Volcanoes swell before blasting

Pronounced uplift of volcano centres seems to be a reliable sign of imminent eruption along Indonesia's west Sunda arc, one of the most active volcanic regions on Earth.

Estelle Chaussard and Falk Amelung of the University of Miami in Florida conducted a radar remote-sensing survey of volcanic inflation in 76 historically active volcanoes on the islands of Sumatra, Java and Bali between 2006 and 2009. Of six volcanoes that showed a clear uplift signal during this period, three أ¢â‚¬â€‌ Sinabung (pictured), Kerinci and Slamet أ¢â‚¬â€‌ erupted soon after.

The authors conclude that measurable inflation is a frequent precursor to volcanic eruptions in regions where magma reservoirs are typically located at relatively shallow depths, as in Indonesia. The findings could improve forecasts of volcanic activity.