3.4

M3.4 Earthquake 78 km SE of Atka, AlaskaJuly 26, 2026

2026-07-26 14:10:19 UTC (1 day ago) · approx. 2:10 AM UTC-12 local

MagnitudeM3.4(ml)
Time14:10 UTC2:10 AM UTC-12
Depth35.0 kmshallow crustal
Coordinates51.776°, -173.291°
Felt byNo felt reports
Status✓ Reviewed by USGS

On July 26, 2026 at 14:10 UTC, a magnitude 3.4 shallow crustal earthquake struck 78 km SE of Atka, Alaska, at a depth of 35.0 km and coordinates 51.7759°, -173.2906°.

Physical scale: An earthquake of magnitude 3.4 releases seismic energy equivalent to roughly 1.9 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 134 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 1 day ago 99 km SE of Atka, Alaska. Since the mainshock, the USGS has recorded 12 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 51.78°, -173.29°

Earthquake Details

Magnitude
3.4 ml
Depth
35.0 km
shallow crustal
Location
51.7759°N
-173.2906°E

Technical Information

Event ID
us7000t3nw
Event Type
earthquake
Status
✓ Reviewed
Significance
178
Stations Used
8
Azimuthal Gap
320.0°
Min Station Distance
0.704°
RMS Residual
0.49 sec
Last Updated
2026-07-27 14:22:24 UTC

Common Questions

How strong was the magnitude 3.4 earthquake near Atka, Alaska?

The magnitude 3.4 earthquake that struck 78 km SE of Atka, Alaska on July 26, 2026 at 14:10 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 3.4 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 3.4 earthquake is an aftershock of the larger magnitude 5.8 mainshock that occurred earlier 99 km SE of Atka, Alaska. Aftershocks are smaller earthquakes triggered by stress changes from the mainshock.

Understanding This Data

Magnitude 3.4 earthquakes are typically only recorded by instruments.

Learn more about magnitude →

Authoritative source: USGS event page (event ID: us7000t3nw). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2026, July 26, 2026). M3.4 Earthquake 78 km SE of Atka, AlaskaJuly 26, 2026. Retrieved July 27, 2026 from https://www.earthquaketracker.org/earthquakes/event/us7000t3nw/