Largest Earthquakes by State and Territory

We're transitioning to a new system, so this webpage is being phased out and is no longer maintained as of 04/12. A replacement is under development.

List of Earthquakes

This webpage is updated in January of each year to incorporate any relevant data from the previous year.
All earthquake dates are UTC, not local time.

Map of Earthquakes

For each state, the following list gives the largest historical earthquake that had its epicenter in that state. The earthquakes are those with the highest magnitudes, as measured from seismographs or as inferred from the intensities produced by the earthquakes. The time periods for which there are complete records of large earhquakes varies from about three centuries in some eastern states to slightly more than a century in some western states. Be aware that the highest historical intensities in some states did not come from shocks that had their epicenters within the states' borders, but rather from earthquakes whose epicenters were in nearby states.

State Date Time UTC Latitude Longitude Magnitude Intensity
Alabama 1916 10 18 22:04 33.5N 86.5W 5.1 VII
Alaska 1964 03 28 03:36:14.0 61.04N 147.73W 9.2 X
Arizona 1959 07 21 17:39:29 36.80N 112.37W 5.6 VI
Arkansas 1811 12 16 08:15 35.6N 90.4W ~7.7 XI
California 1857 01 09 16:24 35.7N 120.3W 7.9 IX
California 1906 04 18 13:12:21 37.75N 122.55W 7.8 XI
Colorado 1882 11 08 01:30 40.5N 105.5W 6.6 VII
Connecticut 1791 05 16 13:00 41.5N 72.5W VII
Delaware 1871 10 09 14:40 39.7N 75.5W VII
Florida 1780 02 06 30.4N 87.2W VI
Florida 1879 01 13 04:45 29.5N 82.0W VI
Georgia 1914 03 05 20:05 33.5N 83.5W 4.5 V
Guam 1993 08 08 08:34:24 12.92N 144.80E 7.8 IX
Hawaii 1868 04 03 02:25 19.0N 155.5W 7.9 X
Idaho 1983 10 28 14:06:06.5 43.974N 113.916W 6.9 IX
Illinois 1968 11 09 17:01:40.5 37.911N 88.373W 5.4 VII
Illinois 2008 04 18 09:36:59.1 38.452N 87.886W 5.4 VII
Indiana 1909 09 27 09:45 39.8N 87.2W 5.1 VII
Iowa 1905 04 13 16:30 40.4N 91.4W V
Kansas 1867 04 24 20:22 39.2N 96.3W 5.1 VII
Kentucky 1980 07 27 18:52:21.4 38.193N 83.891W 5.2 VII
Louisiana 1930 10 19 12:17 30.0N 91.0W 4.2 VI
Maine 1904 03 21 06:04 45.0N 67.2W 5.1 VII
Maryland 2010 07 16 09:04:46.5 39.184N 77.287W 3.4 IV
Massachusetts 1755 11 18 09:11:35 42.7N 70.3W VIII
Michigan 1947 08 10 02:46:41.3 41.928N 85.004W 4.6 VI
Minnesota 1975 07 09 14:54:15.1 45.669N 96.041W 4.6 VI
Mississippi 1931 12 17 03:36 33.8N 90.1W 4.6 VI
Missouri 1812 02 07 09:45 36.5N 89.6W ~7.7 XII
Montana 1959 08 18 06:37:13.5 44.712N 111.215W 7.3 X
Nebraska 1877 11 15 17:45 41.0N 97.0W 5.1 VII
Nebraska 1964 03 28 10:08:46.5 42.997N 101.798W 5.1 VII
Nevada 1932 12 21 06:10:05 38.51N 118.08W 7.2 X
New Hampshire 1940 12 20 07:27:26.2 43.872N 71.370W 5.5 VII
New Hampshire 1940 12 24 13:43:45.0 43.908N 71.283W 5.5 VII
New Jersey 1783 11 30 03:50 41.0N 74.5W 5.3 VI
New Mexico 1906 11 15 12:15 34.0N 107.0W VII
New York 1944 09 05 04:38:45.7 44.958N 74.723W 5.8 VIII
North Carolina 1916 02 21 23:39 35.5N 82.5W 5.2 VII
North Dakota 1909 05 16 04:15 49.0N 104.0W 5.5 VI
Ohio 1937 03 09 05:44:35.5 40.470N 84.280W 5.4 VIII
Oklahoma 2011 11 06 03:53:10 35.537N 96.747W 5.6
Oregon 1910 08 05 01:31:36 42.0N 127.0W 6.8 Felt
Oregon 1993 09 21 03:28:55.4 42.314N 122.012W 6.0 VII
Pennsylvania 1998 09 25 19:52:52.1 41.495N 80.388W 5.2 VI
Puerto Rico 1787 05 02 8.0
Puerto Rico 1918 10 11 14:14:00 7.5
Rhode Island 1976 03 11 08:29:32.2 41.56N 71.21W 3.5 VI
South Carolina 1886 09 01 02:51 32.9N 80.0W 7.3 X
South Dakota 1911 06 02 22:34 44.2N 98.2W 4.5 V
Tennessee 1865 08 17 15:00 36.0N 89.5W 5.0 VII
Texas 1931 08 16 11:40:22.3 30.502N 104.575W 5.8 VIII
Utah 1934 03 12 15:05:40 41.7N 112.8W 6.6 VIII
Vermont 1962 04 10 14:30:45.2 44.114N 72.972W 4.2 V
Virginia 1897 05 31 18:58 37.3N 80.7W 5.9 VIII
Washington 1872 12 15 05:40 47.9N 120.3W 6.8 IX
West Virginia 1969 11 20 01:00:09.3 37.449N 80.932W 4.5 VI
Wisconsin 1947 05 06 21:27 43.00N 87.90W V
Wyoming 1959 08 18 07:56:16.8 44.699N 110.705W 6.5 Felt

Explanation

Most of the earthquakes listed in "The Largest Earthquakes, State by State" are those with the largest magnitudes for each state listed in the work of Carl W. Stover and Jerry L. Coffman, 1993, Seismicity of the United States, 1568-1989 (Revised), U.S. Geological Survey Professional Paper 1527. Data on post-1989 earthquakes and on earthquakes too small to be included in the study of Stover and Coffman (they considered earthquakes with magnitudes of 4.5 or greater, or with intensities of VI or greater) come from other publications of the U.S. Geological Survey and the U.S. Coast and Geodetic Survey.

Not all the pre-instrumental earthquakes listed in Stover and Coffman have magnitude estimates associated with them, and in some cases a pre-instrumental earthquake is listed as largest if the characteristics of its intensity distribution (e.g., maximum intensity and area over which the earthquake was felt) imply that the earthquake would have had a higher magnitude than any other earthquake in the state.

For some states, the two largest earthquakes are listed, if the data listed in Stover and Coffman's study imply that the shocks were of nearly equal size.

Two earthquakes of different magnitude are listed for Oregon: the 1910 earthquake was the largest historical shock within the state's boundaries, but it occurred too far offshore to cause damage, whereas the damaging 1993 earthquake was the largest historical earthquake beneath the land area of Oregon.