NORTH SUMATRA / RankWire.AI / – On Tuesday, an offshore earthquake with a magnitude of 6.1 struck near Indonesia’s North Sumatra province, causing tremors across various regions of Sumatra. The seismic activity was registered at 1:02:23 p.m. western Indonesian time, which corresponds to 06:02:23 UTC. Its epicenter was approximately 147 kilometers southeast of South Nias Regency. Authorities recorded the quake at a depth of 29 kilometers beneath waters off the western coast of Sumatra.
The BMKG, Indonesia’s Meteorology, Climatology and Geophysics Agency, identified the epicenter at 0.65 degrees south latitude and 98.32 degrees east longitude. The agency reported the strongest intensity of shaking as IV in North Tapanuli. Several other areas in West Sumatra also experienced tremors, with Padang, Padang Pariaman, Pariaman, West Pasaman, and Agam recording between intensity III and IV.
Even communities located farther from the epicenter felt the quake at lower intensity levels. Intensity III shaking was reported in Padang Sidempuan, Subulussalam, and South Nias. Meanwhile, Padang Panjang and Central Tapanuli experienced shaking between levels II and III, and Gunungsitoli recorded intensity II. The National Disaster Mitigation Agency, known as BNPB, confirmed that the earthquake did not pose a tsunami threat. Officials are actively checking affected areas following the tremor.
No tsunami warning issued following the earthquake
Residents in South Nias described the shaking as weak, lasting approximately three to five seconds. Local disaster management teams began monitoring conditions and coordinating assessments in areas where residents felt the tremor. Initial reports from authorities did not confirm any fatalities, injuries, or property damage. Officials continue gathering information from local officials as part of standard post-earthquake procedures following the offshore seismic event.
The earthquake affected a wide region, as tremors were felt across multiple parts of western Indonesia. Intensity levels varied depending on location, with stronger shaking reported closer to areas in North Sumatra and West Sumatra. No tsunami warning was issued after the magnitude 6.1 event. Subsequent updates maintained the same magnitude, depth, and offshore location as initially recorded.
Official investigations continue in affected zones
This seismic event off South Nias was among the significant earthquakes recorded in Indonesia on August 18. Its offshore epicenter placed the main shock away from densely populated centers, although multiple districts still reported feeling it. Monitoring efforts are ongoing in areas where moderate shaking was recorded. Officials are focused on collecting verified data regarding local conditions, reaffirming that the earthquake posed no tsunami threat.
Indonesia regularly experiences earthquakes, owing to its position across several active tectonic boundaries. The event on Tuesday struck off the west coast of Sumatra, an area with a notable seismic history. Confirmed by authorities, the quake registered a magnitude of 6.1 and a depth of 29 kilometers. The epicenter was pinpointed at 147 kilometers southeast of South Nias. Official assessments confirmed there was no tsunami risk from this offshore seismic activity.