基于PMC方法的山东省测震台网监测能力评估  

Analysis of detection capability of Shandong regional seismic network based on PMC method

作　　者：王鹏[1] 郑建常[1] 李铂[1] 

机构地区：[1]山东省地震局,济南250102

出　　处：《地球物理学进展》2016年第6期2408-2414,共7页Progress in Geophysics

基　　金：地震科技星火计划(XH15026);中国地震局震情跟踪青年课题项目(2015010106);山东省地震局重点基金项目共同资助

摘　　要：为了实现对山东区域测震台网监测能力的科学准确的评估,分析山东及邻区地震监测能力的时空分布特征,为该区的地震研究和测震台网的进一步优化布局提供科学依据.本文利用"基于概率的完整性震级"(PMC)方法,通过计算山东测震台网的117个台站对周边地震事件的检测概率、测震台网的合成检测概率以及最小完整性震级,来评估测震台网的监测能力.单台检测概率结果显示,PMC方法可客观反映117个台站对地震事件的监测能力,在距离台站较近的区域,检测概率随着震级和震中距的增大而增大,处于沂沭断裂带中南段的台站对低震级档的地震有较高的监测能力.合成检测概率结果显示,检测概率高值区域主要集中在台站密集的胶东半岛和沂沭带中南段,而靠近山东省界的鲁西和鲁北区域则监测能力较差.最小完整性震级的结果也反映了类似的规律.同时,PMC方法还可以检测不同深度对检测概率空间分布特征的影响.It is particularly important to obtain reliable and Scientific assessments of earthquake detection capability of Shandong regional seismic network,which could be used to monitor its spatial and temporal characteristics of detection capability,to provide a scientific evident for further optimizing the layout of the area＇s seismic networks and seismic studies. Due to many obvious limitations such as the priori assumptions and significant deviation to actual detection capability,the traditional methods including those based on G-R distribution are not suitable. Recently,a Probabilitybased Magnitude of Completeness（ PMC） method was proposed to address these problems（ Schorlemmer and Woessner,2008）. Here we investigate the detection capabilities and recording completeness of Shandong seismic network applying the PMC method to demonstrate its feasibility under such condition. The PMC method was used to assess the earthquake detection capability of Shandong seismic network in the period 2008 ~ 2015. We achieved probability distributions as functions of magnitude and distance for each station representing each station＇s performance during this period. Then,the detection probability for a given magnitude and probabilistic magnitude of completeness are computed by combining the single station detecting capabilities on a grid of points in the target area.The probability of detecting an event of given magnitude is the joint probability that the minimum number of triggering stations 4 have detected it. We obtain the maps of probabilistic magnitude of completeness in the period or at one moment with different depth by searching minimal magnitude that exceeds the desired detection probability. We calculated 117 stations ＇ detected capabilities of Shandong seismic network,and combined detected capability,and minimum magnitude of completeness. The result indicated that the single station detection probability can significantly increased with increasing magnitude and epicentral distance in the area closer to the stat

关 键 词：最小完整性震级 监测能力 PMC 山东测震台网 

分 类 号：P315[天文地球—地震学]