Marshall Islands atomic bomb tests

The Marshall Islands atomic bomb tests were carried out by the United States between July 1946 and August 1958 on Bikini and Enewetak atolls in the Marshall Islands. These tests of nuclear weapons were conducted from the air, from ships, and underwater.

The United States plunged the world headlong into the Atomic Age by unleashing its devastating new invention on Hiroshima and Nagasaki to bring World War II to an apocalyptic conclusion. Although some of the nuclear scientists who had worked on the Manhattan Project researching the atom bomb, notably J. Robert Oppenheimer, strongly opposed further development and testing, the U.S. military believed their new weaponry was now an essential part of their arsenal and that further development of the weaponry was necessary to both develop and signal strength and readiness.

The Marshall Islands, a sparsely populated collection of coral atolls and islands in the central Pacific Ocean, was selected as a suitably remote region for nuclear testing. Bikini, an atoll of about 20 small islands, was forcibly cleared of inhabitants and on July 1, 1946, the first nuclear test was carried out there. Over 12 years, a total of 67 nuclear tests were carried out, almost all at both Bikini and neighboring Enewetak atoll. The first thermonuclear bomb, code-named Ivy Mike, was tested on Enewetak on November 1, 1952.

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On March 1, 1954, a lithium-deuteride-fueled thermonuclear bomb was tested, to far more devastating effect than had been anticipated. This test was called Castle Bravo. It yielded an astonishing 15 megatons, rather than the expected 6, and, at about 1,000 times the size of the bomb dropped on Hiroshima, remains the most powerful nuclear device that the U.S. has ever tested. It vaporized three of Bikini’s islands. The bomb created a fireball nearly 4.5 miles (7.2 km) in diameter and a mushroom cloud about 130,000 feet (39 km) high, and it scattered radioactive debris over a vast area, almost halfway around the world. Radioactive ash rained down on the neighboring atolls, causing the inhabitants to suffer severe burns and sickness, and it had the same effect on the crew of a Japanese fishing boat that was 80 miles (129 km) away. The explosion left a crater that was 6,500 feet (1,981 m) wide and 250 feet (76 m) deep in the bed of the lagoon. Despite the horrific results of this test, the U.S. conducted 55 more bomb tests over the next few years. It has since paid $759 million in compensation to Marshall Islanders, and, more immediately after the 1954 test, $15.3 million to Japan.

Bikini and Enewetak remain contaminated with radiation. Though the coral reefs made a remarkable recovery in the decades following the end of the testing, nothing grown on the radiation-contaminated land is safe to eat, nor can humans live on the atolls. As comedian Bob Hope is said to have put it: “We located the one spot on earth that hadn’t been touched by the war and blew it to hell.”