3.1

M3.1 Earthquake 240 km ESE of Chiniak, AlaskaNovember 11, 2021

2021-11-11 19:41:47 UTC (2021-11-11) · approx. 9:41 AM UTC-10 local

MagnitudeM3.1(ml)
Time19:41 UTC9:41 AM UTC-10
Depth10.0 kmshallow crustal
Coordinates56.622°, -148.746°
Felt byNo felt reports
Status✓ Reviewed by USGS

On November 11, 2021 at 19:41 UTC, a magnitude 3.1 shallow crustal earthquake struck 240 km ESE of Chiniak, Alaska, at a depth of 10.0 km and coordinates 56.6223°, -148.7461°.

Physical scale: An earthquake of magnitude 3.1 releases seismic energy equivalent to roughly 674 kg of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 83 m — a useful intuition for the size of the slip patch on the fault.

Map showing earthquake epicenter at 56.62°, -148.75°

Earthquake Details

Magnitude
3.1 ml
Depth
10.0 km
shallow crustal
Location
56.6223°N
-148.7461°E

Technical Information

Event ID
us7000ftc6
Event Type
earthquake
Status
✓ Reviewed
Significance
148
Azimuthal Gap
254.0°
Min Station Distance
2.390°
RMS Residual
0.54 sec
Last Updated
2022-01-15 20:51:50 UTC

Common Questions

How strong was the magnitude 3.1 earthquake near Chiniak, Alaska?

The magnitude 3.1 earthquake that struck 240 km ESE of Chiniak, Alaska on November 11, 2021 at 19:41 UTC had a depth of 10.0 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 3.1 earthquakes can continue for several days and gradually diminish over time.

Understanding This Data

Magnitude 3.1 earthquakes are typically only recorded by instruments.

Learn more about magnitude →

Authoritative source: USGS event page (event ID: us7000ftc6). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2021, November 11, 2021). M3.1 Earthquake 240 km ESE of Chiniak, AlaskaNovember 11, 2021. Retrieved January 15, 2022 from https://www.earthquaketracker.org/earthquakes/event/us7000ftc6/