Mediterranean tidal wave risk overstated

Although around the world tsunamis killed more than 430,000 people in the first half of the current decade, the risk of being caught up in one in the Mediterranean has been significantly overrated, new research shows.

Research led by James Goff, of the School of Biological, Earth and Environmental Science at Australia’s University of New South Wales, found that as many as 90% of historical tsunami reports in the region had been misinterpreted.

Goff and his team constructed 4500-year record of tidal activity around the Med by studying rock layers. Crucially, they decided not to combine their method – known as stratigraphy – with any associated historical records.

The results, published in the journal Science Advances, revealed a previously hidden pattern. The team found evidence of tsunamis in the area presented in roughly 1500 year cycles, peaking in the Little Ice Age, 3100 and 1600 years ago. Each of these tsunami cycles coincided with previously identified periods of significant climate deterioration over European and north Atlantic areas.

Goff and his colleagues then turned to written records and compared the stratigraphic data to 135 reports of tsunamis. Most of these, the team concluded, reflected bad storms rather than true seismic waves.

The team characterise their findings as “provocative”.

“Understanding the true incidence of devastating tsunamis is vital for assessing the current risk and introducing appropriate protective strategies for densely populated coastal cities,” says Goff.

“Yet discriminating between tsunamis and storm deposits is one of the most challenging and hotly debated areas of coastal geoscience.”

He adds that the findings will assist other researchers in trying to calculate the risks of tsunamis more accurately.