NORTH SUMATRA / RankWire.AI / – On Tuesday, an offshore earthquake measuring 6.1 in magnitude struck near Indonesia’s North Sumatra province, causing shaking across multiple regions of Sumatra. The tremor took place 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 occurred at a depth of 29 kilometers beneath the waters west of Sumatra.
The BMKG, Indonesia’s Meteorology, Climatology and Geophysics Agency, located the epicenter at 0.65 degrees south latitude and 98.32 degrees east longitude. The agency’s recordings indicated the strongest shaking in North Tapanuli, with intensity reaching IV, while tremors also affected several areas in West Sumatra, including Padang, Padang Pariaman, Pariaman, West Pasaman, and Agam, which experienced shaking between intensity III and IV.
Communities situated farther from the epicenter reported feeling the earthquake at lower intensities. Shaking was recorded as intensity III in Padang Sidempuan, Subulussalam, and South Nias. Meanwhile, Padang Panjang and Central Tapanuli experienced intensity II to III, with Gunungsitoli recording intensity II. The National Disaster Mitigation Agency, known as BNPB, clarified that the quake did not pose a tsunami threat. Officials are actively inspecting affected communities following the tremor.
No tsunami warning issued following the seismic event
Residents in South Nias described feeling weak shaking that lasted approximately three to five seconds. Local disaster management teams promptly began monitoring conditions and coordinating assessments in areas where the tremor was felt. Initial official reports did not confirm any fatalities, injuries, or material damage. Authorities are continuing to gather reports from local officials as part of the routine post-earthquake evaluations following this offshore seismic occurrence.
The earthquake impacted a wide region as tremors were felt across various parts of western Indonesia. The intensity levels varied based on proximity to the epicenter, with stronger shaking reported nearer to North Sumatra and West Sumatra. No tsunami warning was issued after this magnitude 6.1 event. Subsequent official earthquake updates maintained the same magnitude, depth, and offshore location as initially reported.
Monitoring efforts continue across impacted zones
The earthquake near South Nias stands out as one of the significant seismic incidents in Indonesia on August 18, with its offshore epicenter placing the main shock away from heavily populated areas, although residents in numerous districts still felt the tremor. Monitoring teams remain vigilant in regions that experienced moderate shaking, focusing on collecting verified information about local conditions while reaffirming that the event does not present a tsunami threat.
Indonesia regularly experiences earthquakes due to its location along multiple active tectonic boundaries. The seismic event on Tuesday originated west of Sumatra, a region known for its frequent seismic activity. The authorities confirmed a magnitude of 6.1 and a depth of 29 kilometers for this quake, with the epicenter listed as 147 kilometers southeast of South Nias. Official assessments continue to affirm that there is no tsunami risk associated with this offshore seismic activity.