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Cascadia Historic Earthquake Catalog, 1793-1929
Covering Washington, Oregon and Southern British Columbia

Provided by: The Pacific Northwest Seismic Network
About the Cascadia Historic Earthquake Catalog       One-line catalog format

1793-1849 .... 1850s .... 1860s .... 1870s .... 1880s .... 1890s .... 1900s .... 1910s .... 1920s .... 1930s (not complete) .... Other Cascadia Catalogs

  
Individual Event Report
Event #581 - Summary, and parameter estimates with source IDs                                           
Off Cape Mendocino. 'Earthquake History of the US' says: "...strongly shook the Cape Mendocino region and toppled many chimneys in the area. This earthquake was probably associated with the Mendocino Fracture Zone." Townley and Allen say: "A severe shock was felt in northern California and southern Oregon ... The origin was at sea off Cape Mendocino." The MWR lists no reports from Oregon weather observers on this date. No newspaper accounts have been researched.
TIME LOCATION MAGNITUDE MAX. INTENSITY FELT AREA
YR MO DAY HR MIN AM/PM Time
Type
LAT(N) LON(W) DEP
(km)
MAG Mag
Type
Felt
Plc.
Felt
St.
Inten-
sity
Int.
Type
Felt
Area
Felt
Area
Int.
Felt
Area
Units
1923  22  40.50  124.50    7.20  G-R  off Cape Mendocino  CA  VII  MM       
TA-OR - 551 USEQS - 2537 - MISC - 2542 USEQS - 2537 -

Underlying Source Material
Source ID Publication Pub Date Pub Details
2542  The San Andreas Fault System, California, Chapter 6: "Earthquake History, 1769-1989" by William L. Ellsworth, USGS Professional Paper 1515. 1990  1990  p. 169, 185 
Transcription: January 22, 1923 (M=7.2)
The earthquake of January 22, 1923, strongly shook the Cape Mendocino region and toppled many chimneys in the area. This earthquake was probably associated with the Mendocino Fracture Zone.

From Table 6.1:
1923/1/22, 09:04 GMT, M=7.2, 40.5N, 124.5W, Cape Mendocino, MG-R=7.2, MS=7.3, MI=6.3,6.8
 
Source ID Publication Pub Date Pub Details
551  Townley, S.D. and M.W. Allen, 1939, Descriptive Catalog of earthquakes of the Pacific Coast of the United States 1769 to 1928, Chapter II, Earthquakes in Oregon--1846-1928, BSSA, V. 29, No. 1, pp. 253-258.  1939   
Transcription: 1923 January 22. 1:04 a.m. Southwestern Oregon. A severe shock was felt in northern California and southern Oregon on January 22, 1923. The origin was at sea off Cape Mendocino. For a full account see the California list.
 
Source ID Publication Pub Date Pub Details
2537  U. S. Dept. of Commerce, 1973, Earthquake History of the United States, V. 41-1, revised ed., pp. 137-189  1973   
Transcription: 1923, January 22. Off Cape Mendocino. At Upper Matole, Petrolia, Dyerville, and Pepperwood, houses were damaged and chimneys were thrown down. Slight damage at Eureka; shock lasted 45 seconds. The shock was felt 200 miles from the epicenter, but was not noted at many places at less distances because of the time of day so the area of perceptibility is uncertain. Felt on a number of vessels at sea. Magnitude 7.3.

1923, Jan. 22, 01:04 PST, Off Cape Mendocino, 40.5 124.5, MM VII-VIII
 
Source ID Publication Pub Date Pub Details
643  Reid, unpub., Scrapbook and Cardfile, on microfilm at USGS in Menlo Park     
Transcription: Southern Oregon 41 degrees N; 124.6 degrees W PST 1:04:18 am 22 Jan, 1923 Origin off the coast of N. California at position given.
 
Source ID Publication Pub Date Pub Details
406  Byerly, Perry, 1952, Pacific Coast Earthquakes, Condon Lecture, pp. 33-38  1952  U.W. Library, N979 B991p, Special Collections) 
Transcription: 1923, January 22 Epicenter off Cape Mendocino. Felt in northern California and southern Oregon.
 


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