Wednesday, April 12, 2006

Gunflint Lodge

But What About the Ice?

It's fine to talk about birds and all the other signs of spring but for most of us the burning question is, "When will the ice go out?" As we think about this, let's look at the actual process of ice-out.

This process started several weeks ago when the ice "lifted." The term means that a tiny crack appear between the ice and the shore all around the lake. That left a huge chuck of ice floating on the lake. It's an important step because now this chunk of ice can be moved back and forth by the wind. Each little move crushes more ice against the shore. Sometimes the portions of ice are actually blown up onto the shore where they quickly melt.

The next step is for the rivers and streams into the lake to start flowing freely. On Gunflint the main river is the Cross River which flows into the west end of the lake. The river's flow eats away at the floating ice. Right now the ice has cleared to about 100 feet out from the river entrance. Eventually this entire bay will be cleared of ice by the river.

At the same time the wind, sun, and rain are taking their toll on the main ice chunk. It is getting blacker and blacker as it weakens. In the spring we speak of this ice as being "honeycombed." No matter how thick , this is weak ice because of all the air pockets forming. Also there is no way to predict where the ice is solid and where a walker would fall through. Of the three factors working on this ice, the most important is the wind. Wind will really weaken the ice and it will blow in from shore to shore. If you go down to the lake shore, you can actually hear the ice "tinkle" as tiny pieces break free.

For the next 1-2 weeks we will be seeing this ice flow move around. The large bays on Gunflint will literally melt free but not the main of the lake. That chunk of ice is waiting for the perfect west wind. One day that wind will start blowing the rotten ice down the lake to the east end. As soon as the ice moves up onto the shore, wind and sun will melt it almost immediately. In a day or two, the entire lake will be free of ice. There won't even be any ice left on the shore.

Right now we have started the process of moving this ice chunk around. The Cross River is freely flowing into Gunflint. Today, however, there is no wind so most of the ice will just sit there. It will probably be about the first of the month before we have open water on the lake. Anyway, that's my guess today.

Sue Kerfoot

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