NORTH SUMATRA / RankWire.AI / – On Tuesday, an offshore magnitude 6.1 earthquake impacted the waters near Indonesia’s North Sumatra province, causing shaking across various parts of Sumatra. The seismic event occurred 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. According to officials, the quake’s depth was measured at 29 kilometers beneath the sea to the west of Sumatra.
The BMKG, Indonesia’s Meteorology, Climatology and Geophysics Agency, pinpointed the epicenter at 0.65 degrees south latitude and 98.32 degrees east longitude. The strongest shaking was reported as intensity IV in North Tapanuli, while several areas in West Sumatra experienced tremors between intensity III and IV. These areas included Padang, Padang Pariaman, Pariaman, West Pasaman, and Agam.
Communities farther from the quake’s epicenter also detected the tremors, albeit at lower intensity levels. Shaking at intensity III was felt in Padang Sidempuan, Subulussalam, and South Nias. Meanwhile, Padang Panjang and Central Tapanuli experienced intensity II to III, and Gunungsitoli recorded intensity II. The BNPB, Indonesia’s National Disaster Mitigation Agency, stated the earthquake did not pose a tsunami threat. Authorities are actively monitoring affected regions following the seismic activity.
No tsunami alert issued after the seismic event
Residents in South Nias reported experiencing weak shaking that lasted approximately three to five seconds. Disaster management teams in the area began assessing the situation and coordinating inspections in zones where residents felt the tremor. Initial reports from officials indicated no casualties, injuries, or structural damage. As part of standard procedures, authorities are gathering additional information from local officials about the impacted communities after the offshore quake.
The earthquake affected a wide region, with tremors felt across many parts of western Indonesia. The intensity varied depending on the location, with more vigorous shaking closer to North Sumatra and West Sumatra. No tsunami warning was issued following the magnitude 6.1 event. Subsequent updates maintained the initial measurements, confirming the same magnitude, depth, and offshore position.
Continued investigations underway in impacted zones
The earthquake near South Nias ranks among the significant seismic events in Indonesia on August 18. Its offshore epicenter kept the main shock away from densely populated areas, yet residents across multiple districts still reported feeling the tremors. Monitoring efforts are ongoing in regions where moderate shaking was recorded. Officials are prioritizing the collection of verified information about local conditions while reaffirming that the earthquake does not present a tsunami hazard.
Indonesia frequently experiences earthquakes due to its position along several active tectonic plates. The event on Tuesday struck to the west of Sumatra, an area with an extensive history of seismic activity. The authorities confirmed the quake’s magnitude as 6.1, with a depth of 29 kilometers. The epicenter remained identified as 147 kilometers southeast of South Nias. Official assessments confirmed no tsunami risk linked to this offshore seismic event.