foreshock
/ˈfɔrˌʃɑk/
noun
- A small earthquake that occurs before a larger earthquake (the mainshock) in the same area.
- The foreshock was barely noticeable, but it served as a warning for people to prepare.
- Residents felt a mild foreshock, but no one expected the powerful quake that followed.
- Seismologists recorded a foreshock hours before the major earthquake struck the city.
Synonyms