The earthquake struck at 19:03 local time (12:03 UTC) at a moderate depth of 52.8 km (Indonesian BMKG stated that the earthquake struck at a depth of 10 km). The epicentre was located 147 km off the coast of Sumur, an area which had been previously destroyed by another tsunami in December 2018. Indonesian geological agency BMKG recorded the magnitude of the earthquake as 7.4 while the USGS recorded it as a magnitude 6.9 earthquake. BMKG subsequently revised the magnitude to 6.9 and its hypocentre to 48 km.