Earth & SkyGreek → English
Hypocenter
/ˈhaɪpoʊˌsɛntər/noun
The underground point where an earthquake actually begins, or the ground point directly below an air-burst explosion.
The Greek roots
ὑπό
hypó
under, beneath
κέντρον
kéntron
sharp point, centre
Literally: “the point beneath”
The story of the word
Seismologists needed two words, one for where the rock breaks and one for the patch of surface above it, so they built hypocentre against epicentre. The Greek κέντρον was originally an ox-goad, a sharp stick, and got its geometrical sense from the fixed spike of a compass. Japanese accounts of Hiroshima and Nagasaki use the word in its other sense, the spot on the ground under the detonation.
- How it travelled
- Ancient Greek → scientific coinage → English
- First recorded
- 20th century
Same family
epicentercenterhypodermichypothesis
In a sentence
The hypocenter lay eleven kilometres down, which is why the shaking was felt so widely.