Greek Island Shows Signs of Volcanic Unrest

The volcanic caldera on the picturesque tourist island of Santorini is showing signs of unrest. But researchers detecting the caldera's movement say it doesn't necessarily mean an eruption is imminent.

The Greek island was the site of one of the most massive volcanic eruptions in history 3,600 years ago. That eruption, which created tsunamis 40 feet (12 meters) tall, may have spawned the legend of the lost city of Atlantis. The volcano last erupted in 1950, albeit on a much smaller scale.

Global positioning system (GPS) sensors placed on the caldera have detected renewed movement after decades of peace. The earth around the caldera (a depression at the top of a volcano) is deforming, or expanding outward, researchers report in an upcoming article in the journal Geophysical Research Letters. GPS instruments on the northern part of Santorini have moved between 1.9 and 3.5 inches (5 to 9 centimeters) since January 2011, said study researcher Andrew Newman, a geophysicist at Georgia Tech in Atlanta. Source