摘要
对甘肃省平凉、松山、古丰、山丹、高台、嘉峪关、瓜州7个台站的地电场分钟值、小时值的日变特征进行了对比,对2012年3月地电场小时值进行了频谱分析,同时结合地磁场H分量、分量应变(固体潮)进行了对比分析。结果表明:1地电场静日的日变化都很明显,呈明显"双峰"和"单谷"形态,并且NS向与EW向变化形态基本相同;各台站同测向及相互之间的自相关系数基本在0.85;不同台站之间同测向的相关系数多数在0.75以上;这是地磁场H分量与固体潮共同影响的结果。2通过频谱分析各台站的优势周期主要以12h和8h为主,但存在差异性,谱值最大相差20倍。3各台站的日变幅也不尽相同,其中,差异性主要表现为与地磁场和固体潮影响量的差异性,并与台站的位置、地质构造、电性结构、浅层电阻率等有很大关系。
Through comparing variation of daily value of geoelectric field data in Pingliang, Songshan, Gufeng, Shandan, Gaotai, Jiayuguan and Guazhou based on its minute value and hour value, we analyze frenquency-spectrum of its hour value in March 2012, combined with component of H of geomagnetic field and component strain （earth tides）, and then extracted change characteristics and difference of geoelectric field. The results show that： （1） Daily changes of geoelectric field in quiet day are significant, which is shaped by double peak and one valley, and the changes are almost the same in NS and EW direction. Auto-correlation in each observation direction and the same observation directions of each station remain a high value at 0.85. Correlation coefficients of the same observation direction mainly exceed 0.75. The result is controlled by both H component of geomagnetic field and earth tides. （2） Frequency-spectrum analysis suggest that the dominant cycle of each station is mainly 12 hours or 8 hours, but the spectrum value shows significant variation, even reaching as high as 20 times. （3） Amplitudes of daily change in each station not only show similarities, but also present remarkble difference. （4） These differences are very likely caused by the difference of geomagnetic field and earth tides, station location, geological structure, electrical structure and shallow resistivity.
出处
《震灾防御技术》
CSCD
北大核心
2015年第2期435-446,共12页
Technology for Earthquake Disaster Prevention
基金
国家自然科学基金(41374080)资助
关键词
地电场
日变化
周期
变化特征
Geoelectricfield
Diuenalvarition
Period
FFT
Changing characteristics
