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An "ice volcano" sounds like an oxymoron. How could there possibly be ice anywhere near a volcano? While it may sound strange, the world is a peculiar place. Ice volcanoes are actually a common occurrence — especially along the shores of colder regions. So, what are ice volcanoes and how are they formed?

Volcanoes of Ice

Aerial view of Greenland landscape, showing large snowcapped hills and rocky outcroppings
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An ice volcano isn't like a regular volcano. They’re not hot, dangerous, or even mountainous. Instead, ice volcanoes look like small snowy hills that form over a frozen body of water. These hills can reach anywhere from three to 25 feet tall.

Ice volcanoes form in large arcs along bodies of water with multiple volcanoes making up each arc. When a wave rolls in just right, water is forced up through the tops of the hills, which causes an “eruption” of freezing water. While the eruption itself isn’t considered dangerous, the water does shoot out of holes in the frozen sheet of ice. To avoid falling into the holes, ice volcanoes are best viewed from a distance.

Where Are Ice Volcanoes?

Lake Michigan from the beach
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Ice volcanoes can be found along the shorelines of any environment with rough surf and cold weather. Most of the ice volcanoes in the world form along the shores of the Great Lakes in the United States and Canada. It’s not uncommon to find dozens of them covering the icy waters of Lake Michigan, Lake Superior, and Lake Erie.

Making an Ice Volcano

Aerial view of mountain ranges covered in snow and ice
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To make an ice volcano, you need three things: large waves, cold weather, and lots of ice. As the ice forms on top of the body of water, the waves continue to crash into the side of the ice shelf. Large waves carry a lot of momentum. Sometimes, when a wave crashes into the side of an ice shelf, the water explodes up and over the ice. In regions where the ice completely covers the surface of the water, the crashing waves can gather enough momentum to “erupt” through cracks in the ice. Water that erupts from the cracks in the ice freezes over time to form a small mound that looks like a mountain. When a big wave comes along, the tiny mountains erupt in a shower of cold water to create an ice volcano.

Where Are Cryovolcanoes?

Viluchinsky volcano surrounded by snow
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Yes, “cryo” technically means ice, but although a cryovolcano's etymology is similar to an ice volcano, the two shouldn't be confused. These volcanoes are exponentially more extreme than the ice volcanoes of the Great Lakes. Cryovolcanoes can be found only in space. Instead of the -25 degrees Fahrenheit temperature of Lake Superior, cryovolcanoes prefer the -290 degrees Fahrenheit temperature of Saturn’s moon Titan, for example.

Cryovolcanoes work in essentially the same way that Earth’s volcanoes do. Deep below the crust of a planet or moon, substances are heated, melted, and sent upwards through an opening. Once the liquid substances reach the surface, they contact the cold air and solidify to form new ground. For Earth's volcanoes, the “substance” is molten rock. On a celestial body where the temperatures dip below -290 Fahrenheit, the “substances” tend to be liquid water, methane, and ammonia.

Unanswered Questions

View of the milky way with silhouette of mountains
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So far, not much is known about cryovolcanoes and most of what’s “known” is based on theoretical science. Researchers have seen geological activity on Saturn’s moon Titan, Pluto, and the exoplanet Ceres. Since there’s no way that it could possibly get hot enough on any of these celestial bodies to create magma, cryovolcanoes are the solution. But don’t worry! You won’t accidentally stumble upon one on your winter ski trip to Colorado.