They look otherworldly, like flying saucers that dropped into the water and froze, or ancient, ice-encapsulated jellyfish. In fact, these icy circles are frozen methane bubbles – pockets of gas that, when trapped underwater and frozen, form a spectacular landscape.
Found in winter in high northern latitude lakes like Lake Abraham in Alberta, Canada, these gas bubbles are created when dead leaves, grass and animals fall into the water, sink and are eaten by bacteria that excrete methane. The gas is released as bubbles that transform into tens of thousands of icy white disks when they come into contact with frozen water, Quora user Mayur Kanaiya explains.
It’s a stunning, but potentially dangerous sight. This potent greenhouse gas not only warms the planet, but also is highly flammable. Come spring, when the ice melts, the methane bubbles pop and fizz in a spectacular release – but if anyone happens to light a match nearby, the masses of methane will ignite into a giant explosion.