BMKG Bandung Says Loud Booms Were Skyquakes, Possibly Originating Underground

Loud booms heard across Greater Bandung from Friday night into the early hours of Saturday were identified by BMKG Bandung as skyquakes, not sounds caused by an eruption of Mount Anak Krakatau.

Suaidi Ahadi, head of BMKG’s Class I Geophysical Station in Bandung, said the agency received reports of the phenomenon in Greater Bandung. It received no similar reports from Jakarta, Banten or Bogor.

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The volcanic activity at Krakatau that happened around the same time did not have the effect of a skyquake. That is why it occurred in Bandung, and only Greater Bandung and its surroundings heard it.

He said volcanic activity at Krakatau, which occurred around the same time, did not produce the skyquake heard in Bandung. The sound was heard only in Greater Bandung and nearby areas, he said during a media discussion held by video conference.

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This phenomenon usually occurs because of swarm earthquakes, or small earthquakes, or earthquakes in karst areas. It was also heard in Cianjur.

Suaidi added that skyquakes usually occur alongside swarm earthquakes, small earthquakes or earthquakes in karst regions. A similar boom was heard during the Cianjur earthquake, including during the 2025 Cianjur earthquake.

However, BMKG recorded no earthquake at the Lembang Fault, Cimandiri Fault or other faults in the Greater Bandung area during this event.

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For today’s event, we recorded no earthquake, either at the active faults, the Lembang Fault, the Cimandiri Fault or several other faults, at that time in Greater Bandung.