Marseille, Alexandria and Istanbul prepare for Mediterranean tsunami

Japan’s 2011 tsunami was 40m high but 1.5m waves can move cars. The 2004 tsunami, in which 230,000 people died, was a ‘wake-up call’, Unesco says. Photograph: Kim Kyung-Hoon/Reuters

A tsunami could soon hit major cities on or near the Mediterranean Sea including Marseille, Alexandria and Istanbul, with a nearly 100% chance of a wave reaching more than a metre high in the next 30 years, according to Unesco.

The risk of a tsunami in Mediterranean coastal communities is predicted to soar as sea levels rise. While communities in the Pacific and Indian Ocean, where most tsunamis occur, were often aware of the dangers, it was underestimated in other coastal regions, including the Mediterranean, Unesco said.