Wiktionary
hypocenter
alt. (context US English) (alternative spelling of hypocentre English) n. (context US English) (alternative spelling of hypocentre English)
Wikipedia
Hypocenter
A hypocenter (or hypocentre) (from [hypόkentron] for 'below the center') is the point of origin of an earthquake or a subsurface nuclear explosion. It is a synonym of the focus. Confusingly, the term hypocenter is also used as a synonym for ground zero, the surface point directly beneath a nuclear airburst.
Usage examples of "hypocenter".
Three or more points, or in this case earthquake hypocenters, describe a plane.