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The Honolulu Advertiser
Posted on: Monday, April 9, 2007

Experts to report on October quakes

By Kevin Dayton
Advertiser Big Island Bureau

HILO, Hawai'i — More than 400 seismologists will gather on the Big Island this week to review hundreds of papers on the latest research into causes and effects of earthquakes as part of the annual meeting of the Seismological Society of America.

Friday morning's session at the Hilton Waikoloa Village will be devoted to papers probing the causes and the responses to the magnitude 6.7 and 6.0 earthquakes last Oct. 15 that did an estimated $200 million damage to Big Island homes, businesses and public facilities.

Among the topics covered in the presentations on Wednesday, Thursday and Friday will be scientists' efforts to predict earthquakes or provide early warning for seismic events; research to identify areas with the greatest earthquake risks; and the interactions between earthquakes and volcanoes.

The papers will include a report by scientists at University of California, Berkeley who are testing a "pre-prototype" model of an early warning system for earthquakes in Northern California. The system is designed to detect the onset of an earthquake and instantly produce an estimate of the expected peak ground motion.

Since San Francisco Bay Area residents live on the faults, scientists say even an extremely fast system would provide less than a minute of warning, at best, for that region.

However, those seconds could be critical if the alarm were linked to systems such as the automated Bay Area Rapid Transit system, allowing the trains to slow from their cruising speed of 60 mph just before the shock hits.

The latest seismic research designed to improve scientists' ability to detect the "seismic footprint" of underground nuclear explosions will be the subject of another paper.

Presentations on the Kiholo Bay earthquakes of Oct. 15, 2006, will include a discussion by Big Island Mayor Harry Kim and county Public Works Deputy Director Jiro Sumada on lessons learned during the response to those earthquakes.

Analysis of damage done by the earthquakes to homes and public facilities also will be presented, including findings that about one out of 25 homes on the Big Island was damaged.

A report by the engineering firm Martin & Chock found that among the damaged homes, those built using post-on-pier construction were 2.5 times more likely to be tagged as entirely or partly unusable as homes built on concrete slabs.

Another presentation by experts compares the earthquake damage estimates generated by a computer model with the best estimates of the damage from the Kiholo quakes.

The authors of that paper estimate that the losses from a repeat of the 1868 earthquake centered near Pahala, which was believed to be a magnitude 7.9 temblor, would generate two to three times the estimated $200 million in losses from the Kiholo quakes.

Reach Kevin Dayton at kdayton@honoluluadvertiser.com.