A team of scientists based in Japan and Germany has found an unusual lake of liquid co₂ beneath the seabed, says a recent National Geographic report. The co₂ lake, discovered by Fumio Inagaki of the Japan Agency for Marine-Earth Science and Technology in Yokosuka and colleagues, was first reported in the online edition of the Proceedings of the National Academy of Sciences of the us.

Inagaki's team found the lake while studying undersea volcanic hot spots in the East China Sea off the coast of Taiwan. The lake's presence at 1,400 metres below the sea level was unexpected, for normally liquid co₂ has to be at a depth of 3,000 metres so that it remains dense enough under high pressure and does not rise.But in this case, co₂ has been moving upward from a deep magma chamber; as it nears the sediment, it encounters cold water in the top layer of the sediment and forms a type of ice called co₂ hydrate. The ice creates a cap to trap additional liquid co₂ beneath it. The discovery, however, offers clues to better understand the viability of carbon sequestration and how it might affect undersea ecosystems.