Tougher codes kept California quake damage down

An expert with the U.S. Geological Survey said tough buildings codes enacted after the deadly Northridge, Calif., quake in 1994 is the reason Tuesday's earthquake caused only minor damage.

By Consulting Specifying Engineer Staff August 1, 2008

One reason the California earthquake caused only minor damage was new, tough building codes enacted since the deadly Northridge quake in 1994, according to an expert with the U.S. Geological Survey (USGS).

Tuesday’s quake “was located in an area that’s been almost completely built since about 1995,” seismologist Lucy Jones said. “We had major changes in the building codes because of what we learned in Northridge. And the most modern construction is really much, much better to withstand earthquakes than earlier buildings. There weren’t many older buildings nearby.”

The magnitude-5.4 earthquake in metropolitan Los Angeles, California, caused no serious damage or injuries, but experts say it’s a reminder that the “Big One” could happen at any time.

Seismologist Jones heads a U.S. Geological Survey team working on earthquake preparedness.

She says it should be possible to set up a warning system that would send out an alert after an earthquake begins, giving people a few seconds’ warning that could be a lifesaver.

“We could do some very simple things like bringing alarms into operating rooms, so the surgeon pulls the scalpel out of your chest,” she said.

“You could have all elevators in the city connected to this so that they move to the nearest floor and open the door and you don’t get caught in the elevator during the earthquake. You could stop handling of toxic materials.”

Tuesday’s earthquake was “a sample, a small sample” of what earthquakes can do, said Kate Hutton, a seismologist at the California Institute of Technology. iReport.com: Cameras capture drama unfolding.

“Every earthquake relieves some stress,” Hutton said. “It’s usually only a drop in the ocean. In other words, the amount of stress released by this earthquake is minuscule compared to the amount that’s built up and is building up for the Big One when it happens some day in the future.”

And when will that be?

“From a geologist’s point of view, the answer has to be soon,” she said. “But geologists are used to thinking on millions of years and thousands of years time scale, so I don’t think that gives any useful information for people, except be prepared at any time because it could happen at any time.”

There is a 99% chance of California experiencing a quake of magnitude 6.7 or more within the next 30 years, according to the Uniform California Earthquake Rupture Forecast, sponsored by the U.S. Geological Survey, the California Geological Survey and the Southern California Earthquake Center in a report published in Science Daily in April.

The largest earthquake in recent years in California was a magnitude 7.1 in 1999, Hutton said. But it was centered in the desert, near Twentynine Palms, in a sparsely populated area

The Northridge earthquake in 1994 was magnitude 6.7. It killed 60 people and caused major damage in the Los Angeles area.

Tuesday’s quake struck about 11:42 a.m., according to the USGS. Its epicenter was about 2 miles southwest of Chino Hills and about 5 miles southeast of Diamond Bar.

Los Angeles police said a downtown hotel sustained some structural damage, but no one was injured, and the building was not evacuated. There were some unconfirmed reports of minor injuries.

Despite the absence of serious damage or injuries, some Los Angeles-area residents were left rattled. The quake was felt as far south as San Diego, and the Usaid it received reports of light shaking as far away as Rosamond, California, about 55 miles north-northeast of Los Angeles

The quake knocked out a ground radar system at Los Angeles International Airport, but that did not interfere with operations, according to the Federal Aviation Administration. Tiles fell from the ceiling in one terminal as water flowed from a burst pipe.
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