低频事件类别及特征分析

The low frequency events category and characteristics analysis

通过分析全球记录到的各类低频地震,主要类型如:ETS(低频震颤与滑移事件)、LFT(低频震颤)、SSE(慢滑移事件)、VLF(超低频事件)、DLF(深低频事件)等,介绍了主要低频事件与天然地震的波形和频谱特征.发现不同国家地区记录到的ETS,LFT,SSE等低频事件均有相近的周期范围.文中将低频震动事件进行类别划分,获得频率-持续时间分类示意图,结果表明全球主要地区记录的低频事件、火山地震、天然地震、台风和地脉动等,都有特定的频率范围和持续时间,可以从图上大体区分出低频震动事件的属性特点,为低频事件的判别提供依据.通过对低频信息的频率范围,波形特征等的深入分析和确认,可提供有价值的地震前兆信息.

Through the analysis of all kinds of low frequency earthquake of global record, the main types such as： ETS （Epidemic tremor and slip event）, LFT （low frequency tremor）, SSE （slow slip event）, VLF （very low frequency event）, DLF （deep low-frequency event）, it introduced the main low frequency events and natural seismic waveform and spectrum characteristics. The analysis shows that in different countries recorded by the events of ETS, LFT, SSE, each kind of events has similar period range. By the low frequency events classification, we obtained frequency-duration classification diagrammatic map. The main low frequency events recorded in the map indicate that, the volcanic earthquakes, natural earthquake, typhoon and tremor, each has its certain range of frequencies and duration. It can distinguish from the diagrammatic map the vibration event attributes and the characteristics identification of low frequency events. Through the frequency range of low frequency information and waveform features analysis and confirmation, it can provide valuable earthquake precursor information.