1997年全球地震活动综述

OVERVIEW OF THE GLOBAL SEISMICITY IN 1997

１９９７年全球地震活动继续呈下降趋势。全年共发生６级以上地震９５次，有３次大地震。本年度６级以上浅源地震频数显著减少，全年只有７６次，ｂ值为０．７０，为１９６４年以来的最低值。本年度亚欧带地震在全球的比重显著增加。中国大陆地震约比全球活动滞后两年。目前全球仍处于地震高活动期中，５年内有可能出现第二个峰值。

The global seismicity during the year 1997 remained decreasing. Altogether there were 95 earthquakes of M ≥6 occurring in the world in 1997, including 3 large earthquakes. In 1997, the frequency of shallow focus earthquakes decreased significantly; altogether there were only 76 shallow earthquakes with the b value of 0 7,the lowest value since 1964.The proportion of the seismicity of Eurasian seismic belt notably increased in the global seismicity. The variation of seismicity in the Chinese mainland occurred two years later than that of the global seismicity. Now,the whole world is still in the period of high seismicity,the second peak value may probably come within five years.