How strong was the 133 km SE of Old Harbor, Alaska earthquake?
The 133 km SE of Old Harbor, Alaska earthquake had a magnitude of 5.6 mww, classified as a "Moderate" earthquake on the magnitude scale. Earthquakes of this magnitude can cause damage to poorly constructed buildings and are felt widely.
Where exactly did this earthquake occur and how deep was it?
This earthquake struck at coordinates 56.2482N, 151.9738W, at a depth of 12.0 km. Shallow earthquakes (under 20 km) tend to cause more surface damage than deeper events.
Did this earthquake trigger a tsunami warning?
Yes, a tsunami advisory or warning was associated with this earthquake. Coastal residents in affected areas should always follow local emergency management guidance during tsunami events. Even small tsunamis can produce dangerous currents.
How many people felt this earthquake?
No felt reports were submitted to the USGS for this earthquake. This may indicate the earthquake occurred in a remote area with few nearby residents, or the shaking was too minor to be widely noticed.
When did this earthquake happen and how significant was it?
This earthquake occurred on September 1, 2025 at 20:02:09. The USGS assigned it a significance score of 482 out of a possible 3,000, which factors in magnitude, felt reports, and potential impact. This is a moderately significant seismic event. The PAGER alert level was "green", indicating the estimated level of response needed.