2017 North Korean nuclear test

2017 North Korean nuclear test
Graphic from the United States Geological Survey showing the location of seismic activity at the time of the test
Information
Country	North Korea
Test site	41°20′35″N 129°02′10″E / 41.343°N 129.036°E / 41.343; 129.036Coordinates: 41°20′35″N 129°02′10″E / 41.343°N 129.036°E / 41.343; 129.036 Punggye-ri Nuclear Test Site, Kilju County
Period	12:00:01, 3 September 2017 (2017-09-03T12:00:01) UTC+08:30 (03:30:01 UTC)
Number of tests	1
Max. yield	108 ± 48 kilotons of TNT (450 ± 200 TJ) University of Science and Technology of China 140 kilotons of TNT (590 TJ): U.S. intelligence, later given as 70-280 kiloton range 160 kilotons of TNT (670 TJ): Japanese Government revised estimates based on Comprehensive Nuclear-Test-Ban Treaty Organization 250 kilotons of TNT (1,000 TJ) NORSAR revised estimate based on a tremor of 6.1M
Test chronology
← September 2016 test

North Korea conducted its sixth nuclear test on 3 September 2017, stating it had tested a thermonuclear weapon (hydrogen bomb).

The United States Geological Survey reported an earthquake of 6.3-magnitude not far from North Korea's Punggye-ri nuclear test site. South Korean authorities said the earthquake seemed to be artificial, consistent with a nuclear test. The USGS, as well as China Earthquake Networks Center, reported that the initial event was followed by a second, smaller, earthquake at the site, several minutes later, which was characterized as a collapse of the cavity.

The North Korean government said it has detonated a hydrogen bomb that could be loaded onto an intercontinental ballistic missile (ICBM). The announcement stated the warhead had a variable yield "the explosive power of which is adjustable from tens kiloton to hundreds kiloton ... which can be detonated even at high altitudes for super-powerful EMP attack". A later technical announcement called the device a "two-stage thermo-nuclear weapon" and stated experimental measurements were fully compatible with the design specification, and there had been no leakage of radioactive materials from the underground nuclear test.

Photographs of North Korean leader Kim Jong-un inspecting a device resembling a thermonuclear weapon warhead were released a few hours before the test.

On the day of the test the chief of the South Korean parliament's defense committee, Kim Young-Woo, stated the nuclear yield was equivalent to about 100 kilotons of TNT (100 kt): "The North's latest test is estimated to have a yield of up to 100 kilotons, though it is a provisional report." The independent seismic monitoring agency NORSAR estimated that the blast had a yield of about 120 kilotons, based on a seismic magnitude of 5.8.