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 agency said the quake is presumed to have been a natural one, the country's Yonhap news agency reported雷泽电子网页版They 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 presum雷泽电子网页版ed to have occurred naturally," 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