3.3

M3.3 Earthquake 50 km SSE of Atka, Alaska — August 1, 2026

2026-08-01 23:59:22 UTC (2026-08-01) · approx. 11:59 AM UTC-12 local

MagnitudeM3.3(mb)
Time23:59 UTC≈ 11:59 AM UTC-12
Depth35.0 kmshallow crustal
Coordinates51.802°, -173.833°
Felt byNo felt reports
Status✓ Reviewed by USGS

On August 1, 2026 at 23:59 UTC, a magnitude 3.3 shallow crustal earthquake struck 50 km SSE of Atka, Alaska, at a depth of 35.0 km and coordinates 51.8021°, -173.8329°.

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.

Map showing earthquake epicenter at 51.80°, -173.83°

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 M3.3 earthquake near 50 km SSE of Atka, Alaska

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

Earthquake Details

Magnitude
3.3 mb
Depth
35.0 km
shallow crustal
Location
51.8021°N
-173.8329°E
Intensity (MMI)
2.5
weak

Technical Information

Event ID
us6000tht2
Event Type
earthquake
Status
✓ Reviewed
Significance
168
Stations Used
43
Azimuthal Gap
203.0°
Min Station Distance
0.459°
RMS Residual
0.77 sec
Last Updated
2026-08-22 21:59:20 UTC

Common Questions

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

The magnitude 3.3 earthquake that struck 50 km SSE of Atka, Alaska on August 1, 2026 at 23:59 UTC had a depth of 35.0 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 3.3 earthquakes can continue for several days and gradually diminish over time.

Understanding This Data

Magnitude 3.3 earthquakes are typically only recorded by instruments.

Learn more about magnitude →

Authoritative source: USGS event page (event ID: us6000tht2). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2026, August 1, 2026). M3.3 Earthquake 50 km SSE of Atka, Alaska — August 1, 2026. Retrieved August 22, 2026 from https://www.earthquaketracker.org/earthquakes/event/us6000tht2/