Location	Date/Time	Magnitude
1	Prince William Sound, Alaska	1964 03/28, 03:36:14	9.2
2	Andreanof Islands, Alaska	1957 03/09, 14:22:31	9.1
3	Rat Islands, Alaska	1965 02/04, 05:01:21.6 and 08:40:42.1	8.7
4	East of Shumagin Islands, Alaska	1938 11/10, 20:18:41.2	8.3
5	Lituya Bay, Alaska	1958 07/10, 06:15:53.6	8.3
6	Yakutat Bay, Alaska	1899 09/10, 17:04 and 21:41	8.2
7	Near Cape Yakataga, Alaska	1899 09/04, 00:22	8.2
8	Andreanof Islands, Alaska	1986 05/07, 22:47:12	8.0
9	New Madrid, Missouri	1812 02/07, 09:45	7.9
10	Fort Tejon, California	1857 01/09, 16:24	7.9
11	Ka'u District, Island of Hawaii	1868 04/03, 02:25	7.9
12	Kodiak Island, Alaska	1900 10/09, 12:25	7.9
13	Gulf of Alaska, Alaska	1987 11/30, 19:23:19.5	7.9
14	Owens Valley, California	1872 03/26, 10:30	7.8
15	Imperial Valley, California	1892 02/24, 07:20	7.8
16	San Francisco, California	1906 04/18, 13:12:21	7.7
17	Pleasant Valley, Nevada	1915 10/03, 06:52:48.0	7.7
18	New Madrid, Missouri	1812 01/23, 15:00	7.6
19	Landers, California	1992 06/28, 11:57:34	7.6
20	Kern County, California	1952 07/21, 11:52:14.0	7.5
21	West of Lompoc, California	1927 11/04, 13:50	7.3
22	Dixie Valley, Nevada	1954 12/16, 11:07:11	7.3
23	Hebgen Lake, Montana	1959 08/18, 06:37:13.5	7.3
24	Borah Peak, Idaho	1983 10/28, 14:06:06.5	7.3
25	West of Eureka, California	1922 01/31, 13:17:22	7.3

Note: Widely differing magnitudes have been computed for some of these earthquakes; the values differ according to the methods and data used. For example, some sources list the magnitude of the 8.7 Rat Islands earthquake as low as 7.7. On the other hand, some sources list the magnitude of the February 7, 1812 New Madrid quake as high as 8.8. Similar variations exist for most events on this list, although generally not so large as for the examples given.

In general, the magnitudes given in the list above have been determined from the seismic moment, when available. For very large earthquakes, the moment magnitude is considered to be a more accurate determination than the traditional amplitude magnitude computation procedures. Note that all of these values can be called "magnitudes on the Richter scale," regardless of the method used to compute them.