1966年邢台Ms7．2级地震的前震序列分析
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摘要
断层或裂纹在其失稳破裂之前都要经历准静态的加速扩展过程。加速是失稳的一个必要条件。加速释放是成核在脆性层中的大地震的普遍前兆。且可将该加速过程简要地概括为地震释放速率比例于失稳破裂前剩余时间的负幂。基于这一原理，对１９６６年３月２２日河北邢台Ｍｓ７．２级地震的前震序列进行了回顾性分析，表明序列中大的前震，特别是主震，其失稳破裂时间和震级可成功地被估算，但要求所测系数ｒ２这极大。在主震时间的估算中，使其处于发展中的序列，所得误差可小于所用最后一个数据点与主震之间剩余时间的一半或更少。
Fault or crack must all undergo a quasistatic accelerating extension process before the instability occurs. The acceleration is a necessary condition of instability. The accelerating release is an universal precursory of a great earthquake which nucleates within the brittle seismogenic layer. This acceleratig process can be summarized briefly as the cumulative seismic releasing rate to be proportional to the inverse power of the remaining time to failure. Based on this principle, the foreShock' sequences of the Xingtai Ms 7. 2 earthquake, Hebei Province, on March 22 in 1966 are analysed. It is shown clearly that the time-to-failure and magnitudes of the large foreshocks in the sequence, especially the main shock , can be predicted successfully by linearized regression, but the maximum coefficient r must be obtained . In the estimates of main-shock time, making it in the developing sequences, the errors can be less than one-half the time remaining between the time of the last data point used and the main shock or far less.
Fault or crack must all undergo a quasistatic accelerating extension process before the instability occurs. The acceleration is a necessary condition of instability. The accelerating release is an universal precursory of a great earthquake which nucleates within the brittle seismogenic layer. This acceleratig process can be summarized briefly as the cumulative seismic releasing rate to be proportional to the inverse power of the remaining time to failure. Based on this principle, the foreShock' sequences of the Xingtai Ms 7. 2 earthquake, Hebei Province, on March 22 in 1966 are analysed. It is shown clearly that the time-to-failure and magnitudes of the large foreshocks in the sequence, especially the main shock , can be predicted successfully by linearized regression, but the maximum coefficient r must be obtained . In the estimates of main-shock time, making it in the developing sequences, the errors can be less than one-half the time remaining between the time of the last data point used and the main shock or far less.
引文
1Raleigh，B，G．Bennett，H．Craig，T．Hanks，P．Molnar，A．Nur’J．Savage，C．Scholz，R．TurnerandF．Wu，PredictionoftheHaichengearthquake，Eos，Trans．Am．Geophys．Un，1977，58，PP．256—272．2Jones，L．M，andP．Molnar，Somcharacteristicsofforeshockandtheirpossiblerelationshiptoearthquakepredic－tionandPrenonitorysliPonfaults，J．Geophys．Res．，1979，84，PP．3596—3608；3刘正荣．地震频度衰减与地震预报的再研究．地震预报方法实用化研究文集．地震学专辑．北京：学术书刊出版社．1989．194—2034Papadopoulos，G．A，Long—termacceleratingforeshockactivitymayindicatetheoccurrencetimeofstrongshockintheWesternHellenicarc，Tectono—physics，1988，152，PP．179—192；5大中康誉．1992，在物理定律基础上建立预报理论的方案，彭岩译自《日本东京大学地震研究所汇编特集》，国际地震动态，1994．（1）26—286ChenY．T，＆L．Knopoff，Simulationofearthquakesequences，Geophys．J．R．astr．Soc，1987，91，PP．693—709；7Yamashita，T，andL．Knopoff，Amodelofforeshockoccurrence，Geophys．J，1989，96，PP．389—399；8Saito，M．，Forecastingtimeofslopefailurebytertiarycreep，Proc．7thInternat．Conf．onSoilMechanicsandFoundationEngineering，1969，2，PP．677—6839Atkinson，B．K，，Subcriticalcrackgrowthingeologicalmaterials，J．Geophys．Res．，1984，89，PP．4077—411410Das，S，andC．H．Scholz，Theoryoftime—dependentruptureintheEarth，J．Geophys．Res，1981，86，PP．6039—605111LEchie，F．A，andD．R．Hayhurst，Constitutiveequationforcreeprupture，ActaMetall．，1977，25，pp．1059—107712河北省地震局．邢台地震目录（196年7月—1975年12月）．北京；地震出版社，1976．13ChenPelshanandChenHaitong，ScalinglawandItsapplicationstoearthquatkestatisticalrelations，Tectono－physics，1989，166，pp．53—7214左兆荣，吴建平，巫志玲．地幔波震级的规范化标定与观测．地球物理学报，1993，36（5）：621—63215Bennioff，H，Earthquakeandrockcreep．Part1：Creepcharacteristicsofrockandtheoriginofafershocks．Bull．Seismol．Soc．Am，1951，41，1，PP．31—6216尹样础，郑天愉．地震孕育过程的流变模式．中国科学，1982，10：922—93017Yamasbita，T，andL．Knopoff，Modelofaftershockoccurrence，Geophys．J．R．astr．Soc，91，PP．13—2618Dieterich，J，Amodelforthenucleationofearthquakeslip，inS．Das，J．BoatwrightandC．H．Scholz（cditors），Earthquakesourcemechanics．Am．Geophys．Union．Geophys．Monogr．，37，PP．37—4719Stuart，W．D，andG．M．Mavko，Earthquakeinstabilityonastrlk—slipfualt，J．Geophys．Res，1979，84，No．BS，PP．2155—2160
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