How strong was the 181 km SE of Chignik, Alaska earthquake?
The 181 km SE of Chignik, 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 55.0710N, 156.4993W, at a depth of 36.8 km. This intermediate depth can still produce significant shaking at the surface.
Did this earthquake trigger a tsunami warning?
No tsunami warning was issued for this earthquake. Earthquakes below magnitude 6.5 rarely generate dangerous tsunamis, though localized effects are possible in rare cases.
How many people felt this earthquake?
2 people submitted felt reports to the USGS for this earthquake. The Community Decimal Intensity (CDI) reached 2.0, indicating light shaking noticed by some people. The Modified Mercalli Intensity (MMI) was estimated at 3.3.
When did this earthquake happen and how significant was it?
This earthquake occurred on September 17, 2021 at 02:51:55. The USGS assigned it a significance score of 483 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.