利用直达P波测定地方震震源深度的探讨  

Discussion on the measurement of the depth of local earthquake sources using direct P-wave

作　　者：王登伟 

机构地区：[1]西昌地震中心站,中国四川615022

出　　处：《地震地磁观测与研究》2010年第5期45-48,共4页Seismological and Geomagnetic Observation and Research

基　　金：国家自然科学基金资助项目(40872209);地壳所中央公益性基本科研业务专项基金支持项目(ZDJ2007-4);地震数据整理加工课题资助

摘　　要：震源深度是地震时空参数中的基本参数,是目前最难测准的参数之一。可以使用直达P波测定震源深度。要确保测定结果的精度,必须加密台网观测点,使台间距的大小与震源深度相当。利用四川省西昌和冕宁大桥水库两个遥测地震台网的直达P波资料,测定发生在其监控区域内137个地震的震源深度。结果发现,该区域地震的平均深度和深度下限存在随震级增大而增加的现象。其中有部分地震的震源深度,利用本研究方法测定的结果与使用遥测地震台网计算机定位程序输出的结果相差较大。作者认为,这部分地震使用计算机定位程序得出的震源深度有较大的误差。Focal depth of earthquakes is one basic parameter of the special-temporal parameters that is hard to measure precisely. One measurement method is using the direct P-wave arrival The accuracy of measurement, however, is depended on the epicenter of the nearest station, which should be equal to or near the focal depth. In this paper, using the direct P-wave arri- val data from two remote sensing seismic networks located in Xichang and in Daqiao reser- voir, Mianning, Sichuan Province, the focal depths of 137 earthquakes in the monitoring are- a are determined. It was found that the average and low limit of focal depths of regional earthquakes increase with the magnitudes of the earthquakes. Among all the focal depths, some depths determined by the method presented here are much different with that obtained from the automatic computer location software. We consider that the depths of this part of earthquakes given by computer location program are with large error.

关 键 词：震源深度 台间距 直达波 震源深度下限 

分 类 号：P315.33[天文地球—地震学]