西北地震学报2013，Vol.35Issue(2)：385-393,9.DOI:10.3969/j.issn.1000-0844.2013.02.0385
东北地区M≥5.0地震前中等地震集中活动的震兆研究
Research on the Precursor of Moderate Earthquakes before M≥5.0 Seimic in the Northeast Region
摘要
Abstract
In this paper,three parameters(E,T,and R)were used as tools to describe the activities of moderate earthquakes defined by statistical analysis of 11 earthquakes (M≥5.0)in the northeast region of China.The results showed that seismic activity in this area had obvious regional characteristics such that intense seismic activity of ML≥4.0 earthquakes was observed prior to allM≥5.0 earthquakes in Liaoning and to the west of the Nenjiang fracture.The final moderate earthquakes prior to theM≥5.0 earthquakes generally occurred within six months.The interval average was three months; the shortest period was 0.7 month in Liaoning Province.In addition,the interval ranged from two to nine months with a four-month average west of the Nenjiang fracture.However,intensive moderate earthquake activity was not observed prior to M≥5.0 earthquakes east of the fracture.The probability of the expected M≥5.0 earthquake occurring in the area of Yingkou-Haicheng-Xiuyan was more than 75％,which was accompanied by enhanced moderate earthquake intensity.If a foreshock sequence existed,its epicenter was located in the scope of 22 km near the larger earthquake.Essentially,the epicenter of M≥5.0 earthquake occurring to the west of the Nenjiang fracture was located in the vicinity of the initial or latest moderate earthquake area,at a distance of 11～67 km.Therefore,the ETR method has some significance in determining the epicenter of nextM≥5.0 earthquake after the occurrence of moderate seismic activity.关键词
东北地区/震兆/嫩江断裂/中等地震/集中活动Key words
The northeast region of China/ Precursor/ Nenjiang fracture/ Moderate earthquake/ Activity of concentration分类
天文与地球科学引用本文复制引用
曹凤娟,焦明若,王亮,王岩,李彤霞..东北地区M≥5.0地震前中等地震集中活动的震兆研究[J].西北地震学报,2013,35(2):385-393,9.基金项目
辽宁省地震局重点实验室项目(LZD1102) （LZD1102）
