*LONDON – Tsunamis will become more common and more ferocious with globalwarming, scientists have warned after a study found that the rise in globalsea level will increase the risk of coastal cities being wiped out.*
Smaller earthquakes that currently pose no serious tsunami threat couldunleash waves capable of inundating coastal cities, researchers found in astudy focusing on the city of Macau in China.
Currently, it is considered safe from tsunamis, despite lying within amajor earthquake zone.
At today’s sea level, it would take a very powerful earthquake tipping pastmagnitude 8.8 to cause widespread tsunami flooding in Macau.
But a half-meter rise in sea level – predicted to occur in the region by2060 – could more than double the chances of a huge tsunami swamping theterritory, according to the research.
A three-foot sea level rise, expected by 2100, would increase the risk byup to 4.7 times.
The source of the earthquake danger is the Manila Trench, a massive crackin the floor of the South China Sea formed by the collision of two tectonicplates. It has generated numerous earthquakes, though none larger thanmagnitude 7.8 since the 1560s.
A modest rise in sea levels would greatly amplify the tsunami threat fromsmaller earthquakes, the computer simulation study showed.
Lead researcher Dr. Robert Weiss, from Virginia Polytechnic Institute andState University (Virginia Tech) in the US, said: “Our research shows thatsea-level rise can significantly increase the tsunami hazard, which meansthat smaller tsunamis in the future can have the same adverse impacts asbig tsunamis would today.
“The South China Sea is an excellent starting point for such a studybecause it is an ocean with the rapid sea-level rise and also the locationof many mega cities with significant worldwide consequences if impacted.”
The team’s findings are reported in the journal Science Advances. -Agencies