How fast-rising magma contributed to deadly volcano
Magma from the deadly eruption of Irazú in Costa Rica decades ago, recently helped researchers better understand quickly erupting volcanos. Now scientists hope to learn more by investigating other volcanic sites.
NASA Earth Observatory
Molten rock from Earth's hellishly hot mantle can punch through miles of overlying crust in a matter of months, a new study finds.
Before the deadly 1963 eruption of Irazú volcano in Costa Rica, magma surged 22 miles (35 kilometers) in about two months, traveling from the mantle to the volcano's shallow magma chamber, researchers report in the Aug. 1 issue of the journal Nature. The evidence comes from geochemical tests on crystals of the mineral olivine from ash erupted in 1963. Layers in the crystals helped re-create the magma's pre-eruption journey.
The discovery at Irazú helps confirm other clues for high-speed magma ascents, such as deep-seated earthquakes before eruptions at Mount Pinatubo in the Philippines and Iceland's Eyjafjallajökull volcano, the researchers said. Seismic tremors struck near the mantle below Pinatubo and Eyjafjallajökull in the weeks and months before the blasts. And other geochemical tracers in lava also suggest magma could shoot to the surface from the mantle in mere months. But the new study is the first hard evidence of a fast mode in volcanoes, Ruprecht said. [Amazing Images: Volcanoes from Space]
Page 1 of 4