“Rotten Ice” Stay off the Ice!

The term “rotten ice” is an U.S. Coast Guard classification used to describe, usually in late winter, old melting ice.  It is also called weak or soft ice. This year with the warm days we have had, there will be many places on the river where there may be rotten ice.  

When ice begins to thaw, the ice may be solid on the surface while unfrozen water may be channeling the underside.  Rotten ice is white, brittle, and mixed with snow or filled with air bubbles. This ice is very dangerous and can break under lightweights. Even the weight of one person can break through this ice.

There is an old saying about crossing ice, “thick and blue, tried and true - thin and crispy, way too risky - when in doubt, don’t go out.”  When deciding whether to go out on the ice, it is extremely important to spend time assessing the conditions.  What looks safe from the shore may be dangerous as you venture out.  Keep in mind factors such as water currents, water depth, snow cover, and the temperature.  These things can all negatively impact the strength of ice.

In general, two weeks or more of below freezing temperatures are needed to make ice capable of holding up large weights.  However, when thaws have occurred, the safety of ice cannot be determined by usual methods.  There is always the danger of there being spongy or honeycombed ice beneath what appears to be safe ice.  Even though testing one spot may show that particular area deep enough to support heavy weights, a few feet away because of thaws and other factors might be unsafe. A few inches of clear ice may be strong enough to support you, while a foot of air-bubbled rotten ice will not.

The ice conditions we are seeing this winter should be treated like it were late winter, old ice.  Ice formed by melting snow is milky colored and is very weak.  It is always a good idea to presume that ice covered with snow is not safe.  The inch thickness guide used by many fishermen is not recommended as a safety guide, as ice seldom forms at a uniform rate.  If there is water near the shoreline proceed with great caution.  It is important, too, to avoid areas with protruding logs, plants, brush, and docks.  These structures absorb heat from the sun weakening the ice around them.

Ice thick enough to hold the weight of a car must be 8 to 12” thick without rotten ice below.  A car traveling on ice creates a pressure wave, if the water is four feet deep, driving faster than nine miles per hour can shatter the ice.  Remember you take a risk anytime you venture onto the ice.  This year with the thaw we have had it probably is a good idea to abandon any thoughts of using the ice for traveling. Temperatures above freezing for 24 hours or more will result in loss of ice strength to a point where the conditions are no longer safe.

The following are ways to help yourself, if you do break through while walking on the ice.  If you cannot get up onto the ice it is important to stay calm and do not attempt to swim as this will cause you to lose body heat faster. The only time you may swim is to reach a boat or floating object or the shore IF it is nearby.  Carrying a whistle would be helpful because now you could blow it hoping to attract someone’s attention. Whatever you do, do it slowly to conserve your body heat.

If you fall through the ice remember this acronym HELP (heat escape lessening position).  To assume a heat escape lessening position bring your knees to your chest and keep your arms at your sides while clapping your hands.  If you can, cover your head; but remove your snowmobile helmet because it can fill with water.

To help someone who has fallen in DO NOT GO ON THE ICE!  Phone for help.  From a safe distance on solid ground throw whatever you can to the person. Throw a rope, a branch, a pole, etc.  If you cannot reach the person, go for help.

It seems like every year we lose community members because of river ice related accidents.  So, let us be aware of the dangers and live and little longer.