地震活动期、幕最大地震M1的估计及中-长期地震趋势预测

摘要

This paper proposed one method, which uses the linear relation between the mid-dle-low magnitude and cumulative frequency to obtain the linear relation between magnitudeand interval frequency. The maximum earthquake magnitude M1 can be calculated by using thelinear relation between magnitude and interval frequency. The calculation results show that:by using the linear relation between magnitude and interval frequency, the estimated maximumearthquake magnitude M1 is closer to the observed maximum earthquake magnitude in one seis-mic period or episode than that estimated by using the relation between magnitude and cumula-tive frequency. The later one is often overestimated. The evolutional characteristics of the rela-tion curve between magnitude and cumulative frequency, and the estimated maximum earth-quake magnitude M1 by using the linear relation between magnitude and interval frequency cangive the new information in the medium-long term earthquake trend prediction for one seismicperiod or episode. The investigation shows that the seismic episode started from 1979 in Chinais coming to the end, a seismic ally quiet period is close to the end in the area of the North-Eastern side of Pamirs.%提出一种地震活动期、幕最大地震M1的估计方法：利用中低震级累计频度∑N与震级近似的直线关系得到间隔地震频度N与震级的线性关系。用间隔频度N与震级的线性关系估计最大地震M1。结果表明，以震级-间隔频度的线性关系估计的M1比震级-累计频度关系得到的M1更接近实际发生的最大地震震级，震级-累计频度关系得到的M1通常被高估。基于震级-累计频度关系曲线的特征和震级-间隔频度的线性关系估计的最大地震M1，可为中-长期地震趋势预测提供新的信息。研究表明，中国大陆自1979年开始的地震幕即将结束，而帕米尔东北侧自1915年以来的地震平静期也将结束。