Here's How Big North Korea's Latest Nuclear Test Actually Was

npr.org

North Korea has conducted six nuclear tests. As this chart of seismic activity shows, the latest test on Sept. 3 was roughly an order of magnitude larger than earlier ones.

When North Korea conducted its latest nuclear test, the ground trembled more than 3,000 miles away in western Kazakhstan. Recording the shaking was AS059, an automated seismic station that's part of a global network designed to detect underground nuclear explosions.

The network is run by the Comprehensive Nuclear-Test-Ban Treaty Organization(CTBTO), a U.N.-affiliated group devoted to monitoring for illicit nuclear tests. While the test ban treaty itself is not yet in force, the United States and other nations fund the monitoring network.

This wasn't the first time a North Korean bomb shook AS059. The station has detected each of the North's six nuclear tests. But as the above chart shows, this test on Sept. 3 was far more powerful than previous ones. In fact, 36 of the CTBTO's seismic stations contributed to the initial analysis and more than 100 recorded the event, which the organization says was equivalent to a magnitude 6.1 earthquake. (The U.S. Geological Survey put the blast closer to 6.3 in magnitude.)

The shaking was also reportedly felt in China, and satellite photos show the explosion also triggered rock slides near the test site.