Shocking Discovery! There's a Lake of Liquid Carbon Dioxide on the Ocean Floor!

Far below the sunlit surface of the ocean, in environments defined by crushing pressure and frigid temperatures, scientists have uncovered extraordinary pools of liquid carbon dioxide. These deep-sea anomalies typically form in areas of intense geological activity, such as near hydrothermal vents where volcanic magma releases carbon dioxide-rich fluids into the surrounding seawater. The unique conditions at these depths are critical, as the immense pressure causes carbon dioxide to transform into a liquid state, while the low temperatures help maintain its stability.

At depths usually exceeding 3,000 meters, liquid carbon dioxide becomes denser than the surrounding seawater, allowing it to collect in depressions on the ocean floor, much like water in a terrestrial lake. Often, a cap of carbon dioxide hydrate, a solid ice-like compound, forms at the interface between the liquid CO2 and the seawater. This hydrate layer acts as a seal, trapping the liquid carbon dioxide beneath and preventing it from dissolving rapidly into the ocean.

The discovery of these subterranean carbon reservoirs over the past two decades has provided invaluable insights into Earth's complex carbon cycle and the potential for extreme life forms. While individual droplets of liquid CO2 were observed as early as 1990, the concept of extensive, stable "lakes" of this substance is a more recent understanding, challenging previous assumptions about deep-sea chemistry. These remarkable environments serve as natural laboratories for studying how carbon behaves under extreme conditions and how life adapts to such alien (Review) worlds.