摘要
2010年6月28日至8月15日，在广西凌云与凤山交界持续发生了高密集、高集中、高频率的震群活动，共记录地震3071次，其中ML 2~2.9级地震41次，3级以上地震3次，最大为7月1日10时27分3.2级地震。对此次震群的空间分布范围、2级以上地震震源机制解P轴优势方向、 b值特征、应力降等进行了分析研究。结果表明，此次震群震中集中，深度较浅，震源机制解P轴没有形成优势分布，序列参数b值较高，约为1.21，应力降主要分布在0.19~2.0 Mpa之间，认为广西凌云-凤山交界3级震群是属于低应力背景下的地震活动，不具有前兆震群和前震序列的性质。分析结果对正确了解此次震群的特征、正确判断地震趋势具有一定的帮助作用。
From June 28 to April 15 2010, high density, high concentrate, high frequency earthquake swarm occurred in the boundary area of Lingyun and Fengshan in Guangxi, 3 071 earthquakes were recorded, among of them, 41 events with 2.0 ≤ML≤2.9, 3 events with ML≥3.0, the maximum event with ML3.2 occurred in 1st July. The paper analyses the space boundary of earthquake swarm, P axis edge direction of earthquake focus mechanism of events with ML≥2.0, b value characteristic, stress drop. The results show that： the epicenter of earthquake swarm are concentration; the depth is very shallow; earthquake focus mechanism of P axis position haven＆#39;t the predominance distribution; b value is very high, which is about 1.21; stress drop value is mainly distributed between 0.19-2.0 Mpa. We found that M 3.0 earthquake swarm occurred in low stress level in the boundary area of Lingyun and Fengshan, the earthquake swarm don＆#39;t have the precursory earthquake swarm and the foreshock sequence. These results have some helpful for a proper understanding of the characteristics of the earthquake swarm, and the right judging of the earthquake trend.
出处
《华南地震》
2014年第1期11-20,共10页
South China Journal of Seismology
基金
广西科学研究与技术开发计划项目(桂科攻1140004-2)
广西科学研究与技术开发计划项目(桂科攻10123012-21)课题资助
关键词
震群
震源机制解
应力降
震源深度
广西凌云-凤山
Earthquake swarm
Focal mechanism solutions
Stress drop
Focal depth
Lingyun and Feng shan in Guangxi
