This is the 7417th most frequent Japanese word.
余震
Aftershock.
Here, '余震' is used to refer to aftershocks—secondary tremors occurring after the main seismic event.
昨晩の地震の余震がまだ続いている。
The aftershocks of last night's earthquake are still continuing.
In this context, '余震' is used to indicate the potential occurrence of aftershocks as a hazard.
余震の恐れがあるので注意してください。
Please be cautious as there is a risk of aftershocks.
Here, '余震' is describing the direct impact caused by aftershocks on infrastructure.