http://www.newsweek.com/hidden-magma-chamber-critical-point-poses-serious-threat-1774119

A giant magma chamber has been discovered growing underneath an active submarine volcano in Greece.

Scientists, who have published a study on the chamber in the American Geophysical Union's Geochemistry, Geophysics, and Geosystems, have determined that the magma chamber under Kolumbo increases the chances of a future eruption. They believe it could reach a critical point in the next 150 years and pose a "serious threat."