信宜-廉江断裂地震活动状态分析  

Analysis on Stress State in Xinyi-Lianjiang Fault Area

作　　者：黄元敏[1] 杜龙 邵叶[1] 王振亚 

机构地区：[1]广东省地震局,广州510070 [2]中核工程有限公司 [3]湛江市地震局,广东湛江524043

出　　处：《华南地震》2016年第4期14-19,共6页South China Journal of Seismology

基　　金：中国地震局"2016年度震情跟踪定向工作任务"(2016010111);湛江市地震局"粤桂琼交界地区未来5年地震趋势及对策研究"项目资助

摘　　要：利用1972年1月1日至2016年3月31日粤桂交界地区地震台网记录的地震资料,获得了信宜-廉江断裂带及附近区域b值、a值和T_L值等多个地震活动性参数的空间分布图像,讨论了断裂带的应力状态。研究结果表明:信宜-廉江断裂带地震活动性参数分布具有明显的空间差异性。断裂带西南端的北部湾海域段落具有低b值、低a值和最短的复发间隔T_L值的参数组合特征,表明该段落已处于高应力闭锁状态,具有发生中强地震的应力条件。信宜-廉江断裂带中部与遂溪断裂带交汇的区域应力水平和闭锁程度低于北部湾地区,但需要关注遂溪断裂带上中强地震对该断裂带的应力触发作用。高州水库区域小地震活跃,应力释放以小震持续活动为主。Using the seismic data recorded by the Guangdong and Guangxi regional seismic network from January 1st, 1972 to March 31st, 2016, the paper obtained the spatial distribution of several seismicity parameters （including a and b values in the frequency-magnitude relationship, and the local recurrence intervals TL） in Xinyi-Lianjiang fault and its surrounding area to discuss the stress state in the fault. The results show that： the spatial distribution of several seismieity parameters was significantly heterogeneous in the fault area. The Beibu Gulf area in the southwest section of the fault had the characteristic of the low b-value, low a- value, and the shortest recurrence intervals TL. All these implied that this section of the fault might have been locked under the high stress and more likely to generate moderate-strong earthquakes. The stress state and the degree of locking in the central section of fault, where it is the intersection of Xinyi-Lianjiang fault and Suixi fault, were lower than Beibu Gulf section. Because it was the intersection of two faults, the stress tiggering on Xinyi-Lianjiang fault from the moderate-strong earthquakes in Suixi fault could not be ignored. There were a lot of small earthquake in Gaozhou reservoir area, and its stress release was mainly based on the small earthquake activity.

关 键 词：地震活动性参数 信宜-廉江断裂带 应力状态 闭锁 

分 类 号：P315.5[天文地球—地震学]