Earthquake vs. Aftershock — What's the Difference?

An earthquake (also known as a quake, tremor or temblor) is the shaking of the surface of the Earth resulting from a sudden release of energy in the Earth's lithosphere that creates seismic waves. Earthquakes can range in size from those that are so weak that they cannot be felt to those violent enough to propel objects and people into the air, and wreak destruction across entire cities.

In seismology, an aftershock is a smaller earthquake that follows a larger earthquake, in the same area of the main shock, caused as the displaced crust adjusts to the effects of the main shock. Large earthquakes can have hundreds to thousands of instrumentally detectable aftershocks, which steadily decrease in magnitude and frequency according to known laws.

A sudden movement of the earth's crust caused by the release of stress accumulated along geologic faults or by volcanic activity. Also called seism, temblor.

A quake of lesser magnitude, usually one of a series, following a large earthquake in the same area.

A shaking of the ground, caused by volcanic activity or movement around geologic faults.

A further reaction following the shock of a deeply disturbing occurrence or revelation

(planetary geology) Such a quake specifically occurring on the planet Earth, as opposed to other celestial bodies.

An earthquake that follows in the same vicinity as another, usually larger, earthquake (the "mainshock").

(figuratively) A sudden and intense upheaval; a severely disruptive event.

(figuratively) By extension, any result or consequence following a major event.

(intransitive) To undergo an earthquake.

Emotional and physical distress following a traumatic event.

A shaking, trembling, or concussion of the earth, due to subterranean causes, often accompanied by a rumbling noise. The wave of shock sometimes traverses half a hemisphere, destroying cities and many thousand lives; - called also earthdin, earthquave, and earthshock.

A tremor (or one of a series of tremors) occurring after the main shock of an earthquake

Like, or characteristic of, an earthquake; loud; startling.

Shaking and vibration at the surface of the earth resulting from underground movement along a fault plane of from volcanic activity

A disturbance that is extremely disruptive;