Lives Could Have Been Saved in Mentawai, Tsunami Expert Says

Dessy Sagita Jakarta Globe 17 Nov 10;

Jakarta. The large number of fatalities caused by the tsunami that devastated the Mentawai Islands off the coast of West Sumatra last month could have been avoided if the much-hyped early warning system had worked properly, an expert says.

“It’s a pity that so many people died unnecessarily when it’s actually easy to evacuate,” Costas Synolakis, director of the Tsunami Research Center at the University of Southern California, said on Tuesday.

Synolakis said that after the 7.7-magnitude earthquake struck off Mentawai, some people saw the warning about a tsunami on television.

“But that was in Sikakap, the biggest city in Mentawai,” he said. “There were many other villages that didn’t even have electricity, they received absolutely no warning to evacuate.”

He said the main flaw of the German-Indonesian Tsunami Warning System (GITWS) set up in the area was in the dissemination of information to the public.

“It isn’t enough to say that an earthquake has happened and how big it is — the main point is to make sure that the warning goes through to the last village,” he said.

He added that what Indonesia really needed was a warning system connected to a network of solar-powered sirens, given that many coastal areas across the country were not connected to the national electricity grid.

“So when an earthquake happens, the sirens will be blaring, waking people up, and they’ll evacuate,” he said.

He said the warning system should also be able to provide a good measurement of the water level to prevent false alarms.

The German authorities previously issued a statement saying their system worked properly on the day, sending warnings via satellite to 400 institutions in Indonesia, including the police, local emergency centers and the media.

The warning aired by the Indonesian government on television was not direct enough to force people to evacuate because it only warned of the “potential for a tsunami,” Synolakis said.

“Don’t say that there’s a potential for a tsunami, say that there will be a tsunami, evacuate now,” he said.

Because Indonesia was located in the Pacific Ring of Fire and would always face the threat of a tsunami, the people should be taught that any earthquake lasting more than 30 seconds should prompt an evacuation, he said.

They should understand that such a quake is strong enough to generate a tsunami, even if the shaking is not very strong, he said.

Synolakis also said it was crucial for Indonesians to stop spreading rumors of larger quakes and tsunamis immediately after a disaster. Because of these rampant rumors, he argued, many of the survivors in the Mentawais now live with a sense of complete helplessness.

“It’s unfortunate that Indonesia is a laboratory for major disasters, but the whole world can learn to save lives from this condition,” he said.

“The most important thing is to live in peace with nature.”

Synolakis, who recently concluded a visit to the Mentawais, said the earthquake that led to the tsunami was particularly noteworthy because even at a magnitude of 7.7, it did not cause much shaking on land, thereby failing to alert the islanders that there had been a major quake.

“Most people we talked to said they could feel the earthquake, but since it wasn’t big enough, they decided to go back to sleep instead of evacuating,” he said.

He added that 10 percent of all earthquakes across the Indonesian archipelago shared similar traits of not producing much shaking but were still capable of generating powerful tsunamis.

Synolakis said the purpose of his visit to Indonesia was to study the mechanics of this rare phenomenon of “tsunami earthquakes,” in cooperation with the Bandung Institute of Technology (ITB) and the US Natural Science Foundation.

“If we can find the answers, we will able to save more lives,” he said.