Appendix A: Significant Historical Earthquakes in the Pacific Northwest

Date Magnitudes Source Comments
Jan . 26, 1700 9 SZ Dated by Japanese tsunami
Oct. 23, 1853 5.7 ? Eureka area, wharf sank 4 feet, intensity VII
Mar. 20, 1855 ? ? Eureka, intensity VI, affected flow of streams
Jun. 14, 1857 ? ? Eureka, intensity VI
Nov. 13, 1860 5.7 ? Humboldt Bay, chimney, plaster damage, VII
Oct. 29, 1864 5.5 SC Georgia Strait
Oct. 1, 1865 5.4-5.7 ? Eureka, fissure Ft. Humboldt, VII-VIII
Mar. 2, 1871 5.9 ? Petrolia, damage Rohnerville, intensity VIII
Dec. 15, 1872 6.8 CR Entiat, WA
Nov. 23, 1873 6.7 SC CA-OR border, damage to Crescent City
Sep. 30, 1875 5.8 ? SE of Eureka, intensity VII
Oct. 12, 1877 5.2 CR Portland, OR, intensity VII, 2 events
May 9, 1878 5.8 TF Mendocino FZ, chimneys collapsed in Petrolia, CA
Apr. 30, 1882 <6? SC? South Puget Sound
Jan. 28, 1884 5.7 ? N. of Hoopa, intensity V
Jul. 25, 1890 6 ? Damage at Ferndale and Petrolia, CA
Nov. 29, 1891 ? ? Puget Sound
Sep. 30, 1894 5.6-5.8 ? Near Miranda, S. Humboldt Co.
Jan. 3, 1896 5.3 ? N. Puget Sound
Apr. 15, 1898 6.8 ? Mendocino coast, Ft. Bragg-Greenwood, intensity IX
Apr. 16, 1899 6.4 SO Offshore Arcata, damage to Eureka, CA, Gorda Plate
Dec. 9, 1903 ? SO Offshore Eureka
Mar. 17, 1904 5.3 ? 60 km NW Seattle, intensity VII
Apr. 23, 1906 6.4 ? McKinleyville, Ferndale, Eureka, Trinidad, intensity VII
Jan. 11, 1909 6 SC San Juan and Gulf islands, intensity VII
May 18, 1909 ? ? Petrolia, chimneys damaged, intensity VIII
Oct. 28, 1909 6.4 ? Rio Dell, Rohnerville, Upper Mattole, intensity VIII
Mar. 19, 1910 6 SO Offshore Petrolia, intensity V
Aug. 22, 1914 6.75 TF Blanco Fracture Zone
Dec. 31, 1915 6.2-6.5 ? Offshore Cape Mendocino
Jun. 10, 1917 6.5 TF Blanco Fracture Zone
Aug. 18, 1915 5.6 CR North Cascades, VII
Jul. 15, 1918 6-6.5 SO Offshore Arcata, VI
Dec. 6, 1918 7 CR Vancouver Island W. coast
Sep. 15, 1919 ? ? Eureka, Chimneys fell, intensity VI
Jan. 24, 1920 5.5 SC Georgia Strait
Jan. 26, 1922 6 TF? Offshore Cape Mendocino
Jan. 31, 1922 7.3-7.6 SO 37 mi. W of Arcata, CA, VI, felt Klamath Falls
Jan. 22, 1923 6.5-7.3 TF Mendocino FZ; damage at Petrolia, intensity VIII
Feb. 24, 1924 5.75 TF Blanco Fracture Zone
Jun. 4, 1925 6 ? Offshore W of Orick, CA
Jun. 5, 1926 6 TF Blanco Fracture Zone
Dec. 10, 1926 6 SO Gorda Plate, 80 mi. W of Eureka, CA
Feb. 9, 1928 5.8 SC? SW Vancouver Island
Sep. 11, 1928 6.3 TF Blanco Fracture Zone
May 26, 1929 7.0 TF SE end of Queen Charlotte Fracture Zone
Sep. 23, 1930 5-5.5 ? Chimneys fell in Eureka, VII
Mar. 10, 1931 5.6 ? Offshore C. Mendocino
Sep. 9, 1931 5.8 ? Offshore Eureka, chimneys damaged, intensity VI
Mar. 2, 1932 5.6 TF? 112 mi W. C. Mendocino
Jun. 6, 1932 6.4 SC One death at Arcata, damage at Eureka
Jun. 20, 1932 5.5 TF Blanco Fracture Zone
Jul. 17, 1932 5.2 CR Duvall, NE of Seattle, VII
Mar. 26, 1933 5.5 TF Blanco Fracture Zone
Jul. 6, 1934 6.5 SO 56 mi. W of Trinidad, CA
Jan. 2, 1935 5.8 ? Offshore C. Mendocino, intensity V
Apr. 30, 1936 5.5 TF Blanco Fracture Zone
Jun. 3, 1936 5.8 TF? 93 mi. W. C. Mendocino
Jul. 16, 1936 5.1-5.5 CR Milton-Freewater, near OR-WA border
Sep. 25, 1936 6.2 TF Blanco Fracture Zone
Nov. 5, 1936 6 TF Blanco Fracture Zone
Feb. 6, 1937 5.7-5.8 ? Offshore C. Mendocino, slight damage
Nov. 10, 1937 5.75 TF Blanco Fracture Zone
Aug. 3, 1938 5.6 TF Blanco Fracture Zone
Sep. 11, 1938 5.5 ? SE C. Mendocino, slight damage Ferndale
Nov. 13, 1939 5.5-6.2 SC Puget Sound region, intensity VII
Nov. 17, 1940 6 TF Blanco Fracture Zone
Nov. 19, 1940 5.5 ? Offshore C. Mendocino, slight damage
Feb. 9, 1941 6.4-6.6 SO 60 mi. W of Eureka, NW C. Mendocino
May 13, 1941 6 ? Offshore C. Mendocino
Oct. 2, 1941 6.4 SC 30 mi. W of C. Mendocino
Oct. 31, 1941 5.5 TF Blanco Fracture Zone
Mar. 6, 1944 5.75 TF Blanco Fracture Zone
Dec. 30, 1944 5.75 TF Blanco Fracture Zone
Apr. 29, 1945 5.9 CR 50 km SE of Seattle, intensity VII
May 19, 1945 6.2 ? Offshore C. Mendocino
Feb. 15, 1946 5.6-6.4 SC Puget Sound region
Jun. 23, 1946 7.3 CR Central Vancouver Island
Sep. 23, 1947 5.6 ? Offshore C. Mendocino, intensity VII
May 25, 1948 5.5 TF Blanco Fracture Zone
May 25, 1948 5.8 TF Blanco Fracture Zone
Mar. 24, 1949 5.9 SO 93 mi. W of Orick
Apr. 13, 1949 7.1 SC Olympia, WA, intensity VIII
Aug. 22, 1949 8.1 TF Queen Charlotte Fracture Zone
Aug. 24, 1949 5.5 TF Blanco Fracture Zone
Feb. 23, 1951 5.6 TF Blanco Fracture Zone
Jun. 16, 1951 5.5 TF Blanco Fracture Zone
Jun. 17, 1951 6 TF Blanco Fracture Zone
Oct. 8, 1951 5.8-6 TF 10 mi W Petrolia; 6 mi W of Punta Gorda
Aug. 20, 1952 6 TF Blanco Fracture Zone
Nov. 25, 1954 6.1-6.3 TF 65 mi. W Punta Gorda, Mendocino Fracture Zone
Dec. 21, 1954 6.5-6.6 CR $3.1 million damage, 1 death, 12 mi NE Arcata
Aug. 23, 1955 6.25 TF Blanco Fracture Zone
Feb. 19, 1956 6.8 SO Pacific Plate NW of Vancouver Is.
Oct. 11, 1956 6 ? NW of C. Mendocino, slight damage Ferndale
Dec. 21, 1956 6.7 SO small plate near Queen Charlotte Fracture Zone
Dec. 16, 1957 5.9 SO W. of Vancouver Is., NE of Nootka Fault
Jul. 23, 1959 5.8 SO 56 mi. W Trinidad, CA
Aug. 5, 1959 5-5.5 CR near Chelan, WA, intensity VI
Sep. 26, 1959 6.1 TF Blanco Fracture Zone
Jun. 5, 1960 5.7 SO Offshore Arcata, intensity VI
Aug. 9, 1960 6-6.2 TF Felt S. OR to San Francisco
Apr. 6. 1961 5-5.5 TF 11 mi W C. Mendocino, landslides
Aug. 23, 1962 5.6 SO Offshore Crescent City
Nov. 5, 1962 5.2-5.5 CR OR-WA border near Portland, OR, VII
Jul. 13, 1964 5.5 TF Blanco Fracture Zone
Oct. 1, 1964 5.5 5.5 TF Blanco Fracture Zone
Oct. 29, 1964 5.5 SC Georgia Strait
Apr. 29, 1965 6.5 SC Seattle, WA, intensity VIII
May 31, 1965 5.5 TF Blanco Fracture Zone
Dec. 10, 1967 5.6-5.8 TF 12 mi. W. of Petrolia, CA, slight damage
May 8, 1968 6.1 TF Blanco Fracture Zone
Jun. 26, 1968 5.5-5.9 TF Offshore C. Mendocino
May 8, 1969 5.5 TF Blanco Fracture Zone
Jun. 24, 1970 7.4 TF? Queen Charlotte TF or N. America Plate
Nov. 26, 1970 6 TF Blanco Fracture Zone
Mar. 13, 1971 6.1 SO W. of Vancouver Island
Jul. 23, 1972 6.4 SO W. of Vancouver Island
Jun. 7, 1975 5.2-5.7 SC Fortuna, CA
Nov. 26, 1976 6.3 SO Gorda Plate, 93 mi. NW of Eureka
Dec. 9, 1976 5.5 TF Blanco Fracture Zone
Dec. 20, 1976 6.7 SO W. of Vancouver Is.
Jun. 2, 1978 5.5 CR Brooks Peninsula, NW Vancouver Is.
Jul. 25, 1978 5.5 CR Brooks Peninsula, NW Vancouver Is.
May 18, 1980 5.1 CR Eruption of Mt. St. Helens
Nov. 8, 1980 6.9-7.4 SO 30 mi. W Trinidad, $1.75 million damage
Dec. 17, 1980 6.8 SO W. of Vancouver Is.
Feb. 14, 1981 5.5 CR Elk Lake, WA on St. Helens seismic zone
Nov. 3, 1981 6.4 TF Blanco Fracture Zone
Aug. 24, 1983 5.5 TF Offshore C. Mendocino
Sep. 10, 1984 6.6 TF 166 mi W of Eureka, felt OR to San Francisco
Mar. 13, 1985 6.3 TF Blanco Fracture Zone
Jul. 31, 1987 5.5 SO or SC Just off C. Mendocino
Oct. 23, 1988 5.5 TF Blanco Fracture Zone
Jul 13, 1991 6.7-6.9 SO 50 mi WNW of Crescent City
Aug. 16, 1991 5.9-6.3 SO 62 mi W of Crescent City
Aug. 17, 1991 6.2 CR Honeydew, CA, chimney, foundation damage
Aug. 17, 1991 6.9-7.1 SO 62 mi W of Crescent City
Mar. 7, 1992 5.3-5.6 CR S. of Petrolia, landslides, foundation damage
Apr. 6, 1992 6.8 TF W. Vancouver Is., Revere-Dellwood-Wilson Fracture Zone
Apr. 25, 1992 7.1 SZ Tsunami, coastal uplift, $48 million damage
Apr. 26, 1992 6.6 SO 17 mi. WNW Petrolia, damage to Scotia
Apr. 26, 1992 6.7 SO 16 mi. W Petrolia, added damage
Aug. 21, 1992 5.5 TF Blanco Fracture Zone
Mar. 25, 1993 5.6 CR Scotts Mills, OR, E of Salem
Apr. 26, 1993 6.5 SO 15 mi W of Petrolia
Sep. 20, 1993 6 TF Mendocino Fracture Zone, 85 mi W C. Mendocino
Sep. 20, 1993 5.9, 6 CR 2 eqs. W. Klamath Falls, OR
Sep. 1, 1994 6.9-7.2 TF 88 mi. W C. Mendocino, felt OR to San Francisco
Oct. 27, 1994 5.6 TF Blanco Fracture Zone
Feb. 18, 1995 6.6 SO 88 mi. WSW Eureka
Jul. 24, 1996 6 SO 115 mi. W Crescent City
Jan. 21, 1997 5.7 TF 1 mi NW of Punta Gorda
Oct. 4, 1997 5.7 SO 65 mi. W Trinidad, CA
Nov. 27, 1998 5.6 SO 60 mi. W Ferndale, CA
Jul. 2, 1999 5.8 SC Satsop, WA
Jan. 20, 2000 6.1 TF Blanco Fracture Zone
Mar. 16, 2000 5.9 TF 52 mi W Petrolia
Jun. 2, 2000 6.2 TF Blanco Fracture Zone
Jan. 13, 2001 5.6 SO 62 mi. W Eureka
Feb. 28, 2001 6.8 SC Nisqually Earthquake, S. Puget Sound, VII-VIII
Jul. 9, 2002 6 TF Blanco Fracture Zone
Sep. 2, 2002 5.7 TF Blanco Fracture Zone
Jan. 16, 2003 6.2 TF Blanco Fracture Zone
Nov. 19, 2007 5.8 TF Blanco Fracture Zone
Mar. 30, 2008 5 TF Blanco Fracture Zone (swarm)
Mar. 8, 2011 5.0 TF Blanco Fracture Zone
Oct. 27, 2012 7.8 TF Queen Charlotte Fracture Zone
Apr. 24, 2014 4.8 TF Queen Charlotte Fracture Zone
Nov. 27, 2014 4 CR Sheldon Wildlife Refuge, NV (swarm)
Jan. 28, 2015 5.7 TF Mendocino Fracture Zone

Magnitudes for pre-seismograph earthquakes are corrected intensity magnitudes where available. Key to source: CR, crustal; SO, slab, offshore; SC, slab, beneath the continent; SZ, subduction zone; TF, transform fault