3.0

M3.0 Earthquake 244 km SSW of Akhiok, Alaska — August 5, 2021

2021-08-05 19:52:39 UTC (2021-08-05) · approx. 9:52 AM UTC-10 local

MagnitudeM3.0(ml)
Time19:52 UTC≈ 9:52 AM UTC-10
Depth7.0 kmshallow crustal
Coordinates54.836°, -155.238°
Felt byNo felt reports
Status✓ Reviewed by USGS

On August 5, 2021 at 19:52 UTC, a magnitude 3.0 shallow crustal earthquake struck 244 km SSW of Akhiok, Alaska, at a depth of 7.0 km and coordinates 54.8362°, -155.2376°.

Physical scale: An earthquake of magnitude 3.0 releases seismic energy equivalent to roughly 477 kg of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 71 m — a useful intuition for the size of the slip patch on the fault.

Map showing earthquake epicenter at 54.84°, -155.24°

Earthquake Details

Magnitude
3.0 ml
Depth
7.0 km
shallow crustal
Location
54.8362°N
-155.2376°E

Technical Information

Event ID
ak0219z78rxj
Event Type
earthquake
Status
✓ Reviewed
Significance
138
RMS Residual
0.43 sec
Last Updated
2021-10-14 01:07:53 UTC

Common Questions

How strong was the magnitude 3.0 earthquake near Akhiok, Alaska?

The magnitude 3.0 earthquake that struck 244 km SSW of Akhiok, Alaska on August 5, 2021 at 19:52 UTC had a depth of 7.0 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 3.0 earthquakes can continue for several days and gradually diminish over time.

Understanding This Data

Magnitude 3.0 earthquakes are typically only recorded by instruments.

Learn more about magnitude →

Authoritative source: USGS event page (event ID: ak0219z78rxj). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2021, August 5, 2021). M3.0 Earthquake 244 km SSW of Akhiok, Alaska — August 5, 2021. Retrieved October 14, 2021 from https://www.earthquaketracker.org/earthquakes/event/ak0219z78rxj/