This page is about Operation Ivy, the nuclear test. For the punk band, see Operation Ivy (band).

Operation Ivy was the eighth series of American nuclear tests coming after Tumbler-Snapper and before Upshot-Knothole. The two explosions were staged in late 1952 at the Pacific Proving Ground .

The first device, codenamed Mike, was 20 ft (6 m) high, 6 ft 8 in (2 m) wide, and weighed 140,000 lb (63.5 t), and was the first hydrogen bomb based on the Teller-Ulam configuration. Too large to be deployed as a weapon, it was built to demonstrate the power and possibility of using nuclear fusion as a principle for larger-yield nuclear weapons than previously possible. It was detonated on Elugelab Island in the Enewetak Atoll of the Marshall Islands. It yielded 10.4 megatons of explosive power, over 450 times the power of the bomb that fell on Nagasaki. The detonation obliterated Elugelab, leaving an underwater crater 6,240 ft (1.9 km) wide and 164 ft (50 m) deep where an island had once been.