Northwest prepared for earthquake

Associated Press

SEATTLE (AP) -- It was the largest earthquake in the Pacific Northwest in more than half a century, registering a magnitude of 6.8. But most of the region's buildings and bridges appeared to have made it through relatively unscathed.

The earthquake started deep in the earth, which meant a lot of its energy had been diluted once it hit the surface, said Bill Steele, a seismology lab coordinator at the University of Washington.

The earthquake was also well spread out, with shaking being felt as far away as Salt Lake City. This reduced its impact in any one place, Steele said.

``Clearly, this was the best possible kind of magnitude quake one can have,'' he said.

Experts also credited efforts to make structures in the area more capable of withstanding earthquakes. Most buildings built since the mid-1970s comply with seismology codes designed to make them capable of standing up to quakes much stronger than Wednesday's temblor.

``The code worked, but it wasn't tested to the full extent,'' Steele said. ``We're kind of below the threshold of the current code design factors.''

Vikram Prakash, an associate professor at the UW's architecture department, studied structures in India last year before an earthquake that devastated parts of that country. Skimping contractors compounded damage from a 7.9-magnitude earthquake that killed thousands of people there, Prakash said.

Building codes here made structures much better able to withstand Wednesday's quake, Prakash said. For example, most residential buildings are made with wood, which is better suited to adjust to earthquakes than masonry. And taller buildings have vertical shear-walls that run through them, making them more rigid, he said.

Without such preparations, ``I'm sure we would have seen a lot more (damage),'' he said.

There no reports of major damage to bridges in the area, officials at the state Department of Transportation said.

A $65 million retrofitting program that started in 1990 saw improvements made on more than 300 bridges across the state, said Ed Henley, a bridge management engineer for the department. By early Wednesday afternoon, Henley said he knew of no bridges that were extensively damaged in the quake, although several remained closed for closer inspection.

``That's what we know right now. We don't have any red lights going off,'' Henley said. ``We would look at the retrofit program as having paid for itself and shown a success.''

The Olympian Copyright 2000

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