North Korea nuclear test: What was tested; what is a hydrogen bomb; what happens next?

North Korea announced Sunday that it detonated a miniaturized thermonuclear device – a device that would make it easier to launch a nuclear weapon against the United States, its territories and its allies along the Pacific Rim. 

Below is a story that explains the difference between a hydrogen bomb and a thermonuclear or atomic bomb. The story was originally published in January when North Korea claimed to have tested a hydrogen bomb.

North Korean officials claim to have detonated a hydrogen bomb Wednesday, shocking the world community and triggering action from the United Nations.

The country’s state news agency KCNA said Kim Jong-un ordered the test at 10 a.m. local time on Wednesday that would cause “all-out charge to bring earlier the final victory of the revolutionary cause of Juche (North Korean ideology),” The Associated Press reported.

While there is some doubt the weapon exploded is a hydrogen bomb, the claim that North Korea has developed a “miniaturized” weapon – which the state media is calling a “H-bomb of justice,” has raised questions and concerns around the globe.

Here are a few questions and answers about what took place in North Korea Wednesday.

We are not sure if what was exploded was a hydrogen bomb or an atomic one. What is the difference?

An atomic bomb is produced using fission, meaning you are splitting atoms. The atoms you are splitting are very large ones – uranium or plutonium – and the process releases energy in a chain reaction process. (Imagine a compressed spring being released)

A hydrogen bomb (some call it a thermonuclear bomb) uses fusion. The fusion process is more complex than the fission process because it requires an enormous amount of energy in order to trigger it. In fact, an atomic bomb is used in a hydrogen bomb to generate enough energy to start the fusion process. The explosion of the atomic bomb in a hydrogen bomb’s core starts a reaction in deuterium/tritium, isotopes of hydrogen, that leads to a massive amount of energy being released.

Which is worse?

While both are devastating devices, a hydrogen bomb is capable of far more destruction in a single incident. The power of a nuclear weapon is measured in something called yield. The yield for an atomic bomb is expressed in tons – 1 kiloton up to hundreds of kilotons. The bomb dropped on Hiroshima, Japan, in World War II – Little Boy -- was 15 kilotons. The yield for a hydrogen bomb is expressed in megatons, or millions of tons. Hydrogen bombs can be thousands of times larger in yield (power) than atomic bombs. In theory, a hydrogen bomb could have no upper limit, save practical size.

The bomb has been described as “miniaturized” why is that a problem?

If the warhead is small, it is easier to deliver to a target.

Does the US have hydrogen bombs?

All of the U.S. nuclear weapons are hydrogen bombs that are surprisingly small – think of the size of a metal trash can. Most have the power – or yield – of 200,000-400,000 tons of TNT. The United States is estimated to have about 2,150 operational warheads, according to the Federation of American Scientists.

Which countries have a hydrogen bomb?

In addition to the United States, Russia, Britain, France, and China all have hydrogen bombs.

There is some skepticism surrounding the claim that North Korea exploded a hydrogen bomb. Could they really have done it?

Some think that a hydrogen bomb is beyond the capabilities of North Korea, despite their claim Wednesday. However there is some evidence a test of some weapon happened. There was an earthquake measuring 5.1 on the Richter Scale at the time the bomb was supposed to have been exploded. A South Korean spy agency report says the yield of the test Wednesday is estimated at 6.0 kilotons – far smaller than a hydrogen bomb would yield. Even a failed H-bomb test would be expected to expend more energy. For whatever was tested, there was enough evidence to kick into gear a special meeting of the UN Security Council.

What will the Security Council do?

Since 2006 – the year of North Korea’s first nuclear weapons test -- the U.N. Security Council has adopted four resolutions condemning the country’s weapons testing and imposing sanctions.