Ice 2010Viki Mather April 1, 2010
Nobody had been on the ice for a week, maybe two. Except for us. We were on the ice every day…until Tuesday.
Tuesday morning the ice was fine! The overnight temperature dipped to –6, and the ice was hard as a rock. OK, hard as a soft rock. I could whack it with my pole and make a small dent. Sometimes when I whacked, I’d get a splintering of hairline cracks. I could look at these, and clearly see the ice was well over 4 inches thick. And this was good, because 4 inches of ice in spring is not enough. Mostly there were 7 to 12 inches of ice. And after that cold night, it was all very hard.
I walked out a couple hundred yards to the first pressure crack. The ice had buckled one way and another, lifting here and dipping there. The ice thinned at the edges where it rose and fell, but I found a wide section where it had not buckled…tested it with my pole, and easily stepped across.
In the distance I could see a much bigger crack…one that extended across the entire width of the lake. I walked over there, and followed this crack to the far shore.
The myriad of patterns on the ice surface changed continually. Most of the ice was very clear. I could see the thousands of air bubbles trapped inside. I could see hairline cracks that went all the way through the ice. And this was reassuring, because I could see that the bubbles and the hairline cracks went down a foot or more. Clearly, there was a lot of ice. The beauty of it all was breathtaking.
BOOM!!! My heart skipped a beat. Adrenaline rushed through my veins. I spread my weight and lowered my pole…all in a fraction of a second. Then I took a deep breath and continued my walk. The big grumbles and booming cracking noises always happen when the ice is expanding, as it did that morning as the sun tried to warm the cool air. There was no danger at all…there was no place for the ice to go as it stretched in the morning sun.
Still, it was the stretching and shrinking of the ice that created these pressure cracks. Over the past week, temperatures fluctuated from +15 to –15. That makes the ice move. But since it has nowhere to go, it pushes up at the pressure cracks. The ice that gets pushed down tends to melt faster than the ice that gets pushed up. That’s how I was able to walk right to the edge of the biggest crack on the lake to take this picture. I stood on nearly a foot of ice, looking down at the skim of new ice that had formed on the open water overnight.
I thoroughly enjoyed walking on the ice for more than an hour. I reluctantly stepped ashore, with thoughts of going back for another walk in the afternoon. But alas, it was not to be. By afternoon the ice near shore had gone soft all the way through. It was six inches thick, but had no strength at all. I easily poked a hole through with a single whack of my pole. My ice walking days were over.