When Will It Blow?

Gravity could provide clues to the timing of volcanic eruptions

PREDICTING VOLCANIC ERUPTIONS IS A NOTORIOUSLY inexact science, and no one knows that better than people along the "ring of fire" that extends through Southeast Asia. Without warning last week the Philippines' Mayon volcano blew up, killing at least 68 and driving thousands from their homes.

There is hope, though, that forecasts will improve. In Nature, geophysicist Hazel Rymer and colleagues at England's Open University reported a possible sign of an impending eruption: shifts in gravity. They found that the gravitational field around Italy's Mount Etna increased sharply six months before it spewed forth in December 1991.

Rymer cautions that gravity...

Want the full story?

Subscribe Now


Get TIME the way you want it

  • One Week Digital Pass — $4.99
  • Monthly Pay-As-You-Go DIGITAL ACCESS$2.99
  • One Year ALL ACCESSJust $30!   Best Deal!
    Print Magazine + Digital Edition + Subscriber-only Content on TIME.com

Learn more about the benefits of being a TIME subscriber

If you are already a subscriber sign up — registration is free!