
Ice Balls & Ice Volcanoes
Here in the northern hemisphere, we are in the last weeks of Meteorological Winter (Astronomical Winter still has exactly one full month until the Vernal Equinox pulls us into spring).
When big cold and big lakes combine sometimes unusual phenomena arise. The Great Lakes of the United States and Canada are prime locations for today’s topics and, indeed, Lake Michigan has produced Ice Balls and Ice Volcanoes in the past week. Let’s take a look at these icy wonders.

In the above image, you can see conditions have created some ice concentrations on the shores of Lake Michigan. When temperatures are just below freezing on shallow shores, waves can cause ice balls to form. The water starts to develop slush on the banks, then wind and waves mold the solids into orbs. The balls then consolidate since the temperature at the shore is below the freezing point.
According to the Detroit Free Press, Holland State Park on Lake Michigan witnessed ice balls last week. Thousands were the size of baseballs or softballs, but some reached the size of bowling balls or exercise/yoga balls. The phenomenon has happened in the past across the world, including in Finland and Russia.


As fantastic as the frigid phenomenon of Ice Balls is, I promised you two frosty wonders.
Under similar conditions, but with stronger waves, Ice Volcanoes might appear. According to Cort Spholten, a National Weather Service meteorologist, ice volcanoes can occur when waves hit sheets of accumulated ice. If the waves break through the sheet to form channels, the water that freezes on top of the sheet slowly coalesces into a conical shape. When the cone retains an opening, shooting water resembles an erupting volcano.


Ice Balls and Ice Volcanoes in one week. Quite the period for Lake Michigan!
Further Reading and Exploration
Great Lakes Ice Analysis – National Weather Service
Great Lakes Commission website
The Living Great Lakes: Searching for the Heart of the Inland Seas – by Jerry Dennis (e-book version)