Commenting on the paper, Prof David Pyle, a volcanologist from Oxford University said: "This new work on Santorini sheds new light on what happens in the lead-up to the rare catastrophic eruptions, like the Bronze Age 'Minoan' eruption, which happen every 20,000 years or so.
"The new evidence from mineral grains appears to strengthen the idea, which has been developing in recent years, that large magma systems appear to awaken from long periods of repose only shortly (months, years or decades) prior to eruption.
"That is, the magma which eventually erupts appears to rise into position, in the top few kilometres of the crust, only a short time before the eruption begins."
However, he said the next problem was to try to understand what was causing this accelerated build up of magma.
"The challenge for volcanologists is to understand what it is that causes these bursts of melt movement; to understand where the melts have come from, and to be able to recognise their signals before an eruption begins.
[link to www.bbc.co.uk
a good article i recommended to read whole article if somebody is intresting about volcanoes.