2014年10月1日越西M5.0(或M_L5.2)地震发生在川滇块体东边界历史地震强度较低的大凉山断裂带中段。基于四川区域地震台网记录的波形资料,利用CAP(Cut and Paste)波形反演方法,计算了越西M5.0地震的震源机制解与震源矩心深度,初步分析了...2014年10月1日越西M5.0(或M_L5.2)地震发生在川滇块体东边界历史地震强度较低的大凉山断裂带中段。基于四川区域地震台网记录的波形资料,利用CAP(Cut and Paste)波形反演方法,计算了越西M5.0地震的震源机制解与震源矩心深度,初步分析了本次地震的发震构造。同时,利用波形资料,计算了该地震的视应力值,并与2001年以来附近区域M_L≥4.0地震的视应力值进行了对比分析。研究结果表明,越西M5.0地震震源机制解节面I走向256°/倾角62°/滑动角167°,节面Ⅱ走向352°/倾角79°/滑动角29°;P轴方位121°,仰角11°,近水平;T轴方位217°,仰角28°;震源矩心深度为11km;矩震级约为MW5.1。根据节面参数与震中附近的主要构造展布,认为此次地震的发震构造为大凉山断裂带中段分支断裂——NNW向普雄断裂,与该断裂走向相近的节面Ⅱ为同震破裂面。本次地震为兼具小量逆冲分量的左旋走滑型地震,是NNW向大凉山断裂带在近水平的NWW-SEE向主压应力作用下左旋走滑活动所致。此外,利用波形资料计算获得的越西M5.0地震的视应力值(0.99MPa)高于汶川8.0级地震后其附近区域的地震视应力,反映了震源区当前的背景应力水平相对较高,有利于中、强地震的发生,越西地震的视应力高值还可能反映了川滇块体整个东边界区域当前的应力水平在逐渐升高,因而发生强震的危险性也在升高。展开更多
The North-South Seismic Belt was analyzed using gravity observation data from 2011 to 2015, and the nontidal analysis results show that there was a nonlinear gravity change at both the Chengdu and Guza seismostations ...The North-South Seismic Belt was analyzed using gravity observation data from 2011 to 2015, and the nontidal analysis results show that there was a nonlinear gravity change at both the Chengdu and Guza seismostations one month before the Leshan M5.0 earthquake.展开更多
The epicenter of the M5.0 earthquake occurring in Jinghe County, Xinjiang on October 16, 2011, is located in Tuoli Township. The intensity of the meizoseismal area is VI. The seismic damage investigation shows that th...The epicenter of the M5.0 earthquake occurring in Jinghe County, Xinjiang on October 16, 2011, is located in Tuoli Township. The intensity of the meizoseismal area is VI. The seismic damage investigation shows that the houses are mainly mud-clay style and the seismic damage characteristics take on an obvious regional nature. The damage degree varies relative to the field conditions.展开更多
文摘2014年10月1日越西M5.0(或M_L5.2)地震发生在川滇块体东边界历史地震强度较低的大凉山断裂带中段。基于四川区域地震台网记录的波形资料,利用CAP(Cut and Paste)波形反演方法,计算了越西M5.0地震的震源机制解与震源矩心深度,初步分析了本次地震的发震构造。同时,利用波形资料,计算了该地震的视应力值,并与2001年以来附近区域M_L≥4.0地震的视应力值进行了对比分析。研究结果表明,越西M5.0地震震源机制解节面I走向256°/倾角62°/滑动角167°,节面Ⅱ走向352°/倾角79°/滑动角29°;P轴方位121°,仰角11°,近水平;T轴方位217°,仰角28°;震源矩心深度为11km;矩震级约为MW5.1。根据节面参数与震中附近的主要构造展布,认为此次地震的发震构造为大凉山断裂带中段分支断裂——NNW向普雄断裂,与该断裂走向相近的节面Ⅱ为同震破裂面。本次地震为兼具小量逆冲分量的左旋走滑型地震,是NNW向大凉山断裂带在近水平的NWW-SEE向主压应力作用下左旋走滑活动所致。此外,利用波形资料计算获得的越西M5.0地震的视应力值(0.99MPa)高于汶川8.0级地震后其附近区域的地震视应力,反映了震源区当前的背景应力水平相对较高,有利于中、强地震的发生,越西地震的视应力高值还可能反映了川滇块体整个东边界区域当前的应力水平在逐渐升高,因而发生强震的危险性也在升高。
基金supported by the Director Foundation of Institute of Seismology,China Earthquake Administration(201326123)the National Natural Science Foundation of China(41204058,41474064)the Ministry of Science and Technology major instrument special sub topic(2012YQ10022506)
文摘The North-South Seismic Belt was analyzed using gravity observation data from 2011 to 2015, and the nontidal analysis results show that there was a nonlinear gravity change at both the Chengdu and Guza seismostations one month before the Leshan M5.0 earthquake.
基金Supported by the Earthquake Science Foundation Project of Earthguake Administration of Xinjiang Uygur Autonomous Region ( 201112)the Program of Earthquake Risk Assessment on Actine Faults in Key Monitoring Region of China ( 2200409)
文摘The epicenter of the M5.0 earthquake occurring in Jinghe County, Xinjiang on October 16, 2011, is located in Tuoli Township. The intensity of the meizoseismal area is VI. The seismic damage investigation shows that the houses are mainly mud-clay style and the seismic damage characteristics take on an obvious regional nature. The damage degree varies relative to the field conditions.
