SEOUL, South Korea — South Korea’s weather agency said a magnitude 3.0 earthquake was detected in North Korea on Saturday around where the country recently conducted a nuclear test, but it assessed the quake as natural.
The quake was detected in an area around Kilju, in northeastern North Korea, about 20 kilometers (12 miles) southeast of where the North conducted its sixth and most powerful nuclear test on Sept. 3, according to an official from Seoul’s Korea Meteorological Administration.
China’s official Xinhua News Agency said earlier that the country’s seismic service detected a magnitude 3.4 quake in North Korea and saw the likely cause as an explosion. But the official from the South Korean agency said the analysis of seismic waves and the lack of sound waves clearly showed that the quake wasn’t caused by an artificial explosion. She spoke on condition of anonymity, citing office rules.
While there was media speculation that the earthquake may have been caused by the collapse of a tunnel weakened by this month’s nuclear test, another Korea Meteorological Administration official, who also didn’t want to be named, said the agency sees such possibilities as low.
The U.S. Geological Survey said that it detected a magnitude 3.5 quake in the area of previous North Korean nuclear tests, but that it was unable to confirm whether the event was natural.
North Korea’s weakest nuclear test, its first one, conducted in 2006, generated a magnitude 4.3 quake. The USGS measured this month’s nuclear test at magnitude 6.3. The latest test was followed by a second magnitude 4.1 quake that some experts said could have been caused by a tunnel collapsing after the explosion.
North Korea has been maintaining a torrid pace in nuclear and weapons tests as it accelerates its pursuit of nuclear weapons that could viably target the United States and its allies in Asia.
North Korea said its recent nuclear test was a detonation of a thermonuclear weapon built for its developmental intercontinental ballistic missiles. In two July flight tests, those missiles showed potential capability to reach deep into the U.S. mainland when perfected.
