注水诱发地震的谱振幅相关系数及视应力研究  

Study on Correlation Coefficient of Spectral Amplitude and Apparent Stress of Water Injection Induced Earthquake

作　　者：张致伟[1] 乔慧珍[1] 吴朋[1] 宫悦[1] 赵小艳[2] 

机构地区：[1]四川省地震局,四川成都610041 [2]云南省地震局,云南昆明650224

出　　处：《地震研究》2015年第1期42-50,181,共9页Journal of Seismological Research

基　　金：地震科技星火计划项目(XH14045Y);中国地震局监测预报司震情跟踪青年课题(2013020102)联合资助

摘　　要：以四川自贡和长宁两个注水地区为例,基于区域测震台网记录的数字地震波形资料和观测报告,分析注水诱发地震的谱振幅相关系数特征及其与当地加压注水数据的关系,并结合表征绝对应力水平的视应力综合分析研究自贡和长宁地区的应力状态。结果表明,自贡和长宁地区注水诱发地震的谱振幅相关系数均在高值波动,其均值分别为0.89和0.90,且变化过程与加压注水数据具有很好的相关性。分析认为加压注水对局部区域应力场产生扰动影响,使地下浅层裂隙呈优势取向排列,引发的中小地震震源机制表现出较好的相似性,但其视应力结果显示研究区域的应力水平并不高。Taking Zigong and Changning which are both water injection areas in Sichuan as the study regions,based on digital seismic waveform recorded by regional seismic netw ork and observation report,we analyze the characteristic of correlation coefficient of spectral amplitude of water injection induced earthquake and the relationship betw een correlation coefficient and water injection data. Then combining the apparent stress which represents the absolute stress level,we analyze the stress intensity of the tw o study regions. The result shows that the correlation coefficients of spectral amplitude of water injection induced earthquakes both fluctuate at high value and the average values are 0. 89 and 0. 90 in Zigong and Changning areas respectively,and the changing process of correlation coefficient has a good correlation with water injection data. The pressurized water injection has the disturbance influence on stress field in local region,thus the fractures of underground shallow layer arrange in predominant direction,and the focal mechanisms of water injection induced small-moderate earthquakes shows good similarity,however,the apparent stress results indicate that the stress is lower in the study region.

关 键 词：注水诱发地震 Q值 场地响应 谱振幅相关系数 视应力 

分 类 号：P315.727[天文地球—地震学]