鲁西地区中小地震震源参数特征分析  

Characterization of Seismic Source Parameters of Small-and Medium-Earthquakes in Western Shandong,China

作　　者：陈亚红 廖发圣 张正帅[2] 徐芳芳[1] 申茂正 蔡璐 董春勇 CHEN Yahong;LIAO Fasheng;ZHANG Zhengshuai;XU Fangfang;SHEN Maozheng;CAI Lu;DONG Chunyong(Heze Earthquake Center Station,Shandong Earthquake Agency,Heze 430071,Shandong,China;Shandong Earthquake Agency,Jinan 250100,Shandong,China)

机构地区：[1]山东省地震局菏泽地震监测中心站,山东菏泽274000 [2]山东省地震局,山东济南250102

出　　处：《地震研究》2025年第2期341-350,共10页Journal of Seismological Research

基　　金：中国地震局监测、预报、科研三结合课题(3JH-202402033);山东省地震局合同制项目(YB2430)。

摘　　要：利用2013年1月—2023年7月山东地震台网记录到的鲁西地区的地震波形资料,基于高频截止震源模型,使用稳健的最小二乘方法拟合研究区内的震源谱,得到了236个中小地震的震源参数。结果显示:(1)地震矩M_(0)为10^(11)~10^(14)N·m,与近震震级M_(L)存在显著的正相关关系:lgM_(0)=0.956M_(L)+10.421;拐角频率为2~15 Hz,拐角频率与矩震级之间有较好的相关关系,震级越大,拐角频率越低。(2)鲁西地区地震视应力为0.01~1.630 4 MPa,平均视应力为0.30 MPa。(3)地震多发生在视应力高值区域和高、低值过渡区域,鲁西地区的视应力高值主要分布在聊考断裂带的中北段、长清断裂以西和苍山—尼山断裂带附近的微山地区,菏泽、聊城、微山地区为低b值,低b值区域与视应力高值区域分布较为接近,反映出较高的背景应力水平,表明这些区域可能是鲁西地区中强地震的潜在震源区。On the basis of the high-frequency cut-off source model,we use the robust least-squares method to fit the seismic waveform data recorded by the Shandong Seismic Networks in the period from January 2013 to July 2023 in western Shandong area,and get the source parameters of 236 small-and medium-earthquakes.The results show:The seismic moment M_(0) is distributed between 10^(11)-10^(14) N·m,and there is a positive correlation between the seismic moment and the magnitude M_(L):lgM_(0)=0.956 M_(L)+10.421.The inflection frequency is in the range of 2-15 Hz,and shows a good correlation with the moment magnitude:the larger the magnitude,and the lower the inflection frequency;②The visual stress is higher in Western Shandong area in 2017-2019,suggesting some enhancement of the stress field level in this area,and followed by a series of small-and medium-earthquakes;The spatial distribution characteristics of the visual stress show that earthquakes mostly occur in the interior and edge of the high visual stress zone,and the high visual stress is mainly distributed in the north and central parts of the Liaokao fracture zone,the Changqing rupture zone and Weishan area in western Shandong.Meanwhile,b-values are low in these areas.In the study area,the low b-value area and the high stress area is close to each other,reflecting the high seismic level.This suggests that these areas are potential medium-and strong-earthquake areas in western Shandong in future.

关 键 词：震源参数 高频截止模型 拐角频率 视应力 应力降 B值 

分 类 号：P315.33[天文地球—地震学]