用数字化地震波形资料分析云南及邻区环境剪应力场
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摘要
利用昆明数字化地震台网记录的数字化地震波形资料,测算了云南及邻区2002年到2004年8月2 513个中小地震的剪应力值0τ和矩震级值MW,分析了它们之间的相关关系。研究表明,地震剪应力值与地震大小存在线性依赖关系,地震越大,环境剪应力场越强,强震的发生需要较强的剪应力场环境。小地震在较弱的环境剪应力场状态下也可以发生,随机性较强。在环境剪应力场较强的地方,会发生强震,也会发生数量众多的中小地震。而在环境剪应力场较弱的地方,往往只会发生中小震。统计分析表明,通常,中小地震的0τ<10 MPa,将0τ≥10 MPa的地震视为高剪应力值地震,高剪应力值地震集中分布的区域,或应力等值线大于10 MPa的分布区即为高应力值区,高剪应力值分布区是环境剪应力场的异常分布区,它的形成和分布往往与强震的发生有关。据此,对云南省环境剪应力场动态变化及其与地震活动的关系作了分析研究。
In order to study the relation between the environment shear stress field change and seismic activity in the Yunnan area,we calculated the shear stress value τ_0 and moment magnitude value M_W of(2513) moderate-small earthquakes on the basis of the waveform data recorded by Kunming Regional Digital Seismic Network,and found there exists linear correlation between environment shear stress value and the size of an earthquake,namely,the bigger the shock is,the stronger the environment shear stress is.In the places with strong environment shear stress,it is possible to occur a strong earthquake or lots of moderate or small earthquakes;however,in the places with weak environment shear stress,it is possible just to occur moderate or small earthquakes.The statistical analysis shows that,usually,τ_0 <10 MPa for moderate-small earthquakes,while the occurrence of the strong earthquake is often relative to the forming and distribution of high shear stress value areas,i.e.,the areas concentrated by high shear stress value earthquakes(τ_0 ≥10 MPa) or with the stress isolines more than 10 MPa.
In order to study the relation between the environment shear stress field change and seismic activity in the Yunnan area,we calculated the shear stress value τ_0 and moment magnitude value M_W of(2513) moderate-small earthquakes on the basis of the waveform data recorded by Kunming Regional Digital Seismic Network,and found there exists linear correlation between environment shear stress value and the size of an earthquake,namely,the bigger the shock is,the stronger the environment shear stress is.In the places with strong environment shear stress,it is possible to occur a strong earthquake or lots of moderate or small earthquakes;however,in the places with weak environment shear stress,it is possible just to occur moderate or small earthquakes.The statistical analysis shows that,usually,τ_0 <10 MPa for moderate-small earthquakes,while the occurrence of the strong earthquake is often relative to the forming and distribution of high shear stress value areas,i.e.,the areas concentrated by high shear stress value earthquakes(τ_0 ≥10 MPa) or with the stress isolines more than 10 MPa.
引文
[1]陈培善,白彤霞,肖磊.根据环境应力场寻找中国大陆地区的潜在震源区[J].地震学报,1995,17(3):294-304.
[2]陈培善,肖磊,白彤霞,等.美国南加州的构造环境应力场和地震危险区[J].地震学报,1998,20(2):128-136.
[3]陈培善,谷继成,李文香.从断裂力学观点研究地震的破裂过程和地震预报[J].地球物理学报,1977,20(3):185-201.
[4]陈培善,卓玉茹,金严,等.唐山地震前后京津唐张地区的应力场[J].地球物理学报.1978,21(1):34-58.
[5]陈培善.分析地震波估算地壳内的应力值[J].地震学报.1981,3(3):251-263.
[6]陈培善,肖磊,白彤霞,等.唐山地震序列的环境应力场[J].地震学报,1994,16(4):440-447.
[7]陈培善,Duda S J.峰值速度和加速度对环境剪应力的依赖性[J].地球物理学报,1993,36(2):185-194.
[8]陈培善,荣玉仿,白彤霞.断裂力学地震破裂模式和应力降模式的比较及其应用[J].地球物理学报,2002,45(Supp.):175-188.
[9]王绍晋,张俊伟,王,等.云南及邻区环境剪应力场时间分布与强震活动[J].地震研究,2004,27(2):165-172.
[2]陈培善,肖磊,白彤霞,等.美国南加州的构造环境应力场和地震危险区[J].地震学报,1998,20(2):128-136.
[3]陈培善,谷继成,李文香.从断裂力学观点研究地震的破裂过程和地震预报[J].地球物理学报,1977,20(3):185-201.
[4]陈培善,卓玉茹,金严,等.唐山地震前后京津唐张地区的应力场[J].地球物理学报.1978,21(1):34-58.
[5]陈培善.分析地震波估算地壳内的应力值[J].地震学报.1981,3(3):251-263.
[6]陈培善,肖磊,白彤霞,等.唐山地震序列的环境应力场[J].地震学报,1994,16(4):440-447.
[7]陈培善,Duda S J.峰值速度和加速度对环境剪应力的依赖性[J].地球物理学报,1993,36(2):185-194.
[8]陈培善,荣玉仿,白彤霞.断裂力学地震破裂模式和应力降模式的比较及其应用[J].地球物理学报,2002,45(Supp.):175-188.
[9]王绍晋,张俊伟,王,等.云南及邻区环境剪应力场时间分布与强震活动[J].地震研究,2004,27(2):165-172.
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