NORTH SUMATRA / RankWire.AI / – On Tuesday, an offshore earthquake measuring 6.1 in magnitude struck near Indonesia’s North Sumatra province, causing tremors across various regions of Sumatra. The seismic event took place at 1:02:23 p.m. western Indonesian time, which corresponds to 06:02:23 UTC. Its epicenter was located approximately 147 kilometers southeast of South Nias Regency. Officials recorded the quake at a depth of 29 kilometers beneath waters west of Sumatra.
The BMKG, Indonesia’s Meteorology, Climatology and Geophysics Agency, determined the epicenter at 0.65 degrees south latitude and 98.32 degrees east longitude. The agency’s data indicated that North Tapanuli experienced the strongest shaking at intensity IV. Several other areas in West Sumatra, including Padang, Padang Pariaman, Pariaman, West Pasaman, and Agam, felt tremors with an intensity between III and IV.
Communities located farther from the epicenter also experienced the earthquake, albeit with lower intensity. Shake levels of III were recorded in Padang Sidempuan, Subulussalam, and South Nias. In Padang Panjang and Central Tapanuli, intensity ranged from II to III, while Gunungsitoli reported intensity II. The National Disaster Mitigation Agency, BNPB, stated that this earthquake posed no threat of triggering a tsunami. Authorities proceeded with assessments in affected communities following the tremor.
Tsunami warning not issued after the seismic event
People in South Nias described feeling weak tremors that lasted around three to five seconds. Local disaster management teams initiated monitoring efforts and coordinated evaluations in areas where residents reported the shaking. Initial official reports confirmed no fatalities, injuries, or significant property damage. Authorities continue to gather reports from local officials as part of routine post-earthquake assessments after the offshore seismic activity.
The earthquake impacted a large region because tremors were felt in numerous communities across western Indonesia. The intensity varied depending on proximity to the epicenter, with stronger shaking recorded closer to parts of North Sumatra and West Sumatra. No tsunami warning followed the magnitude 6.1 event. Subsequent official updates maintained the same magnitude, depth, and offshore location as initially reported.
Authorities maintain ongoing investigations in affected zones
The seismic event near South Nias is among the notable earthquakes documented in Indonesia on August 18. While its offshore epicenter placed the main shock away from densely populated areas, residents across several districts still felt the tremors. Monitoring efforts are ongoing in zones that experienced moderate shaking. Officials are prioritizing the collection of verified data on local impacts, reaffirming that the earthquake does not pose a tsunami threat.
Indonesia frequently experiences seismic activity due to its position along multiple active tectonic boundaries. The event on Tuesday struck west of Sumatra, a region known for frequent earthquakes. For this seismic event, authorities confirmed a magnitude of 6.1 and a depth of 29 kilometers. The epicenter was identified as 147 kilometers southeast of South Nias. Official assessments confirmed there was no tsunami threat from this offshore quake.