2020年6月26日于田MS6.4地震前和田地电场LURR异常演化特征  

LURR ANOMALY EVOLUTIONARY CHARACTERISTICS OF HETIAN GEOELECTRIC FIELD BEFORE YUTIAN MS6.4 EARTHQUAKE ON JUNE 26TH,2020

作　　者：于晨 王淑艳 王亚丽[1] 马未宇[1] 余怀忠[1,3] YU Chen;WANG Shu-yan;WANG Ya-li;MA Wei-yu;YU Huai-zhong(China Earthquake Networks Center,Beijing 100045,China;Academy of Electronics and Information Technology,China Electronics Technology Corporation,Beijing 100041,China;Earthquake Agency of the Xinjiang Uygur Autonomous Region,Urumqi 830011,Xinjiang,China)

机构地区：[1]中国地震台网中心,北京100045 [2]中国电子科技集团公司电子科学研究院,北京100041 [3]新疆维吾尔自治区地震局,新疆乌鲁木齐830011

出　　处：《内陆地震》2020年第3期274-285,共12页Inland Earthquake

基　　金：国家重点研发计划(2018YFE0109700、2018YFC1503506).

摘　　要：加卸载响应比(Load/Unload Response Ratio,LURR)是根据岩石介质本构关系的动态演化特征提出的地震预测方法。采用以固体潮在断层面处引起的库仑破裂应力变化判断加卸载的方法,以地电场观测资料为响应量,计算2020年6月26日新疆于田MS6.4地震周边的和田地电场长、短极距共6个测道的LURR异常时序曲线。结果表明:在于田地震前1~3个月,和田地电场长、短极距的北南向和北西向共4个测道出现了LURR曲线逐渐增大的同步变化;结合2017年九寨沟M S7.0和2016年云龙M S5.0地震的计算结果,基于电磁观测资料的震前LURR异常并非是单一案例,震前都出现了“平静—增大—恢复—发震”的共性特征,这可能反映了孕震区介质因微裂隙的产生和扩展导致流体在裂隙中的运移引起动电效应,进而引起地下电磁场变化。Load/unload response ratio(LURR)is an earthquake prediction method based on the dynamic evolution characteristics of the stress-strain constitutive relationship of rock media.In the method of judging loading and unloading based on the change of Coulomb fracture stress caused by earth tide at fault plane,we calculated the LURR anomaly time series curves of six intems of Hetian geoelectric field long and short polar distance around Yutian MS6.4 earthquake on June 26th,2020.The results show that:1~3 months before Yutian earthquake,LURR curves of four items in the north-south and north-west directions of the long and short polar distance of the geoelectric field gradually increased synchronously.Compared with the calculation results of Jiuzhaigou M S7.0 earthquake in 2017 and Yunlong M S5.0 earthquake in 2016,LURR anomaly based on electromagnetic observation data is not a single case.The common characteristics of"calm-increase-recovery-earthquake"appear before earthquakes,which may reflect that the generation and expansion of micro cracks in the medium in the seismogenic area lead to the migration of fluid in the fracture,leading to further underground electromagnetic field changes.

关 键 词：加卸载响应比 地电场 于田MS6.4地震 LURR异常 

分 类 号：P315.7[天文地球—地震学]