In reply to tspoon1981:
> Back to your misunderstanding of word evolution, a quick google seems to confirm that there is in fact a common definition and a scientific definition.
More to the point, the common definition doesn't simply mean the geographic or positional centre point, rather the focus of activity or the point most closely associated. E.g. it may be claimed, with some justification, that Sheffield has at times been the epicentre of UK climbing, though I'm pretty sure it's never been notably central in any geographic sense. 'Epicentre' carries an implication that 'centre' by itself cannot as easily convey.