利用重力资料检测日本9.0级地震激发的地球自由振荡  

Detecting the Free Oscillations of the Earth Excited by the Japan M9.0 Earthquake Using Gravity Observation Data

作　　者：姚家骏[1] 万永革[2] 王培玲[1] 屠泓为[1] 马震[1] 

机构地区：[1]青海省地震局,青海西宁810001 [2]中国地震局地球物理研究所,北京100081

出　　处：《地震研究》2012年第1期53-58,157,共6页Journal of Seismological Research

基　　金：地震科技星火计划项目(XH12051Y);青海省地震科学基金(2010A04)联合资助

摘　　要：利用格尔木基准地震台重力观测资料,检测到2011年3月11日日本东海岸9.0级特大地震激发0S0～0S40之间的球型自由振荡,其中有0S0、0S13、0S22、0S26、0S30共5个振型的观测频率值与理论频率值偏差近似为0。同时发现0S2、0S3振型有明显的谱线分裂现象,但是0S32、0S37振型未与周围噪音区分开,观测效果不明显。整体平均偏差约为0.10%,观测频率值与理论频率值有很好的相符,这不但说明了PREM模型理论的正确性,也说明了格尔木基准地震台重力资料质量的优良,研究结果对了解地球内部结构有一定的帮助。By use of the gravity digital observation data recorded at Golmud Reference Seismological Station,we detect the spherical free oscillation between the mode of 0S0 and 0S40 stimulated by the M9.0 earthquake occurred on March 11,2011 in Japan.The difference between the theoretical and the observed frequency values of the mode of 0S0、 0S13、 0S22、 0S26、 0S30 is almost zero.Meanwhile,we find that the mode of 0S2 and 0S3 have the phenomenon of spectra line splitting.But it is difficult to identify the mode of 0S32 and 0S37,because they are drowned in the noises.The whole mean deviation is about 0.10%,which shows that there is a good agreement between observed and theoretical frequency values.The results not only suggest the validity of the theory of Preliminary Reference Earth Model,but also show the excellent of gravity data recorded at Golmud Reference Seismological Station,so it maybe helpful to understand the structure in deep earth.

关 键 词：地球自由振荡 重力观测数据 日本9.0级地震 格尔木基准地震台 

分 类 号：P315.7[天文地球—地震学]