Historical accounts describe how on 21-7-365 an earthquake and subsequent tsunami destroyed cities and drowned thousands of people in coastal regions from Nile Delta to modern-day Dubrovnik in the eastern Mediterranean.

AMCG Make Ancient Tidal Wave

Historical accounts describe how on 21 July AD 365 an earthquake and subsequent tsunami destroyed cities and drowned thousands of people in coastal regions from the Nile Delta to modern-day Dubrovnik in the eastern Mediterranean. The event resulted in rich agricultural lands of the Nile delta being abandoned and an exodus from populous hill cities. If such an event were to occur today it would have catastrophic consequences for densely populated regions of the Mediterranean.

In a study led by Beth Shaw from Cambridge University, Gerard Gorman, Chris Pain and Matthew Piggot of ESE’s Applied Modelling and Computation Group (AMCG), have been working to recreate the tsunami that devastated the Mediterranean in AD 365, in order to determine exactly how the earthquake and tsunami occurred. Using evidence for uplift on Crete, provided by raised ancient shorelines, and observations of faults and modern observations of microearthquakes, the team identified possible candidate faults that may have caused the tsunami-generating displacements. Using their world-leading ocean model Gorman, Pain and Piggot then generated their own tsunamis, as computer simulations, for the candidate faults to determine whether they reproduced the historical records of the event.

The modelled tsunami recreates a devastating direct wave sweeping eastwards along the African coast towards the Nile Delta concentrating destruction at the offshore island of Pharos (the site of the famous lighthouse). The wave even travelled northwest into the Adriatic causing significant damage. The simulations, however, show how the size of subsequent waves, generated by reflections from the shore, was minimised by interference due to the irregular coastline of the enclosed Mediterranean Basin.

Based on the tectonic strain generated by the ongoing closure of the Mediterranean, focused around the northwards dipping Hellenic subduction zone, the research team suggest that tsunami-generating earthquakes in the Mediterranean might be expected every 800 years.
The last event occurred in 1303 suggesting the Eastern Mediterranean remains under threat from tsunami.

Associated Personnel

• Gerald Gorman 
• Chris Pain
• Matthew Piggott 

Links

• Nature Geoscience