Ubtao's Tiny Terraform

You touch the ground beneath you and ask Ubtao, god of creation, to cause it to vibrate. Each creature in a 20-foot cube below the ground's surface must make a Dexterity saving throw. A creature takes 4d6 bludgeoning damage and has its movement speed halved until the end of its next turn on a failed save, or half as much damage on a successful one.

You briefly learn the location of each creature that takes damage from this spell.

At Higher Levels. When you cast this spell using a spell slot of 3rd level or higher, the damage increases by 1d6 for each slot level above 2nd.