论文部分内容阅读
对中国东部１４次中强地震前地震活动的中期平静特征进行了深入研究．使用了归一化的ＮＴ和ＬＴ图及地震活动统计量βｎ．βｎ等值线分布中的每一点给出了地震活动程度及其相应的持续时间和结束时间，由此可以定量确定中期平静时间段．还总结了中强地震前几种不同的地震活动方式．总的特征是主震前地震活动的速率增强，然后转为低活动速率，ＮＴ与ＬＴ曲线呈现非规则的正弦波形变化．
The mid-term seismological characteristics of 14 moderate earthquakes in eastern China were studied in depth. The normalized N-T and L-T maps and seismic activity statistics βn were used. Each point in the distribution of βn isoline gives the degree of seismic activity and its corresponding duration and end time, from which the mid-term calm period can be quantitatively determined. It also summarizes several different types of earthquakes before the strong earthquakes. The general feature is that the rate of seismic activity increases before the main shock and then to the low activity rate. The N-T and L-T curves show an irregular sinusoidal waveform.