Microearthquake

Part of speech: noun

Definitions

1. A minor seismic disturbance resulting from tectonic shifts that usually goes unnoticed by people
2. A low-intensity tremor originating in the Earth's crust that is often imperceptible to humans
3. A small-scale seismic event occurring within the Earth that typically does not cause significant damage and is rarely felt by individuals

Etymology: The word is a plain compound: "micro-" joined to "earthquake," so it names a tremor too small for most people to feel. The first element comes from Ancient Greek "mīkrós," meaning "small," which reached English through modern scientific Greek-derived combining forms rather than as an everyday word. "Micro-" was used this way long before seismology needed it, and it became a productive prefix for measurable quantities of all kinds. The second element has a longer ancestry. "Earthquake" descends from Old English "eorþe" (earth) and "cwacian" (to shake or tremble), with the "quake" part traceable to Proto-Germanic "*kwakōnąn," a verb meaning to tremble. Middle English speakers combined these into "erthequake," which later shifted toward the modern spelling. Joining the two gives a term that describes a shaking so slight that it is detected by instruments rather than felt. Its meaning follows directly from its parts: the Greek "small" attached to the Germanic "earth-shaking."

Synonyms: tremor, shake