Lessons learned


POSTED: Sunday, October 25, 2009

Tsunami and civil defense experts in Hawaii say last month's earthquake and tsunami in Samoa should raise awareness of the threat of a similar disaster happening here.

The worst-case scenario for Hawaii is a local earthquake off the Big Island generating a tsunami that hits the Kona coast within five minutes and could hit Maui and Honolulu within 15 to 30 minutes, said Gerard Fryer, a tsunami expert with the Pacific Tsunami Warning Center, who recently returned from American Samoa.

Fryer said the center should be able to issue a tsunami warning within three minutes of the earthquake and is working on getting the warning time down to within two minutes.

But one of the lessons of the Samoa tsunami is that people who live on the coast should not wait for a warning.

“;You gotta know what to do. You can't always depend on the siren,”; said Ed Teixeira, state vice director of civil defense.

Teixeira and Fryer said residents who live in tsunami zones should have an evacuation plan to get to higher ground or to a higher floor in a concrete, multi-story building.


The other lesson learned is that public education and awareness about tsunamis saved lives, the experts said.

“;That certainly was the big lesson for Samoa,”; Fryer said. “;The people knew what to do.”;

Fryer said some residents knew right after the earthquake that a tsunami could be generated. Others recognized the signs when the water receded.

“;I don't think anybody went towards the ocean,”; he said.

Even with the higher awareness, a total of 186 people died in American Samoa, independent Samoa and Tonga in the Sept. 29 disaster.

Every tsunami gives scientists and civil defense experts an opportunity to improve their planning, Teixeira said.

State and county civil defense officials and the Pacific Tsunami Warning Center were on conference calls within minutes of the Samoa earthquake, Teixeira said, a system developed after an 8.3 earthquake in the Kuril Islands north of Japan in November 2006.

Fryer said another possible lesson from Samoa is that driving away may not be the best way to flee a tsunami.

He said a group of 40 schoolchildren in Samoa were in a bus and only about 150 feet away from high ground when their bus was hit by the wave. They would have been better off running to high ground, he said.

A breadfruit tree kept the bus from overturning, Fryer said. “;It was a very close thing,”; he said. “;They all survived.”;

Research and computer models based on past tsunamis also help scientists better predict the likelihood of a tsunami hitting Hawaii, Fryer said.

“;We can improve the reliability of the system,”; he said. “;We can improve the warnings so only those places truly at hazard get the warnings ... Every tsunami helps us do that.”;

If the Samoa earthquake had happened 10 years ago, Fryer said, the warning center and civil defense officials would have likely ordered everyone away from the coast.

But because of improved computer modeling, Fryer said, “;for several events now, we have managed to avoid calling for a full coastal evacuation.”;

University of Hawaii researcher Kwok Fai Cheung recently updated the tsunami inundation zone maps for Hawaii based on new computer modeling, Fryer said. Those new maps are being evaluated by county and state civil defense officials and will soon be made public, he said.

The recent Samoa tsunami will help civil defense agencies make the case that the new maps need to be adopted, Fryer said.

“;In many ways the Samoa tsunami is really going to help us in Hawaii,”; he said. “;It has raised awareness.”;