Cryovolcano

Cryovolcanoes can erupt on icy moons or bodies in debris belts, but rather than spewing molten rock (magma), they erupt volatiles like ammonia, water or nitrogen and methane. The ejected cryomagma then condenses into a solid, thus changing the surface composition of the icy body.

These "ice volcanoes" can be driven by seasonal heating releasing volatile compounds and dust from beneath the world's surface.