Indonesia earthquake: 1,624 aftershocks follow M7.7 quake in Flores, leaving 53 dead

Flores, NTT, Indonesia – A devastating magnitude 7.7 earthquake rocked the Flores region of East Nusa Tenggara (NTT) on August 15, 2026, unleashing a series of powerful aftershocks and triggering tsunami warnings across the archipelago. The Indonesian Meteorology, Climatology, and Geophysics Agency (BMKG) reported a staggering 1,624 aftershocks, with magnitudes ranging from 1.3 to 6.2, in the wake of the initial tremor.

Of these aftershocks, 23 registered above magnitude 5, and 59 were felt by the local population. The initial earthquake, which occurred at 04:58 WIB, had a shallow depth and was attributed to tectonic activity in the Flores Back-Arc region, characterized by a thrust fault mechanism. BMKG issued a tsunami early warning within minutes, indicating potential wave heights of up to 3 meters (Siaga) and less than 0.5 meters (Waspada) for various coastal areas.

The tsunami early warning was eventually lifted after approximately two and a half hours. However, the seismic event caused significant devastation. Preliminary reports indicate 53 fatalities and 137 injuries. The earthquake's impact was most severe in areas like West Manggarai, Manggarai, East Manggarai, Sikka, and Maumere, where damage varied from moderate to severe.

Observations from tide gauge stations confirmed that the earthquake generated tsunami waves at 16 locations across four provinces: NTT, West Nusa Tenggara (NTB), South Sulawesi, and Southeast Sulawesi. The highest wave recorded was 1.605 meters in Pota, East Manggarai, NTT, while the lowest was 0.14 meters in Bakalang, Alor, NTT. BMKG has deployed joint teams to conduct post-earthquake surveys, assess ground response, monitor aftershocks, and verify tsunami impacts to aid in recovery and reconstruction efforts.