Santorini Volcano’s Ballooning Magma Lifts the Island

According to a new survey carried out by an international team led by Oxford University and a scientist from the University of Bristol, the molten rock beneath Santorini's volcano has expanded by 10-20 million cubic meters between January 2011 and April 2012.

The researchers used satellite radar images and Global Positioning System receivers (GPS) that can detect movements of Earth's surface even to few millimeters.

The ballooning' of magma has seen the surface of the island rise 8-14 centimeters during this period, the researchers found.

Santorini, the site that remains as the largest volcanic eruptions in history was shattered after the Minoan eruption that occurred 3,600 years ago, burying the islands of Santorini under meters of pumice. This survey was carried in the week's Nature Geoscience.

The recent findings are helping the scientist's understand more about the inner working of the volcano. But the researchers cannot predict when the next eruption would occur.

Last year January 2011 series of earthquakes were detected beneath the Santoini Island. According to the researchers most of them were so small they could only be detected with sensitive seismometers. This was the first sign of activity beneath the volcano after 25 years. 

Signs of movement of Earth's surface on Santorini were detected by Michelle Parks, an Oxford University student with the help of satellite radar images.

Parks, the author of the paper said: "During my field visits to Santorini in 2011, it became apparent that many of the locals were aware of a change in the behaviour of their volcano. The tour guides, who visit the volcano several times a day, would update me on changes in the amount of strong smelling gas being released from the summit, or changes in the colour of the water in some of the bays around the islands.

"On one particular day in April 2011, two guides told me they had felt an earthquake while they were on the volcano and that the motion of the ground had actually made them jump. Locals working in restaurants on the main island of Thera became aware of the increase in earthquake activity due to the vibration and clinking of glasses in their bars."

Co-author, Dr Juliet Biggs of the University of Bristol's School of Earth Sciences said: "People were obviously aware that something was happening to the volcano, but it wasn't until we saw the changes in the GPS, and the uplift on the radar images that we really knew that molten rock was being injected at such a shallow level beneath the volcano. Many volcanologists study the rocks produced by old eruptions to understand what happened in the past, so it's exciting to use cutting-edge satellite technology to link that to what's going on in the volcanic plumbing system right now."

The scientists have noticed a decline in the earthquake activity in the past few months.