HISTORY OF GEOLOGY DIVISION STUDENT AWARD PAPER: CORE DRILLING AT BIKINI AND ENIWETOK ATOLLS, 1947-1952

The surveys conducted in connection with the Operation Crossroads nuclear weapons test in 1946-47 made Bikini Atoll the most carefully studied coral reef in the world. Two members of the scientific crew, Harry S. Ladd and Joshua I. Tracey, Jr., led an effort to bore through the reef to basement rock in order to test competing theories of atoll formation. Obtaining core samples from deep beneath a living reef was first suggested by Charles Darwin, whose subsidence theory implied that remains of shallow-water corals would be discovered in situ even at great depths. The crew at Bikini worked around the clock, and their progress was reported by a cascade of military press releases until they ran out of drill pipe while still in reef limestone at 2556 feet. In 1952 Ladd resumed this work at the new Pacific proving ground, and obtained cores from the foundation of Eniwetok Atoll that were widely hailed as the final proof of Darwin's theory.

This paper is based on a study of formerly classified Army and Navy documents and the personal papers of the geologists at Bikini and Eniwetok. Ladd advocated atoll drilling in a secret report during World War II and this plan was adapted, with some modifications, for inclusion in the Bikini survey. The commanders in charge of the controversial weapons test then seized upon the potential public relations benefit of carrying out Darwin's crucial experiment. Regular press releases about this “newsworthy...science stor[y]” were actually stipulated in the 1947 Operation Plan as a means of “forestall[ing] much press criticism and speculation of a harmful nature.” This publicity almost certainly helped to encourage a widespread belief that research into coral reef formation had been stagnant from Darwin's time until the heroic achievements at Bikini and Eniwetok. In fact, reef science flourished in the first half of the twentieth century as well, and the existence of an ongoing debate over various theories of atoll formation helps to explain why the issue was ever taken up during the Crossroads tests. It also clarifies why Ladd, who was not a supporter of Darwin's theory before the war, was always at pains in subsequent years to specify that although Bikini and Eniwetok had undergone “Darwinian subsidence,” they did not appear to have passed through the fringing reef and barrier reef stages that Darwin postulated.