Use caution when venturing out onto ice.
Like most matter, water gets denser and heavier as it cools -- at least initially. As winter's cold air descends upon it, chilling top-water sinks to the bottom, and warmer, less-dense, lighter bottom-water rises towards the top, resulting in a total, refreshing circulation of a pond or lake.
This movement continues until all the water below the surface is about 4 degrees Celsius (39.2 degrees Fahrenheit). At that point, water begins to express its magical uniqueness.
You'd logically think ice would form from the bottom up, but this great exception to the rule of cold affecting density is vital to both ice fishermen and all the life within our freezing waters.
For water to freeze on its surface, all the water below must first cool to the critical 39.2 degrees F. Despite even subzero air temperatures, very deep water sometimes never freezes because its column below may never reach that uniform temperature. But when the entire water column dips to 39.2 degrees F, the stage is set for an unexpected reversal.
As the surface water begins to get even colder, instead of becoming more dense and heavier still, it begins expanding -- and getting lighter. At this point, very cold water starts to float on top of less cold water. As this lighter surface water chills further to 32 degrees F (0 C), it freezes on the now sufficiently cold under-surface.
The consequences of water behaving like all other normal matter would be catastrophic. If ice were to form from the bottom of a lake or pond upwards, all life in that water would eventually freeze and die.
The freezing of water from the top down is critical for aquatic life -- including amphibians that burrow in mud -- to survive in brutally cold winters, since surface ice actually helps insulate and slow the cooling of the water below.
Ice fishermen don't really need to know chemistry and properties of matter. It's crystal-clear to all of them there's nothing more magical than water. All that's needed are good old-fashioned cold winters, and 2015 thus far has been frigid enough to get them excited.
But every year, there are many ice-related accidents turning the magic black. While the vast majority of accidents will occur on our icy driveways and roads, taking a horrific toll on hips, arms, legs, and backs, a surprising number will occur on our lakes and ponds. Roughly a half-dozen North American ice fishermen can be expected to die each year from drowning or hypothermia. Safety is paramount.
The first consideration is walking out on safe ice. Below two inches thick, ice can't be trusted, though every year, some of our most avid ice fishermen will venture out on thin ice to ply their long-anticipated passion. Four inches is plenty safe for walkers if the water is uniformly covered. But ice can be deceptive. I've seen ice six inches thick in one area and only an inch thick on an adjacent spot. No body of water has an ice cover that is uniformly thick on its entire surface. Cautious fishermen may prudently measure depths every 150 feet or so.
Ways of measuring ice are numerous and relatively easy. An ice chisel and tape measure are most common. An ice augur, whether electric, hand, or gas-powered works much faster. Gas augurs work the fastest. They're also the heaviest and noisiest. A cordless, easily carried drill with a long, three-quarter-inch wood auger bit can also quickly get through most ice here, making frequent testing relatively easy.
Despite ubiquitous media warnings, every year several people plunge through on snowmobiles, which require at least five inches of support. Cars should have eight to 12 inches, and medium-sized trucks should have at least a foot. That being said, all recommendations are inadequate if too many people congregate too closely, whether walking, parking or driving. Two walkers should probably be about six feet from each other when exploring.
It's helpful to be aware of varying ice color. Gray, dark, porous or slushy ice spots are generally unsafe. Blue ice is ideally hard, thick, and what we're looking for.
But what if you still fall in? My son and I would never go out without a partner and a pair of ice picks.
Extricating yourself from a plunge can prove impossible without them, as your clothing absorbs many pounds of water and the ice you try to grab on to affords no hold. The critically vital ice picks should float and be attached to you by a string or rope. You can make your own with a pair of screwdrivers or large, thick nails. You should try to get back on the ice right where you fell in. That's the known borderline of safe ice.
If you can't get out on your own, your partner should get prone, spreading his weight out on the ice and extend a rope, pole, branch, belt, augur, or any other extended object for you to grab. An arm's length might not be safe enough for either of you. Even a jacket or pullover could be a lifesaver. Time is of the essence. You have mere minutes to extricate yourself before your muscles stiffen from the cold. Once out, roll at least six feet from the hole before you attempt to stand.
Then you need to get warm, and fast. Your wet clothing will likely freeze quickly when it contacts the air. Most ice-fishing fatalities are caused by hypothermia. Quick access to a change of clothing and a warm vehicle can make all the difference.
There are huge pike, bass, pickerel, trout, calicoes and delicious yellow perch now awaiting our tilts and jiggers. But we need to always remember that ice can be magical -- or miserable -- depending on how well we understand and respect it.
Contact Mark Blazis