3.3

M3.3 Earthquake 93 km SSE of Atka, AlaskaAugust 5, 2026

2026-08-05 12:38:05 UTC (2 days ago) · approx. 12:38 AM UTC-12 local

MagnitudeM3.3(ml)
Time12:38 UTC12:38 AM UTC-12
Depth10.3 kmshallow crustal
Coordinates51.467°, -173.535°
Felt byNo felt reports
Status✓ Reviewed by USGS

On August 5, 2026 at 12:38 UTC, a magnitude 3.3 shallow crustal earthquake struck 93 km SSE of Atka, Alaska, at a depth of 10.3 km and coordinates 51.4670°, -173.5350°.

Physical scale: An earthquake of magnitude 3.3 releases seismic energy equivalent to roughly 1.3 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 114 m — a useful intuition for the size of the slip patch on the fault.

This earthquake is part of an ongoing aftershock sequence following the magnitude 5.8 mainshock that occurred 12 days ago 109 km SE of Atka, Alaska. Since the mainshock, the USGS has recorded 53 aftershocks in this area. Aftershock activity is expected to continue for days to weeks as stresses on surrounding faults redistribute.

Map showing earthquake epicenter at 51.47°, -173.53°

Earthquake Details

Magnitude
3.3 ml
Depth
10.3 km
shallow crustal
Location
51.4670°N
-173.5350°E

Technical Information

Event ID
aka2026pjxzzo
Event Type
earthquake
Status
✓ Reviewed
Significance
168
Stations Used
37
Azimuthal Gap
213.0°
Min Station Distance
0.800°
RMS Residual
0.60 sec
Last Updated
2026-08-07 20:17:22 UTC

Common Questions

How strong was the magnitude 3.3 earthquake near Atka, Alaska?

The magnitude 3.3 earthquake that struck 93 km SSE of Atka, Alaska on August 5, 2026 at 12:38 UTC had a depth of 10.3 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 3.3 earthquakes can continue for several days and gradually diminish over time.

Is this the same earthquake as the M5.8 one earlier?

No. This magnitude 3.3 earthquake is an aftershock of the larger magnitude 5.8 mainshock that occurred earlier 109 km SE of Atka, Alaska. Aftershocks are smaller earthquakes triggered by stress changes from the mainshock.

Understanding This Data

Magnitude 3.3 earthquakes are typically only recorded by instruments.

Learn more about magnitude →

Authoritative source: USGS event page (event ID: aka2026pjxzzo). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2026, August 5, 2026). M3.3 Earthquake 93 km SSE of Atka, AlaskaAugust 5, 2026. Retrieved August 7, 2026 from https://www.earthquaketracker.org/earthquakes/event/aka2026pjxzzo/