3.1

M3.1 Earthquake 229 km ESE of Attu Station, AlaskaJuly 9, 2026

2026-07-09 23:30:30 UTC (2026-07-09) · approx. 11:30 AM UTC+12 local

MagnitudeM3.1(ml)
Time23:30 UTC11:30 AM UTC+12
Depth5.0 kmshallow crustal
Coordinates52.074°, 176.315°
Felt byNo felt reports
Status✓ Reviewed by USGS

On July 9, 2026 at 23:30 UTC, a magnitude 3.1 shallow crustal earthquake struck 229 km ESE of Attu Station, Alaska, at a depth of 5.0 km and coordinates 52.0740°, 176.3150°.

Physical scale: An earthquake of magnitude 3.1 releases seismic energy equivalent to roughly 674 kg of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 83 m — a useful intuition for the size of the slip patch on the fault.

Map showing earthquake epicenter at 52.07°, 176.31°

Earthquake Details

Magnitude
3.1 ml
Depth
5.0 km
shallow crustal
Location
52.0740°N
176.3150°E

Technical Information

Event ID
aka2026nmxemr
Event Type
earthquake
Status
✓ Reviewed
Significance
148
Stations Used
9
Azimuthal Gap
187.0°
Min Station Distance
1.400°
RMS Residual
1.00 sec
Last Updated
2026-07-17 20:50:57 UTC

Common Questions

How strong was the magnitude 3.1 earthquake near Attu Station, Alaska?

The magnitude 3.1 earthquake that struck 229 km ESE of Attu Station, Alaska on July 9, 2026 at 23:30 UTC had a depth of 5.0 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 3.1 earthquakes can continue for several days and gradually diminish over time.

Understanding This Data

Magnitude 3.1 earthquakes are typically only recorded by instruments.

Learn more about magnitude →

Authoritative source: USGS event page (event ID: aka2026nmxemr). All scientific values on this page are sourced verbatim from the USGS feed.

Cite this page: EarthquakeTracker.org. (2026, July 9, 2026). M3.1 Earthquake 229 km ESE of Attu Station, AlaskaJuly 9, 2026. Retrieved July 17, 2026 from https://www.earthquaketracker.org/earthquakes/event/aka2026nmxemr/