2022年青海门源MS6.9地震前地电场频谱特征研究

应用最大熵谱法研究2022年1月8日青海门源M_S6.9地震震中周围松山、山丹、高台、瓜州地电场台站的观测数据,分析地震发生前后地电场功率谱密度变化。结果表明：(1)门源地震发生前,松山等4个台站的地电场低频成分功率谱密度值出现增大的现象;(2)4个台站在门源地震前谱值变化的时间基本同步;(3)结合微裂隙机制及“多点场”观点,对比分析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。

Frequency spectrum characteristics of geoelectric field beforethe 2022 Menyuan MS6.9 earthquake in Qinghai Province

In this paper,we used the maximum entropy spectrum method to study the geoelectric field data observed by the Songshan,Shandan,Gaotai,and Guazhou stations around the epicenter of Menyuan M_S6.9 earthquake on January 8,2022,and analyzed the power spectral density (PSD) variation of geoelectric field before and after the earthquake.The results show that:(1) The increased PSD of low frequency components was recorded before the Menyuan M_S6.9 earthquake by the four stations;(2) The changes of PSD before the Menyuan earthquake were basically synchronous in the four stations;(3) Combined with the microfracture mechanism and the viewpoint of "multi-point field",we drew the conclusion that the electromagnetic anomalies before the Menyuan M_S6.9 earthquake were mainly caused by the electromagnetic radiation generated by the focal development.