1994年全球地震活动综述

OVERVIEW OF THE GLOBAL SEISMICITY IN 1994

１９９４年全球地震活动属于高水平，有４次大深震和４次浅源大地震。全球全年共发生６级以上地震１３４次，超过１９９３年。全球地震活动中心仍在太平洋西北边缘地震带。１０月４日的千岛群岛地震是最大的浅源地震；６月９日的玻利维亚地震是最大的深源地震。１９９４年全球地震活动开始转折，揭开强烈活动期的序幕。各大地震带的Ａ（ｂ）值几乎按同一比例上升，显示全球地震整体性增强。全球地震Ａ（ｂ）值在６月和１０月有两次高峰。中国大陆地震活动比去年有回升，Ａ（ｂ）值由７．１７升至７．２１，１９９５年呈继续上升的趋势。

The global seismicity during the year 1994 was of high level,with 4 large deep earthquakesand 4 large shallow earthquakes taking place. There were 134 earthquakes of magnitude over 6 oc-curring in the world in 1994,exceeding the total number of 1993.The global seismicity was stillconcentrated along the northwest marginal seismic belt of the Pacific.The Kurile lsland earth-quake occurring on October 4 was the largest shallow-focus earthquake,and the Bolivian earth-quake occurring on June 9 was the largest deep-focus earthquake. The activation of the globalseismicity in 1994 seemed to unveil the prelude of strong seismic activities in the world.TheA(b) values in different large seismic belts almost increased in the same proportion,indicatingseismicity increases of the entire globe. There were two peak-value periods for the A(b)values re-spectively in June and October. The seismicity in the Chinese mainland seemed to increase com-pared to that of the previous year,with the A(b)value of 7.17 increasing to 7.21;and the generaltendency of seismicity continues to be lncreasing in 1995.