Churn Earth

the very ground beneath your enemies feat is now an enemy to them as it folds over and crashes into itself ignorant of the life atop it. Each creature in a 20-foot-radius Sphere centered on that point makes a Dexterity saving throw, on a failed save they take 8d6 Bludgeoning damage or half as much on a successful save.  

Using a Higher-Level Spell Slot. The damage increases by 1d6 for each spell slot level above 3.