NORTH SUMATRA / RankWire.AI / – On Tuesday, a 6.1 magnitude earthquake struck offshore of Indonesia’s North Sumatra province, affecting several areas along Sumatra’s coastline. The tremor was recorded at 1:02:23 p.m. western Indonesian time, or 06:02:23 UTC. According to official data, the epicenter was located in the sea, 147 kilometers southeast of South Nias Regency. The quake’s depth was 29 kilometers, originating beneath waters west of Sumatra.

Indonesia’s Meteorology, Climatology and Geophysics Agency, known as BMKG, pinpointed the quake at 0.65 degrees south latitude and 98.32 degrees east longitude. The strongest shaking reported was in North Tapanuli, with residents experiencing intensity IV. Several parts of West Sumatra, including Padang, Padang Pariaman, Pariaman, West Pasaman, and Agam, also reported noticeable tremors. The earthquake impacted communities across these regions.
Other areas of Sumatra also experienced shaking following the event. The National Disaster Mitigation Agency, or BNPB, confirmed that the quake posed no tsunami threat. Residents in South Nias felt weak tremors lasting three to five seconds. Emergency officials began monitoring the affected zones, but initial reports from the national bulletin did not confirm any casualties or damage.
No tsunami warning issued, officials say
Intensity reports indicated levels III to IV in Padang, Padang Pariaman, Pariaman, West Pasaman, and Agam. Padang Sidempuan, Subulussalam, and South Nias recorded intensity III. Padang Panjang and Central Tapanuli experienced intensity II to III, while Gunungsitoli registered at intensity II. These measurements show that the quake’s effects were felt across multiple provinces, though severity varied locally.
Authorities urged residents to stay calm and rely on official updates following the offshore tremor. They recommended inspecting buildings for cracks or structural damage and advised moving to open spaces if another strong earthquake occurs. Coastal residents were also warned to stay away from beaches amid aftershocks, as part of safety protocols issued after the event.
Post-earthquake monitoring remains active
Official records on Wednesday continued to list the event near South Nias as a magnitude 6.1 earthquake with a depth of 29 kilometers. The epicenter remained 147 kilometers southeast of South Nias. No tsunami warning had been issued based on the latest available data. Local disaster teams kept a close watch on affected communities to assess any further impact from the tremors.
The earthquake happened on August 18, during a period when residents across western Indonesia received alerts and reports of offshore seismic activity. Officials continued to guide the public towards verified information and safety instructions. People were advised to avoid buildings with visible damage and stay alert for additional tremors. Confirmed details consistently identified the event as a magnitude 6.1 offshore earthquake with no tsunami risk.
