邵武—河源断裂带地震活动特征分析

Analysis on the Characteristics of Seismicity in the Shaowu-Heyuan Fault Zone

根据中国地震台网正式目录结果,通过对1970年以来邵武—河源断裂带地震活动特征分析后认为:NNE向的邵武—河源断裂带与其南段的次一级NW向河源—海丰断裂带相互交汇,与其中段的次一级EW向全南—寻乌断裂带相互交汇,多组断裂的交汇处容易积累应力,造成中强以上地震反复发生;在邵武—河源断裂带上所发生的地震活动具有主-余震型(或震群型)特点;在邵武—河源断裂带上的M≥4.0及以上地震主要发生在该断裂带南段与次一级NW向河源—海丰断裂交汇处的附近地区,且该断裂带地震活动空间分布明显呈现南段地震活动性强、中段地震活动性较弱和北段地震活动性最弱的特征。

Based on analysis of the seismicity of the Shaowu-Heyuan fault zone since 1970,we suggest that this NNE-trending fault zone intersects with the secondary NW-trending Heyuan-Haifeng fault zone in the south.Moreover,the fault zone intersects with the secondary EW-trending Quannan-Xunwu fault zone in the middle.The aforementioned fault intersections indicate a potential seismic risk area for repeated moderate and strong earthquakes.The seismicity in the Shaowu-Heyuan fault zone shows the characteristics of a main-aftershock type(or an earthquake swarm type).Earthquakes with magnitude M≥4.0 in the Shaowu-Heyuan fault zone mainly occurred near the intersections of the two sections.The spatial distribution of the seismicity in the fault zone is obvious,which shows the characteristics of strong seismicity along the southern section,whereas seismicity along the middle and northern sections decreases gradually.