China News Network, February 28th. According to the official Weibo news of the National Seismological Network, the China Seismological Network officially determined that it occurred at 07:56 on February 28 in Yongshan County (28.09 degrees north latitude, 103.51 degrees east longitude) in Zhaotong City, Yunnan Province. A magnitude 3.9 earthquake with a focal depth of 12 kilometers.
Image source: Official Weibo of National Seismological Network