You will not see many living things above the ocean surface hundreds of kilometers southeast of Madagascar –an albatross or an occasional fishing vessel is allowed divide the hours of loneliness. But under the surface, lava from Earth’s mantle has raised a long underwater mountain range with a flat top extending 5 kilometers above the sea bed. His name, the Atlantis Bank, strangely applies; here microbial communities have somehow found a way to thrive, deep in the lower crust of the Earth.
Scientists on board the research vessel JOIDES Resolution visited the unique geology as part of Expedition 360 of the International Ocean Discovery Program (IODP). They drilled 809 meters in the crust, revealing new insights into the types of organisms in which they can survive The most remote locations of the Earth.
“There is a community there,” Virginia Edgcombe, the corresponding author and associate scientist of the Woods Hole Oceanographic Institute, told Gizmodo. It’s a slow-growing, low-biomass community, but it’s there. “That is exciting because it expands our view of the habitable biosphere on Earth and only indicates that life is possible in the lower crust.”
Previous research has already shown that microorganisms live deep in the top crust, but there is less information about what thrives in the bottom crust. The Atlantis Bank provides a unique insight into this region; there tectonic activity has exposed much of the lower crust at about 700 meters below sea level. Scientists from the expedition drilled into the crust and pulled cores up 10 meters at a time, which they analyzed both on the boat and in the laboratory. This area is one of the closest exercises ever to hit the Earth’s mantle.
The researchers had to make sure that no contaminants got into their samples. They contained a chemical tracer in the drilling fluid and then removed the outer layers of the core that were clearly contaminated. Possibly tracer stayed in a monster, they could throw it away. They also analyzed the samples in sterile environments containing nutrient-rich petri dishes that would have sprouted with the invading life had there been external contaminants in the room.
A large number of experiments analyzed the core monsters for DNA and RNA, fat molecules and other life support materials. The core revealed the signatures of sparsely populated but present and active microbial life, including relatives of the same species of organisms that live in deep-sea vents and even fungi feeding on the dead. These organisms did not make their own food – they survived on carbon molecules that somehow permeated the deep crevices in the crust of seawater that leaked.
Jennifer Biddle, associate professorr at the University of Delaware Who was not involved in the study, but who reviewed the paper found it exciting that life could still exist at this location, so deep in the earth and so close to the mantle. She was convinced that this deep-crust life really existed thacalls for the variety of different tests that all indicated the presence of this microbial community.
“It shows that microbes are everywhere,” Biddle told Gizmodo. “You don’t expect it to have rock in it. But there are little cracks that have just enough activity to keep things going. That’s great to think about: there’s so much life on Earth that it ends up in every crack it may fit in. ”
These findings are bittersweet for those hoping that a similar life exists on a different planets. Yes, these microbes survive the extreme – but they are still there participate in the global nutrient cycles that take care of the food that keeps them alive instead of being isolated individuals who survive without any external input.
But here on Earth, the study at least supports the cliché Jurassic Park: “Life finds a way.”