4 magnitude earthquake recorded on Saturday near the Democratic People's Republic of Korea's most recent nuclear test site was "natural"The test prompted global condemnation, leading the United Nations Security Council to unanimously adopt new sanctions that include restricting the DPRK's oil shipmentsmanbetx在线The report said the analysis of seismic waves and the lack of sound waves clearly showed the quake was not caused by an artificial explosion, citing an unnamed weather agency official from the ROKThe center previously issued a notice saying it suspected another test because the epicenter was located on the surface4 magnitude quake would be much smaller than the quakes caused by previous DPRK nuclear tests, the report saidmanbetx在线After the incident, the center quickly organized seismological bureaus and geological institutions to evaluate the situation, it said