Something menacing - and explosive - lurks beneath the surface of the frozen Abraham Lake in Alberta, Canada. The crisp, bluish-white, cotton wool-like formations are actually frozen bubbles of flammable methane gas trapped in the icy manmade lake.
As spring sets in and the lake thaws, the bubbles break free and rise to the top. And when the ice cracks, the bubbles escape and vanish into the atmosphere. The methane in the lake is created when bacteria decomposes organic matter in the water. This organic matter includes plants, leaves, trees and also animals that have died and fallen into the lake.