4.0

M4.0 Earthquake 136 km WNW of Arctic Village, AlaskaJuly 29, 2023

2023-07-29 19:32:49 UTC (2023-07-29) · approx. 9:32 AM UTC-10 local

MagnitudeM4.0(mwr)
Time19:32 UTC9:32 AM UTC-10
Depth1.3 kmshallow crustal
Coordinates68.620°, -148.583°
Felt byNo felt reports
Status✓ Reviewed by USGS

On July 29, 2023 at 19:32 UTC, a magnitude 4.0 shallow crustal earthquake struck 136 km WNW of Arctic Village, Alaska, at a depth of 1.3 km and coordinates 68.6196°, -148.5829°.

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 68.62°, -148.58°

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 136 km WNW of Arctic Village, Alaska

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

Earthquake Details

Magnitude
4.0 mwr
Depth
1.3 km
shallow crustal
Location
68.6196°N
-148.5829°E
Intensity (MMI)
3.7
light

Technical Information

Event ID
ak0239nmd2xz
Event Type
earthquake
Status
✓ Reviewed
Significance
246
RMS Residual
0.65 sec
Last Updated
2023-09-30 21:36:33 UTC

Common Questions

How strong was the magnitude 4.0 earthquake near Arctic Village, Alaska?

The magnitude 4.0 earthquake that struck 136 km WNW of Arctic Village, Alaska on July 29, 2023 at 19:32 UTC had a depth of 1.3 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: ak0239nmd2xz). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2023, July 29, 2023). M4.0 Earthquake 136 km WNW of Arctic Village, AlaskaJuly 29, 2023. Retrieved September 30, 2023 from https://www.earthquaketracker.org/earthquakes/event/ak0239nmd2xz/