4.0

M4.0 Earthquake 25 km W of Salamatof, AlaskaJune 20, 2022

2022-06-20 19:09:51 UTC (2022-06-20) · approx. 9:09 AM UTC-10 local

MagnitudeM4.0(mb)
Time19:09 UTC9:09 AM UTC-10
Depth75.0 kmintermediate depth
Coordinates60.616°, -151.793°
Felt byNo felt reports
Status✓ Reviewed by USGS· green PAGER
green Alertno significant casualties or damage expected

On June 20, 2022 at 19:09 UTC, a magnitude 4.0 intermediate depth earthquake struck 25 km W of Salamatof, Alaska, at a depth of 75.0 km and coordinates 60.6161°, -151.7926°. The nearest populated place is Cohoe (population 1,364).

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 60.62°, -151.79°

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 25 km W of Salamatof, Alaska

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

Population exposure (USGS PAGER)

Estimated population that experienced each level of shaking. Based on the USGS PAGER rapid impact assessment, which combines ShakeMap output with global population grids.

Shaking intensity (MMI)DescriptionPopulation exposed
MMI 3weak84,098

Earthquake Details

Magnitude
4.0 mb
Depth
75.0 km
intermediate depth
Location
60.6161°N
-151.7926°E
Intensity (MMI)
3.0
weak

Technical Information

Event ID
ak0227v49mcw
Event Type
earthquake
Status
✓ Reviewed
Significance
246
RMS Residual
1.06 sec
Last Updated
2022-08-28 03:19:24 UTC

Common Questions

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

The magnitude 4.0 earthquake that struck 25 km W of Salamatof, Alaska on June 20, 2022 at 19:09 UTC had a depth of 75.0 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: ak0227v49mcw). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2022, June 20, 2022). M4.0 Earthquake 25 km W of Salamatof, AlaskaJune 20, 2022. Retrieved August 28, 2022 from https://www.earthquaketracker.org/earthquakes/event/ak0227v49mcw/