Reverberate

You touch the ground at your feet with the metal ring, creating an impact that shakes the earth ahead of you. Creatures and unattended objects touching the ground in a 15-foot cone emanating from you take 4d6 thunder damage, and creatures fall prone; a creature that makes a successful Dexterity saving throw takes half the damage and does not fall prone.

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.