The mainshocks and their aftershocks, as well as the focal mechanisms (the ‘beachballs’) of the mainshocks. The mechanisms are also consistent with the NIED Aqua CMT (Japan) catalog and the Global CMT (Columbia University) catalog. The Korean Meteorological Administration locates the 15 November 2017 earthquakes about 5 km (3 mi) east of the pictured Yangsan Fault (red line).