Tremor

You unleash a small, localized tremor in a 10-foot burst within 30 feet. Each creature in the area takes 1d8 per 2 levels (rounded up) bludgeoning damage with a basic Fortitude save against your class DC. A creature that critically fails is knocked Prone. Earth and stone in the area is difficult terrain until the start of your next turn.

Level (+2) The damage increases by 1d8.