The disappearance of a tectonic plate into Earth’s interior may be responsible for the distinctive bend in the chain of underwater mountains and islands that includes the Hawaiian archipelago.
A reconstruction of the mantle flowing under the Pacific Ocean about 50 million years ago suggests that the submergence of the Izanagi Plate near East Asia reversed the flow’s direction. This mantle U-turn could have immobilized the mantle-dwelling plume of magma that built the mountain ranges, the researchers report online March 24 in Geophysical Research Letters. The abrupt stop probably caused the roughly 120-degree kink in the Hawaiian-Emperor seamount chain as Earth’s crust moved westward over the plume, they conclude.