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Meager ice cover on Lake Superior this winter

Except for coastline areas, Lake Superior is mostly open water this winter.
The U.S. Coast Guard's Alder breaks up ice in Thunder Bay in this file photograph. Unlike years previous, Lake Superior's ice coverage this season is a meager 8.2 per cent. (Jamie Smith,

Most of Lake Superior remains ice-free at mid-February, which improves the chances of an early start to navigation this spring.

Data obtained by from The Great Lakes Environmental Research Laboratory in Ann Arbor, Michigan shows only 8.2 per cent of the largest great lake is currently ice-covered, which is virtually identical to the situation last year at the same time. 

George Leshkevich, who manages the facility for the U.S. government's National Oceanic and Atmospheric Administration, noted that "Last year was a strong El Nino year, and that seems to be kind of carrying over to this year, too, although maybe it's not as strong."

Leshkevich said any ice that has formed is essentially in bays and harbours along various parts of the shoreline, but "the rest is pretty much open water."

It's in sharp contrast to February 13, 2014 when nearly 95 per cent of Lake Superior wore a blanket of ice.

"We're seeing a lot more variability [in ice cover] now," he said. "We get a couple of severe years, then a couple of more mild years, and we've seen these swings since about 1998."

The average mid-February ice cover on Lake Superior over the past five decades has been about 37 per cent.

In the spring of 2014, navigation opened in Thunder Bay several weeks later than normal due to the heavy ice cover.

But the amount of ice on Superior in any given winter has the potential to have impact beyond just shipping. It can also slow the arrival of warmer weather in spring, and may even affect fish spawning.