North Korea claims to have successfully tested a hydrogen bomb

A reported earthquake in North Korea Wednesday raised suspicion that the secretive nation has conducted its first nuclear weapons test in more than two years, in defiance of continuing UN sanctions.

Shortly after the seismic tremor, North Korea surprised analysts by saying it had conducted a successful hydrogen bomb test. A hydrogen bomb is generally considered to be more powerful than a typical nuclear explosive.
The U.S. Geological Service reported that a magnitude-5.1 earthquake occurred 30.4 miles from the city of Kilju, North Korea, where the country's Punggye-ri nuclear test site is located.
That is the same area where North Korea conducted nuclear tests in 2006, 2009 and 2013.
The USGS put the depth of the earthquake at 6 miles below the surface, but the South Korea's geological agency said it was near the surface. The earthquake was detected just after 10 a.m. Tokyo time (8 p.m. ET).
A hydrogen bomb, also called a thermonuclear bomb, uses fusion in a chain reaction to create a more powerful detonation than a typical atomic bomb, which uses fission. A hydrogen bomb uses an atomic bomb inside its core to set off fusion reactions that have a devastating effect.