On ice II

06 Apr 2010

Who would have thought that in April there would still be ice on the rivers in Winnipeg? Well, I suppose that on the low temp side of Winnipeg one might expect just about anything…

Ice on the Assiniboine river is today mostly gone. We have had a warm March. At least that is what I thought when looking at the Assiniboine river at Munson Park.

The Assiniboine, a bit high The Assiniboine, a bit high

But when I came a little upstream on my bicycle, there was a surprise…

The ice on the river was far from gone. Melting, yes, probably. But it was still there.

No ice to go on… No ice to go on…

The ice was in chunks and with lots of debris. And from bank to bank. Somewhere in the river must be a natural dam of some kind that is holding up all this ice.

When last winter I went on the river, there was a place where water was going over the ice, by –26C. I thought that this was done manually to create a better skating rink.

Water on ice Water on ice

However, when I went there later, the skating rink was closed off with signs telling me that the place was dangerous. It appeared that the river was frozen from top to bottom. Not surprising by –26C. The remaining water was pushed up over the ice, only to disappear later on underneath it. Obviously those places are dangerous.

The ice gathering on the river today is “simply” a matter of “gathering” not of an ice dam or something alike. The ice is moving, stopping and then moving again.

Obviously when it stops, the buildup of ice will hold the incoming water too.

 Ice free, more or less Ice free, more or less

When there is enough water to make the ice float again, the buildup breaks and the ice will float away. Until the next shallow place in the river.

Landing ice Landing ice

And while the ice is building up, it will arrive on the banks of the river with incredible force. Last year, the ice was uprooting trees and scraping off bark. This year the ice is “civilised” enough not to kill too many trees. Apparently only the ones already in peril are taken hostage…

Building up Building up

For the ice behind the gathering, of course it looks menacing. Water will rise 3 to 4 feet behind the “wall” and then surge through, take the ice and leave a “clean” landscape behind. It seems this is normal spring behaviour for a river like the Assiniboine.

Ice and utility wires Ice and utility wires

My guess is that within two weeks, all this ice will be gone and forgotten.

May spring begin! At last…