Quake felt here, but only minor damage is done

Monday, Oct. 18, 1999 | 11:38 a.m.

Sun reporter Jace Radke contributed to this report.

For people living in Los Angeles, Las Vegas and Phoenix, luck and location prevented deaths and serious injuries from the 7.0 magnitude earthquake that struck California early Saturday morning.

In Las Vegas the shock registered about a 5.0 magnitude on a seismograph running at UNLV's Geoscience Department.

The quake hit the Pisgah fault, thought to be inactive, in the middle of the California desert about 150 miles southwest of Las Vegas and was the largest temblor felt in the Las Vegas Valley since the 7.3 magnitude Landers, Calif., quake in 1992.

Only a handful of minor injuries was reported from Saturday's temblor, compared with the Landers quake that left one person dead, injured 400 and caused nearly $100 million in damages in California.

During Saturday's quake, tourists staying in high-rise resorts in Las Vegas felt the earthquake's motion perhaps more than other valley residents, because the shock waves are magnified in skyscrapers.

The only reported damage occurred in four rooms at the Golden Nugget hotel-casino when sprinklers went off on the 21st floor.

Catherine Koster and her sister were awakened by the quake as they slept in their room at the high rise Mirage hotel-casino.

"It woke us up, and I didn't know what was happening," said Koster, a Chicago native. "The bed started sliding and the wood console that held the TV was creaking."

Julie Koster, who also lives in Chicago, had been in an earthquake before.

"I lived in Southern California about nine years ago, but I'd forgotten what these (earthquakes) were like, and I didn't want to remember," Julie Koster said.

For geologists the quake was not unexpected, although the date and time of when a jolt will occur is always a surprise. California, Alaska and Nevada are the three most seismically active states in the nation.

"It's a wakeup call," retired Nevada Test Site seismologist Jim O'Donnell said Sunday.

If Saturday's quake had hit downtown Los Angeles or Las Vegas, the casualties would have been catastrophic, O'Donnell said. He volunteered to help set up the university's active seismic station earlier this year.

A similar quake at Yucca Mountain, 90 miles northwest of Las Vegas, the site of a proposed high-level nuclear waste repository, would not be catastropic, however, according to Department of Energy scientists. The repository, which has not yet been approved, is being engineered to withstand a 7.0 magnitude earthquake.

The earthquake did no damage at Yucca Mountain, which is 240 miles northeast of the epicenter.

Some 36 known faults run along and around Yucca Mountain, but DOE scientists believe the faults are inactive. Two faults go through the proposed repository.

A more intense earthquake, DOE scientists say, would not jeopardize the repository but would likely cause damage to structures above ground.

Saturday's main quake lasted 10 to 15 seconds, but aftershocks are still rumbling across the desert, including 18 aftershocks of 4.0 magnitude or larger than appeared on the local monitor by noon Saturday.

So what are the chances that a 7.0 magnitude temblor will rock the Las Vegas Valley?

Not likely, if the scientists are reading the Earth's record correctly.

There has never been any structural damage from an earthquake recorded in Las Vegas, Clark County Building Department Director Ron Lynn said.

Major resort hotels have evacuation plans in place to remove guests from their rooms in case of an earthquake striking some of the 20 known faults in the Las Vegas Valley. Geologists know of 265 faults in Nevada.

But the Nevada Seismic Council is paying more attention to earthquake potential as the population continues to grow. For most of the state, scientists do not have enough information to date past quakes.

From a worldwide perspective, 7.0 magnitude or greater earthquakes strike from 15 to 20 times a year, Susan Hough of the U.S. Geological Survey in Pasadena, Calif., said.

The reason people are becoming more earthquake-conscious is because temblors have jolted more populated areas in Taiwan and Turkey as well as California this decade, Hough said.