How a U.S. Hydrogen Bomb Accidentally Turned a Pacific Island into Jello

An American hydrogen bomb test in 1954 threw up an estimated "two hundred billion pounds of coral reef and the sea floor," after the weapons yield turned out to be nearly three times what U.S. scientists had expected.

The test, called 'Castle Bravo,' took place on the Bikini Atoll, a coral reef that forms part of the Marshall Islands, on March 1, 1954.

Following the explosion radiation spread across 15 separate islands and atolls, causing many to be evacuated, with locals later suffering from cancerous tumors and birth defects.

By 1995 the U.S. Government had paid out $43.2 million in compensation to 1,196 claimants, according to the National Claims Tribunal.

Nevada desert nuclear weapons test in 1957
The detonation of the atomic bomb nicknamed "Smokey," as part of Operation PLUMBBOB in the Nevada desert, 1957. Several Pacific islands had to be evacuated after the test of another nuclear bomb in 1954, which turned out to be more powerful than expected. CORBIS/GETTY

Eric Schlosser wrote about the test, then the largest artificial explosion in history, in his 2013 book Command and Control: Nuclear Weapons, the Damascus Accident, and the Illusion of Safety.

Bernard O'Keefe, the lead scientist in the firing bunker when the explosion took place, described how the building felt like it was moved by nuclear detonation.

According to Schlosser, another scientist in the bunker commented: "Is this building moving or am I getting dizzy?"

O'Keefe replied: "Oh my God it is, it's moving."

He later described how, during the explosion, the bunker felt like it was "resting on a bowl of jelly."

Describing the aftermath, Schlosser wrote: "A light rain of ash white that looked like snowflakes began to fall. Then pebbles and rocks began dropping from the sky.

"The men ran back into the bunker, slammed the door shut, detected high levels of radioactivity within the bunker, and after a few moments of confusion, turned off the air conditioning unit."

Whilst this did cause radiation levels to fall within the bunker, they continued to increase outside of it.

The bomb's bigger than expected yield, along with a shift in wind direction, resulted in a larger fallout zone than had been anticipated.

After 48 hours the inhabited islands of Rongelap and Rongerik were evacuated due to radiation.

In 1957 residents were allowed to move back to Rongelap, but discovered the food they used to eat had either disappeared or made them ill, leading to a second evacuation.

The disaster took place during the early stages of the Cold War, with the U.S. locked in competition with the Soviet Union which carried out its first nuclear test in 1949. The only other nuclear armed power at the time was Britain, which successfully tested its first atomic bomb in 1952.

In late October this year, Russian President Vladimir Putin oversaw nuclear drills, which were described on state TV as mock attacks on the U.S. and U.K.

The same month saw President Biden warn Russia that the use of nuclear weapons in Ukraine, where the Kremlin's forces had suffered a number of reverses, would be "a serious, serious mistake."

In the event of a nuclear strike on the U.S. President Biden could board one of four 'Doomsday planes,' modified Boeing 747-200s designed to act as mobile command posts during a nuclear conflict.