An innovative research has demonstrated for the first time in many years that life can indeed survive nearly 1,400 meters underneath the oceanic crust. This layer of the ground was until now one of the few ares on our planet where only limited numbers of studies were carried out.
The microbes uncovered in this unlikely environment were few and spaced far apart from each other, but the fact of the matter remains that they manage to endure at locations where nothing else would be able to survive.
One of the things that really stands out about the new study is that it found microorganisms living in the deepest layer of the oceanic crust, which lies directly above the planet's mantle.
The mantle, a thick layer of molten magma inside Earth, surrounds the solid iron core. It is here that volcanic eruptions originate from, and tectonic plates submerge to meet a fiery end.
Right on top of it lies the gabbroic layer of the oceanic crust, which is where the bacteria were recovered from. The layer is made up of a dense, greenish rock, which has rarely been studied, despite its obvious significance.
Researchers in charge of the new work say that their drilling project is the first-ever designed specifically to check for sings of life in this particular layer of crust. On land, similar projects have dug incredibly deep into landmasses.
The research was only made possible by the existence of the Atlantis Massif, a large underwater mountain. Ancient tectonic processes pushed the gabbroic layer into the range of drilling ships.
Postdoctoral fellow Olivia Mason, from the US Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab), conducted the research effort. She says the discoveries in itself are not amazing.
Lifeforms exist in the basaltic layer of the oceanic crust, the one immediately above the gabbroic one. What surprised the team was that the two layers did not share any species in common.
“We did not see any overlay in the microbial community at all, so that was a surprise,” the team leader explains for Our Amazing Planet
The microorganisms discovered during the drilling were apparently living off hydrocarbons, hydrogen and carbon-based organic chemicals that can be found in oil as well.
This discovery raises the tantalizing possibility that the substances are developed inside the Earth itself, and not only by burying organic matter and waiting for it to decompose.
The process through which hydrocarbons develop at such depths is currently a mystery, but its discovery already raised a lot of eyebrows, so follow-up studies are very likely to be conducted.