Book 30, Question 28
Why do bubbles get trapped in lake ice?
Lake water holds dissolved air, and the mud at the bottom of some lakes gives off bubbles of gas, mostly methane.
As the lake freezes from the top down, rising bubbles get caught in the ice and freeze in layers, like stacked white coins. In a few lakes, such as Abraham Lake in Alberta, the bubbles are so large and plentiful that the ice looks like a frozen sky. Never walk on ice unless a grown-up says it is safe.
Watch the videoWatch on YouTubeSee the series on Amazon
Quick answers
Why do bubbles get trapped in lake ice?
Microbes decompose organic carbon in the lake sediments, and in the thawed-out zone under the lake, into methane gas that bubbles to the surface.
Source: NASA
More fun facts
- The researchers can see stacks of bubbles, separated by thin films of ice, like a time-lapse photograph showing where the bubbles are coming from under the lake.
- The bubbles and the rate of gas release vary across a lake, and from lake to lake.
- Labyrinths of cracks in the ice show where methane could escape, sending the gas into the atmosphere.
- Due to the unique clarity of Lake Abraham’s icy surface, it has become a popular spot to see and photograph methane formations.