Characteristics and causes of coseismic surface rupture triggered by the "5.22" MS 7.4 Earthquake in Maduo, Qinghai, and their significance

An MS 7.4 earthquake occurred in Maduo County, Guoluo Tibetan Prefecture, Qinghai Province at 02:04 on May 22, 2021(Beijing time), which is the largest one in China after the 2008 Wenchuan MS 8.0 earthquake. Finding out the distribution and characteristics of its coseismic surface rupture in time is of great significance for the identification of seismogenic structure, regional earthquake prevention and disaster reduction. Combining the post-earthquake field investigation with the results from the interpretation and analysis of high-resolution satellite remote sensing images, aftershock data and UAV low altitude photogrammetry, we got a preliminary judgment on the characteristics of six typical seismic surface ruptures. Firstly, the surface rupture caused by the Maduo earthquake is mainly distributed along the southeastern segment of the known South Branch of the East Kunlun fault zone, the kunlunshankou-Jiangcuo fault. It indicates that the Jiangcuo fault should be the seismogenic fault of the earthquake. Se