Education and Careers

Q: In this age of many earthquakes and such like, I have always appreciated how lucky I am to be living in - what seems - a relatively safe part of the world (Great Britain). But if, say, the active volcano on the island of Santorini erupted, would it be inconceivable to think that the effects from such an eruption could trigger a collapse of the Rock of Gibraltar and hence cause a giant Tsunami to head towards the shores of England?

From Mr Mark Newton (October 2009)

Reply by Prof David Pyle

The short answer: yes, it is inconceivable!

Santorini volcano in Greece does have a history of explosive eruptions - but they are rare, with about 12 major events known from the past 250,000 years. The last such eruption, which is often called the Minoan eruption, happened about 3600 years ago. This was a large eruption (larger than the 1883 eruption of Krakatoa, Indonesia, for example), and some scientists have speculated that it may have caused a tsunami which affected parts of the eastern Mediterranean (including, perhaps, parts of the northern shores of Crete), but it has actually proved difficult to find compelling geological evidence for this.

If there was another eruption of the same size as the Minoan eruption, and if the collapse of the volcanic debris into the sea was sufficient to trigger a tsunami, it is highly unlikely that there would be any major impact from the tsunami outside the southern Aegean Sea. Of course, any water wave triggered by this event would probably be detectable by sensitive tide-gauges over long distances: the distant ripples from the Krakatoa tsunami were traced many thousands of kilometres from the source.

Of course, the next eruption of Santorini will most probably not be an explosive eruption at all - but, judging by the activity of the past 300 years, will most likely involve a series of slowly flowing lava flows, with minor explosions as they enter the sea.