Scientists know methane is released from deep-sea vents, but its source has long been a mystery.
Now a team from Woods Hole Oceanographic Institution, US, may have the answer. Analysis of 160 rock samples from across the world’s oceans provides evidence, they say, of the formation and abundance of abiotic methane – methane formed by chemical reactions that don’t involve organic matter.
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, a rock-forming mineral, the researchers write in a paper published in Proceedings of the National Academy of Science.
As the mineral cools, the water trapped inside undergoes a chemical reaction, a process called serpentinisation, which forms hydrogen and methane.
“Here’s a source of chemical energy that’s being created by geology,” says co-author Jeffrey 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 adds. And elsewhere in the solar system, methane produced through the same process could provide an energy source for basic life forms.
Originally published by Cosmos as Geology creates chemical energy
Cosmos
Cosmos is a quarterly science magazine. We aim to inspire curiosity in ‘The Science of Everything’ and make the world of science accessible to everyone.
Read science facts, not fiction...
There’s never been a more important time to explain the facts, cherish evidence-based knowledge and to showcase the latest scientific, technological and engineering breakthroughs. Cosmos is published by The Royal Institution of Australia, a charity dedicated to connecting people with the world of science. Financial contributions, however big or small, help us provide access to trusted science information at a time when the world needs it most. Please support us by making a donation or purchasing a subscription today.
