Mediterranean tsunami could 'swamp' Greece, Italy and Libyan coasts


Highly populated coastal areas of Greece and Italy would be inundated if a moderately powerful earthquake in the Mediterranean triggered a tsunami, research has shown.

Scientists simulated what would happen if a magnitude 7 earthquake occurred beneath the Mediterranean sea off Sicily or Crete.

The results showed that low-lying areas up to five metres (16 feet) above sea level would be swamped by the resulting tsunami. Italy, Greece and Libya could all be hit by the waves, with up to 3.5 square kilometres (1.35 sq miles) of the island of Crete submerged.

A large tsunami occurs in the Mediterranean once a century on average. In 1908, thousands of people died when a magnitude seven earthquake struck the Messina region of Italy, generating waves more than 10 metres (33 feet) high.

In the year 365 AD, a cluster of strong tremors off the coast of Crete triggered a tsunami that destroyed ancient cities in Greece, Italy and Egypt, killing some 5,000 people in Alexandria alone.

Dr Achilleas Samaras, from the University of Bologna in Italy, who led the computer modelling study, said: "Although the simulated earthquake-induced tsunamis are not small, there has been a recorded history of significantly larger events, in terms of earthquake magnitude and main shock areas, taking place in the region."

About 130 million people live around the rim of the Mediterranean, and many would have very little warning before being hit by a tsunami.

The team, whose results appear in the journal Ocean Science, programmed their simulation with information about sea floor depth and shoreline topography.

"We wanted to find out how coastal areas would be affected by tsunamis in a region that is not only the most active in the Mediterranean in terms of seismicity and tectonic movements, but has also experienced numerous tsunami events in the past," said Dr Samaras.

"We simulate tsunami generation by introducing earthquake-generated displacements at either the sea bed or the surface. The model then simulates how these disturbances - the tsunami waves - propagate and are transformed as they reach the nearshore and inundate coastal areas."