2006年7月4日河北文安M_S5.1地震前震中周围地区小震视应力随时间的变化  

Temporal Changes in Apparent Stresses of Small Earthquakes around the Epicentral Area Prier to the July 4,2006 Wenan,Hebei Earthquake(M_S=5.1)

作　　者：陈学忠[1] 李艳娥[1] 

机构地区：[1]中国地震局地球物理研究所

出　　处：《中国地震》2007年第4期327-336,共10页Earthquake Research in China

基　　金：地震科学联合基金(106024);地震行业科研专项(200708023)资助

摘　　要：2006年7月4日河北文安发生MS5.1地震,震前的2001年10月始在震区附近形成了ML≥1.5地震空区,这次地震发生在该空区边缘。本文在近震源条件下,根据Brune模式,利用北京数字遥测地震台网观测到的波形资料,测定了该空区边缘发生的20次ML≥2.0地震的地震矩和地震能量,进而计算了地震视应力,分析了空区形成过程中这些地震的视应力随时间的变化。结果表明,2004年出现了明显的视应力升高过程。这说明该空区的形成伴随着应力的增强过程,可能具有预测意义。Earthquakes with ML≥1.5 circled a gap in the vicinity of the epicenter from October,2001 before the Wenan,Hebei earthquake（Ms=5.1）occurring on edge of the gap on July 4,2006.On the condition of near-source,the Brune model is employed to determine the moments and seismic energies of 20 earthquakes with ML≥2.0 occurring on the edge of the gap with seismic waveform data recorded by the Beijing Digital Seismic Network,and the apparent stresses of the 20 earthquakes are calculated.The temporal changes in the apparent stress during the formation of the gap are analyzed.The results show that there is an ascent of the apparent stress in 2004.It reflects that the formation of the gap could be accompanied by increase in the stress.

关 键 词：文安地震 空区 视应力 

分 类 号：P315[天文地球—地震学]