玛多7.4级地震前临震微波动现象研究

强震临震微波动是强震临震阶段优势频率集中在11～16 Hz、频谱形态较为整齐的临震异常脉动记录。利用"兰州临震微波动实时监控与跟踪系统"的数据资料,对2021年5月22日玛多7.4级地震震中200 km半径的范围内台站的临震微波动事件进行分析。认为震前距离震中67 km的巴颜喀拉台EW通道存在显著异常,达到杨立明提出的异常跟踪指标;10个测震台站中的8个在本次地震前记录到了临震微波动事件,震中南侧台站记录到的事件多于北侧。

Phenomenon of microwave fluctuation before the MaduoM7.4 earthquake

The phenomenon of microwave fluctuation impending strong earthquake is a type of abnormal pulsation record; its dominant frequency of spectrum focuses on 11-16 Hz and frequency spectral morphology appears fairly orderly. Based on the data from " real-time monitoring and tracking system of microwave fluctuation impending earthquake in Lanzhou" , the events of microwave fluctuation impending earthquake recorded by stations within 200 km of the Maduo M7.4 earthquake on May 22, 2021 were analyzed. It is considered that the EW channel of Bayan Har station, 67 km from the epicenter, was abnormal before the earthquake, which reaches the anomaly tracking index proposed by Yang Liming. The events of microwave fluctuation impending earthquake were recorded by eight seismic stations before the earthquake, and more events were recorded in the south of the epicenter than in the north.