epicentre

Short definition from Wiktionary

Noun

1. 1
   The point on the land or water surface directly above the focus, or hypocentre, of an earthquake.
2. 2
   The point on the surface of the earth directly above an underground explosion.
3. 3
   The focal point of any activity, especially if dangerous or destructive.
4. 4
   The geographical area in which an ongoing disaster, illness, crisis, or other destructive event is currently most severe.

Verb

1. 1
   Of an earthquake: to have its epicentre (at a specified location).