Ice does all kinds of weird things on the Great Lakes: It forms perfect balls on the shore and piles up in heaving ice tsunamis when winds on the lake are violent in winter. But maybe the most exciting of the Great Lakes ice spectacles are the ice volcanoes.
Ice volcanoes are not, of course, real volcanoes belching magma from the bowels of the planet — it's impossible for Earth volcanoes to spew ice, though other planets and moons in our solar system have cryovolcanoes, which erupt frozen liquid like ammonia and water. No, these earthly ice volcanoes have three ingredients: water, freezing temperatures (so that the water will freeze after it erupts out of the holes) and choppy waters. It's kind of a treat to get to see them, if only because it can remind you of how lucky you are to be able to go home to some nice warm blankies and a cup of tea.
Ice volcanoes form when it's really cold outside — at least 32 degrees F (0 degrees C), or even "several degrees below freezing," according to researchers at Michigan Tech University, and cold enough to form a sheet of ice along the edge of the water. High winds out on the water create waves that break through the bottom of this shore-hugging ice, causing water and slush to squirt up onto the surface of it. From here, a little mound of ice forms around this hole, and grows each time more water shoots up through it. In this way the ice forms a cone around the hole, similar to that of a volcano.
Of course, conditions have to be just perfect for ice volcanoes to form, and they don't stay around forever. For starters, it has to be very cold — cold enough for ice to form along the shore, which doesn't always happen — but also it must stay cold around the clock so the ice cone doesn't melt. Finally, the winds out on bodies of water such as the Great Lakes need to be whipping up waves forceful enough to shoot water up through the hole in the ice shelf. Ice volcanoes have been seen along the northern shores of Lake Superior and Lake Erie, too, and can presumably form on any body of water where the same conditions occur.
When ice volcanoes happen, they're a sight to behold. But please don't climb on them — they're hollow and thus not as sturdy as the surrounding ice. And once you fall into an ice volcano, it's hard to get you back out.