Its when two powerful tectonic plates smash into each other and lockup. The pressure builds and builds and BUILDS! suddenly the weaker one gives in and the other greater unleashes a dominating quake, pushes the weak in any direction it wants.
Carolina by 20.
oof. I just reminded myself. Loma Prieta. Well,that takes some laffs out of that metaphor.
If this is a premonition..