3.4

M3.4 Earthquake 151 km SW of Adak, AlaskaApril 20, 2026

2026-04-20 05:40:42 UTC (19 hours ago)

On April 20, 2026 at 05:40 UTC, a magnitude 3.4 shallow crustal earthquake struck 151 km SW of Adak, Alaska, at a depth of 13.5 km and coordinates 51.0620°, -178.3930°.

Map showing earthquake epicenter at 51.06°, -178.39°

Earthquake Details

Magnitude
3.4 ml
Depth
13.5 km
shallow crustal
Location
51.0620°N
-178.3930°E

Technical Information

Event ID
aka2026hsnlns
Event Type
earthquake
Status
✓ Reviewed
Significance
178
Stations Used
24
Azimuthal Gap
232.0°
Min Station Distance
0.600°
RMS Residual
0.70 sec
Last Updated
2026-04-20 21:20:28 UTC

Common Questions

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

The magnitude 3.4 earthquake that struck 151 km SW of Adak, Alaska on April 20, 2026 at 05:40 UTC had a depth of 13.5 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.

What should I do after an earthquake?

If you were in the affected area: check yourself and others for injuries, inspect your home for damage, and be prepared for aftershocks. For detailed guidance, see our earthquake safety guide and emergency planning resources.