摘要
1993年第二季度,全球地震活动仍为中等偏低水平。1992年全球常b值A(b)值比1991年高0.1,1993年下半年地震活动将高于上半年。美洲地震带将开始下一个地震活动轮回。太平洋西北边缘带地震活动有很大增强。华北地震中期背景由5—6级提高到6级左右。全球深震活动1989年后正在逐年减少,浅源地震正在逐年增多。
During the second quarter of the year 1993, the global seismicity was still of medium level or slightly lower. The global A (b) value with constant b value in 1992 was higher by 0. 1 than that of 1991; and the seismicity in the later half of the year 1993 will be nigher than that of the first half of the year. A new cycle of seismicity will begin along the American seismic belt. The seimicity has greatly increased along the northwest marginal zone of the Pacific. The medium-term background of seismicity in North China has increased from magnitude 5— 6 to magnitude 6 or so. The global deep-focus seismicity has been reducing and that of shallow earthquakes has been increasing year after year since 1989.
出处
《国际地震动态》
1993年第11期9-12,共4页
Recent Developments in World Seismology
关键词
地震活动性
地球
globe
seismicity
Americas
the northwest of the Pacific
North China
