摘要
本文对我国东部十几次中强震前地震活动的中期和短期(短临)平静特征进行了深入的研究。对中期平静,使用了归一化的N—t和L—t图,及地震活动统计量β_n,由此定量确定中期平静的时间段。对短期平静,使用了归一化的N—t和L—t曲线,并结合主震前小震活动集中分布确定短期(短临)平静及未来主震的可能位置,根据研究区域内发生的标志地震震级估计未来主震的震级。本文还总结了中强震前几种不同的地震活动方式,但总的特征是震前地震活动的速率增强然后转为低活动速率,其N—t与L—t,曲线呈现非规则的正弦波形变化。
In this paper the characteristics of the mediam and short-term seismic quiescen-ces before 14 moderate and strong earthquakes in the eastern China are further studied . For the mediam-term quiescence, the nomalized N-T and L-T curves are used, and also the statistical parameters βn values are adopted. Based on this the time interval of mediam-term quiescence is quantitatively determined . For the short-term quiescence, the authors use the nomalized N-T and L-T curves and the concen-trative distribution of small earthquakes before the mainshock to determine the short-term quiescence and the possible location of the forthcoming earthquakes. The magnitude of the forthcoming mainshock may be estimated by the magnitude of ' signal earthquake' occurred in the discussed region. This paper summarized several seismic activity patterns befor moderate and strong earthquakes, the general feature is the change in seismicity from the incremental rate to the lowering rate before moderate and strong earthquakes, and their N-T and L-T curves exhibit irregular variation of sine waves.
出处
《地震》
CSCD
北大核心
1994年第1期48-56,共9页
Earthquake
关键词
地震预报
短期预报
地震活动性
seismic quiescence
statistical parameter of seismicity
concentrative dis- tribution of small eqrthquakes
