BMKG Records 4,258 Aftershocks in NTT Following M7.7 Earthquake
TEMPO.CO, Jakarta – The Meteorology, Climatology, and Geophysics Agency (BMKG) recorded 4,258 aftershocks following the magnitude 7.7 earthquake in Flores, East Nusa Tenggara (NTT), as of Friday, August 21, 2026, at 5:00 a.m. local time.
Latest Details
Of the total aftershocks, residents directly felt 118 tremors, 31 of which registered magnitudes above 5.0.BMKG Earthquake and Tsunami Center Director Wijayanto predicted that this sequence of aftershocks will persist for the next three to four weeks.
He noted that the initial phase of the aftershock sequence continues to exhibit a complex temporal pattern that has yet to stabilize."Aftershock activity in the first few days is relatively high and has not shown a significant pattern of decay.
Daily seismic occurrences reached 704 on the first day, rose to 746 on the second day, hovered between 668, 649, and 627 from the third to fifth days, before climbing again to 802 on the sixth day," Wijayanto said in a statement on Friday, August 21, 2026.According to BMKG monitoring, the aftershock sequence has produced several significant tremors with perceived intensities of IV–VI MMI, which were strongly felt by local residents.
The agency noted that notable tremors occurred on August 19, 2026, at 11:17 p.m. with a magnitude of 5.6, and on August 20, 2026, at 5:45 a.m. with a magnitude of 5.8.Another significant shock struck on August 20, 2026, at 9:47 a.m. with a magnitude of 5.8, triggering secondary damage to already affected buildings and bridges, as well as inducing landslides in several locations.According to Wijayanto, seismic relocation data indicates that the aftershocks are not distributed evenly, but have instead formed several distinct clusters.
