EAST GRAND RAPIDS, Mich. (WOOD) — A four-day thaw ended with record high temperatures on Thursday in the upper 50s, which has some rescue crews concerned.
Lake ice is never 100 percent safe, and can be increasingly unstable when weather conditions endure big swings in temperature.
A day in the 50s with a warm breeze is typically the most devastating to ice stability. Just one day near 60 with a breeze, like West Michigan experienced Thursday, is enough to eliminate at least 2 inches of ice thickness from a shelf.
Rainwater often only erodes about one-sixteenth of an inch of ice, and on sunny days the ice melts mostly from the bottom up.
As of Wednesday, the Kent County Sheriff’s Department had measured several inland lakes as having 8 to 10 inches of ice thickness. They were quick to add that ice thickness and quality can vary significantly even from foot-to-foot.
Ice quality is important along with thickness. Ice that breaks off in chips and shavings when hit with a pole is much stronger than ice that breaks off in chunks. Opaque ice often holds more air bubbles and isn’t as trusted as several inches of clear ice. Old ice is usually not as stable as new ice.
Recent melt and rain means road salt is being swept off the pavement and into storm drains. Many inland lakes receive the water that pours into storm drains. This means parts of inland lakes could have a higher concentration of diluted road salt, which acts to lower the freezing point of water.
East Grand Rapids Department of Public Safety Sgt. Jeff Metternich said ice fishermen need to know where those drainage areas are so they can steer clear of them, especially after thaws.
Metternich said his team averages about one legitimate ice rescue a year. He said often, it’s bystanders that call in ice falls after they hear someone crying out. It is essential anyone attempting a walk on the ice knows that ice is never completely safe.
It is recommended people check ice thickness and quality frequently. There must be at least 4 inches of good, solid ice to support a person walking.
“The majority of the people that go out on the ice are not wearing rescue suits they’re wearing snowmobile suits, they’re wearing construction clothing, they’re wearing multiple layers that keep them warm, but once those become wet, they become heavy,” he said.
Life jackets can make a big difference between floating and sinking in the frigid water should the ice give way.