Scientists at the Pacific Tsunami Warning Center in 'Ewa Beach continue to look at ways to improve their response to events such as the massive earthquake that struck Chile in late February, prompting a statewide tsunami warning and evacuation along coastal areas.

Gerard Fryer, geophysicist at the warning center, provided an overview of the agency's response to the tsunami at a gathering last night at the P.F. Chang's restaurant in Kaka'ako. The Honolulu Science Cafe, a monthly event sponsored by the Hawaii Academy of Science, is an informal meeting that allows face-to-face conversations with scientists on timely topics.

Fryer discussed the Pacific Tsunami Warning Center's response to the magnitude 8.8 earthquake off the coast of Chile on Feb. 27. He said based on the size of the quake and initial readings from Deep-ocean Assessment and Reporting of Tsunamis, or DART, buoys, the center forecast tsunami waves of 10 feet on Hawai'i shores.

A tsunami warning was issued here and coastal areas evacuated, but the waves that finally reached the Islands were half the predicted size and caused little damage. But because some areas, such as Hilo and Kahului, are more susceptible to tsunamis, Fryer said, the warning remained in effect despite updated predictions that the waves would not be as big as first anticipated.

Fryer said state and county officials might want to consider changing the tsunami warning system by adding a level between a watch and warning. He said Japan has a three-step warning system.

"At about the time the sirens went off at 6 in the morning, we were pretty darn sure that the tsunami would not be much above 1 meter in height anywhere," Fryer said. "That meant that the all-or-nothing evacuation that we have in Hawai'i actually evacuated too many people. We can make life easier for the general public by not over-evacuating."

He said there are hazards and costs involved in mass evacuations, so warnings are not issued unless "we're absolutely sure."

"The Alaska Tsunami Warning Center, they tell their people if you call a full evacuation of the West Coast, in the resulting traffic one person at least is going to die," Fryer said. "So if you press that button, you're killing somebody."

He said that isn't necessarily the case in Hawai'i, but warnings are taken very seriously. Fryer pointed to tsunami scares in 1986 and 1994 that led to massive traffic jams as people attempted to get to higher ground and said officials have learned from those "unnecessary evacuations."

With improved technology and these experiences in mind, the center did not issue tsunami warnings following large earthquakes at Japan's Kuril Islands in 2006 and in the Sāmoas last year, he said.

Fryer also said the center has improved its notification system since the Chilean earthquake. He said the center sent out its first message 13 minutes after the quake, but has since improved to 11 minutes and "we're striving to speed them up."

In Hawai'i, he said, a message is sent within three minutes of a local earthquake. Fryer said the goal is to get a notification of an earthquake out "within two minutes of the beginning of the shaking."

"The trickiest problem is issuing a warning locally, right where the earthquake is," Fryer said. "The tsunami is going to take sometime before you have a chance to measure it, but by that time it may have killed someone."