3,422 Aftershocks Rock Flores, NTT

Aftershocks continue to shake the Flores region of East Nusa Tenggara (NTT) following the magnitude 7.7 earthquake on 15 August. To date, 3,422 aftershocks have been recorded, with the largest measuring magnitude 6.2.

“As of 20 August 2026 at 06.00 WIB, BMKG monitoring results show 3,422 aftershock activities with the largest magnitude of M 6.2,” said Wijayanto, Director of Earthquakes and Tsunamis at BMKG, in a statement on Thursday (20/8/2026).

The public has been urged to remain calm and not be influenced by unverified information.

“Ensure that official information comes only from BMKG, disseminated through verified official communication channels,” Wijayanto stressed.

On Thursday at 06.45 WITA, a magnitude 5.8 aftershock shook Flores Island. Residents were reported to have run out of their homes. Analysis by the Meteorology, Climatology and Geophysics Agency (BMKG) shows the earthquake had updated parameters of magnitude 5.8 at a depth of 10 kilometres.

“The earthquake epicentre is located at coordinates 8.35°S 120.63°E, precisely on land 34 km northeast of Ruteng, Manggarai, NTT. Tsunami modelling results show this earthquake has no tsunami potential,” Wijayanto said.

Given the epicentre location and hypocentre depth, the earthquake is classified as a shallow event caused by Flores Back-Arc Thrust activity. Source mechanism analysis indicates the earthquake had a normal fault movement mechanism.