Magma pockets surrounding Earth’s core could explain hot-spot volcanism

Science : Hawaii and Yellowstone National Park are far from the tectonic plate boundaries that provide openings to Earth’s mantle, which makes the presence of magma near the surface in those areas something of a mystery. Alexander Goncharov of the Carnegie Institution of Washington and his colleagues believe they have found an explanation. They subjected a glass, which had a similar chemical composition to magma, to pressures equivalent to those found between the planet’s mantle and outer core, some 3000 km below Earth’s surface. As the pressure increased, the atomic structure of the glass changed, allowing heat to pass through the material more quickly. They propose that pockets of magma surrounding the outer core may get squeezed and heated up by the extreme pressure there and then transfer that localized heating to the mantle, creating plumes of hot mantle rock that rise to the crust, even in areas far from active tectonic regions. Although they admit that the theory is plausible, some scientists point out that it isn’t certain that magma behaves the same way as the glass. Until a similar experiment is done with molten rock, the researchers’ findings remain speculative.