4.1

M4.1 Earthquake 74 km SSW of Sand Point, AlaskaAugust 30, 2023

2023-08-30 20:27:53 UTC (2023-08-30) · approx. 9:27 AM UTC-11 local

MagnitudeM4.1(mb)
Time20:27 UTC9:27 AM UTC-11
Depth55.7 kmshallow crustal
Coordinates54.756°, -161.071°
Felt byNo felt reports
Status✓ Reviewed by USGS

On August 30, 2023 at 20:27 UTC, a magnitude 4.1 shallow crustal earthquake struck 74 km SSW of Sand Point, Alaska, at a depth of 55.7 km and coordinates 54.7556°, -161.0709°.

Physical scale: An earthquake of magnitude 4.1 releases seismic energy equivalent to roughly 21 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 406 m — a useful intuition for the size of the slip patch on the fault.

Map showing earthquake epicenter at 54.76°, -161.07°

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 M4.1 earthquake near 74 km SSW of Sand Point, Alaska

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

Earthquake Details

Magnitude
4.1 mb
Depth
55.7 km
shallow crustal
Location
54.7556°N
-161.0709°E
Intensity (MMI)
1.8
weak

Technical Information

Event ID
us7000ks6s
Event Type
earthquake
Status
✓ Reviewed
Significance
259
Stations Used
71
Azimuthal Gap
198.0°
Min Station Distance
0.686°
RMS Residual
0.85 sec
Last Updated
2023-11-04 21:35:55 UTC

Common Questions

How strong was the magnitude 4.1 earthquake near Sand Point, Alaska?

The magnitude 4.1 earthquake that struck 74 km SSW of Sand Point, Alaska on August 30, 2023 at 20:27 UTC had a depth of 55.7 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 4.1 earthquakes can continue for several days and gradually diminish over time.

Understanding This Data

Magnitude 4.1 earthquakes are often felt but rarely cause damage.

Learn more about magnitude →

Authoritative source: USGS event page (event ID: us7000ks6s). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2023, August 30, 2023). M4.1 Earthquake 74 km SSW of Sand Point, AlaskaAugust 30, 2023. Retrieved November 4, 2023 from https://www.earthquaketracker.org/earthquakes/event/us7000ks6s/