While this stunning image of frozen Abraham Lake in Alberta, Canada may look like a perfectly tranquil and picturesque postcard scene, something more menacing – and explosive – lurks beneath the surface. 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. The matter sinks to the bottom, where bacteria begin to break it all down, producing methane in the process.
On top of this, manmade lakes and reservoirs are created by flooding dry land – such that the water covers previously existing vegetation and soil and causes them to decompose. Organic matter from natural ecosystems, farms and sewage systems also gets washed into these bodies of water, increasing decomposition rates.