CIA Says Seismic Event Near Russian Test Site Not a Nuclear Explosion

IN EARLY NOVEMBER, the CIA announced that the August 16 seismic event located in the general area of the Russian nuclear test site at Novaya Zemlya was not a nuclear explosion. The CIA determination ended speculation as to whether Russia had abandoned its unilateral moratorium on nuclear testing and violated international law by defeating the "object and purpose" of the Comprehensive Test Ban (CTB) Treaty, which it has signed. Despite this announcement, however, the agency has not concluded whether the seismic event was an earthquake or an explosion.

The controversy surrounding the seismic event became public in late August when The Washington Times reported that U.S. officials suspected that Russia had conducted an underground nuclear test at Novaya Zemlya. (See ACT, August 1997.) Although Russia had strongly denied conducting such a test, there was no consensus within the U.S. government at that time as to either the nature of the event or its location. As the U.S. investigation proceeded, however, it became clear that the seismic event did not occur at Novaya Zemlya but rather 130 kilometers away below the bottom of the Kara Sea. Even though the location lent strong support to the view that the seismic event was an underwater earthquake, the U.S. government took more than two months to rule out the possibility that it could have been a nuclear explosion.

According to the November 4 CIA statement summarizing the conclusions of an independent panel convened by Director of Central Intelligence George Tenet to review the seismic event, Russia had conducted nuclear weapons related experiments at Novaya Zemlya in mid August. The panel concluded, however, that the seismic event, "was almost certainly not associated with the activities at Novaya Zemlya and was not nuclear." Nevertheless, it asserted that, based on the seismic data, "experts cannot say with certainty whether the Kara Sea event was an explosion or an earthquake." The panel also maintained that the activity at Novaya Zemlya, and the simultaneous event in the Kara Sea "demonstrate the difficulty of accurately identifying and assessing weapons experiments or tests with very low yields."

The panel consisted of Richard Kerr, former deputy director of central intelligence; Sidney Drell, a Stanford University physicist; Roger Hagengruber, vice president of Sandia National Laboratory; and Eugene Herrin, a Southern Methodist University physicist.

Although the U.S. government has announced that the seismic event was not a nuclear explosion, its reluctance to characterize the event as an earthquake is at odds with the views of many respected seismologists. For instance, Lynn Sykes, a professor at the Lamont Doherty Earth Observatory of Columbia University, said October 20, "a strong consensus has developed among experts in the seismological communities in the United States, the United Kingdom, Norway and Canada who are concerned with nuclear verification that the event of the 16th was, in fact, a small earthquake."