What Do the 1992 and 2026 Flores Earthquakes Have in Common?

TEMPO.CO, Jakarta - The M7.7 earthquake that struck Indonesia’s Flores region on August 15, 2026, has drawn comparisons with the devastating M7.9 earthquake that hit the same region 34 years ago.

Irwan Meilano, a professor at the Bandung Institute of Technology’s (ITB) Faculty of Earth Sciences and Technology, said the two earthquakes occurred in remarkably similar locations and involved similar seismic mechanisms.

The distance between the sources of the 2026 and 1992 earthquakes is less than 40 kilometers.

“They are very close and similar,” Irwan said in an official statement on Saturday.

So, what happened in 1992, and why are experts paying attention to the Flores Back-Arc today?

What Happened in the 1992 Flores Earthquake?

On December 12, 1992, a M7.9 earthquake struck offshore Flores, about 35 kilometers north of Maumere in East Nusa Tenggara.

The earthquake triggered a devastating tsunami, with waves reaching up to 25 meters. An underwater landslide contributed to the tsunami, according to Irwan.

The waves swept through coastal settlements, destroyed boats and buried farmland under marine sand and mud.

The disaster killed around 2,000 people and injured about 400 others. Many residents were also left homeless.

The earthquake damaged major roads, severed bridges and destroyed public facilities in Maumere.

The 1992 disaster remains one of Indonesia’s deadliest earthquake and tsunami events.

Why Is the Flores Back-Arc Important?

Both earthquakes occurred in the Flores Back-Arc, a tectonically active zone north of Flores.

The region has a history of significant seismic activity. It produced a M6.6 earthquake in 2009 and a series of earthquakes north of Lombok in 2018, Irwan said.

Research by ITB and the National Center for Earthquake Studies (Pusgen) has also indicated that some segments of the Flores Back-Arc have yet to produce major earthquakes.

This does not mean another major earthquake is imminent. Rather, it highlights the region’s continuing seismic potential.

How Was the 2026 Earthquake Different?

The M7.7 earthquake struck offshore on August 15, with its epicenter about 30 kilometers northeast of Nagekeo, East Nusa Tenggara.

The earthquake occurred at a depth of about 15 kilometers and was generated by thrust-fault movement along the Flores Back-Arc Thrust, according to Indonesia’s Meteorology, Climatology, and Geophysical Agency (BMKG).

The shaking reached level V on the Modified Mercalli Intensity (MMI) scale in Ende, Borong and Ruteng. It was also recorded at level VI in Wolowae, Nagekeo, and Bajawa.

The earthquake caused damage to homes and public facilities in several areas, including Maumere, West Manggarai and Labuan Bajo. Maumere Port and Hotel Jayakarta Bajo also sustained damage.

Did the 2026 Earthquake Trigger a Tsunami?

Yes, but the tsunami was far smaller than the one recorded in 1992.

BMKG issued an early tsunami warning after the earthquake. A tsunami wave measuring 0.94 meters was recorded in Maurole, Ende, while waves of 0.17 meters were recorded in Dompu.

The warning was lifted at 7:30 a.m. local time on Saturday.

The contrast with 1992 is significant. The earlier earthquake generated tsunami waves of up to 25 meters, in part because of an underwater landslide.

How Severe Was the 2026 Disaster?

As of 6:48 p.m. local time on Saturday, the National Disaster Mitigation Agency (BNPB) had recorded 47 deaths.

Manggarai recorded 24 fatalities, East Manggarai 17, and Sikka three. West Manggarai, Ngada and Ende each reported one death.

BNPB also recorded 157 heavily damaged houses, 41 moderately damaged houses and 148 lightly damaged houses.

Damage was reported at 87 educational facilities, 18 health facilities, five places of worship and six government offices, along with other public infrastructure.

What Do Experts Say About Future Risks?

The similarities between the 1992 and 2026 earthquakes do not mean that another tsunami or major earthquake will necessarily occur.

However, the events underscore the seismic risks associated with the Flores Back-Arc.

Irwan said ITB and Pusgen research indicates that parts of the zone remain capable of producing earthquakes. For communities living along Flores and surrounding islands, the history serves as a reminder of the importance of earthquake preparedness, tsunami awareness and reliable early-warning systems.