BMKG: Decades Needed Before Another Major Earthquake Hits Flores, NTT

The Meteorology, Climatology, and Geophysical Agency (BMKG) announced on August 19, 2026, that it will take decades for the back-arc thrust fault in Flores, East Nusa Tenggara (NTT), to accumulate enough energy to produce another earthquake as powerful as the recent magnitude 7.7 disaster. According to BMKG Head Teuku Faisal Fathani, speaking at the parliamentary complex in Senayan, Jakarta, the massive release of energy has dramatically reduced immediate large-scale threats, even as cumulative aftershocks surpass thousands of events.

Geological Reset and the Long-Term Outlook for Flores

Communities across Nusa Tenggara Timur have spent days grappling with fear following the severe M 7.7 seismic event. Relief efforts remain active, with South Sulawesi gathering 25 tons of aid for affected populations, and the Ministry of Home Affairs deploying personnel to ensure government support reaches survivors on the ground, as detailed by detikNews. Additionally, two field hospitals have been dispatched to Manggarai and Nagekeo by the Ministry of State Apparatus Empowerment and Bureaucratic Reform to manage medical demands.

Addressing public anxiety regarding subsequent catastrophic shocks, Teuku Faisal Fathani emphasized that the underlying fault system requires an extensive geological cycle to rebuild stress levels. “It must be ensured that it takes up to decades for the back-arc thrust fault in Flores to accumulate energy and produce an earthquake as large as the one that occurred now,” Teuku stated to reporters on Wednesday, August 19, 2026, as reported by Kompas.com and detikNews. While smaller or moderate tremors remain possible in the intervening years, the maximum potential energy along this specific segment has largely discharged.

Corroborating this assessment, BMKG Earthquake and Tsunami Director Wijayanto noted that the tectonic structure in northern Flores possesses a maximum potential energy ceiling of approximately M 7.8. Because the recent primary shock reached M 7.7, the system has effectively tapped its primary energy reserve. Consequently, secondary seismic activity follows a steady downward trajectory.

Aftershock Decay and Coastal Safety Protocols

Data compiled by the National Disaster Management Agency (BNPB) and BMKG highlights a continuous downward trend in seismic frequency. By late afternoon on August 19, 2026, agencies recorded 3,055 aftershocks. Among these, the largest measured M 6.2, while the smallest dipped to M 1.1, with exactly 88 events directly felt by residents.

BMKG projects that complete pelurhan, or the gradual decay of seismic activity, will require roughly three to four weeks given the sheer scale of the initial M 7.7 rupture. Coastal residents who initially fled inland out of fear of a catastrophic tsunami have been urged by officials to remain calm. According to BMKG leadership, Indonesia’s early warning infrastructure operates on strict protocols capable of issuing tsunami alerts within three minutes of a major offshore rupture. Mitigating future risks now depends heavily on municipal preparedness, regional evacuation drills, and maintaining clear signage across coastal zones.

As recovery operations continue across NTT, the primary focus shifts from immediate emergency shelter management toward long-term structural resilience. Authorities emphasize that while seismic stability will return to the region over the coming weeks, maintaining vigilance and adhering to established evacuation protocols remain vital safeguards for all coastal communities.