2020年新疆于田M_(S)6.4地震和田台地电场异常的测道差异性  

The Azimuth Difference of the Geoelectric Field Anomaly of Hetian Station in the 2020 Yutian M_(S)6.4 Earthquake, Xinjiang

作　　者：王宇 谭大诚[1,2] 邱大琼 张锋[3] 陈亮 WANG Yu;TAN Da-cheng;QIU Da-qiong;ZHANG Feng;CHEN Liang(Lanzhou Institute of Seismology,China Eart hquake Administration,Lanzhou 730000,China;Earthquake Administration of Gansu Province,Lanzhou 730000.China;Earthquake Agency of Xinjiang Uygur Autonomous Region,Urumqi 830011,China)

机构地区：[1]中国地震局兰州地震研究所,甘肃兰州730000 [2]甘肃省地震局,甘肃兰州730000 [3]新疆维吾尔自治区地震局,新疆乌鲁木齐830011

出　　处：《地震》2021年第2期180-189,共10页Earthquake

基　　金：中国地震局监测司2020年任务项目(zx1903006,zx2004002)。

摘　　要：和田地电场台站距离2020年6月26日于田M_(S)6.4地震震中约305km,该台不同方位测道之间相关系数均值在0.8左右,应用多极距原理获知震前两月该台地电场数据中“近场”信息较复杂,但具有一定程度的可靠性。计算该台不同极距测道的优势方位角α和不同方位测道间相关系数δNS/NW,获知震前数月长、短极距α、δNS/NW存在不同的异常现象。2011—2019年,和田台周边300km范围发生了6次M_(S)5.0以上地震,这种异常现象的差异具有类似特点。这反映出在同一场地,地电场长、短极距观测装置对周边中强地震的映震能力可能存在差异性。The Hetian geoelectric field station is located about 305 km away from the epicenter of the Yutian M_(S)6.4 earthquake on June 26,2020.The mean value of the correlation coefficient between the stations in different azimuths is about 0.8.The multipole distance principle is used to obtain the geoelectric field of the station two months before the earthquake.The"near field"information from the data is more complex,but it has a certain degree of reliability.The dominant azimuthαof the station with different polar distances and the correlation coefficientδNS/NW between the different azimuths have been calculated,which indicates that there are different anomalies in the long and short polar distancesαandδNS/NW several months before the earthquake.From 2011 to 2019,6 earthquakes above MS5.0 occurred in the 300 km area around Hotan Station,which has similar geoelectric abnormal phenomenon characteristics with the Yutian M_(S)6.4 earthquake.This reflects that at the same site,there may be differences between the long and short pole distance observation devices for geoelectric field monitoring on moderate and strong earthquakes.

关 键 词：2020年于田M_(S)6.4地震 地电场 多测道 异常 差异 

分 类 号：P315.7[天文地球—地震学]