M3.9 earthquake 185 km WNW of Adak, Alaska

A magnitude 3.9 earthquake struck 185 km WNW of Adak, Alaska on Sat, Jun 3, 2023, 6:32 PM HADT (03:32 UTC), 205 km (128 mi) below the surface.

A larger quake followed: M5.3 135 km WSW of Adak, Alaska. This one was a foreshock.

Map

Where this earthquake was located, with the others nearby. Select one for its page.

Different scales measure different things and differ by a few tenths. The USGS marks one as preferred, and it is the one this page uses.

Mag.	Scale	Computed by	Notes
3.9	mb, body-wave	USGS National Earthquake Information Center	Preferred · Reviewed · ±0.182 · 8 stations
3.7	ML, local (Richter)	Alaska Earthquake Center	Preliminary

No one has reported feeling this quake to the USGS.

Reviewed by a seismologist.

Within 100 km, magnitude 1.5 and up: 136 in the 60 days after this one and 28 in the 30 days before it.

The first 60 of 136.

From the USGS Earthquake Hazards Program and its partner networks, event us7000k79s (also filed as ak02374ea04e). Read Fri, Oct 2, 2026, 9:13 AM UTC.