The Michigan Department of Natural Resources is warning outdoor enthusiasts to exercise caution on the ice, and to understand factors that determine ice strength.
“Don’t assume the ice is safe just because a lake or stream looks frozen,” said Lt. Tom Wanless, DNR recreational safety programs supervisor. “There are several factors that can determine the strength of the ice. Understanding and recognizing these factors, as well as using common sense and caution, will allow you to have a more enjoyable outdoor experience and to make it home safely.”
Here are things to consider before venturing out: You can’t always determine the strength of ice simply by its look, its thickness, the temperature or whether the ice is covered with snow. New ice generally is stronger than old ice. While a couple of inches of new, clear ice may be strong enough to support a person, a foot of old ice riddled with air bubbles may not. Clear ice that has a bluish tint is the strongest. Ice formed by melted and refrozen snow appears milky, and often is porous and weak. Ice covered by snow always should be presumed unsafe. Snow acts like an insulating blanket and slows the freezing process, making the ice thinner and weaker. If there is slush on the ice, stay off. Slush ice is only about half as strong as clear ice and indicates the ice no longer is freezing from the bottom. Be especially cautious in areas where air temperatures have fluctuated. A warm spell may take several days to weaken the ice. But when temperatures vary widely, causing ice to thaw during the day and refreeze at night, the result is a weak, spongy or honeycombed ice that is unsafe. The DNR does not recommend the standard “inch-thickness” guide used by many outdoor enthusiasts to determine ice safety. A minimum of 4 inches of clear ice is needed to support an average person’s weight, but since ice seldom forms at a uniform rate it is important to check the thickness with a spud and ruler every few steps. Deep inland lakes take longer to freeze than shallow lakes. Ice cover on lakes with strong currents or chain-of-lakes systems also is more unpredictable. Ice near shore tends to be much weaker because of shifting, expansion and heat from sunlight reflecting off the bottom. If there’s ice on the lake but water around the shoreline, proceed with caution. Avoid areas with protruding logs, brush, plants and docks as they can absorb heat from the sun and weaken the surrounding ice.To learn more about staying safe on the water, or in the woods, visit the DNR website by clicking here.
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