基于克里金方法的区域震相走时标定技术研究  

A calibration study on travel times for regional seismic phases using Kriging interpolation

作　　者：苏亚军[1] 靳平[1] 潘常周[1] 肖卫国[1] 

机构地区：[1]西北核技术研究所,中国西安710613

出　　处：《地震学报》2010年第4期445-456,共12页Acta Seismologica Sinica

基　　金：军控核查技术项目(5133101)资助

摘　　要：在台网比较稀疏的情况下,台站走时标定是提高低震级事件定位、识别能力的重要手段.为了提高稀疏台网的定位精度,首先利用标定事件和IASPEI1991走时表以及中国大陆走时表,计算了初至P波和Lg波到AAK,MAKZ,NIL,TLG以及WMQ等5个台站的走时残差;接着,采用非平稳贝叶斯克里金方法和走时残差数据构造上述台站的走时校正曲面;最后,通过加入和不加入走时校正定位一系列位置准确的发生在新疆地区的地震事件评估克里金走时校正的有效性.结果表明,克里金走时校正能够较大地提高稀疏台网的定位精度,同时有效地缩小误差椭圆的面积.Calibrating travel times of seismic phases recorded at specific stations is an important means to improve event location and discriminating low-magnitude seismic events recorded by a sparse station network.In an effort to improve sparse network event location,we firstly calculate first arrival P-wave and Lg-wave travel-time residuals for the calibration events relative to the IASPEI1991 or China's Mainland velocity model at stations AAK,MAKZ,NIL,TLG and WMQ.We then use the residual data and non-stationary Bayesian Kriging approach to form continuous travel-time correction surfaces for the above mentioned stations.Lastly,the effectiveness of the Kriging interpolated travel-time correction surfaces is evaluated by locating,with and without corrections,a series of seismic events which occurred in Xinjiang Uygur Autonomous Region and have already had accurate locations.Results obtained show that the Krigged correction surfaces can improve the accuracy of event location by a sparse network and reduce the area of confidence ellipses effectively.

关 键 词：地震 定位 走时 标定 克里金 

分 类 号：P315.63[天文地球—地震学]