PlainQuake

Earthquakes in Alaska

8,804 earthquakes (M4+) recorded in Alaska between 2005-2025. Data from USGS.

Alaska has recorded 8,804 earthquakes of magnitude 4.0 or greater between 2005 and 2025, including 110 significant events at M6.0 or above. The strongest quake reached magnitude 7.9 near 261 km SE of Chiniak, Alaska. The most active year on record was 1957, with 57 events.

Seismic Profile of Alaska

Alaska: 8,804 M4+ events (2005–2025) — 110 significant (M6+), strongest M7.9 near 261 km SE of Chiniak, Alaska, avg magnitude 4.5, ~71 M4+ events/year across 124 active years. Depth profile: 702 shallow / 39 intermediate / 0 deep (95% shallow). Peak year: 1957 (57 events). USGS catalog scope + ShakeMap methodology →

How to read these figures: every count on this page comes from the USGS Comprehensive Earthquake Catalog (ComCat), the federal record of more than 1,000 instrumentally measured events logged across the United States since 2005. A higher total does not always mean a state faces more danger, because catalog totals reflect both genuine activity and the density of seismic stations that detect smaller tremors. Shallow events under 70 kilometers deep produce the strongest surface shaking for a given magnitude, so the shallow share above matters as much as the raw count when you gauge real-world risk. Magnitude values can be revised for weeks after an event as analysts refine waveform data, which is why our maximum and average figures may differ slightly from a first headline. For the authoritative, site-specific hazard estimate behind any building decision, consult the USGS National Seismic Hazard Model rather than these summary statistics. Our methodology page documents the exact query, the 2005 to 2025 window, and the magnitude thresholds used here.

Total Earthquakes

8,804

Significant (M6+)

110

Maximum Magnitude

7.9

Avg Magnitude

4.5

Records

741

Coverage

2005-2025

Source

USGS ComCat

Shallow event share (<70 km depth) 95.0%

USGS PGA Hazard Tier — Alaska

PGA hazard tier estimate for Alaska — Alaska (USGS NSHM)

Hazard35%32%22%11%Low (PGA <0.05g)Moderate (0.05-0.15g)High (0.15-0.30g)Very High (>0.30g)
PGA hazard tier estimate for Alaska — Alaska (USGS NSHM)

Tier estimate derived from Alaska's catalog rank and maximum magnitude. For the authoritative site-specific PGA, query the USGS Unified Hazard Tool.

Seismic Activity in Alaska

Alaska has experienced 8,804 earthquakes of magnitude 4.0 or greater since 2005, based on data from the U.S. Geological Survey (USGS) Comprehensive Earthquake Catalog. Of these, 110 were significant events reaching magnitude 6.0 or above — the threshold where structural damage becomes likely. The strongest recorded event reached magnitude 7.9.

Seismic activity in Alaska has varied over the recording period, with 124 years of data available. Recent years show continued monitoring by USGS stations across the state. Understanding historical patterns helps communities prepare through building codes, emergency plans, and public awareness.

Events by Year

2025

3

2024

5

2023

2

2022

5

2021

5

2020

5

2019

4

2018

7

2017

6

2016

4

2015

5

2014

9

2013

6

2012

5

2011

4

2010

7

2009

3

2008

7

2007

10

2006

5

2005

2

2004

3

2003

7

2002

4

2001

6

2000

3

1999

7

1998

3

1997

6

1996

6

1995

5

1994

1

1993

6

1992

11

1991

5

1990

6

1989

9

1988

7

1987

11

1986

10

1985

10

1983

4

1982

3

1981

1

1980

2

1979

6

1978

2

1977

7

1975

4

1974

5

1973

5

1972

5

1971

7

1970

9

1969

3

1968

8

1967

4

1966

6

1965

20

1964

29

1963

5

1962

7

1961

9

1960

7

1959

4

1958

12

1957

57

1956

9

1955

12

1954

4

1953

4

1952

6

1951

3

1950

6

1949

2

1948

9

1947

3

1946

12

1945

6

1944

3

1943

2

1942

7

1941

5

1940

16

1939

6

1938

5

1937

3

1936

3

1935

3

1934

6

1933

12

1932

8

1931

4

1930

7

1929

14

1928

1

1927

10

1926

7

1925

3

1924

4

1923

5

1922

2

1921

1

1920

3

1919

2

1918

4

1917

7

1916

4

1915

2

1914

1

1913

4

1912

7

1911

4

1910

2

1909

2

1908

2

1907

3

1906

4

1905

4

1904

1

1903

2

1902

1

1901

2

1900

1

Significant Earthquakes (741)

Mag Location Depth
6.0 12 km WNW of Susitna, Alaska 69.4 km
6.2 91 km SSE of Sand Point, Alaska 40.0 km
6.2 88 km SSE of Adak, Alaska 17.0 km
6.1 126 km SSW of Adak, Alaska 10.0 km
6.3 104 km SSW of Adak, Alaska 19.0 km
6.3 108 km SSW of Adak, Alaska 18.0 km
6.0 168 km SW of Nikolski, Alaska 41.0 km
6.0 169 km SW of Nikolski, Alaska 28.0 km
6.1 116 km SE of Adak, Alaska 20.0 km
6.4 78 km NNW of Adak, Alaska 174.0 km
6.3 Rat Islands, Aleutian Islands, Alaska 73.0 km
6.3 Rat Islands, Aleutian Islands, Alaska 105.0 km
6.2 71 km S of Unalaska, Alaska 29.0 km
6.6 53 km SE of Nikolski, Alaska 19.0 km
6.8 100 km SE of Nikolski, Alaska 20.0 km
6.9 112 km E of Chignik, Alaska 51.6 km
6.1 187 km WSW of Adak, Alaska 18.0 km
6.9 125 km SE of Perryville, Alaska 20.7 km
6.1 73 km N of Chickaloon, Alaska 44.0 km
6.1 230 km WSW of Adak, Alaska 21.0 km
6.4 46 km ESE of Nikolski, Alaska 23.0 km
6.1 75 km SW of Sand Point, Alaska 35.1 km
6.1 101 km ESE of Sand Point, Alaska 16.5 km
6.1 240 km WSW of Adak, Alaska 17.0 km
6.2 84 km W of Adak, Alaska 10.0 km
6.0 127 km SW of Adak, Alaska 28.0 km
6.3 95 km SE of Adak, Alaska 20.0 km
6.0 127 km WSW of Adak, Alaska 30.0 km
6.4 Rat Islands, Aleutian Islands, Alaska 8.0 km
6.0 87 km SE of King Cove, Alaska 31.0 km
7.1 1 km SE of Point MacKenzie, Alaska 46.7 km
6.3 97 km SW of Adak, Alaska 20.0 km
6.5 108 km WSW of Adak, Alaska 33.9 km
6.0 73 km SSW of Kaktovik, Alaska 16.2 km
6.4 89 km SW of Kaktovik, Alaska 15.8 km
7.9 261 km SE of Chiniak, Alaska 14.1 km
6.5 247 km ESE of Attu Station, Alaska 119.0 km
6.8 200 km NW of Attu Station, Alaska 5.0 km
6.2 135 km W of Adak, Alaska 13.0 km
6.3 48 km NW of Mosquito Lake, Alaska 2.5 km
6.2 47 km NW of Mosquito Lake, Alaska 10.0 km
6.2 63 km W of Attu Station, Alaska 20.0 km
6.2 42 km E of Port Heiden, Alaska 11.4 km
6.0 75 km S of Atka, Alaska 17.0 km
6.3 72 km SSE of Atka, Alaska 19.0 km
7.1 47 km ESE of Pedro Bay, Alaska 125.6 km
6.5 99 km SE of Atka, Alaska 15.0 km
6.0 104 km SSW of Nikolski, Alaska 20.0 km
6.4 52 km ENE of Pedro Bay, Alaska 119.3 km
6.9 Fox Islands, Aleutian Islands, Alaska 29.0 km
6.8 117 km SSE of Ugashik, Alaska 72.6 km
6.2 22 km WSW of Skwentna, Alaska 108.9 km
6.0 40 km WNW of Elfin Cove, Alaska 10.0 km
6.0 90 km NNW of Yakutat, Alaska 10.0 km
6.3 248 km ESE of Attu Station, Alaska 4.0 km
6.0 Rat Islands, Aleutian Islands, Alaska 106.6 km
6.0 Rat Islands, Aleutian Islands, Alaska 101.9 km
6.0 Rat Islands, Aleutian Islands, Alaska 102.8 km
7.9 Rat Islands, Aleutian Islands, Alaska 109.0 km
6.1 210 km WNW of Nikolski, Alaska 265.0 km
6.1 77 km SSW of Atka, Alaska 24.0 km
6.0 82 km SSW of Atka, Alaska 17.0 km
6.5 81 km SSW of Atka, Alaska 20.0 km
6.0 118 km SSW of Atka, Alaska 18.0 km
7.0 101 km SW of Atka, Alaska 29.0 km
7.5 110 km SW of Edna Bay, Alaska 8.7 km
6.0 83 km SE of Attu Station, Alaska 26.0 km
6.3 266 km SW of Yakutat, Alaska 9.0 km
6.4 118 km WSW of Adak, Alaska 16.0 km
6.2 102 km ESE of Nikolski, Alaska 13.0 km
6.0 119 km WNW of Attu Station, Alaska 14.0 km
6.0 32 km NNW of Attu Station, Alaska 15.0 km
6.9 170 km E of Atka, Alaska 32.0 km
6.1 72 km ESE of King Cove, Alaska 36.0 km
7.3 Fox Islands, Aleutian Islands, Alaska 52.0 km
6.4 139 km WNW of Attu Station, Alaska 18.0 km
6.0 120 km ESE of Adak, Alaska 27.7 km
6.4 104 km ESE of Adak, Alaska 19.0 km
6.5 70 km SE of Adak, Alaska 23.5 km
6.4 148 km WSW of Adak, Alaska 27.0 km
6.0 59 km WSW of Nikolski, Alaska 10.0 km
6.7 66 km W of Nikolski, Alaska 14.0 km
6.4 123 km ESE of Nikolski, Alaska 14.0 km
6.5 127 km E of Nikolski, Alaska 24.0 km
6.1 Rat Islands, Aleutian Islands, Alaska 22.0 km
6.1 72 km S of Atka, Alaska 36.0 km
6.0 122 km SSE of Akhiok, Alaska 20.0 km
6.3 Rat Islands, Aleutian Islands, Alaska 27.0 km
6.6 61 km W of Adak, Alaska 14.0 km
6.6 174 km W of Adak, Alaska 13.0 km
6.4 187 km W of Adak, Alaska 11.0 km
6.2 146 km WNW of Adak, Alaska 132.0 km
6.4 60 km SE of Nikolski, Alaska 25.0 km
6.3 171 km WSW of Adak, Alaska 25.0 km
7.2 207 km WSW of Adak, Alaska 34.0 km
6.0 131 km WSW of Adak, Alaska 28.0 km
6.3 72 km SSE of King Cove, Alaska 32.0 km
6.5 184 km SSW of Adak, Alaska 9.0 km
6.7 239 km WSW of Adak, Alaska 21.0 km
6.1 74 km SE of Nikolski, Alaska 15.0 km

Showing first 100 of 741 earthquakes.

Learn More About Earthquakes

Guides to help you understand earthquake data, preparedness, and risk.

Earthquake Risk in the US

Which states face the highest seismic risk and why.

Earthquake Preparedness Guide

What to do before, during, and after an earthquake.

Most Seismically Active US Regions

Top earthquake zones ranked by frequency and intensity.

Related Data for Alaska

Explore hazard, climate, and insurance data from other federal sources. Storm and climate datasets originate with the NOAA National Centers for Environmental Information; you can also browse the source NOAA Storm Events Database directly.

PlainHazard — Alaska Disasters

FEMA disaster declarations and NOAA storm events for Alaska.

PlainClimate — Alaska Climate

NOAA 30-year climate normals for cities in Alaska.

PlainInsure — Alaska Insurance

NAIC insurance market data including premiums and loss ratios for Alaska.

PlainCities — Alaska Cities

Census demographic and economic data for cities in Alaska.

Source: USGS ComCat (Comprehensive Earthquake Catalog) + USGS National Seismic Hazard Model + FEMA NEHRP USGS earthquake event catalog for Alaska + 2023 USGS National Seismic Hazard Model PGA classes (FEMA Seismic Design Categories A-F) · 2024 USGS ComCat updated continuously; magnitude/depth/location revised as analysis evolves. Seismic hazard model published in 2023, applies to 50-year, 2% probability-of-exceedance ground motion estimates.

Frequently Asked Questions

How many earthquakes have occurred in Alaska? ▼
Alaska has recorded 8,804 earthquakes of magnitude 4.0 or greater between 2005 and 2025, with 110 significant events (M6+). The average magnitude of recorded events is 4.5.
What was the largest earthquake in Alaska? ▼
The largest recorded earthquake in Alaska (2005-2025) was a magnitude 7.9 event near 261 km SE of Chiniak, Alaska on Jan 23, 2018. It occurred at a depth of 14.1 km.
Is Alaska at risk for earthquakes? ▼
Alaska has significant seismic activity with 8,804 recorded events (M4+) in the USGS dataset. Earthquake risk depends on proximity to fault lines, soil conditions, and building standards. USGS maintains real-time monitoring at earthquake.usgs.gov.
How often do earthquakes happen in Alaska? ▼
Based on USGS data from 2005 to 2025, Alaska averages approximately 71 earthquakes (M4+) per year. The most seismically active year was 1957 with 57 recorded events. Frequency can vary significantly from year to year depending on tectonic stress and fault activity.
How deep are earthquakes in Alaska? ▼
The average earthquake depth in Alaska is 31.0 km. 702 events (95%) were shallow (under 70 km), which tend to cause the most surface damage. Shallow earthquakes generally produce stronger ground shaking than deeper ones of similar magnitude.
Does Alaska have earthquake building codes? ▼
Building codes in Alaska follow standards set by the International Building Code (IBC), which incorporates USGS seismic hazard maps. Given Alaska's significant seismic activity (8,804 events M4+), structures are required to meet enhanced seismic design requirements. Specific requirements vary by jurisdiction and structure type.

Data Sources

Primary Source: U.S. Geological Survey (USGS), Earthquake Hazards Program, Comprehensive Earthquake Catalog (ComCat), 2005–2025. Includes all seismic events of magnitude 4.0 and above within Alaska. Data accessed via USGS Earthquake API.

Methodology: Magnitude values follow the moment magnitude scale (Mw). Depth is measured in kilometers from the surface. Events are classified as shallow (<70 km), intermediate (70–300 km), or deep (>300 km).

Read our methodology — how this data is sourced, computed, and verified.

Related

Browse all → | Rankings →
Data sourced from official U.S. government datasets. See our methodology for details. Retrieved and formatted by PlainQuake Editorial