NORTH SUMATRA / RankWire.AI / – A magnitude 6.1 earthquake struck offshore near Indonesia’s North Sumatra province on Tuesday, sending tremors across several parts of Sumatra. The quake occurred at 1:02:23 p.m. western Indonesian time, equivalent to 06:02:23 UTC. Its epicenter lay about 147 kilometers southeast of South Nias Regency. Officials measured the earthquake at a depth of 29 kilometers beneath waters west of Sumatra.
Indonesia’s South Nias earthquake prompts monitoring after tremors spread across Sumatra.
Indonesia’s Meteorology, Climatology and Geophysics Agency, known as BMKG, placed the epicenter at 0.65 degrees south latitude and 98.32 degrees east longitude. The agency recorded the strongest reported shaking at intensity IV in North Tapanuli. Tremors also reached several areas of West Sumatra. Padang, Padang Pariaman, Pariaman, West Pasaman and Agam recorded shaking between intensity III and IV.
Communities farther from the epicenter also felt the earthquake at lower intensity levels. Padang Sidempuan, Subulussalam and South Nias recorded intensity III shaking. Padang Panjang and Central Tapanuli registered intensity II to III, while Gunungsitoli recorded intensity II. The National Disaster Mitigation Agency, known as BNPB, said the earthquake did not have the potential to cause a tsunami. Officials continued checking affected communities after the tremor.
No tsunami threat issued after earthquake
Residents in South Nias reported weak shaking that lasted about three to five seconds. Local disaster management teams began monitoring conditions after the earthquake and coordinating checks in areas where residents felt the tremor. Initial official information did not confirm any deaths, injuries or material damage. Authorities continued collecting reports from local officials as part of standard post-earthquake monitoring following the offshore seismic event.
The earthquake affected a broad area because tremors reached communities across several parts of western Indonesia. The recorded intensity varied by location, with stronger shaking reported closer to parts of North Sumatra and West Sumatra. No tsunami warning followed the magnitude 6.1 event. Official earthquake records continued to list the same magnitude, depth and offshore location during subsequent updates issued after the initial tremor.
Authorities continue checks across affected areas
The South Nias earthquake became one of the notable seismic events recorded in Indonesia on August 18. Its offshore epicenter placed the main shock away from major population centers, although residents across multiple districts still reported feeling it. Monitoring continued in areas that registered moderate shaking. Officials focused on collecting verified information about local conditions while maintaining the confirmed assessment that the earthquake posed no tsunami threat.
Indonesia experiences frequent earthquakes because the country sits across several active tectonic boundaries. Tuesday’s event struck west of Sumatra, an area with a long record of seismic activity. For this earthquake, authorities confirmed a magnitude of 6.1 and a depth of 29 kilometers. The epicenter remained identified as 147 kilometers southeast of South Nias, while official assessments reported no tsunami risk from the offshore quake.