PlainQuake

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Earthquake Risk Calculator

Select a US state to assess its earthquake risk from 20 years of USGS ComCat data, historical counts, maximum magnitude, yearly frequency, and a computed risk level.

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4 of 39 tracked U.S. states and territories carry a computed "Very High" risk level -- pick any state above for its full breakdown.

39
states & territories tracked
4
rated "Very High" risk

According to the U.S. Geological Survey's Earthquake Hazards Program, as of 2026-07-19 the ComCat catalog this calculator draws from records 315,341 magnitude-4+ earthquakes worldwide since 2005, every state's risk level computed from that same dataset using the methodology described on our methodology page.

Alaska

Very High Risk

Alaska has extremely high seismic activity with 8,960 recorded M4+ events and 116 significant (M6+) earthquakes. Active fault systems pose ongoing risk.

What this measures: based on historical USGS earthquake frequency and magnitude for Alaska (M4+, 2005-2025), not a predictive seismic-hazard assessment. Actual risk to any specific building also depends on local building codes, soil type, and construction quality, not seismic history alone.

Total Earthquakes

8,960

Max Magnitude

8.2

Significant (M6+)

116

Avg Magnitude

4.5

Strongest Recorded Earthquakes

Magnitude Location
M9.2 The 1964 Prince William Sound, Alaska Earthquake
M8.6 1957 Atka, Alaska Earthquake
M8.6 1946 Unimak Island, Alaska Earthquake
M8.2 1938 Semidi Islands, Alaska Earthquake
M8.2 2021 Chignik, Alaska Earthquake

Earthquake Frequency by Year

Year Events Max Mag
2026 3 6.4
2025 4 7.3
2024 5 6.3
2023 3 7.2
2022 5 6.8
2021 6 8.2
2020 7 7.8
2019 4 6.4
2018 7 7.9
2017 6 6.8
2016 4 7.1
2015 5 6.9
2014 9 7.9
2013 6 7.5
2012 5 6.4
2011 4 7.3
2010 7 6.7
2009 3 6.5
2008 7 6.6
2007 10 7.2
2006 5 6.6
2005 2 6.8
2004 3 6.8
2003 7 7.8
2002 5 7.9
2001 6 6.9
2000 3 6.5
1999 7 7.0
1998 3 6.3
1997 6 6.7
1996 6 7.9
1995 5 6.5
1994 1 6.2
1993 6 6.9
1992 11 6.9
1991 5 7.0
1990 6 7.1
1989 9 7.0
1988 7 7.8
1987 11 7.9
1986 11 8.0
1985 10 6.6
1983 4 6.6
1982 3 6.4
1981 1 7.0
1980 2 6.9
1979 6 7.1
1978 2 6.7
1977 7 6.7
1975 4 7.6
1974 5 6.5
1973 5 6.7
1972 5 7.6
1971 7 7.0
1970 9 7.1
1969 3 6.9
1968 8 6.6
1967 4 6.8
1966 6 6.9
1965 20 7.8
1964 30 9.2
1963 5 6.6
1962 7 6.5
1961 9 6.5
1960 7 6.8
1959 4 6.3
1958 12 7.8
1957 58 8.6
1956 9 6.5
1955 12 6.8
1954 4 6.8
1953 4 7.0
1952 6 6.5
1951 3 6.9
1950 6 6.4
1949 2 6.6
1948 9 7.1
1947 3 7.1
1946 13 8.6
1945 6 6.2
1944 3 6.6
1943 2 6.9
1942 7 6.3
1941 5 6.5
1940 16 7.0
1939 6 7.2
1938 6 8.2
1937 3 7.1
1936 3 6.8
1935 3 6.9
1934 6 6.8
1933 12 6.8
1932 8 6.8
1931 4 6.3
1930 7 6.7
1929 14 7.9
1928 1 7.0
1927 10 7.2
1926 7 6.9
1925 3 6.6
1924 4 6.4
1923 5 7.0
1922 2 6.8
1921 1 6.2
1920 3 6.3
1919 2 6.2
1918 4 6.2
1917 7 7.4
1916 5 7.4
1915 2 6.4
1914 1 6.5
1913 4 6.9
1912 7 7.2
1911 4 6.9
1910 2 7.0
1909 2 7.0
1908 2 6.7
1907 3 7.4
1906 4 7.0
1905 4 7.6
1904 1 7.3
1903 2 7.0
1902 1 7.0
1901 2 7.1
1900 1 7.9

Events in 125 of 21 monitoring years (595% frequency).

View full state profile → Browse all states →

What to do with your risk level

Alaska tops the leaderboard at "Very High" risk, 8,960 M4+ events on record, but every state has SOME computed risk level.

  • Select any of the 39 tracked states above to see its own event count, strongest recorded magnitude, and yearly trend. Browse all states
  • Risk level is computed from three signals (total events, strongest magnitude, significant-event count) - see exactly how a level is assigned. Read the methodology

Risk levels are relative rankings within this dataset (USGS M4+ catalog, 2005–present), not an official USGS or FEMA hazard designation.

Frequently Asked Questions

How is earthquake risk level determined? ▼
Risk levels (Low, Moderate, High, Very High) are determined by combining total earthquake count, maximum recorded magnitude, number of significant events (M6+), and the frequency of seismic activity across the 2005-2025 monitoring period.
What data does this calculator use? ▼
The calculator uses the USGS Comprehensive Earthquake Catalog (ComCat), covering earthquakes of magnitude 4.0 and above worldwide since 2005, over 310,000 events. US state figures are aggregated from that same global M4+ record.
Does low risk mean no earthquake danger? ▼
No. Low risk means fewer recorded events in the USGS dataset, but earthquakes can occur in any state. Areas with low historical activity can still experience damaging events. Always follow FEMA and USGS preparedness guidelines regardless of risk level.
What counts as a significant earthquake? ▼
For this calculator, significant earthquakes are those with magnitude 6.0 or greater. These events can cause substantial damage to buildings and infrastructure, especially in areas without seismic building codes.
How often is the data updated? ▼
The database covers USGS ComCat records from 2005 through 2025. Historical data is stable; new events are added periodically.

Data: USGS Comprehensive Earthquake Catalog (ComCat), magnitude 4.0+ worldwide since 2005. Risk levels are computed assessments and should not replace official USGS or FEMA hazard maps.

According to the US Geological Survey Earthquake Hazards Program, PlainQuake's figures are rendered directly from 315,341 recorded M4+ earthquakes and 14,428 significant M6+ events (USGS ComCat, 2005-present) -- no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 2026-07-19.