GRAND HAVEN, Mich. (WOOD) — Ice balls and ice rings were seen flowing down the Grand River in Grand Haven this week.
Visit Grand Haven, a tourism Facebook page for the city, posted video of the icy Grand Haven channel on Tuesday, which had already been viewed more than 296,000 times as of Wednesday afternoon.
These ice formations start as a clump of slushy ice called “frazzle ice.” Slushy ice surrounds a clump of more solid ice in the middle. The frazzle ice hits the edge of the more solid ice and freezes at the outer edge. The ice can rotate in the water, causing the ice to take on a spherical shape. When the shape remains relatively flat, it’s called ice pancakes.
The formations require the right conditions: If the wind is too strong, it can break up the ice. If the wind is calm, the ice freezes into a solid sheet, like it does on most inland lakes.
The ice balls and pancake ice have recently been forming at the mouth of rivers. The river water, which is near the freezing mark, has been colder than the water of central Lake Michigan, which is still a few degrees above freezing.