Flores Aftershocks Reach 13,863 as BMKG Reports Weakening Sequence

Labuan Bajo — Indonesia’s Meteorology, Climatology and Geophysics Agency (BMKG) has recorded 13,863 aftershocks in Flores, East Nusa Tenggara, as of Wednesday, 9 September 2026 at 05:00 Western Indonesia Time (WIB), following the magnitude 7.7 main earthquake on 15 August 2026.

BMKG data published that day show the aftershock sequence is beginning to weaken, even as seismic activity continues in the region.

According to BMKG figures cited by several national outlets, the aftershocks range from magnitude 0.9 to 6.2. Of the total, 38 events had magnitudes above 5.0, while 183 were reported as felt by residents.

BMKG officials have stressed that this decline in activity does not mean the sequence has ended, and that further earthquakes remain possible in the coming weeks.

Latest BMKG figures

• Total aftershocks: 13,863
• Magnitude range: 0.9 to 6.2
• Above magnitude 5: 38 events
• Felt by residents: 183 events

Aftershocks expected for weeks

BMKG has described the Flores aftershock pattern as entering a phase of gradual decline as energy from the 15 August mainshock is released.

In coverage of BMKG’s update on 9 September, national broadcasters reported that the agency expects aftershocks to continue for roughly three to four weeks from the time of the main quake, although the frequency and strength are likely to keep decreasing.

BMKG has advised residents to remain calm but vigilant, and to follow information from official channels rather than unverified social media posts.

The agency also urges communities in areas heavily affected by the 7.7-magnitude earthquake to stay alert to potential aftershocks that could further damage weakened structures or trigger landslides.

Human impact and official casualty figures

Indonesia’s National Disaster Management Agency (BNPB) reported on Tuesday, 8 September 2026, that 135 people had died as a result of the Flores earthquake.

BNPB’s spokesperson said the figure includes 48 deaths attributed to the direct impacts of the earthquake and 87 deaths classified as indirect impacts, such as incidents occurring during evacuation or in the aftermath of the disaster.

BNPB also reported hundreds of injuries and widespread damage to homes and public facilities across several districts in East Nusa Tenggara, particularly in the Flores region.

The casualty figures underline that a reduction in aftershock numbers is a trend in seismic activity rather than a signal that existing hazards have disappeared.

Damaged buildings, unstable slopes and disrupted access routes can remain dangerous even as aftershocks diminish, and authorities continue to urge residents to pay attention to local disaster management guidance on safe areas, temporary shelters and infrastructure repairs.

BMKG and BNPB say they are continuing field surveys and data collection to support mitigation, reconstruction planning and improvements to early warning and public awareness for future seismic events in Flores and surrounding islands.

Sources

• RRI English – "BMKG Records 13863 Aftershocks After Flores Earthquake"
• Suara Surabaya – "Gempa Susulan Flores Capai 13.863 Kali, BMKG Prakirakan Berlangsung 3-4 Minggu"
• TVRI News – "Update Terbaru, Gempa Susulan Flores M7,7 Capai 13.863 Kejadian"
• BMKG – "Gempa Flores Meluruh, BMKG Ungkap Hasil Survei Lapangan sebagai Basis Mitigasi dan Rekonstruksi"
• Okezone News – "Update! BNPB Sebut 135 Orang Meninggal Akibat Gempa di NTT"
• Kontan – "BNPB: Update Korban Meninggal Gempa NTT Capai 135 Orang"
• Kompas TV