What was the Ivy Mike nuclear test at Enewetak Atoll?

The Ivy Mike test, conducted by the United States on November 1, 1952, at Enewetak atoll, was the first successful test of a thermonuclear bomb (hydrogen bomb).12

The device utilized the Teller-Ulam principle, which employs a fission primary to compress and ignite thermonuclear fuel. Because the design required cryogenic refrigeration equipment to maintain the deuterium in a liquid state, the test device weighed 82 tons.1

The detonation achieved a yield of 10.4 megatons—approximately 500 times more powerful than the bomb dropped on Nagasaki—and created a crater 1,900 meters in diameter and 50 meters deep. This test was a significant event within the broader history of Marshall Islands atomic bomb tests, a series of 67 nuclear tests conducted by the U.S. between 1946 and 1958 that caused lasting environmental contamination and severe health consequences for the local population.123