4.0

M4.0 Earthquake 22 km NNE of Larsen Bay, AlaskaJuly 10, 2022

2022-07-10 23:10:35 UTC (2022-07-10) · approx. 1:10 PM UTC-10 local

MagnitudeM4.0(mb)
Time23:10 UTC1:10 PM UTC-10
Depth44.8 kmshallow crustal
Coordinates57.736°, -153.899°
Felt byNo felt reports
Status✓ Reviewed by USGS

On July 10, 2022 at 23:10 UTC, a magnitude 4.0 shallow crustal earthquake struck 22 km NNE of Larsen Bay, Alaska, at a depth of 44.8 km and coordinates 57.7356°, -153.8987°.

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 57.74°, -153.90°

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 22 km NNE of Larsen Bay, Alaska

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

Earthquake Details

Magnitude
4.0 mb
Depth
44.8 km
shallow crustal
Location
57.7356°N
-153.8987°E
Intensity (MMI)
2.3
weak

Technical Information

Event ID
ak0228s9eh5g
Event Type
earthquake
Status
✓ Reviewed
Significance
246
RMS Residual
0.69 sec
Last Updated
2022-09-24 21:26:00 UTC

Common Questions

How strong was the magnitude 4.0 earthquake near Larsen Bay, Alaska?

The magnitude 4.0 earthquake that struck 22 km NNE of Larsen Bay, Alaska on July 10, 2022 at 23:10 UTC had a depth of 44.8 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: ak0228s9eh5g). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2022, July 10, 2022). M4.0 Earthquake 22 km NNE of Larsen Bay, AlaskaJuly 10, 2022. Retrieved September 24, 2022 from https://www.earthquaketracker.org/earthquakes/event/ak0228s9eh5g/