岩体声发射与地震活动相关性和地震预报

Earthquake prediction and correlation between rock mass acoustic emission and seismic activity

为研究声发射(AE)技术用于地震预测的可行性,在花岗岩地下隧道内布置AE系统和地震仪同时开展AE及地震监测.采用多模态统计方法分析了35 d监测期内AE与地震活动的时间相关性,并观测了AE时间序列的b值和自然时间方差κ_(1)的演化.实验结果表明:包含爆发的AE特性变化预示着主震的临近,其密集爆发与临近的3.2级及2.4级主震密切相关;主震发震前,b值出现连续下降的趋势并降至1以下的最小b值,自然时间方差从0.07迅速减小到接近零的最小值;多模态统计方法得到的AE时间分布的变化趋势比地震活动早,能提前约17 h预测主震事件.因此,AE与地震活动有很强的相关性,可作为地震前兆.实测结果为AE用于地震预报提供了可能性和观测证据.

To study the feasibility of acoustic emission(AE)technology for earthquake prediction,the AE system and seismometer were arranged in the granite underground tunnel to conduct AE and seismic monitoring simultaneously.The temporal correlation between AE and seismic activity during the 35 d monitoring period was analyzed by multimodal statistical method,and the evolution of the b-value and natural-time varianceκ_(1) of AE time series was observed.Experimental results show that the change of AE characteristics including the burst indicates the approach of the major earthquake,with its dense burst being closely related to the nearby major earthquakes of magnitude 3.2 and 2.4.Approaching the major earthquake occurrence,the b-value shows a continuous dropping till it reaches the minimum b-value below 1,whereas the natural-time variance decreases rapidly from 0.07 to a minimum value close to zero.The changing trend of AE temporal distributions obtained by multimodal statistical method is earlier than that of seismic activity,anticipating the major earthquake event about 17 h in advance.Therefore,AE has a strong correlation with seismic activity and can be used as earthquake precursors.The measured results provide the possibility and observational evidence for the use of AE in earthquake prediction.