摘要
收集新疆和田地震台地电场数字化以来的连续观测数据,研究台站300 km内发生的M_(s)≥5.5强震前的地电场岩体裂隙变化特征。结果表明,和田地震台地电场观测场地岩体裂隙发育较好,处于长期集中,而且中强以上地震发生前和田台地电场岩体裂隙优势方位角容易发生偏转和大幅度间断性突跳等结构变异。通过和田台周围5次典型震例解析,发现地震越强,其异常出现得越早;地电场异常的方向性与震中方位有一定关联性,但也与震源区的活动断裂构造性质有关,推测部分异常可能来自震源,故震源区构造是信号传播的最佳通道;和田台地电场的震前岩体裂隙优势方位角异常特征多表现为短期异常信息,易发震周期为45~90 do该研究进一步推广和检验了地电场岩体裂隙优势方位角异常分析方法在地震预测预报中的应用。
Continuous observation data since the digitization of geoelectric field at Hetian seismic station in Xinjiang are collected to study variation characteristics of rock fissures in geoelectric field before strong earthquake with Ms≥5.5 within 300 km.The results show that rock mass fractures in Hetian geoelectric field site are well developed and concentrated for a long time,and dominant azimuth of the rock mass fractures are prone to structural variations such as deflection and large intermittent jump before moderate or strong earthquakes.Through analysis of five typical earthquake cases around Hetian station,it is found that the stronger the earthquake is,the earlier the anomaly appears.Directionality of geoelectric field anomaly is related to the epicenter orientation,but also related to the nature of active fault structure in the focal area.It is speculated that some anomalies may come from the focal area,so the structure in focal area is the best channel for signal propagation.Dominant azimuthal anomaly characteristics of rock mass fractures before earthquakes are mostly short-term anomaly information,and the prone period of earthquakes is 45~90 days.This study further popularizes and tests the application of geoelectric field rock fracture dominant azimuth anomaly analysis method in earthquake prediction.
作者
艾萨·伊斯马伊力
陈界宏
次旦
邱大琼
赵江涛
周斌
Aisa Yisimayili;CHEN Jie-hong;CI Dan;QIU Da-qiong;ZHAO Jiang-tao;ZHOU Bin(Earthquake Agency of Xinjiang Uygur Autonomous Region,Urumqi 830011,Xinjiang,China;China University of Geoscience,Wuhan 430074,Hubei,China;Tibet Bureau of Geology and Mineral Exploration and Development,Lasa 854100,Xizang,China)
出处
《内陆地震》
2021年第3期245-252,共8页
Inland Earthquake
基金
中国地震局震情跟踪青年项目(2020010422,2019010409)
中国地震局监测、预报、科研三结合项目(3JH-201901097)
新疆地震科学基金(201703,202001).
关键词
和田台
强震
地电场
优势方位角
Hetian station
Strong motion
Geoelectric field
Dominant azimuth
