foreshock

n.

（地震的）前震；

1. An increase in foreshock activity triggered the evacuation warning.
   前震活动的增加引发了疏散警报。
2. In the Pacific Northwest, there is no evidence of foreshock activity for most historic earthquakes.
   在太平洋西北地区，历史上的大多数地震都没有前震活动的证据。

Foreshock
Foreshock
foreshock
Voyager 1 in the Foreshock, Termination Shock, and Heliosheath
Upstream particles observed in the Earth's foreshock region
The oblique whistler instability in the Earth's foreshock
Foreshock sequence of the 1992 Landers, California, earthquake and its implications for earthquake nucleation
Detailed observations of California foreshock sequences: Implications for the earthquake initiation process
Beam‐driven ion cyclotron harmonic resonances in the terrestrial foreshock
Plasma rest frame distributions of suprathermal ions in the Earth's foreshock region
Solar wind deceleration and MHD turbulence in the Earth's foreshock region: ISEE 1 and 2 and IMP 8 observations
Solar wind deceleration and MHD turbulence in the Earth's foreshock region: ISEE 1 and 2 and IMP 8 observations
Instabilities of low frequency, parallel propagating electromagnetic waves in the Earth's foreshock region