BMKG logs over 15,000 aftershocks after Flores M7.7 quake

East Nusa Tenggara, especially Flores — Indonesia’s meteorology agency has recorded more than fifteen thousand aftershocks in East Nusa Tenggara in the month since the powerful Flores earthquake, with hundreds of tremors felt by residents and smaller quakes still rattling the region.

According to the Meteorology, Climatology and Geophysics Agency (BMKG), 15,722 aftershocks were detected in the 30 days following the magnitude 7.7 earthquake that struck Flores on 15 August 2026.

BMKG data show that these aftershocks ranged from about M0.9 to M6.2, with 190 events felt by the public during the monitoring period ending around 15 September 2026, according to statements by BMKG officials reported by several national media outlets.

BMKG officials said the sequence of aftershocks has entered a decay phase, with the daily and weekly frequency of tremors trending downward one month after the mainshock.

In public briefings in Jakarta, BMKG’s Geophysics division has urged residents across Flores and other parts of East Nusa Tenggara to remain cautious and to follow local disaster management guidance, even as the overall seismic activity shows signs of gradual decline.

The quake sequence has been most active in the Flores region, with monitoring stations recording thousands of small events that were too weak to be felt at the surface.

Local and national media reports citing BMKG’s latest update describe the recent activity as dominated by low-magnitude aftershocks, while noting that a handful of larger tremors above magnitude 5 have also occurred since mid-August.

BMKG has explained that such intensive aftershock sequences are typical after a major crustal earthquake, and that activity is expected to taper off further in the coming months.

Officials have encouraged residents, especially in coastal areas and near steep slopes, to stay informed about official earthquake and tsunami bulletins and to be familiar with evacuation routes.

While the number of felt shocks has been relatively small compared with the total aftershocks recorded, the continuing tremors remain a source of anxiety for communities still recovering from the August mainshock and associated tsunami.

Sources

• Suara.com
• Disway.id
• Tribun Kupang