In the recent week area residents have been treated to a relatively rare phenomenon on some of the nearby smaller bays and shorelines of Lake Superior like Goulais and Batchawana Bays.
The thrill of skating on clear, flat seemingly flawless ice or the illusion of walking on water paired with the effects of an extended lockdown has families flocking to the shores and onto the ice for a few hours of making and recording memories.
The phenomenon known as 'black ice' is not necessarily new however it certainly is one not seen often on the big lake. Most often you find it on smaller inland lakes where conditions may be more favourable.
It has been noted in the past on some of the opposite shorelines of Lake Superior and I have not been successful at finding a history of it for our shorelines to say with certainty we have not seen it in the past.
Black ice actually does form in a few different grades or classifications and is basically the same type of ice sought after by ice sculptors.
Favourable conditions may include, lack of wind, wave action, decaying materials, snow events and even temperatures hovering around the 32-degree mark.
According to internet sources, in theory, liquid water absorbs light wavelengths at different rates and appears clear which basically means visible light can pass through it without being absorbed, reflected or scattered significantly.
Most ice, or varying types of ice, may appear cloudy which generally indicates mineral impurities or air bubbles are locked within its core during the freezing process. As light penetrates the surface it is no longer able to travel in a straight line - it scatters, leaving the appearance of cloudiness or opaqueness.
With perfect conditions the formation of clear ice is possible.
A slow freeze process allows impurities and air time to travel to the surface where bubbles can dissipate. This slow freezing process also allows larger ice crystals to form which means there are fewer surfaces for light to refract or scatter from.
These larger crystals form a stronger bond and harder ice.
Officials are reporting a very low ice cover for Lake Superior to date this year. If you are planning on heading out to take in this natural phenomenon please remember and be prepared for ice safety and changing conditions.