Nuclear Weapon Detonated; 2 Protesters Held

YUCCA FLAT, Nev. —  A nuclear weapon was detonated 1,500 feet beneath the Nevada desert Saturday, generating the force of a moderate earthquake that was felt by some observers on high-rise gambling resorts 85 miles away in Las Vegas.

The test, code-named “Metropolis,” was the first nuclear test announced by the United States this year.

Eleven anti-nuclear protesters held a vigil near the gates of the Nevada Test Site, 30 miles from where the weapon was triggered beneath Yucca Flat, an arid desert flat on the Nevada Test Site.

Two men were arrested on charges of trespassing when they stepped over the government property line at the top-secret Department of Energy facility. Eighteen protesters briefly picketed the Department of Energy building in downtown Las Vegas without incident.

A spokesman at the Earthquake Information Center in Golden, Colo., said the nuclear blast measured 5.1, a magnitude equivalent to a “moderate” earthquake. The recent Upland earthquake in Southern California had a magnitude of 5.5.

Chris West, a spokesman for the Department of Energy, said government observers on the high-rise Fitzgerald’s hotel-casino in downtown Las Vegas reported feeling “a slight earth motion” but were unable to determine the direction of the earth movement.

Observers at the high-rise Regency Towers, a posh condominium on the Las Vegas Country Club near the Strip, also felt slight motion.

There were no other reports of earth motion and no damage, West said.

The detonation at 8 a.m. PST had a yield of 20 to 150 kilotons, or a maximum equivalent of 150,000 tons of TNT. The atomic bomb dropped on Hiroshima during World War II was a 13-kiloton weapon.

U.S. officials announced 12 underground nuclear weapons tests last year at the Nevada Test Site, six of which were in the 20 to 150 kiloton range.

“No radiation escaped into the atmosphere and initial data indicates the test was a success,” West said.

He described the earth motion from a control point 11 miles from ground zero as similar to “sitting in a rowboat and gently rocking back and forth.”

“There were no problems. Everything went fine,” he said.

The detonation sent a funnel of dust into the clear desert sky above ground zero, as the earth bulged skyward about a foot from the force of the underground detonation.

Helicopters and fixed-wing government planes circled above ground zero with radiation monitoring equipment, prepared to track any radiation that might leak into the atmosphere by accident.

The nuclear weapons test, conducted by the Livermore National Laboratory, was the 700th at the Nevada Test Site since the Rhode Island-sized facility became operational in 1951.