Opalescent Pools of Carbon Dioxide Curl Around an Underwater Volcano

Deep in the ocean near Santorini lie ephemeral pools of shimmering carbon dioxide. We’ll tell you how they got there, and why your appreciation of the ocean isn’t nearly poetic enough.

Three-thousand-six-hundred years ago, the volcano on Santorini erupted and took out the Minoan civilization. The area is still a geologic hot spot. It’s shaken by regular earthquakes, but the only thing that must be erupting from the ground is carbon dioxide. When calcium carbonate, which makes up one of the chief components of limestone, is put under pressure and exposed to heat, it can give off a lot of CO2.


Up until now, scientist thought carbon dioxide that was released from the sea bed escaped and mingled with the rest of the ocean water. Then an underwater exploration vehicle went about 250 meters down into the ocean and came upon iridescent pools which had collected in crevices in the rock. These are similar to the pools of brine that are sometimes seen on the ocean floor. The CO2 saturated water is so dense that it separates from the water around it and forms defined underwater “lakes.”

The pools are not permanent. Scientists believe that they eventually mix with the rest of the ocean, so they only are big enough to collect whenever a particularly dense “shower” of carbon dioxide comes up from the ocean floor. They’re acidic, and resistant to life, but some researchers think that it’s microorganisms that make the pool pearlescent.


Check out a short clip of the pools here.

[Source: The Kallisti Limnes]

Images: Woods Hole Oceanographic Institute

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