Lake Michigan Phenomena
By Jane Greiner
Sun Nature Correspondent
Strange things happen from time to time on Lake Michigan. This year, for instance, we all noticed the alewives washing up by the millions along the shore. Kayakers coming into Glen Arbor reported that the lake was a foot deep in alewives as they paddled toward shore. I saw the alewives as glittering ribbons of froth about a hundred yards from shore as I looked down on miles of them from the Empire bluffs.
Other, stranger, things have happened on Lake Michigan. Years ago my mother was walking on the beach below her cottage near Saugatuck when she experienced a once in a lifetime event. Everything was completely normal until she noticed that the lake began to recede. It actually pulled back, almost as if a tide had gone out. Mom said it receded quite a ways out; fifty to a hundred feet of new sand and rock was exposed. There was no mistaking that something different was going on. It was so strange it scared her a little. But she continued to watch and after a few minutes the water all came back to its previous level.
Somehow we found out that what my mother had seen is a rare event called a “seiche.” The Comptons on-line encyclopedia says that lake levels can be changed by various forces:
The amount of rain and snow causes the lake levels to vary. Winds and barometric pressures also heighten and depress them. As air pressure pushes down on one part of the lake, the water surface rises in another part. Waves, called a seiche, result. Tides occur on the Great Lakes but they are small.
Another web site, seagrant.umn.edu gives a more graphic description in an article by Ben Korgen called “Bonanza For Lake Superior: Seiches Do More Than Move Water”
“If you’ve ever experienced a large seiche (pronounced “saysh”) on one of the Great Lakes, it’s something you’ll not soon forget. That so much water can be moved in a relatively short period of time is astounding. Before you know it you’re either left high and dry or inundated with water. Whenever ice is not an inhibiting factor, wind or air pressure changes can cause the entire surface of a lake to rhythmically rock back and forth in the physical process that can form a seiche. According to David Schwab, a scientist with the Great Lakes Environmental Research Lab, “seiche” is a French word that means “to sway back and forth.” It was first applied by a Swiss lake scientist, Francois-
Alphonse Forel in the late 1800s. Forel is also known as the founder of limnology, or the study of lakes.
In Lake Superior, small seiches occur almost continuously. These go largely unnoticed. However, the biggest seiches can bang ships together in harbors, snap their mooring lines, and buckle their plates.
On July 13, 1995, a big Lake Superior seiche left some boats hanging from the docks on their mooring lines when the lake water suddenly retreated. In that seiche, lake water went out and came back within fifteen to twenty minutes at Ashland, Wisconsin; Marquette and Point Iroquois, Michigan; and Rossport, Ontario. People who witnessed it were amazed. In just a few minutes, water levels
changed about three feet.”
I have never been so fortunate as to see a seiche, but I did witness something strange once. This occurred about twenty years ago when I was looking at the lake from my parents’ cottage, high on a bluff south of Saugatuck. I saw something or some “things” moving up the coast just slightly offshore. From my viewpoint high above, it appeared to be a number of very large fish of some sort, swimming along with good sized fins sticking up out of the water. I was observing from about 60 feet above. Each animal appeared to be at least ten feet long because there was that much distance between two fins that seemed to belong to the same fish.
I couldn’t actually see fish. All I saw were moving disturbances in the water, similar to those caused by the prow of a boat, followed closely by things sticking up out of the water. The things sticking up seemed to move in unison with the underwater disturbances, as if attached to a single creature. Imagine a dozen miniature submarines moving along just below the surface with only their conning towers showing. That is like what I saw. Only the indications were that the things were at least ten feet long. I whooped in excitement and ran along the bluff to follow the seemingly gigantic fish. Unfortunately I did not have field glasses with me to get a closer look and the phenomenon was soon out of sight moving steadily northward up the shoreline, moving slightly faster than I could run.
To this day I have no idea what I actually saw. A wild guess is that it might have been a school of salmon swimming in formation with upper fins exposed.
There must be many more strange Lake Michigan occurrences that people living along the lake here have observed. Wouldn’t it be fun if they would share them with us? What interesting limnological phenomena have you observed?
If you care to share your weird Lake Michigan experiences, write me care of the Glen
Arbor Sun, P.O. Box 615 , Glen Arbor, MI 49636 or email me at