Science Under Pressure

MIT-WHOI Joint Program student Emily Sarafian wields a hydraulic jack to demonstrate how to set up a piston-cylinder apparatus. She uses the device to carry out high-temperature, high-pressure experiments on rock samples, simulating conditions inside Earth’s upper mantle. In research published recently in the journal Science, Sarafian combined two very different approaches to geological research—experimental petrology and magnetotellurics, a branch of geophysics—and discovered that the mantle beneath the sea floor could be as much as 110°F hotter than previously thought. A hotter mantle would be more fluid, helping to explain the movement of Earth’s rigid tectonic plates. (Photo by Véronique LaCapra, Woods Hole Oceanographic Institution)