By Sid Perkins
In unprecedented measurements, volcanologists have pinpointed the source of volcanic gases driving a huge lava fountain from deep in Italy’s Mount Etna.
Scientists have long debated the source of the gases that propel fountains of lava skyward during some eruptions. One theory suggests that the magma is boosted by gases fizzing from the material as it nears Earth’s surface. Another view holds that the fountains are driven by reservoirs of gas that build up within a volcano’s plumbing.