Origin of massive methane reservoir identified

Origin of massive methane reservoir identified
The manipulator arm of the remotely operated vehicle Jason samples a stream of fluid from a hydrothermal vent. The fluid contains gases that are in liquid form because of the high pressure of the deep ocean. Credit: Chris German/WHOI/NSF, NASA/ROV Jason 2012, © Woods Hole Oceanographic Institution

New research from Woods Hole Oceanographic Institution (WHOI) published Aug. 19, 2019, in the Proceedings of the National Academy of Science provides evidence of the formation and abundance of abiotic methane—methane formed by chemical reactions that don't involve organic matter—on Earth and shows how the gases could have a similar origin on other planets and moons, even those no longer home to liquid water. Researchers had long noticed methane released from deep-sea vents. But while the gas is plentiful in the atmosphere where it's produced by living things, the source of methane at the seafloor was a mystery.

"Identifying an abiotic source of deep-sea methane has been a problem that we've been wrestling with for many years," says Jeffrey Seewald a senior scientist at WHOI who studies geochemistry in hydrothermal systems and is one of the study's authors.

Of 160 analyzed from across the world's oceans, almost all contained pockets of methane. These oceanic deposits make up a reservoir exceeding the amount of methane in Earth's atmosphere before industrialization, estimates Frieder Klein, a marine geologist at WHOI and lead author of the study.

"We were totally surprised to find this massive pool of abiotic methane in the and mantle," Klein says.

The scientists analyzed rocks using Raman spectroscopy, a laser-based microscope that allows them to identify fluids and minerals in a thin slice of rock. Nearly every sample contained an assemblage of minerals and gases that form when seawater, moving through the deep oceanic crust, is trapped in magma-hot olivine. As the mineral cools, the water trapped inside undergoes a chemical reaction, a process called serpentinization that forms hydrogen and methane. The authors demonstrate that in otherwise inhospitable environments, just two ingredients—water and olivine—can form methane.

"Here's a source of chemical energy that's being created by geology," says Seewald.

On Earth, deep-sea methane might have played a critical role for the evolution of primitive organisms living at hydrothermal vents on the seafloor, Seewald explains. And elsewhere in the solar system, on places like Jupiter's moon Europa and Saturn's Enceladus, methane produced through the same process could provide an energy source for basic life forms.


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More information: Frieder Klein et al, Abiotic methane synthesis and serpentinization in olivine-hosted fluid inclusions, Proceedings of the National Academy of Sciences (2019). DOI: 10.1073/pnas.1907871116
Citation: Origin of massive methane reservoir identified (2019, August 20) retrieved 17 September 2019 from https://phys.org/news/2019-08-massive-methane-reservoir.html
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Aug 21, 2019
You want plastics on mars? No problem. But we dont want plastics on mars.

Aug 21, 2019
So cows farts (as AOC explains) aren't that much to blame after all? And we can still eat beef? I'm sure the liberals will come up with other excuses to try to make us all vegetarian. Oh, and we need to stop using airplanes, too, unless you are Al Gore who can still use his private gas-guzzling jet.


Aug 21, 2019
We could start by stopping burning coal.

Just sayin'.

Aug 21, 2019
@bart_a - it doesnt say whether this methane converts to methane hydride - because you really dont want to mess with that stuff. with warmer oceans it can come out of the hydride form and enter the atmosphere and put another torch under our asses - a reckoning that was excluded from the IPCC 2000 report, which was a big conservative victory at the time (conservative politicians that is, not scientists who are for the most part engaged tn the scientific process which is a method of defining truth).

Aug 21, 2019
The authors demonstrate that in otherwise inhospitable environments, just two ingredients—water and olivine—can form methane.


This statement makes no sense, since there is no Carbon in either of those two ingredients.
Olivine is MgSiO4 & FeSiO4, water is H20. No C.

Aug 21, 2019
The authors demonstrate that in otherwise inhospitable environments, just two ingredients—water and olivine—can form methane.


This statement makes no sense, since there is no Carbon in either of those two ingredients.
Olivine is MgSiO4 & FeSiO4, water is H20. No C.
"When olivine is heated under pressure, it reacts with water and carbon dioxide to create methane, leaving the mineral serpentine behind." -- see Martian methane could come from rocks

Aug 21, 2019
The molecule is simple CH4 and not a complex hydrocarbon chain that constitutes something like petroleum. So the dream of abiotic oil is still a dream, pushed by people such as the Trump acolyte Jerome Corsi under investigation by the FBI.

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