震前次声波异常信号的研究

Research of Abnormal Infrasound Signals before Worldwide Earthquakes

根据美国地质调查局公布的地震目录,2002—2008年全球共发生了92次7级以上的地震.其中,78次震前接收到了次声波异常信号,占84.8%.次声波异常信号的幅值均超过1 000 mV,次声异常信号的频率在10-3 Hz量级.异常信号结束后9 d内发震的有45次,占57.7%.本文以这92个地震为统计对象,讨论了震级M、观测点到震中的距离D与次声波异常信号最大幅值Um的关系.结果表明,次声波异常信号与地震的发生有较好的对应关系,但Um与M、D呈现出复杂的关系.

According to the U.S.Geological Survey,there are 92 earthquakes that M≥7.0 happened worldwide from 2002 to 2008.About 78 of these earthquakes or 84.8% are preceded the signals.The amplitudes of these abnormal infrasound signals were greater than 1000mV,and the frequency of the abnormal infrasound signals was about 10-3Hz.There are 45 or 57.7% of these earthquakes happened within 9 days after the abnormal signals were recorded.In this paper,92 worldwide earthquakes were investigated,and the relationship between the earthquake magnitude,M,the distance of observation points to the epicenter,D and the maximum amplitude of the abnormal signal,Um.The results show that the infrasound abnormal signals have good correlation with earthquakes,but Um vs.M,and D are the complicated relationship.