Refers to a smaller earthquake that follows a larger one (the mainshock). Used in news, warnings, and everyday conversation after a quake.
After a large earthquake, please be careful of aftershocks.
Last night's aftershock had a seismic intensity of 3.
Aftershocks continued for several days after the earthquake.
Residents are living cautiously, on guard for aftershocks.
A large aftershock occurred one hour after the mainshock.
Please stay alert, as there is still a risk of aftershocks.
前震 is a foreshock that occurs before the main earthquake, whereas 余震 is an aftershock that occurs after it.
余震 means an aftershock (defined by timing relative to a main quake), while 微震 refers to the weak intensity of a tremor, not its timing.
地震 can mean any earthquake, but 余震 specifically means an aftershock that follows a larger 地震.
Standard kanji spelling; the word is almost always written this way.
Compound of 余 (yo, 'remaining, leftover') and 震 (shin, 'earthquake'). The reading is on'yomi.