foreshock

• 主震之前发生的较小地震，通常被视为大地震的前兆。

A smaller tremor that occurs before the main shock of an earthquake.

1. Preliminary seismic eventC1formalscientific

   A smaller earthquake that occurs before a larger mainshock, often serving as a warning sign.

   前震

   • Seismologists recorded a foreshock just minutes before the major earthquake struck.
   • The foreshock was barely felt by residents, but it alerted scientists to the impending danger.
   • Not all earthquakes have a foreshock, making prediction difficult.

   反义词aftershock