Research

Heat of mantle sets height of mid-ocean ridges

Temperature, not chemistry

What appears on the surface correlates with temperature deep in the Earth. Higher ridge elevation indicates a hotter mantle — as in Iceland, above, which also appears to sit atop a mantle plume, a vertical jet of hot rock originating from deep in the Earth. Credit: Allison Gale/University of Wisconsin

By  analyzing the speed of seismic waves generated by earthquakes, scientists have shown that temperature differences deep within Earth’s mantle control the elevation and volcanic activity along mid-ocean ridges, the colossal mountain ranges that line the ocean floor. Recent research sheds new light on how temperature in the depths of the mantle influences the contours of the Earth’s crust.