Science: Undetectable & Underground

• Share

Late in 1958, U.S. negotiators met with the Russians and British in Geneva, proposed a system for monitoring nuclear bomb tests based on a network of 180 control stations. The U.S. has been regretting the offer ever since. Only two months later, U.S. scientists exploded a small nuclear device beneath a mesa in Nevada, which proved that such explosions were far harder to detect than the U.S. had supposed. Difficulty is that the Russians have embraced the 180-station system as if they had thought of it themselves. For months they refused even to listen to the U.S.'s new evidence. And then, when they finally consented, they listened in stony disapproval. Last week, after three weeks of futile argument, U.S. and British scientists gave up trying to reach agreement with their Russian counterparts, and adjourned talks until Jan. 12.

"Very disappointing," said the U.S. State Department. Chief problem is in providing a system sensitive enough to distinguish nuclear shocks from normal small earthquakes, of which thousands occur every year. Under the Russian-approved system, U.S. negotiators pointed out, the Nevada shot—a ig-kiloton explosion—would have been read as an earthquake, and therefore ruled out for inspection. New ammunition was a study made by the Rand Corp., at the suggestion of Dr. Edward Teller, director of the Lawrence Radiation Laboratory in Livermore, Calif. Rand mathematicians theorized that any underground explosion can be "decoupled" by placing it in a large enough cavity, and thus can defeat the detection network. If anybody cared enough to dig a cave 3,000 ft. down and 950 ft. in diameter—an excavating job equal to removing a mass of material equal in volume to the concrete in 42 Grand Coulee dams—it would muffle a 300-kiloton bomb so much that the explosion "might be made to appear seismically like one kiloton. This could not be distinguished by the Geneva seismic network from the thousands of natural earthquakes of this magnitude occurring every year." Similarly muffled, an explosion of 100 kilotons might not be detected at all.

The Russians complained that the West was making "tendentious" use of "one-sidedly developed material for the purpose of undermining confidence" in the 180-station control system. The U.S.-British position was that no control system at all might be better than one that lulled the West into an illusion of security, behind which its enemies might test on, the explosions muffled in huge caverns in the depths of Siberia, secret and undetectable.