摘要
应用大地电场岩体裂隙模型,对中国大陆主要块体内电磁环境、装置系统较好的40个台站进行分析,发现80%场地岩体裂隙结构处于发育阶段、15%场地裂隙处于排列有序的长大阶段、5%场地岩体较破碎,这些不同阶段的岩体裂隙结构对应着不同的大地电场幅度、方向变化特征.通过对2013年至2018年3月中国大陆6次典型震例解析,发现在强震震中200km范围内,岩体裂隙处于长大或发育好的场地较集中,而且这些场地在强震前更容易发生岩体剪裂、裂隙优势方位偏转和大幅度突跳等结构变异,200km外场地裂隙优势方位多发生突跳现象.总体上,这些现象还具有时间准同步性、场地选择性特点.
With the model of telluric field rock cracks, this work analyzes 40 geoelectric field stations with better electromagnetic environment and device systems in main blocks of Chinese mainland. It is found that rock crack structure of the 80% sites is in the development stage, that of the 15% is in an orderly stage of growth and the 5% is rather broken. These crack structures of the rock masses at different stages correspond to different magnitudes and direction change features of the telluric field. Six typical earthquakes in China's Mainland from 2013 to March 2018 are analyzed. The results show that rock cracks are in the stage of growth or well developed concentrated at the sites within 200 km to epicenters of major earthquakes, and at these sites occurred more easily structural variations such as rock shear cracks, deflection of preferred orientation of cracks and large jump. Outside 200 km to the epicenters, jumps of preferred orientations of cracks occurred at the sites. On the whole, these phenomena also have features of time quasi-synchronization and site selectivity.
作者
谭大诚
辛建村
王建军
范莹莹
王玮铭
TAN DaCheng;XIN JianCun;WANG JianJun;FAN YingYing;WANG WeiMing(Lanzhou Institute of Seismology,China Earthquake Administration,Lanzhou 730000,China;Earthquake Administration of Gansu Province,Lanzhou 730000,China;Earthquake Administration of Shanxi Province,Xi′an 710068,China)
出处
《地球物理学报》
SCIE
EI
CAS
CSCD
北大核心
2019年第2期558-571,共14页
Chinese Journal of Geophysics
基金
中国地震局监测预报司2017年震情跟踪定向任务(2017020401)
甘肃省省青年科技基金(17JR5RA338)
甘肃省地震局基本科研专项(2013IESLZ02)
关键词
大地电场
裂隙结构
强震
结构变异
特征
Telluric field
Crack structure
Major earthquake
Structural variation
Feature
