新疆2014年于田M_S7.3及2015年皮山M_S6.5地震及其余震序列与潮汐应力的触发关系研究  

Rsearch on Triggering Relationship between Tidal Stress and the 2014 Yutian M_S7.3 Earthquake and 2015 Pishan M_S6.5 Earthquake and Their Aftershock Sequences in Xinjiang Province

作　　者：马青波[1] 解朝娣[1] 向元[2] 王琼[2] 杨思梦 王英楠 MA Qingbo;XIE Chaodi;XIANG Yuan;WANG Qiong;YANG Simeng;WANG Yingnan(School of Resource Environment and Earth Sciences, Yunnan University, Kunming 650091, Yunnan, China;Earthquake Agency of Xinjiang Uyghur Autonomous Region, Urumchi 830011, Xinjiang, China)

机构地区：[1]云南大学资源环境与地球科学学院,云南昆明650091 [2]新疆维吾尔自治区地震局,新疆乌鲁木齐830011

出　　处：《地震研究》2018年第1期104-110,共7页Journal of Seismological Research

基　　金：国家自然科学基金(41574043)资助

摘　　要：选取新疆西昆仑地区的2014年于田M_S7.3和2015年皮山M_S6.5地震及其余震序列为研究对象,对地震目录的完备性进行了分析,并计算了主震发震时刻,主震震源断层面上的潮汐剪应力、正应力,得到主震震源断层面上的潮汐库仑破裂应力;再使用Schuster统计检验方法,分析了2个余震序列的潮汐相位角分布,研究新疆西昆仑地区中强地震及其余震活动与潮汐应力之间的触发关系。结果表明:主震发生时,皮山震源断层面上的潮汐库仑破裂应力为正值,而于田震源断层面上的潮汐库仑破裂应力为负值,说明潮汐应力对皮山主震有明显的触发作用,对于田主震的触发作用不明显。同时,计算结果表明2个余震序列与潮汐应力的统计相关参数P值几乎都小于5%,说明潮汐应力对皮山和于田余震序列均有触发作用。最后ETAS模型计算结果也表明了余震序列对地震震级的弱依赖性,可能与外界触发因素(潮汐)有关。According to the theory of tidal stress triggering,the sequences of the 2014 Yutian MS7. 3 and 2015 Pishan MS6. 5 earthquakes together with their aftershocks were used to study the tidal triggering of earthquakes in the western Kunlun region of the Xinjiang province. First,we analyzed the completeness of all earthquake catalogs and calculated the tidal shear stresses,tidal normal stresses and tidal coulomb failure stresses at the origin time of each earthquake using the fault planes of main shocks. Moreover,in order to study whether there exists a triggering relationship between the strong shock as well as its aftershocks in western Kunlun region and the tidal stress,we calculated the distribution of phase angles of tidal coulomb failure stresses for two earthquake sequences by using the method of Schuster test. The result shows that the coulomb failure stresses are positive on the fault at the occurrence time of Pishan mainshock. And the coulomb failure stresses for Yutian mainshock are negative.This means that the tidal triggering effect is significant for the Pishan mainshock but not obvious for the Yutian mainshock. And the Schuster test shows the P values of the sequences of the Pishan event and the Yutian event are both almost less than 5%. So,there is a tidal triggering effect on two aftershock sequences. In the final,combining with the discussion on ETAS model,it also shows the weak dependence of aftershock sequence on earthquake magnitude,which may be related with the trigger factor outside.

关 键 词：2014年于田MS7.3地震 2015年皮山MS6.5地震 Schuster统计检验 潮汐应力 地震触发 

分 类 号：P315.727[天文地球—地震学]