The Central Weather Bureau estimates that the main quake in the wee hours of September 21 has been followed by nearly 8,000 aftershocks as of September 27, with eight of these registering 6 or greater on the Richter scale. The combined force of all the tremors has exceeded that of 25 atomic bombs, thus making this the largest earthquake of the century in Taiwan.
集集大地震的威力還不僅二十一日當天的主震威力，中央氣象局估計，從二十一到二十七日，台灣全島連續六天的餘震次數近八千次，超過六級以上的強烈餘震有八次，「合起來的威力超過二十五顆原子彈」，是本世紀以來台灣所遭逢規模最大的地震。