Special Report

The Most Powerful Nuclear Explosions in History

The photos of the devastating aftermath of the atomic bomb attacks on Hiroshima and Nagasaki, which helped to hasten the Japanese surrender and the end of World War II, are unforgettable. The sobering reality is that the destructive power of those two bombs pales in comparison to the force of individual nuclear weapons in modern arsenals. (These are 18 of the deadliest weapons of all time.)

To determine the most powerful nuclear explosions in history, 24/7 Wall St. consulted various sources, including The Natural Resources Defense Council, atomicarchive.com, and Wikipedia. We included the 26 tests that yielded at least 4 megatons — about 50 times larger than the U.S. bombing of Hiroshima.

The number of the most powerful nuclear detonations is divided almost equally between the Soviet Union and the United States. One nuclear test by China is on the list. Most of the nuclear explosions occurred either by air drop or on a barge at sea. (It is not surprising to find these countries on the list as they are among the countries that control the world’s nuclear weapons.)

All 13 of the Soviet Union’s most powerful nuclear tests took place within the borders of Russia. The tests occurred on the two islands of Novaya Zemlya on the Russian Arctic coast. This was designated as a nuclear weapons test site in 1954, and the indigenous Nenets people had to be  forcibly relocated. 

The Soviets conducted 130 nuclear tests there between 1955 and 1990. These included the Tsar Bomba, the largest nuclear device ever detonated at 50 megatons of TNT equivalent, nearly 4,000 times more powerful than the Hiroshima bomb. It was set off on  Oct. 30, 1961. The Tsar Bomba blast was more than twice as devastating as the second-biggest explosion on the list.

Nearly all of the American nuclear tests, including most on the list, took place in various atolls in the Marshall Islands in the  South Pacific, dubbed the Pacific Proving Grounds. Bikini Atoll was the site of seven of the largest U.S. nuclear explosions between 1946 and 1958. More than 70 years after the first nuclear weapons were detonated in the atolls, elevated levels of radiation remain there and the atolls are sparsely inhabited.

Three nuclear tests, including the massive Cannikin shot in 1971, were conducted on Amchitka Island in the Aleutian island group in southwest Alaska. Some people performing work related to the underground nuclear tests at Amchitka before Jan. 1, 1974, were exposed to ionizing radiation, the Centers for Disease Control and Prevention.

Click here to see the most powerful nuclear explosions in human history

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