Intensity of volcanic eruptions may depend on magma composition

BBC : The geochemistry of magma may determine the degree of explosivity of volcanic eruptions, according to a study published in Nature Geoscience. Researchers from Cambridge University and Hawaii studied Kilauea, an active volcano in the Hawaiian Islands. Kilauea’s eruptions are sometimes relatively gentle, sometimes explosive. Until now the intensity of volcanic eruptions was thought to depend on the velocity of the lava as it approached the surface. However, by examining the detritus left from 25 separate, historical eruptions that have occurred over the past 600 years, the researchers found that the chemistry of the lava itself differed depending on the type of eruption. They propose that magma with more volatile components is more buoyant, ascends more rapidly, and interacts less with the magma reservoir at the volcano’s summit. The findings may help scientists better assess the potential hazards of an impending eruption and aid risk management.