昌平北大200号台Sacks体应变干扰分析与震例研究  

ANALYSIS OF INTERFERENCE AND EARTHQUAKE CASES FOR SACKS BODY STRAIN IN CHANGPING NO.200 STATION

作　　者：吴利军[1] 胡澜 戴娅琼[1] 鲍玉静 徐磊[4] 冯琼松 

机构地区：[1]中国地震局地震预测研究所,北京100036 [2]湖南省地震局邵阳地震台,湖南邵阳422000 [3]河北省地震局,河北石家庄050021 [4]山东省地震局无棣大山地震台,山东滨州251910 [5]云南省地震局昆明地震台,云南昆明650204

出　　处：《内陆地震》2015年第3期203-212,共10页Inland Earthquake

基　　金：中国地震局监测;预测;科研三结合课题:Sacks体应变临震异常的震例统计研究(154201);地震预测研究所基本科研业务专项(2012IES010202)

摘　　要：对昌平北大200号台Sacks体应变观测值与固体潮、气压、水位关系进行了初步分析,并在干扰分析的基础上对2008年5月12日四川汶川8.0级地震前体应变观测资料进行了震例研究。震前该台体应变观测到的短临异常可靠,异常特征:①汶川地震前体应变记录到1年尺度的趋势异常,表现为拉张性变化,累计量约4 000×10^(-9),与之配套的是临震前兆异常也表现为拉张型的突变;②在2008年3月1日~5月7日体应变记录到了拉张型的间断突变异常;③在2008年4月13日~5月11日记录到间断的形态畸变,其中有4次之后出现压性突变;④在2008年5月1~3日、5、7、9~12日的畸变过程中出现高频成分增多的现象,通过小波分析,发现是震前慢地震引起的。分析结果表明,在对气压、水位等于扰因素分析的基础上,体应变观测出现应变固体潮畸变,并在畸变过程中连续多次出现张性压性突变、高频成分增多等异常现象可作为地震短临预测的指标。The relationship among Sacks body strain tidal solid, atmospheric pressure, and water level at Beida station in Changping were analyzed in this paper. Sacks body strain before Wenchuan earthquake with Ms8.0 was studied based on the interface analysis. The short-ferm anomaly of body strain was considered to be reliable. The Anomaly characteristics included： （1） the trend anomaly as tension change of the body strain deformations for one year scale before Wenchuan earthquake was recorded, and the accumulative amount was about 4 000 ~ 10-9 Besides, the short-term precursor of earthquake was also tension mutations; （2） the intermittent mutation anomaly as tension change of the bodv strain deformations from March 1st to May 7th, 2008 was recorded; （3） four pressure mutations were recorded in shape distortion discontinuity from April 13th to May 1 lth; （4） high fre- quency components were increased in distortion process on May 1st to 3rd ,5th ,7th,9th to 12th. It was caused by slow earthquake before Wenchuan earthquake through wavelet analysis. The abnormal phenomena were summarized and the mechanics were discussed in this paper. Strain tidal solid dis- tortion in body strain deformations, anomalies of continuous repeated tension pressure, mutation, and high frequency components increasing can be regarded as the index of short term and impending earthquake prediction, based on analysis of pressure, water level and other interference factors.

关 键 词：体应变 固体潮畸变 慢地震 短临异常 

分 类 号：P315.7[天文地球—地震学]