摘要
利用b值时空扫描法分析陕甘宁交界区域未来发震趋势,通过对研究区内ML5.0级以上地震进行震例回溯,结果显示有56%的中强地震发生在低b值区域及其边缘,低b值异常对研究区中强震的发震区域有一定的指示意义。从b值空间分布图中选取4个b值低异常区域进行b值时间扫描,发现海原断裂带及其附近区域中强震的发震与b值下降时间对应较好,六盘山断裂带南段和陇县—宝鸡断裂带北段区域b值几年来一直处于下降状态,对断裂带闭锁特征和地震空区等进行综合分析,认为未来海原断裂带及其附近区域需注意b值下降后发生中强震的风险,六盘山断裂带南段和陇县—宝鸡断裂带北段及其附近区域未来有发生强震的可能。最后分析了矿震、余震和最小完整性震级(Mc)对b值计算结果的影响。
The b-value temporal and spatial scanning method is applied to the Shaanxi-Gansu-Ningxia border area to analyze the risk of future seismic trends.By tracing the earthquake cases of M_L5.0 or above in the study area,the results show that that 56%of the moderate earthquakes occur in the region with low b-value and its edge.The low b-value anomaly area has certain indicative significance for the seismogenic region of moderate and strong earthquakes.Four anomaly areas with low b-values are selected from the b-value spatial distribution map for time scanning.It was found that occurrence of moderate and strong earthquakes in the Haiyuan Fault zone and its adjacent areas has a relatively good correspondence with the time of b-value decrease,and the b-value of the southern section of the Liupanshan fault zone and the northern section of the Longxian-Baoji fault zone has been declining for several years.Combining the characteristics of locked fault zones and seismic gap from other researchers'studies,it is concluded that the Haiyuan fault zone and its surrounding areas should be vigilant for the risk of moderate to strong earthquakes due to a decrease in the b-value in the future,and strong earthquakes may occur in the southern section of the Liupanshan fault zone and the northern section of the Longxian-Baoji fault zone and their surrounding areas in the future.Finally,the effects of mine earthquake,aftershock and minimum integrity magnitude(Mc)on the results of b-value calculation are analyzed.
作者
李远林
赵韬
冯亮亮
张高强
LI Yuanlin;ZHAO Tao;FENG Liangliang;ZHANG Gaoqiang(Baoji Earthquake Agency,Baoji 721004,China;Shaanxi Earthquake Agency,Xi'an 710068,China)
出处
《高原地震》
2024年第3期24-35,共12页
Plateau Earthquake Research
基金
2023年度陕西省地震局启航与创新基金“陕甘宁区域b值时空变化特征分析”(项目编号:QC-202310)资助。
关键词
陕甘宁交界区域
b值时空扫描
b值影响因素
矿震
最小完整性震级(Mc)
Shaanxi-Gansu-Ningxia border area
The b-value spatio-temporal scanning
Influencing factors of b-value
Mine earthquake
Minimum integrity magnitude(Mc)
作者简介
李远林(1996-),女,河南洛阳人,硕士研究生,助理工程师,主要从事地震监测工作。E-mail:1191462480@qq.com。
