North Korea warned this week that it might test a hydrogen bomb in the Pacific Ocean, after saying the country had already successfully detonated one.
A hydrogen bomb has never been used in battle by any country, but experts say it has the power to wipe out entire cities and kill significantly more people than the already powerful atomic bomb, which the US dropped in Japan during World War II, killing tens of thousands of people.
As global tensions continue to rise over North Korea’s nuclear weapons program, here’s what to know about atomic and hydrogen bombs:
A hydrogen bomb can be far more powerful than the atomic bombs the US dropped on Japan in World War II. The US conducted the first successful tests of hydrogen bombs in the 1950s. Their yields of 10,000 kilotons and more were several hundred times larger than the bombs that levelled Hiroshima and Nagasaki. Experts believe the yield of North Korea's latest test was at least 140 kilotons, which would make it some seven to eight times as powerful as Hiroshima (15 kilotons) and Nagasaki (about 20).
Atomic bombs rely on fission, or the splitting of the nucleus of an atom, just as nuclear power plants do. The hydrogen bomb uses both fission and fusion – the fusing together of atomic nuclei – to produce more explosive energy. It's the same process that keeps the sun and other stars burning. H-bombs are also known as thermonuclear bombs, because of the extremely high temperature needed to induce fusion. A typical hydrogen bomb is two-stage: First, an atomic fission bomb detonates, and that in turn starts the fusion of a hydrogen isotope in a second section.
The atomic bombs that hit Japan were huge and had to be dropped from planes flying overhead. With its higher power, a hydrogen bomb can be made small enough to fit on the head of an intercontinental missile. The hydrogen bomb is the standard for the five nations with the greatest nuclear weapons capability: Russia, the US, France, China and the UK Other nations may either have it or be working on it, despite a worldwide effort to contain such proliferation.
Source: Associated Press