OVERVIEW: At 0458 HRS UTC+7 on 15 August 2026, BMKG reported a M7.7 earthquake occurred offshore approximately 30 km northeast of Mbay, Nagekeo Regency, East Nusa Tenggara (NTT). BMKG advisory indicated that tsunami is possible for Indonesia, particularly for several coastal areas over East Nusa Tenggara, West Nusa Tenggara, South Sulawesi, and Southeast Sulawesi. The tsunami advisory was ended at 0731 HRS. BMKG reported observed tsunami waves ranging from 0.17–0.94 m in height. Meanwhile, as of 0707 HRS UTC+7, BMKG had recorded 37 aftershocks ranging from M3.6 to M6.2. Data collection and damage assessments are ongoing.
ANALYSIS: According to BMKG, the strongest reported shaking included:
- Aesesa (Nagekeo), Riung (Ngada), and Mbay: approximately VII MMI, with residents reportedly rushing out of buildings and minor structural damage occurring. Wolowae and Bajawa: approximately VI MMI; and Ende, Borong, and Ruteng: approximately V MMI.
- The earthquake was also felt across Flores, parts of Sumba, Adonara, and Solor, and some parts in West Nusa Tenggara.
IMPACTS AND DAMAGES:
- BNPB reported that the earthquake was strongly felt across several areas, from Nusa Tenggara Islands to southern parts of Sulawesi. As of 08:38 WIB, BNPB has reported 2 fatalities and 1 injured person in Sikka Regency, associated with impacts around the El Say Port area. Structural damage has also been reported in Sikka and other affected areas.
- Sikka Regency/Maumere: Structural damage, including building collapse, has been reported in Maumere. Impacts were reported around El Say Port, where casualties were recorded. Damage to buildings and port-related facilities has also been reported.
- Nagekeo and Central/Northern Flores: Strong shaking of up to approximately VII MMI was reported around Mbay/Aesesa. Minor to potentially moderate structural damage is expected in the strongly shaken areas.
- West Nusa Tenggara: Damage to several buildings has also been reported in Bima City following the strong earthquake. Detailed damage figures are not yet available. The earthquake was also felt in Bima City, West Nusa Tenggara, as well as several areas of South Sulawesi.
- Data collection and assessments are ongoing.
RESPONSE EFFORTS:
- BMKG issued warnings and advisories immediately after the earthquake, followed by several tsunami warning updates, and continues to monitor aftershocks and seismic activity.
- BNPB, provincial authorities, and affected BPBDs are conducting rapid impact assessments and coordinating information from affected districts.
- Local governments and relevant-stakeholders are undertaking evacuation, field verification, and initial emergency response activities.
The AHA Centre continues to closely monitor the situation in coordination with BNPB Indonesia and remains ready to provide assistance should the need arise.
DATA SOURCES
ASEAN Disaster Monitoring & Response System (DMRS), ASEAN Disaster Information Network (ADINet); ASEAN Specialised Meteorological Centre (ASMC);
Indonesia: BNPB, BMKG;
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