2008年汶川M_S8.0与2010年玉树M_S7.1地震前电磁现象研究

Electromagnetic phenomena before 2008 Wenchuan M_S8.0 and 2010 Yushu M_S7.1 earthquakes

应用全局小波能谱法对2008年四川汶川MS8.0地震、2010年青海玉树MS7.1地震前地电、地磁场变化情况进行了分析研究.结果表明:①在汶川地震震中周围的台站观测到震前地电、地磁场全局小波能谱值增大的现象;②青藏高原东北缘的代乾等3个地电、地磁台站在玉树地震前均发生显著的小波能谱增大的现象,震后恢复;③对于上述两次大震周边地区的不同台站的不同测道,在震前多次出现谱值时间上同步增大或减少的现象;④距玉树地震震中距离相同的山丹和古丰地电场台站,北南、北西测向长极距在地震前后能谱值的变化几乎一致.基于上述分析,初步研究认为震源孕育激发的电磁辐射是造成震前电磁异常现象的主要原因.

This paper studied the changes of the geoelectric and geomagnetic fields before the 2008 Wenchuan Ms8.0 earthquake in Sichuan Province and the 2010 Yushu Ms7. 1 earthquake in Qinghai Province using the wavelet powerspectrum analysis. The results showed that. @ The increased wavelet power value of the geoelectrie and geomagnetic fields were observed by the geoeleetric stations and the geoelectromagnetic stations near the epicenter before the Wen- chuan earthquake. （~） The wavelet power value of the geoelectric and geomagen- tic fields significantly increased in the TIA station and so on in the northeastern margin of Qinghai-Tibet Plateau before the Yushu earthquake, which recovered after the earthquake. （~） The phenomena that the wavelet power value synchro- nously increased/decreased were recorded more than once at the different chan- nels of different stations near the above two earthquakes. @ The changes of the wavelet power value were almost same observed by the NS and NW channels of Sandan station and Gufeng station, which are at the same distance from the epi- center of Yushu earthquake. Based on the above analysis, we drew the conclu- sion preliminarily that the geoelectromagnetie anomalies were mainly caused by the electromagnetic radiation stimulated by the focal development.