The China Earthquake Administration, of which the CENC is a part, and related departments conducted studies on the infrasonic records of the earthquake and previous quakes including those provoked by nuclear tests on the Korean PeninsulaEarlier, South Korea's weather agebt体育ios版ncy said the quake is presumed to have been a natural one, the country's Yonhap news agency reportedThey concluded that Saturday's quake is a natural one, the seismic service said4 on the Richter scale that occurred Saturday in the Democratic People's Republic of Korea (DPRK) is not the result of a nuclear test, the China Earthquake Networks Center (CENC) said"The quake is presumed to have occurred naturallybt体育ios版," the report quoted an agency official as sayingThe epicenter was roughly the same with a similar shallow earthquake on Sept 3, which turned out to be caused by a nuclear test by the DPRK