基于PMC方法的上海测震台网地震监测能力评估

Evaluation of seismic monitoring capacity of Shanghai Seismic Network based on PMC method

采用基于概率的完整性震级(PMC)方法,选取上海测震台网13个地震台站及周边省市地震台2008—2019年记录的171个地震,计算各地震台及上海测震台网地震监测能力,并模拟增加新的地震台站后台网监测能力的变化。结果显示:①地表基岩台的监测能力较深井台强,且受噪声和地铁影响,市区深井台监测能力较低;②整体上,台站密布的松江和青浦地区,地震监测能力较强,最小完整性震级为ML 0.7。台站稀疏的浦东、奉贤、崇明地区,地震监测能力较弱,最小完整性震级为ML 1.3;③若在上海南部增设奉贤海湾台,可整体提高上海测震台网的监测能力。

We use 171 earthquakes recorded by 13 seismic stations of the Shanghai seismic network and seismic stations in the surrounding area from 2008 to 2019 to evaluate the monitoring capacity of the stations based on the Probability-based Magnitude of Completeness(PMC)method and study the changes in monitoring capacity if new stations were built.The result shows that surface bedrock stations have better monitoring ability than deep well stations and the downtown deep well stations have bad monitoring ability because of noises and subways.On the whole aspect,Songjiang and Qingpu regions where seismic stations are dense have higher monitoring capacity with the Mc of ML 0.7;while Pudong,Fengxian,and Chongming regions have lower monitoring capacity with the Mc of ML 1.3.If we build Fengxian gulf station in the south,the whole monitoring capacity of the Shanghai Seismic Network will enhance.