Silencing the Bomb


Godzilla, Toho, 1954

by Eric Lizon

Silencing the Bomb: One Scientist’s Quest to Halt Nuclear Testing,
by L. R. Sykes,
New York: Columbia University Press, 304 pp.

In Silencing the BombOne Scientist’s Quest to Halt Nuclear Testing, Lynn Sykes offers a fascinating look at the time and effort it took for states, during and after the Cold War, to agree on a Comprehensive Nuclear Test Ban Treaty (CTBT). Sykes’s work contains a sweeping overview of his passion, which is not only seismology but the effect seismology had on the United States’ desire for an international treaty that would ban the testing of nuclear weapons. In 1947, the US began to monitor the testing of nuclear weapons through a classified program called “Long-Range Detection.” Shortly thereafter, on September 23, 1949, President Truman notified the American people that the Soviet Union had successfully conducted a nuclear test. From that point on, monitoring nuclear explosions would be critical to the US. Sykes’s specialty in seismology, differentiating explosions from earthquakes and estimating the yield of explosions (if it was indeed an explosion and not an earthquake) would become invaluable as the US moved closer to a CTBT.

During his fifty years studying seismology, both political and scientific leaders pushed back on the factual information Sykes presented in support of technology’s role in global nuclear treaties. The US government thought the Soviets were trying to muffle the shock waves from nuclear explosions in an attempt to evade detection and disguise the signals, which in the book he calls the theory of “decoupling” (p. 40). Although Sykes consistently proved that his arguments against decoupling were based on factual seismic information gained from test sites, the government continued to concur with theoretical opinions from the Defense Advanced Research Projects Agency (DARPA) and the Defense Science Board (DSB) that states were attempting to use decoupling to circumvent detonation limits set by the 1974 Threshold Test Ban Treaty (TTBT), which limited nuclear detonations to 150 kilotons or less. Sykes continued to trust in his work and in advances in technology. Following early treaties (the TTBT and 1976 Peaceful Nuclear Explosion Treaty), which acknowledged that testing needed more controls, the CTBT was signed in 1996. This book is proof that Sykes has dedicated his career to a very specific specialty for the betterment of mankind, because he knew, as he puts it, that “a major [nuclear] exchange would be a cataclysmic disaster with a level of destruction unprecedented in the entire history of our species” (p. 257).

During most of Sykes’s time studying seismology, the Soviet Union was the primary nuclear threat to the United States. It conducted frequent, high-yield nuclear tests that worried the US. Sykes’s primary mission during the Cold War and beyond was to prove that the risk of decoupling nuclear explosions by the Soviets was not as big as politicians and nuclear deterrence activists portrayed it to be. The topic of decoupling became very critical following the signing of the TTBT. The next sixteen years became known as the “yield wars” (p. 91). During this time, Sykes and other scientists worked diligently to disprove DARPA’s theories about Soviet attempts to decouple nuclear tests and cheat on the TTBT. They focused their studies on the speed of surface waves, P-waves, and later Lg waves following a detonation, which is very similar to the study of waves produced from an earthquake. These theories were disproved by studying the speed of waves as they traveled through different types of rock, salt, air-filled cavities, alluvium (unconsolidated sand and gravel), the Earth’s upper mantle, and water. This was incredibly important because the ground composition at Soviet test sites was very different from where the US conducted tests. By studying the speed of waves (mainly following explosions at the Nevada Test Site), Sykes saw his hard work justified when the Congressional Office of Technology Assessment (OTA) released a report in 1988 stating, “Seismic monitoring is central to considerations of verification, test ban treaties, and national security … unless differences in the transmissions of seismic P waves beneath Eastern Kazakhstan and Nevada were taken into account, the sizes of Soviet explosions were greatly overestimated” (pp. 118-19). This report from the OTA, combined with the continual advancement of seismic measuring technology, assisted in the development of a revised TTBT in 1990, which called for “… measurements for US and Russian weapons tests larger than fifty kilotons” (p. 125), and ultimately the signing of the CTBT.

Throughout Silencing the Bomb, Sykes explains how his research on nuclear yield estimates, his rebuttal to the theory of decoupling, and overall advances in seismic technology helped inform US government officials when entering into treaty discussions. Although the CTBT was signed by the US in 1996, it has not been ratified. During George W. Bush’s initial presidential bid, when asked a question about ratification of the CTBT, he stated, “our nation should continue its moratorium on testing, but in the hard work of halting proliferation, the CTBT is not the answer … it would stop us from ensuring the safety and reliability of our nation’s deterrent” (p. 217). Unfortunately, the fight continues for Sykes. However, this does not diminish his incredible accomplishments, which include his lasting effects on past and future nuclear treaties and his loyalty to making sure states do not ignite a “cataclysmic disaster” (p. 257).

Piece originally published at H-Net Reviews under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 United States License.