"Foreshock" and "aftershock" are relative terms.

答：“前震”和“余震”是两个相关的术语。

The earthquake sequence is foreshock-mainshock-aftershock.

地震序列类型为前震—主震—余震型；

The research on the quiescent foreshock is of great theoretical and practical significance.

寂静地震的研究具有重要的理论与实际意义。

This paper discusses the intensity of the earthquake sequences, which include the foreshock, main shock and aftershock.

本文讨论了地震序列中前震、主震和余震的烈度。

Signal shock and precursory earthquake swarm and foreshock activities always accompany the anomalous space-time patterns of seismic 'ty.

信号震、前兆震群和前震(包括早期前震)的确定应考虑到异常的地震活动时空图象。