The earthquake, which occurred at 4.58 am on Saturday, originated from the Flores Back-Arc Thrust at a depth of just 15 kilometers. BMKG Geophysics Deputy Director Nelly F. Riama explained that the shallow depth and thrust fault movement created a high potential for tsunami generation. Monitoring stations recorded tsunami waves reaching ten coastal points across the region, including Sikka, Kewapante Port, Labuan Bajo, and Kolaka. While the waves did not cause catastrophic inundation, the tremors were intense enough to collapse parts of residential walls in Maumere, West Manggarai, and Labuan Bajo, and to damage facilities at Maumere Port and the Jayakarta Bajo Hotel.
The shaking measured MMI V in the cities of Ende, Borong, and Ruteng, an intensity felt by nearly everyone that woke many sleepers. In Wolowae and Bajawa, the intensity reached MMI VI, frightening residents and causing people to run outdoors. As of 7.07 am, BMKG detected 37 aftershocks ranging from magnitude 3.6 to 6.2. The National Disaster Mitigation Agency (BNPB) confirmed two fatalities in the NTT region, with officials continuing to verify data alongside local authorities.
This event follows a separate seismic incident on Thursday, when a magnitude 7.6 earthquake struck the Northern Molucca Sea. That quake killed one person in the Manado area when falling rubble from a building used by the local sports authority collapsed. BMKG reported that tsunami waves were recorded in five locations during the Thursday event, with the highest wave reaching 0.75 meters in North Minahasa. U.S. tsunami warning authorities had initially flagged a hazard for coasts within 1,000 kilometers of the epicenter but later removed the threat as monitoring data indicated the waves were not hazardous.
Indonesia’s vulnerability to such frequent and powerful seismic events is a direct consequence of its location on the Pacific “Ring of Fire,” a highly active zone where tectonic plates collide. The Flores back-arc, where the Saturday’s earthquake occurred, holds a maximum earthquake potential of magnitude 7.8 to 7.9. BMKG Director Wijayanto noted that a similar magnitude 7.5 earthquake struck the area in 1992, causing widespread damage and a tsunami, marking the second massive release of energy along this fault in nearly three decades.
In the aftermath, a specialized BMKG team has been deployed to the affected sites to conduct thorough damage assessments. Teguh Rahayu, director of engineering seismology at BMKG, outlined ongoing coordination with local disaster mitigation agencies (BPBD) to manage post-earthquake hazards. The primary priority for the National Disaster Mitigation Agency remains safeguarding residents and preventing further casualties from aftershocks or structural failures.
Authorities have urged the public to remain calm and vigilant. Citizens are advised to stay clear of structures exhibiting cracks or structural damage and to rely strictly on official BMKG channels for updates, avoiding the spread of unverified rumors. While the tsunami warnings have been lifted, the seismic activity remains a focus of continuous monitoring, with the potential for further aftershocks posing an ongoing challenge for emergency responders in the region.
