Calculating the threat of tsunami
Box 2 | The disappearance of an ancient civilisation
The disappearance of the Minoan civilisation on the island of Crete in the Aegean Sea about 3500 years ago has intrigued archaeologists for decades. Most agree that it was somehow related to the massive eruption of a volcano on the island of Santorini some 120 kilometres away, but the exact mechanism of the destruction has long been disputed.
One theory is that the Minoans could have been wiped out by falling ash, another is that they were destroyed by a tsunami caused by the volcano. This latter theory is generally held to be more plausible than the first, but until recently there has been little evidence to support it.
Joe Monaghan, a mathematician at Monash University in Melbourne, Victoria, used a computer-based mathematical modelling technique called smoothed particle hydrodynamics to help clarify the mystery. He showed that lava spewed out by the volcano could indeed have generated a tsunami. He also calculated that, given the peculiar sea-bed topography between Santorini and Crete, the tsunami could have produced waves up to 40 metres high.
By modelling the topography of Crete, Monaghan showed that waves of that height would have flooded large chunks of agricultural land on the island and destroyed dwellings. Scientists are now speculating that soil salinisation caused by the inundation, coupled with the destruction of fish stocks due to pollution from the volcano, may have caused food shortages on Crete that eventually led to a revolt by peasants and the ultimate demise of the civilisation.
Boxes
Box 1. What caused the Indian Ocean tsunami on 26 December 2004?
Box 3. The warning system in the Pacific
Related site
Modelling tsunami waves (Monash University, Melbourne,
Victoria)
Further reading
Quakes left Cretan civilisation high and dry (by Kate Ravilious, New Scientist, 8 January 2005, page 9)
Who killed the Minoans (by Bob Johnstone, New Scientist, 21 June 1997, pages 36-39)
Page updated February 2005.