BMKG Records 13,863 Aftershocks After Flores Earthquake

RRI.CO.ID, Jakarta - Aftershocks continued through Wednesday, September 9, 2026, following the magnitude 7.7 earthquake that struck Flores, East Nusa Tenggara (NTT).

As of 5 a.m. Jakarta time, the Meteorology, Climatology, and Geophysics Agency (BMKG) had recorded a total of 13,863 aftershocks in the region.

BMKG reported that the largest aftershock reached magnitude 6.2, while the smallest was recorded at magnitude 0.9.

“A total of 38 aftershocks had magnitudes above 5.0, while 183 of these events were reported to have been felt by the public,” BMKG said in an official statement in Jakarta on Wednesday, September 9, 2026.

BMKG also noted that aftershock activity has begun to show a change in pattern based on the earthquake decay graph, indicating that aftershock intensity is gradually decreasing compared to the earlier phase.

“A pattern of decline is becoming apparent on the decay graph. Consequently, aftershock activity is estimated to continue for approximately three to four weeks,” BMKG said in its update.

This statement marks the latest development in seismic activity following the magnitude 7.7 Flores earthquake. Although the trend is beginning to subside, aftershocks continue to occur and be felt by residents.

On Tuesday night, September 8, 2026, a magnitude 5.0 aftershock was recorded. The following morning, another event occurred with a magnitude of 4.8.

Both earthquakes registered an intensity level of III on the Modified Mercalli Intensity (MMI) scale. At this level, many people feel vibrations indoors, and floors or windowpanes may shake.

The main Flores earthquake, with a magnitude of 7.7, occurred earlier on Saturday, August 15, 2026, at 4:58 a.m. Jakarta time. BMKG stated that it was a shallow earthquake triggered by thrust fault activity within the Flores Back‑Arc Thrust zone.

The series of thousands of aftershocks is part of the Earth’s crustal adjustment process following the main earthquake. BMKG had previously estimated that aftershock activity following the M7.7 Flores earthquake could persist for approximately three to four weeks. (Misni Parjiat)