When you think of a volcano, you typically think "hot" - molten lava and ash, not ice. But the Wisconsin Department of Natural Resources has posted a video of a different kind of "volcano," this one made of ice, along the shore of Green Bay.

As the DNR explains, the "ice volcano" is formed when waves hit a shell of ice. At a weak spot in the ice, a hole forms, and water gushes through. The water splashes up and creates a mound with a hole in the middle, just like a volcano. The DNR says the volcano has disappeared naturally since the video was shot.