By Sid Perkins
From Victoria, British Columbia, at a meeting of the Seismological Society of America
Between October 1961 and October 1989, the former Soviet Union conducted 340 underground nuclear tests at a site near Semipalatinsk, Kazakhstan. A statistical analysis of the times and dates of those tests suggests that the favorite numbers of the test site commanders may have had a significant influence on the precise timing of the detonations.
The month and day of the test appear to have been influenced by human factors, says Vitaly I. Khalturin, a seismologist at the Lamont-Doherty Earth Observatory in Palisades, N.Y. For example, 51 of the 340 tests were conducted in the month of December, but only 8 detonations occurred in January. There’s no natural reason for this disparity, says Khalturin, because the weather in the area is equally miserable in December and January. Similarly, only 16 tests happened during the first 3 days of any month, but 64 explosions were set off in the last 3 days of a month. Both of these patterns held true throughout the 28-year period. Khalturin attributes these statistical curiosities to what he terms the Soviet factor, a tendency for the generals in charge to schedule tests near the end of a year or month to meet a quota.
The minute of the hour at which a detonation occurred also appears to have been left up to the general in charge of the test because Khalturin discovered four different nonrandom patterns in this parameter during the 28 years. For example, between January 1969 and July 1972 about 78 percent of the nuclear tests were detonated during odd-numbered minutes, and more than half of those ended with the number 3. In the 9 years that followed, more than half of the tests happened during minutes that ended in the number 7. These patterns are interesting because 3 and 7 are prominent in many Russian tales, sayings, and proverbs, says Khalturin.
A comparable analysis of the dates and times of the United States’ 828 underground nuclear tests conducted in Nevada between 1957 and 1992 doesn’t show as many patterns. There was only a minor season-associated variation in the number of tests.
One interesting note, however: Whoever scheduled the U.S. atomic tests apparently was superstitious. Fewer than half the expected number of detonations occurred on the 13th day of a month.
