NORTH SUMATRA / RankWire.AI / – On Tuesday, a magnitude 6.1 tremor struck offshore near Indonesia’s North Sumatra province, causing seismic activity across various parts of Sumatra. The earthquake’s occurrence was recorded at 1:02:23 p.m. western Indonesian time, which corresponds to 06:02:23 UTC, with its epicenter approximately 147 kilometers southeast of South Nias Regency. Authorities determined that the quake happened at a depth of 29 kilometers beneath waters off the west coast 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 agency recorded the strongest shaking at intensity IV in North Tapanuli, with tremors also felt across parts of West Sumatra. Cities such as Padang, Padang Pariaman, Pariaman, West Pasaman, and Agam experienced shaking between intensity III and IV.
Communities located farther from the epicenter felt the quake at lower intensities, with Padang Sidempuan, Subulussalam, and South Nias reporting intensity III shaking. 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 that the earthquake did not pose a tsunami threat. Officials are currently verifying the condition of affected areas following the seismic event.
No tsunami alert issued after the quake
In South Nias, residents reported experiencing weak tremors lasting approximately three to five seconds. Local disaster response teams have initiated monitoring and are coordinating assessments in areas where the tremor was felt. Initial reports from officials indicate no confirmed fatalities, injuries, or structural damages. Authorities continue to gather reports from local officials as part of their routine post-earthquake evaluation after the offshore seismic activity.
The earthquake affected a large region, with tremors reaching communities across multiple parts of western Indonesia. Intensity levels varied depending on location, with stronger shaking reported nearer to areas of North Sumatra and West Sumatra. No tsunami warning followed this magnitude 6.1 event. Subsequent official updates maintained the recorded magnitude, depth, and offshore location of the quake.
Response efforts underway in impacted zones
The earthquake near South Nias became one of the significant seismic incidents in Indonesia on August 18. Its offshore epicenter kept the main shock away from major population centers, although residents across several districts still reported feeling the tremor. Monitoring efforts are ongoing in areas that experienced moderate shaking, with officials prioritizing the collection of verified information while reaffirming that the earthquake did not pose a tsunami threat.
Indonesia faces frequent seismic activity due to its position along multiple active tectonic boundaries. The event on Tuesday occurred west of Sumatra, a region with a longstanding history of earthquakes. Confirmed details include a magnitude of 6.1 and a depth of 29 kilometers. The epicenter was recorded as 147 kilometers southeast of South Nias, with official assessments indicating no tsunami risk from this offshore seismic event.