甘—青地区地磁谐波振幅比分析  

Study on the Amplitude Ratio of Geomagnetic Harmonic Wave in Gansu-Qinghai Region

作　　者：戴勇[1] 高立新[1] 张立丰[1] 

机构地区：[1]内蒙古自治区地震局,内蒙古呼和浩特010010

出　　处：《地震工程学报》2016年第1期12-18,25,共8页China Earthquake Engineering Journal

基　　金：2014年度震情跟踪青年课题(2014020401)

摘　　要：以甘肃、青海及周边地区（33°-43°N,94°-107°E）作为研究区,采用谐波振幅比方法处理地磁资料。结果显示：（1）在周边显著地震发生前,位于甘—青地区的嘉峪关、山丹、都兰、湟源和英鸽5个台站地磁谐波振幅比一般存在＂下降-转折-恢复＂异常变化,其持续时间为1-3年,变化幅度为0.03-1.30,地震发生在异常转折或恢复的过程中;（2）所研究的5个地磁台站中,仅山丹台地磁谐波振幅比存在周期间的迁移特征;（3）嘉峪关、山丹两个台站地磁谐波振幅比分别自2010、2011年开始存在＂下降-转折-上升＂异常变化,2012年以来出现YZHx和YZHy不同项之间以及同一项不同周期间不同步迹象,今后应重点关注这两个台站地磁谐波振幅比异常变化。After the completion of projects as part of the ninth and tenth five-year plans,the geomagnetic observatories networks of Gansu and Qinghai provinces have become densely distributed.The Gansu network has four geomagnetic stations and a geomagnetic array,while there are eight geomagnetic stations in the Qinghai network.The two networks have produced a large amount of geomagnetic data since 2008.The Gansu-Qinghai region（33°-43°N,94°-107°E）was identified as the study area for this study.The geomagnetic data in the study area was analyzed using the harmonic amplitude ratio method,and the relationships between the results and the earthquakes in the Gansu-Qinghai region were investigated.Feng Zhi-sheng et al.analyzed the geomagnetic humorous wave amplitude ratios of Chongming,Sheshan,Kashi,and other geomagnetic stations and reported the existence of down-turning-recovery characteristics before and after medium-to-strong earthquakes,which are similar to the earthquake precursor anomaly variations of earth resistivity.We analyzed the geomagnetic harmonic amplitude ratios of Jiayuguan,Shandan,Dulan,Huangyuan,and Yingge geomagnetic stations and reached the same conclusions.The amplitude ratio method has been widely employed for earthquake prediction.The duration of geomagnetic humorous wave amplitude ratio curve abnormalities of earthquakes with M≥5is 1-3years.Earthquakes typically occur at the abnormal twist or recovery points.The anomaly amplitude varies between 0.03 and 1.30.Feng Zhi-sheng et al.reported the occurrence of migration phenomenon among the curves of different periods.Further,there may be some correlation between the distance of the phenomenon and the earthquake epicenter.In this study,the migration phenomenon was observed only in the curves corresponding to the Shandan station,and no obvious correlation was observed between the migration phenomenon and the earthquake epicenter.The judgment standard must be determined when analyzing abnormal variations and summarizing earthquake case studies.Resear

关 键 词：地磁 谐波振幅比 异常 地震 

分 类 号：P318[天文地球—固体地球物理学]