According to officials at the Meteorology, Climatology, and Geophysical Agency (BMKG), the earthquake, which was centred at the sloped of the volcanoes Mount Agung and Mount Batur, occurred on a shallow local fault. Rupture along the fault was caused by the migration of magma in the crust, triggering fault activity. The BMKG has ruled out the Flores Back Arc Thrust Fault as the source of the quake due to the strike-slip focal mechanism indicated by the seismological data.
