foreshock
Tremor before quake
A foreshock is a smaller earthquake that precedes a larger one in the same area.
The term only applies retrospectively—seismologists can't identify a tremor as a foreshock until the main event occurs: What seemed like an isolated quake turned out to be a foreshock.
The word also describes preliminary tremors in other contexts, like the warning signs before a political upheaval.
Alert about danger
- harbingerOne who foreshadows
- omenProphetic indicator
- signalMessage-conveying cue
- indicatorSign revealing status
forerunner · portent · forewarning · presage · prelude · antecedent · predictor · herald
Seismic ground movement
- mainshockLargest earthquake in sequence
- epicenterPoint above seismic origin
- magnitudeSize or scale
- faultImperfection or blame
seismograph · seismometer · tectonics · rupture · P-wave · S-wave · seismology · hypocenter
Rapid oscillating movement
- shakeTrembling or blended treat
- joltAbrupt forceful shake
- shudderConvulsive trembling from fear
- quiverTrembling or arrow case
rumble · oscillation · undulation · movement · ripple · tremble
Warning or watchfulness
- evacuationRemoval from danger
- emergencySerious sudden danger
- drillHole-boring device
- sirenWailing alert device
readiness · advisory · monitoring · detection · prediction · early-warning · hazard · shelter
warning
Alert about danger
indicator · forerunner · portent · forewarning · presage · prelude · antecedent · predictor · herald · sign
earthquake
Seismic ground movement
fault · seismograph · seismometer · tectonics · rupture · P-wave · S-wave · seismology · hypocenter · lithosphere
vibration
Rapid oscillating movement
quiver · rumble · oscillation · undulation · movement · ripple · tremble
alert
Warning or watchfulness
- evacuationRemoval from danger
- emergencySerious sudden danger
- drillHole-boring device
siren · readiness · advisory · monitoring · detection · prediction · early-warning · hazard · shelter
- seismologyearthquake, earthquakes, seismograph, seismicity, seismometer
- Earth soundsrumble, tremor, quake, eruption, landslide
- earthquake effectsearthquake, tremor, tremors, ground shaking, P-waves
- seismic activityearthquake, quake, tremor, mainshock, temblor
- faultsfault, flaw, defect, imperfection, shortcoming
- tectonicsplate tectonics, tectonic plates, tectonic plate, subduction, plate boundaries