4.1

M4.1 Earthquake 115 km ESE of Adak, AlaskaDecember 29, 2023

2023-12-29 21:15:37 UTC (2023-12-29) · approx. 9:15 AM UTC-12 local

MagnitudeM4.1(mb)
Time21:15 UTC9:15 AM UTC-12
Depth38.8 kmshallow crustal
Coordinates51.248°, -175.126°
Felt byNo felt reports
Status✓ Reviewed by USGS

On December 29, 2023 at 21:15 UTC, a magnitude 4.1 shallow crustal earthquake struck 115 km ESE of Adak, Alaska, at a depth of 38.8 km and coordinates 51.2480°, -175.1262°.

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 51.25°, -175.13°

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 115 km ESE of Adak, Alaska

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

Earthquake Details

Magnitude
4.1 mb
Depth
38.8 km
shallow crustal
Location
51.2480°N
-175.1262°E
Intensity (MMI)
1.0
weak

Technical Information

Event ID
us6000m2qx
Event Type
earthquake
Status
✓ Reviewed
Significance
259
Stations Used
28
Azimuthal Gap
218.0°
Min Station Distance
0.892°
RMS Residual
0.60 sec
Last Updated
2024-03-02 21:39:37 UTC

Common Questions

How strong was the magnitude 4.1 earthquake near Adak, Alaska?

The magnitude 4.1 earthquake that struck 115 km ESE of Adak, Alaska on December 29, 2023 at 21:15 UTC had a depth of 38.8 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 4.1 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: us6000m2qx). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2023, December 29, 2023). M4.1 Earthquake 115 km ESE of Adak, AlaskaDecember 29, 2023. Retrieved March 2, 2024 from https://www.earthquaketracker.org/earthquakes/event/us6000m2qx/