Shelf Ice Stretching Along the Shore

It's that time of the winter again, when the surface of Lake Michigan is covered in ice, and the ridges of shelf ice form parallel to the shore. These ice formations are created by cold weather and waves pushing up the water and ice chunks onto the layers of ice on the beach. After a bit of time, the ice builds up into mounds that can reach a height of 15 feet, and stretch for hundreds - or thousands of feet into the lake.

The history of the winter's weather can be told by viewing the ice on the lake. The tall mounds form when the weather is windy, while the flat areas form when there is no wind or when there is a gentle breeze that pushes the floe ice toward the shore. The ice is then frozen in place until the next wind event when mounds once again form at the outer edge of the ice. This creates the familiar hills and valleys often seen on the lake in winter. The lakefront changes as often as the weather in all seasons, but it's especially noticeable in winter when the ice can build, crack, fall, or float, changing the appearance considerably.

In addition to the changes in the ice, the beach changes as well. Wind mixes the sand and snow creating beautiful drifts and layered patterns on the dunes and on the beach. These features change even more quickly than the ice, and these alone are worth a trip to the lake front.

In the image above, the snow and sand mix in the foreground, while the ice on the lake extends almost as far as one can see. If you look closely at the horizon on the right side of the image, you can see the Chicago skyline some 35 miles across Lake Michigan. It's a common thing to see, but not a guarantee on every visit.