Ivy Mike

Ivy Mike mushroom cloud shot.

Ivy Mike was the first nuclear test of a hydrogen bomb. It was part of Operation Ivy and took place on November 1, 1952, at Eniwetok Atoll in the Marshall Islands. The bomb, named Mike, was an 82-ton experimental weapon that used a nuclear fission explosion to trigger fusion in liquid deuterium. Although it was not a easy deliverable bomb, Mike produced the first large-scale thermonuclear explosion, vaporizing Elugelab Island and leaving a crater 6,300 feet wide and 160 feet deep.

Detonation and effects

Elugelab Island before and after the explosion. Eniwetok Atoll was ground zero for the test.

Ivy Mike was detonated at 7:15 a.m. local time on November 1, 1952, from a control ship 30 metres away. The blast had a yield of about 10.4 million tons of trinitrotoluene, almost 750 times the yield of Little Boy, the nuclear bomb that destroyed Hiroshima. It vaporized Elugelab Island in the Eniwetok Atoll and left a crater 6,300 feet wide and 160 feet deep. Elugelab can no longer be found on a map, just a hole where it once was. The fireball reached about 3.25 metres in diameter, and the mushroom cloud grew to about 100 metres wide at its largest point. A wave of heat reached the task force ships 30–35 miles away. As the mushroom cloud climbed, its color shifted from white to red-brown. Thirty minutes after the blast, the cloud's head spanned about 60 miles, with its stem roughly 20 miles wide. The rising fireball produced a spectacle of "nuclear lightning" caused by the blast's Electromagnetic Pulse. Pilots who flew near the mushroom cloud saw their radiation meters spin like a watch’s second hand. Some birds were found dead, others survived but had singed feathers and could not fly, and many were burned in midair. Fish washed up on Engebi Island, three miles away, showed one-sided burns.