BNPB confirms 731 aftershocks after NTT’s M7.7 earthquake

Labuan Bajo — Indonesia’s disaster agency says at least 731 aftershocks were recorded in Nusa Tenggara Timur following the magnitude 7.7 earthquake that struck Flores on Saturday, 15 August 2026, with the largest aftershock reaching magnitude 6.2 according to data from the national meteorological agency.

The figure was presented by National Disaster Management Agency (BNPB) chief Suharyanto during a coordination meeting in West Manggarai on Sunday, 16 August, citing information from the Meteorology, Climatology and Geophysical Agency (BMKG) valid at 08:13 WITA that morning.

BMKG officials separately reported that a total of 731 aftershocks had been recorded by early 16 August, with magnitudes ranging from 1.9 to 6.2, confirming the BNPB count and the size of the strongest event. At that point, authorities noted that no additional large shocks causing severe new damage had been detected.

What the authorities reported

According to BNPB’s account of BMKG data, the sequence of smaller earthquakes was expected to gradually taper off over the following two to three weeks, although residents were advised that aftershocks could continue during that period. Suharyanto urged the public not to panic and to avoid relying on unsupported claims about another major quake.

BMKG’s separate updates in late August and early September indicated that aftershocks did in fact continue well beyond the initial 731 events. The agency reported thousands of additional shocks, all with the largest magnitude still at 6.2. A BMKG press release on 15 September said that by 30 days after the main shock, 15,722 aftershocks had been recorded, again with a maximum magnitude of 6.2.

BMKG also confirmed that the initial tsunami early warning issued after the main earthquake on 15 August was lifted at 07:30 WIB the same morning, after monitoring showed no dangerous tsunami waves. By that time, 37 aftershocks had been detected, between magnitude 3.6 and 6.2.

Implications for residents and visitors

The earthquake sequence affected a wide area of Flores and surrounding islands, including districts frequently used as gateways to marine tourism destinations. BMKG and BNPB statements focused on public safety, advising people to stay calm, follow official guidance and be alert to ongoing seismic activity.

Subsequent BMKG summaries described the aftershock activity as entering a significant decay phase by mid-September, meaning the frequency of events and perceived shaking had decreased compared with the first weeks after the main shock. However, the agency continued to recommend that local governments and communities strengthen building safety, evacuation routes and disaster preparedness in quake-prone areas.

For travellers, divers and marine operators around Labuan Bajo and Komodo National Park, official reports available from BNPB and BMKG do not specify whether harbour operations, boat departures, marine park routes or designated anchorages were adjusted in response to the aftershock sequence. Port procedures, park access rules and operator-level decisions are typically issued through local notices, which were not detailed in the national earthquake and tsunami bulletins reviewed for this report.

Visitors planning sea trips from Labuan Bajo are therefore advised to obtain up-to-date instructions from harbour authorities, park management and their chosen operators, and to follow the latest BMKG earthquake and tsunami information before departure.

Sources

• VIVA Nasional - 731 Kali Gempa Susulan di NTT, Terbesar M 6,2
• IMBC News - 731 Kali Gempa Susulan di NTT, Minggu, sudah 47 Tewas
• BMKG press release - BMKG Akhiri Peringatan Dini Tsunami Pasca-Gempa M7.7 NTT
• Okezone News - 7.429 Gempa Susulan Usai Gempa Besar M7,7 Flores
• Liputan6 Regional - BMKG: 14.993 Gempa Susulan Terjadi Usai Gempa M7,7 Guncang NTT
• Metro TV News - BMKG Catat 11.630 Gempa Susulan Guncang NTT