M 5.7 Earthquake Strikes 228 km ESE of Attu Station, Alaska

What Happened

A moderate earthquake with a magnitude of 5.7 mww was recorded on March 21, 2026, at 21:08:19 UTC. The seismic event occurred at a shallow depth of 9.3 km.

Location Details

The earthquake was centered at coordinates 52.3233°N, 176.4403°E, approximately 228 km east-southeast of Attu Station, Alaska. The depth of 9.339 km is classified as shallow; shallow earthquakes (those less than 20 km deep) are generally felt more strongly than deeper events of the same magnitude.

Impact Assessment

The USGS has assigned this event a “green” alert level, indicating a low likelihood of casualties or significant economic damage. The event data includes a tsunami flag (1), suggesting that residents in the region should monitor official NOAA tsunami warning centers for specific advisories or updates. No felt reports have been submitted to the USGS at this time, and the maximum estimated intensity was 4.446 on the Modified Mercalli Intensity scale.

What You Should Know

A magnitude 5.7 event is classified as a “moderate earthquake.” While such events can cause damage to poorly constructed buildings, they typically result in light damage to well-built structures. Residents in the Aleutian Islands should remain aware of the possibility of aftershocks following this event.

Source

Data provided by the USGS Earthquake Hazards Program.