4.0

M4.0 Earthquake 58 km SSE of Unalaska, AlaskaJanuary 10, 2022

2022-01-10 20:37:00 UTC (2022-01-10) · approx. 9:37 AM UTC-11 local

MagnitudeM4.0(mb)
Time20:37 UTC9:37 AM UTC-11
Depth43.1 kmshallow crustal
Coordinates53.411°, -166.111°
Felt byNo felt reports
Status✓ Reviewed by USGS

On January 10, 2022 at 20:37 UTC, a magnitude 4.0 shallow crustal earthquake struck 58 km SSE of Unalaska, Alaska, at a depth of 43.1 km and coordinates 53.4109°, -166.1109°.

Physical scale: An earthquake of magnitude 4.0 releases seismic energy equivalent to roughly 15 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 347 m — a useful intuition for the size of the slip patch on the fault.

Map showing earthquake epicenter at 53.41°, -166.11°

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 M4.0 earthquake near 58 km SSE of Unalaska, Alaska

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

Earthquake Details

Magnitude
4.0 mb
Depth
43.1 km
shallow crustal
Location
53.4109°N
-166.1109°E
Intensity (MMI)
2.6
weak

Technical Information

Event ID
us7000ganm
Event Type
earthquake
Status
✓ Reviewed
Significance
246
Azimuthal Gap
160.0°
Min Station Distance
0.494°
RMS Residual
0.67 sec
Last Updated
2022-03-19 22:07:37 UTC

Common Questions

How strong was the magnitude 4.0 earthquake near Unalaska, Alaska?

The magnitude 4.0 earthquake that struck 58 km SSE of Unalaska, Alaska on January 10, 2022 at 20:37 UTC had a depth of 43.1 km. For context, this was a light earthquake commonly felt near the epicenter.

Were there aftershocks?

Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.0 earthquakes can continue for several days and gradually diminish over time.

Understanding This Data

Magnitude 4.0 earthquakes are often felt but rarely cause damage.

Learn more about magnitude →

Authoritative source: USGS event page (event ID: us7000ganm). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2022, January 10, 2022). M4.0 Earthquake 58 km SSE of Unalaska, AlaskaJanuary 10, 2022. Retrieved March 19, 2022 from https://www.earthquaketracker.org/earthquakes/event/us7000ganm/