Fact Check: Did Mount Ibu's Eruption Trigger the NTT Earthquake?

False claims circulating on social media have linked a devastating earthquake in Indonesia's East Nusa Tenggara (NTT) province to volcanic activity at Mount Ibu. Posts on Facebook and TikTok suggested that an eruption of Mount Ibu, which allegedly spewed a five-kilometer-high ash column, was followed by the magnitude 7.7 earthquake that struck NTT on August 15, 2026.

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Mount Ibu erupted, sending an ash column 5 km high over Halmahera. Shortly after, a magnitude 7.7 earthquake shook Flores, triggering a tsunami warning.

However, fact-checking efforts have debunked this connection. While Mount Ibu in West Halmahera Regency, North Maluku, did experience significant volcanic activity, its eruptions did not cause the earthquake in NTT. Data shows Mount Ibu erupted 1,375 times between January and August 21, 2026, ranking second nationally for volcanic activity.

On the specific day of the NTT earthquake, August 15, 2026, Mount Ibu erupted seven times, but its ash columns reached heights of only 400 to 800 meters, far short of the five kilometers claimed in the viral posts. Experts emphasize that there is no theoretical link between the two events.

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The volcano's periodic eruptions did not trigger or have any connection to the earthquake in NTT on August 15, 2026.

Heri Andreas, Head of the Geodesy Laboratory at the Bandung Institute of Technology, explained that for an earthquake to be linked to volcanic activity through stress transfer, they must be situated along the same tectonic plate alignment. Given the vast distance between Mount Ibu and NTT, such a mechanism is impossible. The Indonesian Meteorology, Climatology, and Geophysics Agency (BMKG) confirmed that the NTT earthquake originated from movement along the Flores Back-Arc Thrust fault.

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However, such a stress transfer mechanism is impossible between Mount Ibu and the NTT [earthquake] given the vast distance separating them.