2.3

M2.3 Earthquake 9 km ENE of Big Lake, AlaskaDecember 21, 2021

2021-12-21 21:22:23 UTC (2021-12-21) · approx. 11:22 AM UTC-10 local

MagnitudeM2.3(ml)
Time21:22 UTC11:22 AM UTC-10
Depth51.3 kmshallow crustal
Coordinates61.543°, -149.779°
Felt by4DYFI responses
Status✓ Reviewed by USGS

On December 21, 2021 at 21:22 UTC, a magnitude 2.3 shallow crustal earthquake struck 9 km ENE of Big Lake, Alaska, at a depth of 51.3 km and coordinates 61.5431°, -149.7789°.

Physical scale: An earthquake of magnitude 2.3 releases seismic energy equivalent to roughly 42.5 kg of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 23 m — a useful intuition for the size of the slip patch on the fault.

Map showing earthquake epicenter at 61.54°, -149.78°

Did You Feel It? — community-reported shaking

Aggregated felt-report intensity from 4 citizen responses to the USGS Did You Feel It? system. Each colored zone represents the average MMI from reports in that area.

USGS DYFI community-reported intensity map for the M2.3 earthquake near 9 km ENE of Big Lake, Alaska

Source: U.S. Geological Survey Did You Feel It?. View on USGS · submit your own report

Earthquake Details

Magnitude
2.3 ml
Depth
51.3 km
shallow crustal
Location
61.5431°N
-149.7789°E
Felt Reports
4
DYFI responses
Community Intensity
3.4
CDI from reports

Technical Information

Event ID
ak021gbgf2iw
Event Type
earthquake
Status
✓ Reviewed
Significance
83
RMS Residual
0.34 sec
Last Updated
2022-03-01 16:39:03 UTC

Common Questions

How strong was the magnitude 2.3 earthquake near Big Lake, Alaska?

The magnitude 2.3 earthquake that struck 9 km ENE of Big Lake, Alaska on December 21, 2021 at 21:22 UTC had a depth of 51.3 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 2.3 earthquakes can continue for several days and gradually diminish over time.

Understanding This Data

Magnitude 2.3 earthquakes are typically only recorded by instruments.

Learn more about magnitude →

Authoritative source: USGS event page (event ID: ak021gbgf2iw). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2021, December 21, 2021). M2.3 Earthquake 9 km ENE of Big Lake, AlaskaDecember 21, 2021. Retrieved March 1, 2022 from https://www.earthquaketracker.org/earthquakes/event/ak021gbgf2iw/