M3.5 earthquake 186 km W of Adak, Alaska

A magnitude 3.5 earthquake struck 186 km W of Adak, Alaska on Fri, Aug 9, 2024, 7:28 AM HADT (16:28 UTC), 104 km (65 mi) below the surface.

A larger quake followed: M5.4 142 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
3.5	ML, local (Richter)	USGS National Earthquake Information Center	Preferred · Reviewed · ±0.128 · 16 stations
3.3	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: 163 in the 60 days after this one and 103 in the 30 days before it.

The first 60 of 163.

From the USGS Earthquake Hazards Program and its partner networks, event us6000nnqw (also filed as ak024a7f000h). Read Fri, Oct 2, 2026, 2:32 AM UTC.