University of Toronto geoscientists have made a significant breakthrough in plate tectonics, discovering that the Pacific Plate is not as rigid as previously thought but is instead torn by large undersea faults. This challenges traditional views and suggests a more complex interaction between oceanic plates and the Earth’s mantle. Credit: SciTechDaily.com
For millions of years, the Pacific Plate — which constitutes most of the floor of the ocean — has drifted westward to plunge down into Earth’s mantle along undersea trenches or subduction zones that run from Japan to New Zealand and Australia. As the western edge of the plate is pulled down into the mantle, it drags the rest of the plate with it like a tablecloth being pulled from a table.
“It was thought that because the sub-oceanic plateaus are thicker, they should be stronger,” says Gün. “But our models and seismic data show it’s actually the opposite: the plateaus are weaker.” The theory of plate tectonics has been refined over many decades by numerous earth scientists — including U of T’s John Tuzo Wilson who made significant contributions to it during his career.