3.8

M3.8 Earthquake 122 km S of Unalaska, AlaskaAugust 15, 2024

2024-08-15 22:28:34 UTC (2024-08-15) · approx. 11:28 AM UTC-11 local

MagnitudeM3.8(mb)
Time22:28 UTC11:28 AM UTC-11
Depth12.6 kmshallow crustal
Coordinates52.779°, -166.709°
Felt byNo felt reports
Status✓ Reviewed by USGS

On August 15, 2024 at 22:28 UTC, a magnitude 3.8 shallow crustal earthquake struck 122 km S of Unalaska, Alaska, at a depth of 12.6 km and coordinates 52.7791°, -166.7091°.

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 52.78°, -166.71°

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 122 km S of Unalaska, Alaska

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

Earthquake Details

Magnitude
3.8 mb
Depth
12.6 km
shallow crustal
Location
52.7791°N
-166.7091°E
Intensity (MMI)
1.0
weak

Technical Information

Event ID
us7000n7ae
Event Type
earthquake
Status
✓ Reviewed
Significance
222
Stations Used
66
Azimuthal Gap
171.0°
Min Station Distance
0.962°
RMS Residual
0.91 sec
Last Updated
2024-10-26 15:48:50 UTC

Common Questions

How strong was the magnitude 3.8 earthquake near Unalaska, Alaska?

The magnitude 3.8 earthquake that struck 122 km S of Unalaska, Alaska on August 15, 2024 at 22:28 UTC had a depth of 12.6 km. 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: us7000n7ae). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2024, August 15, 2024). M3.8 Earthquake 122 km S of Unalaska, AlaskaAugust 15, 2024. Retrieved October 26, 2024 from https://www.earthquaketracker.org/earthquakes/event/us7000n7ae/