Researchers have explored undersea brine lakes in the past, but for the first time they have discovered underwater carbon dioxide pools.
These pools were found in the Aegean Sea near Santorini, the site of the second largest volcanic eruption in history.
“The volcanic eruption at Santorini in 1600 B.C. wiped out the Minoan civilization living along the Aegean Sea,” said Woods Hole Oceanographic Institution (WHOI) scientist Rich Camilli, lead author of the study in Scientific Reports. “Now these never-before-seen pools in the volcano’s crater may help our civilization answer important questions about how carbon dioxide behaves in the ocean.”
These pools—known as the Kallisti Limnes (“most beautiful lakes” in Ancient Greek)—are rich in amorphous opal, giving the water an iridescent sheen, and have high concentrations of CO2., These pools are all about density, just like a tequila sunrise: The regular water (the orange juice) is less dense than the CO2 pool (the grenadine), and so the pool sinks without mixing with the regular water.
But where do the CO2 and opal particles come from?
The CO2 is probably a result of volcanic and tectonic activity. The volcanic complex of Santorini is the most active part of the Hellenic Volanic Arc, and is subject to many earthquakes as the African plate subducts the Eurasian plate. As subduction occurs, CO2 can be released by magma degassing, or from materials being subjected to enormous pressure and temperature. The opal, they believe, comes from silica-based organisms.
The researchers hope these pools will provide a means of monitoring volcanic activity, as well as answer questions about deepsea carbon storage—which could keep CO2 out of the atmosphere without acidifying the entirety of the ocean.
“We’ve seen pools within the ocean before, but they’ve always been brine pools where dissolved salt released from geologic formations below the seafloor creates the extra density and separates the brine pool from the surrounding seawater,” said Camilli. “In this case, the pools’ increased density isn’t driven by salt – we believe it may be the CO2 itself that makes the water denser and causes it to pool.”
Pictured are the pools in question. (Image credit: Rich Camili/Scientific Reports)