[mad_as_he$$]

Well the rock heads have all kinds of rules. In Kalifornia if it was an adjustment in an adjacent fault that was because of the initial event then they called it an aftershock. There also are some rules about how the depth and lateral distances are judged.

[SoldierDad]

It the long and short of it, I don’t think it really matters whether it was an initial event or an aftershock. We still feel the Earth move under our feet.