Fuel source found hidden under deep sea floor

Scientists have discovered a potential source of free hydrogen gas near tectonic plates under the sea floor.

Free hydrogen gas (H₂) is believed by scientists to be responsible for life being triggered on Earth. If found in large enough quantities, it could be used as a clean burning substitute for fossil fuels as when burnt it emits water. Previously, recent discoveries of H₂ have been found under slow spreading tectonic plates.

Stacey L Worman, a postdoctoral fellow at the University of Texas and lead author, said: “Our model, however, predicts that large quantities of H2 may also be forming within faster-spreading tectonic plates -- regions that collectively underlie roughly half of the Mid-Ocean Ridge.”

The model suggests that total H₂ production occurring under the oceans is at least one order of magnitude more plentiful than under production under continents. It takes into account the effect of tectonic plates spreading and the thickness of serpentinised rocks — rocks created chemically altered by water as they are lifted up by spreading tectonic plates.

Professor Lincoln F. Pratson, from Duke University, who co-authored the study said: “A major benefit of this work is that it provides a testable, tectonic-based model for not only identifying where free hydrogen gas may be forming beneath the seafloor, but also at what rate, and what the total scale of this formation may be, which on a global basis is massive.”

Free hydrogen gas molecules are produced as a by-product of the serpentinisation of rocks. Mining the gas would remove the obstacle of having to split water, using energy, to then burn the H₂ as fuel. Scientists are now trying to work out where exactly the gas goes after it is produced.

If the model’s accuracy can be confirmed, it could provide insight on how hydrogen gas could support life in extreme environments, either on the sea-floor or distant planets.

The research was published in Geophysical Research Letters.