The lingering puzzle on how Earth's tectonic plates are powered has been answered by a new study that challenged a reigning theory.
The postulate has been that Earth's tectonic plates are run by negative buoyancy induced by the plates' cooling. A new research, however, states that at least 50 percent of the plate dynamics is powered by the heat flowing from the core of Earth to the mantle.
Led by David Rowley, a professor at University of Chicago's geophysical sciences department, the study claims that heat is being emitted from the core to the mantle base to move the tectonic plates and 50 percent of plate dynamics owes to the heat from the core.
They drew the conclusions by clubbing observations on the sea ridge East Pacific Rise with the new data gathered from the mantle's flow modeling.
"Based on our models of mantle convection, the mantle may be removing as much as half of Earth's total convective heat budget from the core," Rowley said
The findings have been published in Science Advances.
In terms of quantity, the heat flow between core and mantle can be about 20 terawatts capable of making continents and unmaking cities.
Tectonic Plates
Tectonic plates made of crust and mantle's top portion with Asthenosphere — the viscous and warm part lying below it. The latter works like a conveyor belt in forcing the 15 tectonic plates to ride on it in rendering the current shape of the landscape.
The new study is certain to revolutionize earthquake predictions. Earthquakes mostly originate from the boundaries of tectonic plates and not from the middle of plates. They are triggered by reactivation of ancient faults or rifts on the plates.
"The consequences of this research are very important for all scientists working on the dynamics of the Earth, including plate tectonics, seismic activity, and volcanism," noted Jean Braun from the German Research Centre for Geosciences.
Subduction Theory Inadequate
The new study scores over the old theory that harped on underwater ridges like the East Pacific Rise are passive boundaries between moving plates.
That was on the premise that the East Pacific Rise as a whole did not move east-west for 50 to 80 million years compared to other mid-ocean ridges despite the marginal asymmetric spread of some parts. The new study said the subduction theory is falling short in explaining that process.
The new findings said the plates' are moving from the buoyancy supplied by the heat of the Earth's interior and is reducing the mantle material's density by expanding buoyancy to rise and align with plates adjoining the East Pacific Rise.
Mantle Managing Heat
"The East Pacific Rise is stable because the flow arising from the deep mantle has captured it," Rowley said and added the stability is linked to the controlled mantle upwelling.
According to Braun, if the heat coming from the core is substantial then the total heat contained in the core might be higher than envisaged earlier.
