The earthquake occurred at a shallow depth of 10km, making it susceptible to aftershocks. In a post on X, the NCS said, 'EQ of M: 6.1, On: 20/01/2026 12:51:50 IST, Lat: 5.20 S, Long: 146.03 E, Depth: 10 Km, Location: Bismarck Sea'. Shallow earthquakes are generally more dangerous than deep earthquakes.