Volcanoes, how Santorini’s sea could teach us to predict an eruption

Discovery could help predict subsequent eruptions. Research has shown that the likelihood of volcanic activity on the island resuming is linked to the height of the water level.

Santorini's sea level could help predict the volcano's eruption. The new finding could also be extended to volcanic activity on other islands. The research, carried out by a team at Oxford Brookes University, was published in Nature Geoscience and starts with the hypothesis that a huge explosion at Santorini in Greece caused the collapse of one of the largest civilizations at the time 3,500 years ago. From studying eruptions on the island over the years, scientists have observed that cycles of volcanic activity appear to be driven by the height of sea water.

The Santorini volcano eruption and sea levels

Approximately 3,700 years ago Santorini was part of a much larger island, the center of Minoan culture that sat on a huge volcano that exploded. The eruption caused the formation of a series of small islands on the edge of the caldera. Prior to this event, the volcano had erupted many times, and researchers observed that the cycles were driven by the sea. "Sea level played an important role in determining the timing of eruptions at Santorini, and probably at many other island volcanoes around the world," said the researcher leading the study, Dr. Christopher Satow of Oxford Brookes University.

"The mechanism is quite simple," Satow explained, "lowering sea level removes mass from the Earth's crust and as a result the crust fractures. These fractures allow magma to rise and fuel eruptions at the surface." However, there is a delay between fracture and eruption. All but three of the 211 eruptions in the last 360,000 years occurred 11,000 years after a period when sea levels were at least 40 meters below their current height.

Because of the rising oceans at the end of the last ice age, Santorini would be approaching a fairly safe period, that is, with little risk of eruptions. So climate would have an influence on volcanic activity, and climate change, as ice caps melt, could alter volcanic cycles not only on the Greek island but also in other parts of the world.

If climate affects volcanic activity, the reverse is also true. A team of chemists has identified a substance, in the eruptions that caused Earth's largest extinction, believed to have altered the chemistry of the planet's oceans triggering a domino effect that eventually suffocated animals around the world.

Stefania Bernardini