A tsunami early-warning system is being installed in the Mediterranean by UNESCO as part of an international monitoring network. At the same time, British scientists warn that there could be a repeat of the devastating tsunami of the 4th century AD in the Libyan Sea.
On 21 July, 365 AD, a powerful earthquake off the west coast of Crete, estimated at 8.3-8.5 magnitude on the Richter scale, raised west Crete by eight metres and caused a tsunami which destroyed the harbour of Alexandria.
The Roman historian Ammianus Marcellinus described how the unexpected giant wave flung large ships three kilometres inland, and even onto rooftops. According to other reports, the tsunami drowned thousands of people in Egypt, Greece, Sicily and even modern-day Dubrovnik in the Adriatic Sea. The crops in the Nile delta were destroyed by seawater and the local towns and cities were deserted.
The last tsunami to devastate the east Mediterranean was on 8 August 1303. According to a study published in 2006, the nine-metre wave which struck Alexandria was caused by a 7.8 Richter earthquake off Crete. The tsunami swept across the Libyan Sea in 40 minutes and struck the shores of Africa.