摘要
对于青藏块体中北部1970~2003年间震前弱震记录情况较好的5级以上地震,通过4个基本不相关的参数———地震时间集中度参数Ct、地震空间集中度参数Cd、η值和弱震频次等刻画震前地震的时空集中分布特征以及地震活动的增强与异常平静。通过对计算结果的分析研究,得到青藏块体中北部5级以上地震前,弱震活动的频次往往会出现升高或降低,强度也往往会出现明显增强,并经常会伴随着随时、空集中分布的现象。
For earthquakes with M ≥ 5.0 occurred in middle northern part of the Qinghai-Tibet Block from 1970 ~ 1973 before which weak earthquakes were recorded well, through 4 parameters which are basically not correlated——earthquake time centralization degree parameter C1 value, earthquake space centralization degree parameter Cd value, η value and weak earthquke frequency to describe the time, space centralization distribution features of weak earthquakes and the strength and anomalous quiescence of seismic activity before main shocks. It has been obtained that before earthquakes with M ≥ 5.0 occurred in middle northern part of the Qinghai-Tibet Block, the frequency of weak earthquakes otten shows ascent and drop. The strength often shows obvious enhancement and the centralization distribution as time and space is often accompanying.
出处
《中国地震》
CSCD
北大核心
2005年第3期378-385,共8页
Earthquake Research in China
基金
国家"十五"科技攻关计划(2001BA601B010304)
关键词
青藏块体中北部
弱震活动
统计研究
The middle northerm part of the Qinghai-Tibet Block Weak earthquake activity Statistical study