which once covered 15 million square miles—about a quarter of the Pacific Ocean. For millions of years, it was believed to have been completely consumed by subduction, the process in which one ...

G eoscientists have used earthquakes to study the composition of the lower portion of the Earth’s mantle under the Pacific ...

The Earth’s mantle, stretching up to 1,800 miles thick and making up a whopping 84% of the planet’s volume, used to be ...

(a) Tectonic setting background in the Tonga-Lau-Fiji region. (b) Schematic diagram of the upper mantle structure beneath the Tonga-Lau-Fiji region. A landmark study published in Geoscience—a ...