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Earthquakes in Alaska Earthquake

Alaska Earthquake ranks 163rd of 215 countries by catalogued seismic activity - a country with limited but non-zero seismic activity. Below: the full M6+ event history, magnitude and depth profile, and yearly trend, straight from USGS data.

5
M4+ events (since 2005)
11
Major M6+ (since 1900)
M9.2
Strongest
~0
M4+ per year

The verdict

Alaska Earthquake has logged 5 M4+ earthquakes since 2005 and 11 major M6+ events since 1900, the strongest reaching magnitude 9.2.

#163
of 215 countries by M4+ activity
5
catalogued M4+ events (2005–present)
M9.2
strongest earthquake on record
11
major M6+ events since 1900

Average catalogued magnitude is 7.6 - most events are moderate M4–5 tremors that are felt but rarely cause damage.

Major (M6+) earthquakes in Alaska Earthquake by year

Count of significant (magnitude 6.0+) events catalogued each year

Value

What this shows Alaska Earthquake's most active year for major earthquakes was 2020 (2 M6+ events). Major-quake counts are irregular, they track the episodic release of tectonic stress, not a smooth trend.

Source USGS Comprehensive Earthquake Catalog (ComCat) As of 2025

Magnitude distribution of major events

Breakdown of the 11 significant (M6+) earthquakes on record for Alaska Earthquake.

M8+

6

54.5%

M7.0-7.9

5

45.5%

Depth of major earthquakes

Hypocentral depth of the 11 M6+ events, shallow quakes shake the surface hardest. Average depth: 27 km.

Shallow (<70 km)

11

100.0% of events

Intermediate (70–300 km)

0

0.0% of events

Deep (>300 km)

0

0.0% of events

Strongest earthquakes in Alaska Earthquake

The 10 most powerful events on record (USGS, since 1900).

Mag Location Depth
9.2 The 1964 Prince William Sound, Alaska Earthquake 25.0 km
8.6 1957 Atka, Alaska Earthquake 25.0 km
8.6 1946 Unimak Island, Alaska Earthquake 15.0 km
8.2 1938 Semidi Islands, Alaska Earthquake 35.0 km
8.2 2021 Chignik, Alaska Earthquake 35.0 km
8.0 1986 Atka, Alaska Earthquake 33.0 km
7.9 2002 Denali Fault, Alaska Earthquake 4.2 km
7.8 2020 Perryville, Alaska Earthquake 28.0 km
7.6 2020 Sand Point, Alaska Earthquake 28.4 km
7.3 2025 Sand Point, Alaska Earthquake 38.0 km

Significant earthquake record (11 events)

Every catalogued magnitude-6.0-and-above earthquake in Alaska Earthquake since 1900, most recent first.

Mag Location Depth
7.3 2025 Sand Point, Alaska Earthquake 38.0 km
7.2 2023 Sand Point, Alaska Earthquake 25.0 km
8.2 2021 Chignik, Alaska Earthquake 35.0 km
7.6 2020 Sand Point, Alaska Earthquake 28.4 km
7.8 2020 Perryville, Alaska Earthquake 28.0 km
7.9 2002 Denali Fault, Alaska Earthquake 4.2 km
8.0 1986 Atka, Alaska Earthquake 33.0 km
9.2 The 1964 Prince William Sound, Alaska Earthquake 25.0 km
8.6 1957 Atka, Alaska Earthquake 25.0 km
8.6 1946 Unimak Island, Alaska Earthquake 15.0 km
8.2 1938 Semidi Islands, Alaska Earthquake 35.0 km

Frequently asked questions

How many earthquakes have occurred in Alaska Earthquake?
The USGS catalog records 5 earthquakes of magnitude 4.0 or greater in Alaska Earthquake since 2005, an average of about 0 per year. Separately, 11 significant (M6+) earthquakes are catalogued back to 1900.
What was the strongest earthquake in Alaska Earthquake?
The strongest catalogued earthquake in Alaska Earthquake measured magnitude 9.2. Across the full M4+ catalog the average magnitude is 7.6 - most earthquakes are moderate.
How seismically active is Alaska Earthquake?
By catalogued M4+ activity, Alaska Earthquake ranks 163rd of 215 countries worldwide - a country with limited but non-zero seismic activity. Its busiest year for major (M6+) events was 2020, with 2.
How deep are earthquakes in Alaska Earthquake?
Across the 11 major (M6+) events on record, the average depth is 27 km. 100% were shallow (under 70 km), where surface shaking is strongest at a given magnitude.
Where does this data come from?
Every figure is derived from the USGS Comprehensive Earthquake Catalog (ComCat). M4+ counts cover 2005 onward (the period of consistent global completeness); the significant-event series covers M6+ back to 1900. Nothing is modelled or estimated.

About this data

Every figure on this page is computed directly from the USGS Comprehensive Earthquake Catalog (ComCat), the public-domain record maintained by the USGS Earthquake Hazards Program. Two series are combined: a worldwide catalog of magnitude-4.0-and-above events from 2005 onward, the period over which the global seismograph network reliably detects and locates earthquakes everywhere, and a historical series of significant magnitude-6.0-and-above events stretching back to 1900. Magnitudes use the moment-magnitude scale (Mw), the modern standard that supersedes the older Richter scale; because the scale is logarithmic, each whole step represents roughly thirty-two times more energy released. Depth is measured in kilometres from the surface, and shallow earthquakes generally produce stronger shaking than deep ones of the same magnitude. Counts reflect what instruments recorded, not every tremor that occurred, and recent events can be revised as seismologists refine the catalog.

Source: USGS ComCat, verify with USGS → · See our methodology for the full pipeline.

Disclaimer: PlainQuake is an informational reference for informational purposes only, not an emergency or early-warning service, and not professional engineering or safety advice. For official alerts and guidance, consult the USGS and your local emergency authorities. See our full disclaimer.