3.4

M3.4 Earthquake 72 km NNE of White Mountain, AlaskaDecember 18, 2021

2021-12-18 19:16:13 UTC (2021-12-18) · approx. 8:16 AM UTC-11 local

MagnitudeM3.4(ml)
Time19:16 UTC8:16 AM UTC-11
Depth10.7 kmshallow crustal
Coordinates65.304°, -162.933°
Felt byNo felt reports
Status✓ Reviewed by USGS

On December 18, 2021 at 19:16 UTC, a magnitude 3.4 shallow crustal earthquake struck 72 km NNE of White Mountain, Alaska, at a depth of 10.7 km and coordinates 65.3040°, -162.9329°.

Physical scale: An earthquake of magnitude 3.4 releases seismic energy equivalent to roughly 1.9 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 134 m — a useful intuition for the size of the slip patch on the fault.

Map showing earthquake epicenter at 65.30°, -162.93°

ShakeMap — predicted shaking intensity

Modeled ground-motion intensity contoured on the Modified Mercalli scale (MMI). Computed by the USGS from the moment-tensor solution and regional ground-motion prediction equations.

USGS ShakeMap intensity contours for the M3.4 earthquake near 72 km NNE of White Mountain, Alaska

Source: U.S. Geological Survey ShakeMap. View interactive ShakeMap on USGS

Earthquake Details

Magnitude
3.4 ml
Depth
10.7 km
shallow crustal
Location
65.3040°N
-162.9329°E
Intensity (MMI)
4.2
moderate

Technical Information

Event ID
ak021g6gky07
Event Type
earthquake
Status
✓ Reviewed
Significance
178
RMS Residual
0.77 sec
Last Updated
2022-03-01 16:37:38 UTC

Common Questions

How strong was the magnitude 3.4 earthquake near White Mountain, Alaska?

The magnitude 3.4 earthquake that struck 72 km NNE of White Mountain, Alaska on December 18, 2021 at 19:16 UTC had a depth of 10.7 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 3.4 earthquakes can continue for several days and gradually diminish over time.

Understanding This Data

Magnitude 3.4 earthquakes are typically only recorded by instruments.

Learn more about magnitude →

Authoritative source: USGS event page (event ID: ak021g6gky07). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2021, December 18, 2021). M3.4 Earthquake 72 km NNE of White Mountain, AlaskaDecember 18, 2021. Retrieved March 1, 2022 from https://www.earthquaketracker.org/earthquakes/event/ak021g6gky07/