A nuclear weapon with a force possibly 11 times greater than the atomic bomb dropped on Hiroshima in World War II will be detonated beneath the Nevada desert Thursday morning, the Energy Department said. Jim Boyer, a department spokesman, announced Tuesday the underground weapons test is scheduled for 8 a.m. MST. The weapon is buried 1,600 feet beneath Yucca Flat about 85 miles northwest of Las Vegas on the Nevada Test Site. Earth motion may be felt outside the boundaries of the Nevada Test Site, said Boyer. He said managers of Las Vegas high-rise buildings, where tremors are magnified, have been advised that workers should not be in precarious positions at blast time.