3.8

M3.8 Earthquake 42 km S of Sand Point, AlaskaDecember 25, 2023

2023-12-25 23:39:41 UTC (2023-12-25) · approx. 12:39 PM UTC-11 local

MagnitudeM3.8(mb)
Time23:39 UTC12:39 PM UTC-11
Depth51.5 kmshallow crustal
Coordinates54.954°, -160.429°
Felt by1DYFI response· max MMI 2.5
Status✓ Reviewed by USGS

On December 25, 2023 at 23:39 UTC, a magnitude 3.8 shallow crustal earthquake struck 42 km S of Sand Point, Alaska, at a depth of 51.5 km and coordinates 54.9540°, -160.4288°. The earthquake was reported felt by 1 personacross nearby locations, with a maximum shaking intensity of Modified Mercalli Intensity (MMI) 2.5 (weak).

Physical scale: An earthquake of magnitude 3.8 releases seismic energy equivalent to roughly 7.6 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 252 m — a useful intuition for the size of the slip patch on the fault.

Map showing earthquake epicenter at 54.95°, -160.43°

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 M3.8 earthquake near 42 km S of Sand Point, Alaska

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

Did You Feel It? — community-reported shaking

Aggregated felt-report intensity from 1 citizen response to the USGS Did You Feel It? system. Each colored zone represents the average MMI from reports in that area.

USGS DYFI community-reported intensity map for the M3.8 earthquake near 42 km S of Sand Point, Alaska

Source: U.S. Geological Survey Did You Feel It?. View on USGS · submit your own report

Earthquake Details

Magnitude
3.8 mb
Depth
51.5 km
shallow crustal
Location
54.9540°N
-160.4288°E
Felt Reports
1
DYFI responses
Intensity (MMI)
2.5
weak
Community Intensity
3.8
CDI from reports

Technical Information

Event ID
us7000llf5
Event Type
earthquake
Status
✓ Reviewed
Significance
223
Stations Used
52
Azimuthal Gap
155.0°
Min Station Distance
0.397°
RMS Residual
0.56 sec
Last Updated
2024-03-02 21:39:40 UTC

Common Questions

How strong was the magnitude 3.8 earthquake near Sand Point, Alaska?

The magnitude 3.8 earthquake that struck 42 km S of Sand Point, Alaska on December 25, 2023 at 23:39 UTC had a depth of 51.5 km. It was felt by 1 person with maximum shaking intensity of MMI 2.5 (weak). For context, this was a minor earthquake typically detected only by instruments.

Were there aftershocks?

Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 3.8 earthquakes can continue for several days and gradually diminish over time.

Understanding This Data

Magnitude 3.8 earthquakes are typically only recorded by instruments.

Learn more about magnitude →

Authoritative source: USGS event page (event ID: us7000llf5). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2023, December 25, 2023). M3.8 Earthquake 42 km S of Sand Point, AlaskaDecember 25, 2023. Retrieved March 2, 2024 from https://www.earthquaketracker.org/earthquakes/event/us7000llf5/