Samoa quake exposes tsunami warning limitations

CANBERRA (Reuters) - Successive tsunamis which pounded South Pacific islands, killing more than 100 people, have exposed the limitations of early alert systems set up since the 2004 Indian Ocean tsunami, an expert said on Thursday.

Across the Asia Pacific, early warning systems ranging from beach loudspeaker sirens to deep ocean monitor buoys have been set up over the past four years to alert people of tsunamis and prompt them to seek safety on higher ground.

But the magnitude 8 quake struck too close to the islands of Western Samoa and American Samoa to give much warning, with the resulting tsunami approaching shore at the speed of jet aircraft.

"Tsunami warning systems are useless in most of the countries like Indonesia and Papua New Guinea, because the lead time is too short," said Kevin McCue, president of the Australian Earthquake Engineering Society.

"Far better to educate people to make for high ground immediately after they feel shaking that lasts more than about 30 seconds," McCue said.

The Indian Ocean tsunami raced across almost 5,000 km (3,100 miles) to Africa, Thailand and the Indian subcontinent, arriving with enough power to smash communities, change shorelines and kill as many as 225,000 people.

Tsunamis cross open ocean at speeds up to 800 km (500 miles) an hour, eventually slamming ashore at heights of up to 30 meters (100 feet).

The education of people in the Pacific, the world's most active tsunami region, needs to start in schools, where they should be taught to flee automatically, McCue said.

Samoa had begun that process, with people learning the lessons of 2004 and running tsunami evacuation drills, as well as running a mobile phone system of texted alerts and relying on more basic methods.

"There were police cars going up the road just telling residents to go up to higher ground in a very orderly fashion," tourism official David Vaeafe told Sky News.

"In the mountains, young men were banging gas cylinders as church bells, like they were calling people to church," he said.

The death toll still climbed well above 100.

McCue said Australia and New Zealand should help Pacific nations improve building codes and earthquake monitoring.

(Editing by Sugita Katyal)