Alaska earthquakes

M4.3 earthquake 98 km SSE of Atka, Alaska

A magnitude 4.3 earthquake struck 98 km SSE of Atka, Alaska on Tue, Mar 15, 2016, 1:55 PM HADT (22:55 UTC), 10 km (6 mi) below the surface.

A larger quake followed: M6.0 75 km S of Atka, Alaska. This one was a foreshock.

Map

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

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The earthquake

Magnitude: 4.3 (mb, body-wave), light
Magnitude from: USGS National Earthquake Information Center
Local time: Tue, Mar 15, 2016, 1:55 PM HADT
UTC: 2016-03-15 22:55:11 UTC
Depth: 10.0 km (6.2 mi), shallow
Epicenter: 51.442° N, 173.461° W
Region: Alaska
Tsunami flag: Yes: a large quake in an oceanic region
Status: Reviewed by a seismologist

Magnitude estimates

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
4.3	mb, body-wave	USGS National Earthquake Information Center	Preferred · Reviewed · ±0.051 · 107 stations
4.3	mb, body-wave	Alaska Earthquake Center	Preliminary
4.5	ML, local (Richter)	NOAA National Tsunami Warning Center	Reviewed · 4 stations

Tsunami

The USGS flags a quake this large in an oceanic region. The flag does not mean a tsunami happened; the tsunami warning centers decide that, and their messages are below when they issued any.

Current tsunami warnings: tsunami.gov. Warnings in force in the US also appear on our alerts pages.

Did you feel it?

No one has reported feeling this quake to the USGS.

How well it is located

Reviewed by a seismologist.

Location uncertainty: About 5.6 km horizontally, 1.9 km in depth
Magnitude uncertainty: ±0.05
Depth from: Operator assigned
Station coverage gap: 185°, poorly surrounded by stations
Stations used: 152

Nearby

Within 100 km, magnitude 1.5 and up: at least 199 in the 60 days after this one and 120 in the 30 days before it.

After

The first 60 of at least 199.

Before

Earthquakes today Alaska earthquakes Live radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event us20005a1v (also filed as ak12982364, ak0163geqdv8, at00o43ro3). Read Sun, Oct 4, 2026, 5:33 PM UTC.