Mount St. Helens eruption in 1980
Step aside, crystal balls—another kind of crystal could help scientists forecast eruptions. The structure of microscopic crystals in lava oozing out of volcanoes give clues into when and how a volcano will erupt, according to a study on Mount St. Helens just published in Science.
For six years after Mount St. Helens infamously blew its top in 1980, the volcano in Washington continued to spew and sputter, erupting periodically. Each eruption brought more magma to the surface, and crystals embedded in the magma are snapshots of what happened inside the volcano just before each eruption. They contain concentric circles of elements like iron and magnesium, just like tree rings. Volcanologists examined over 300 of these crystals from Mount St. Helens, each no more than 1/10 of a millimeter in size.