California earthquakes in 1940

274 earthquakes of magnitude 2.5 or more were located in California in 1940. The largest: M6.9 The 1940 Imperial Valley, California Earthquake, May 18, 1940.

From the USGS catalog. Times are local to each quake.

1939 1941

Map

Where every quake of 1940 was located in California. Select one for its page.

Open the live map with earthquakes

Every quake of 1940

Magnitude 2.5 and up, newest first.

The largest

The 25 largest of 1940 in California.

Month by month

Counted by UTC date, which is how the catalog files them.

Month	Quakes	Largest	Where
January 1940	20	4.0	10km NNW of Ocotillo Wells, CA
February 1940	20	4.5	14km E of Ocotillo Wells, CA
March 1940	12	3.3	3km WSW of Beaumont, CA
April 1940	7	4.3	2km NW of Grand Terrace, CA
May 1940	52	6.9	The 1940 Imperial Valley, California Earthquake
June 1940	61	5.0	26km NE of Pine Valley, CA
July 1940	23	4.6	17km E of Mammoth Lakes, CA
August 1940	16	4.0	25km NW of Coalinga, CA
September 1940	10	4.5	near the coast of Northern California
October 1940	25	4.7	8km WSW of Palos Verdes Estates, CA
November 1940	20	4.7	56 km W of Indianola, California
December 1940	8	6.0	44 km SW of Shelter Cove, California

What this means

The catalog is only as complete as the instruments of the time. Worldwide coverage of magnitude 5 and up dates from the 1960s, and of 4.5 from the 1990s; earlier years hold the large quakes and the ones near a station, so a low count in an early year means fewer instruments, not a quiet earth.

By year

Every year the USGS catalog covers.

2020s2020 2021 2022 2023 2024 2025 2026
2010s2010 2011 2012 2013 2014 2015 2016 2017 2018 2019
2000s2000 2001 2002 2003 2004 2005 2006 2007 2008 2009
1990s1990 1991 1992 1993 1994 1995 1996 1997 1998 1999
1980s1980 1981 1982 1983 1984 1985 1986 1987 1988 1989
1970s1970 1971 1972 1973 1974 1975 1976 1977 1978 1979
1960s1960 1961 1962 1963 1964 1965 1966 1967 1968 1969
1950s1950 1951 1952 1953 1954 1955 1956 1957 1958 1959
1940s19401941 1942 1943 1944 1945 1946 1947 1948 1949
1930s1930 1931 1932 1933 1934 1935 1936 1937 1938 1939
1920s1920 1921 1922 1923 1924 1925 1926 1927 1928 1929
1910s1910 1911 1912 1913 1914 1915 1916 1917 1918 1919
1900s1900 1901 1902 1903 1904 1905 1906 1907 1908 1909

Nearby

California now Worldwide in 1940

Sources

Earthquakes, magnitudes, depths, shaking estimates and felt reports from the U.S. Geological Survey Earthquake Hazards Program, read from its live feeds and its catalog back to 1900. Tsunami messages from NOAA’s tsunami warning centers.