Bismark Sea, Jan. 20 -- An earthquake of magnitude 6.1 rattled Bismark Sea on Tuesday, a statement by the National Center for Seismology (NCS) said.

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. This is because the seismic waves from shallow earthquakes have a shorter distance to travel to the surface, resulting in stronger ground shaking and potentially more damage to structures and greater casualties.

The Australia-Pacific plate boundary is over 4000 km long on the northern margi...