3.0

M3.0 Earthquake 126 km SE of Perryville, AlaskaOctober 17, 2021

2021-10-17 19:32:24 UTC (2021-10-17) · approx. 8:32 AM UTC-11 local

MagnitudeM3.0(ml)
Time19:32 UTC8:32 AM UTC-11
Depth27.0 kmshallow crustal
Coordinates55.158°, -157.643°
Felt byNo felt reports
Status✓ Reviewed by USGS

On October 17, 2021 at 19:32 UTC, a magnitude 3.0 shallow crustal earthquake struck 126 km SE of Perryville, Alaska, at a depth of 27.0 km and coordinates 55.1583°, -157.6435°.

Physical scale: An earthquake of magnitude 3.0 releases seismic energy equivalent to roughly 477 kg of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 71 m — a useful intuition for the size of the slip patch on the fault.

Map showing earthquake epicenter at 55.16°, -157.64°

Earthquake Details

Magnitude
3.0 ml
Depth
27.0 km
shallow crustal
Location
55.1583°N
-157.6435°E

Technical Information

Event ID
ak021dbxcts3
Event Type
earthquake
Status
✓ Reviewed
Significance
138
RMS Residual
0.79 sec
Last Updated
2021-12-25 22:58:44 UTC

Common Questions

How strong was the magnitude 3.0 earthquake near Perryville, Alaska?

The magnitude 3.0 earthquake that struck 126 km SE of Perryville, Alaska on October 17, 2021 at 19:32 UTC had a depth of 27.0 km. For context, this was a minor earthquake typically detected only by instruments.

Were there aftershocks?

Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 3.0 earthquakes can continue for several days and gradually diminish over time.

Understanding This Data

Magnitude 3.0 earthquakes are typically only recorded by instruments.

Learn more about magnitude →

Authoritative source: USGS event page (event ID: ak021dbxcts3). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2021, October 17, 2021). M3.0 Earthquake 126 km SE of Perryville, AlaskaOctober 17, 2021. Retrieved December 25, 2021 from https://www.earthquaketracker.org/earthquakes/event/ak021dbxcts3/