History of North Korea nuclear tests dates back almost decade

North Korea's claim to have conducted its first hydrogen bomb test Tuesday is far from the first time the country has made international headlines with its explosions. Here is a brief history of nuclear activity in North Korea.

Oct. 8, 2006 9:35 p.m. ET

North Korea conducts its first nuclear test, becoming the eighth country to hold nuclear weapons. The United States Geographical Survey detects a magnitude 4.2 earthquake on the Korean Peninsula. The test leads to the United Nations placing the country under sanctions, barring it from nuclear and ballistic activity.

May 24, 2009 8:54 p.m. ET

Kim Jong-il's regime tests an underground nuclear device said to be of a similar size to the bombs dropped on Nagasaki and Hiroshima during the Second World War, setting off a magnitude 4.7 earthquake. U.S. President Barack Obama says the test is a "reckless violation of international law."

Feb 12, 2013 9:57 p.m. ET

North Korea makes good on threat to conduct a third nuclear test, detonating a miniaturized device underground, even after being warned by ally China not to proceed with it. This causes an earthquake with a magnitude between 4.9 and 5.2. North Korea's official Korean Central News Agency calls the test a response to "outrageous" hostility from the U.S.

Jan. 5, 2016 8:30 p.m. ET

The Kim Jong-un regime says it has successfully tested a hydrogen bomb, calling it the "H-bomb of justice." According to experts, hydrogen bombs, known as "superbombs" can be more than 1,000 times more powerful than an atomic bomb, the kind North Korea had tested previously.

With monitoring agencies reporting an earthquake with a magnitude of between 4.8 and 5.1, South Korea's spy agency casts doubt on North Korea's claims. It says the test's estimated explosive yield was far lower than would be produced by a hydrogen bomb detonation, even a failed one.