The first underground nuclear weapons test of 1989 was strong enough to shake some highrise buildings in the gambling city of Las Vegas, 80 miles away.

Friday's test, code-named Texarkana, had been scheduled for Thursday but was delayed by snow. It was delayed four hours Friday by low cloud cover at the Nevada Test Site, a 1,350-square mile expanse of des-ert northwest of Las Vegas.The weapon, buried 1,650 feet beneath the surface of Yucca Flat, had an explosive yield equivalent to between 20 and 150 kilotons of TNT, said Energy Department spokesman Jim Boyer, who was at the control center 7.5 miles from ground zero.