influence on the occurrence of subsequent earthquakes.Kashi-Wuqia area is a strong earthquake prone area,and the epicenters are densely distributed along with obvious earthquake triggering or delay effect.There is little effect between earthquakes in Kunlun-Altun area,except the triggering effect of the Yutian MS7.3 earthquake in 2008 on the subsequent Yutian MS7.3 earthquake in 2014.Finally,we also calculated the Coulomb stress changes of surrounding faults caused by strong earthquakes,and the results showed that the Coulomb stress increased along the middle segment of western Boluokenu Fault,the west segment of Kazikearte Fault,the west segment of Muji Fault,and the west segment of Hetian Fault,suggesting the increasing seismic risk.
作者
刘方斌
古丽孜娜提·依德热斯
曲均浩
LIU Fangbin;Gulizinati Yideresi;QU Junhao(College of Earth Environment Science, Lanzhou University, Lanzhou 730000, Gansu, China;Shandong Earthquake Agency, Ji'nan 250102, Shandong, China;Kashi Seismic Station, Xinjiang Earthquake Agency, Kashi 844000, Xinjiang, China)
出处
《地震工程学报》
CSCD
北大核心
2021年第5期1024-1036,共13页
China Earthquake Engineering Journal
基金
山东省自然科学基金(ZR2018PD008)
中国地震局星火计划(XH20034Y,XH191505)。
关键词
新疆地区
震源机制解
区域应力场反演
静态库仑应力变化
地震危险性
Xinjiang area
focal mechanism solution
inversion of regional stress field
static Coulomb stress changes
seismic risk
