Shallow M5.6 earthquake hits northwestern Sumatra, Indonesia

A shallow earthquake measuring M5.6 struck northwestern Sumatra, Indonesia, at 23:37 UTC on October 3, 2026. The event occurred approximately 80 km (50 miles) south of Banda Aceh at a depth of 69.7 km (43.3 miles), according to data from the USGS.

The coordinates place the epicenter inland in northwest Sumatra, within Aceh province. Banda Aceh is the nearest major city, and numerous villages are located throughout this seismically active region. Population density in parts of Aceh is moderate, with several towns dispersed through the area.

Given its inland location in northern Sumatra, the region may include critical infrastructure such as regional roads, local airports, and electrical and telecommunication facilities, which serve both Banda Aceh and surrounding communities.

There is no tsunami threat associated with this earthquake, based on its location and available data.

USGS issued a green alert for this event, indicating a low likelihood of casualties or damage. The maximum estimated intensity reached just above IV on the Modified Mercalli scale. The significance index is 482 (on a scale that runs through 1 000), based on magnitude, felt reports, and estimated impact.

Northern Sumatra is situated along the Sunda megathrust, where the Indo-Australian Plate subducts beneath the Eurasian Plate. This region is known for frequent strong earthquakes due to its tectonic environment.

This information was last updated at 23:58 UTC on October 3, 2026.