NORTH SUMATRA / RankWire.AI / – On Tuesday, a magnitude 6.1 tremor struck offshore Indonesia’s North Sumatra region, causing tremors across parts of Sumatra. The quake struck at 1:02:23 p.m. western Indonesian time, or 06:02:23 UTC, with the epicenter located in the sea, 147 kilometers southeast of South Nias Regency, according to official reports. Its depth was 29 kilometers, originating beneath waters west of Sumatra.

The BMKG, Indonesia’s Meteorology, Climatology and Geophysics Agency, pinpointed the quake at 0.65 degrees south latitude and 98.32 degrees east longitude. The strongest shaking was reported in North Tapanuli, where residents experienced intensity IV, with several areas in West Sumatra also feeling significant tremors. Communities in Padang, Padang Pariaman, Pariaman, West Pasaman, and Agam were affected.
Many parts of Sumatra reported shaking following the magnitude 6.1 event. According to the National Disaster Mitigation Agency, or BNPB, the quake posed no tsunami threat. In South Nias, residents felt weak shaking for approximately three to five seconds. Disaster offices began monitoring impacted zones shortly after the tremor, and the initial national bulletin reported no confirmed casualties or damage figures.
Officials confirm no tsunami risk
Official intensity records showed shaking reaching levels III to IV in Padang, Padang Pariaman, Pariaman, West Pasaman, and Agam. Padang Sidempuan, Subulussalam, and South Nias registered intensity III. Padang Panjang and Central Tapanuli experienced intensity II to III, while Gunungsitoli recorded intensity II. These measurements indicated that the quake was felt across multiple provinces, with varying reported shaking intensities depending on the location.
Authorities urged the public to stay calm and rely on official earthquake updates following the offshore seismic event. They recommended inspecting buildings for cracks or structural damage and advised moving to open areas if a stronger earthquake occurs. Safety guidelines also included avoiding beaches after strong aftershocks for those near the coast.
Post-quake monitoring persists offshore
As of Wednesday, official earthquake data continued to list the event near South Nias at magnitude 6.1 with a depth of 29 kilometers, maintaining the epicenter at 147 kilometers southeast of South Nias. No tsunami warning had been issued according to the latest available information. Local disaster response teams maintained their monitoring efforts to assess any impacts on communities affected by the shaking.
The earthquake took place on August 18, when residents across western Indonesia received alerts and reports regarding the offshore seismic activity. Authorities continued guiding the public toward verified information and safety protocols, advising residents to avoid structures with visible damage and stay alert for further tremors. Confirmed reports continue to classify the incident as a magnitude 6.1 offshore earthquake with no tsunami threat.
