Why Are Ice Volcanoes Erupting on the Shores of Lake Michigan?
by Katherine J. Wu/Smithsonianmag.com
Something very cool is happening on the shores of Lake Michigan. After spitting thousands of variably-sized ice balls into Holland State Park in Michigan state last Friday, its wintry waters have served up a second scoop of frigid fun: ice volcanoes, spewing slushy water out of cone-shaped mounds of ice.
Captured in photographic form by National Weather Service meteorologist Ernie Ostuno at Michigan’s Oval Beach on Sunday, the ice volcanoes aren’t really volcanoes, per se, and have occasionally appeared around the Great Lakes before.
While true volcanoes belch up magma from Earth’s upper mantle, ice volcanoes are a temporary product of partially-frozen lakes. When local temperatures drop, large lakes sometimes end up rimmed by a thin halo of ice, blocking water en route to land. As large, strong waves, buoyed by powerful winds, continue to course toward shore, they build up pressure beneath the ice, and can eventually burst through cracks at the surface. If spray that emerges then freezes and settles back down to the surface, it may accumulate in a hump with a hole, jetting plumes of water out its top each time a new wave rolls in.
In other words, a lot of climatic factors must……