There could be something living thousands of feet beneath the seabed in the western Pacific Ocean. No, it’s probably not Godzilla, but it’s still pretty exciting.
Around 10 kilometers (6.2 miles) beneath the seafloor of the Mariana Trench, the deepest point of the world’s ocean, scientists say there could be possible evidence of life. Their findings are published in the Proceedings of the National Academy of Sciences.
The evidence comes from minerals spewed up from the deep oceanic hydrothermal vents within the Mariana Trench. This is an oceanic trench in the western Pacific Ocean that was formed by the collision of two tectonic plates. It is confirmed to be at least 10,994 meters (36,070 feet) deep at its deepest point, although some studies say it could be more.
Right on this tectonic-plate convergent boundary, in an area known as the Izu-Bonin-Mariana arc, the scientists collected samples of a serpentine mineral that contained trace amounts of organic material. Analysis of the organic material shows that it is very similar to that produced by microbes elsewhere on Earth.
"It's kind of like a message in a bottle," lead author Oliver Plumper, an earth scientist at Utrecht University in the Netherlands, said in a statement. "Although we don’t know the exact origin of the organic material with total precision, our chemical analysis indicates life deep within or even below the mud volcano."
The figure 10 kilometers (6.2 miles) was calculated as this is the depth where the mud volcano's inner temperature reaches the limit that scientists believe life can live up to - approximately 122°C (~251°F).
But what could any potential life form live off all the way down there? When serpentine is formed through the process of serpentinization, it produces methane gas and hydrogen. The researchers note that this could be used as a food source by microbes, much like how other microbial life utilize the serpentinizing systems in the ocean.
"The mud volcanoes are a unique window in deep underground, and enable us to trace processes that would otherwise remain hidden," added Helen King, another earth scientist at the University of Utrecht. "The discovery of the organic material in the lithosphere was particularly interesting since they may indicate a deep biosphere below the mud volcanoes."