Photographed in Banff National Park in Alberta, Canada, the bubbles are made from highly flammable gas methane. Paul Zizka/Caters News Agency
Methane gas bubbles underneath Vermillion Lakes in Banff National Park, Alberta, Canada.
Normally the bubbles would break the surface but in low temperatures they freeze.
The gas, which is emitted by bacteria after they consume dead organic matter, is fairly harmless but the bubbles can cause an explosion if lit.
Vermilion Lakes are a series of lakes located in the Canadian Rocky Mountains.