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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 #481 - Summary, and parameter estimates with source IDs                                           
This is an aftershock of the preceding event. The underlying information here is a single observation from the weather observer in Marblemount. Bradford, 'Earthquake History of the US', and the WPPSS catalog mistakenly give this time for the main shock.
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
1915  18  10      48.50  121.40        Marblemount  WA  III  RF       
TAWA - 1142 USEQS - 949 - - MWR - 2225 -

Underlying Source Material
Source ID Publication Pub Date Pub Details
2225  Monthly Weather Review  1915  V. 43, p. 416 
Transcription: Date: August 18, 1915
Time (Greenwich Civil): 18:00
Location: Marblemount, Wash.
Latitude (deg., min.): 48 32
Longitude (deg.,min.): 121 26
RF Intensity: 3
Number of Shocks: 1
Duration (sec.): 1
Sounds: Faint
Remarks:
Observer: Henry Soll
 
Source ID Publication Pub Date Pub Details
949  U. S. Dept. of Commerce, 1973, Earthquake History of the United States, V. 41-1, revised ed., pp. 89-96  1973   
Transcription: Aug. 18 10:00 Northwestern Washington 48.5 121.4 30,000 V 3-25
 
Source ID Publication Pub Date Pub Details
2512  Washington Public Power Supply System, Preliminary
Safety Analysis Report, Ammendment 23,
WPPSS Nuclear Project No. 1, 1300 MW Nuclear Power Plant, Vol. 2A. 
1977  Table 2R-E1 
Transcription: 59 1915 Aug 18 18:00 Marblemount v TA(265)
1915 Aug 18 18:00 48.50N., 121.40w. 30,000 EP(75,78)
1915 Aug 18 18:00 48 32'N., 121 48.526-W. 30,000 BR(147)
1915 Aug 18 18:00 48.50N., 121.40w. NE(36)
EPB 2 1918 Feb 04 20:35 5loN., 1180W. ml(130,131) Recorded at (VIC)
Victoria,
British Columbia.
 
Source ID Publication Pub Date Pub Details
1142  Townley, S. D. and M. W. Allen, 1939, Descriptive Catalog of Earthquakes of the Pacific Coast of the United States 1769-1928, Chap. III Earthquakes in Washington, 1883-1928, BSSA, V. 29, No. 1, pp. 259-268  1939   
Transcription: 1915 August 18. 6:04 a.m. V. Marblemount, Skagit Co. Felt at Lakeside, Chelan Co., Laurier, Ferry Co.; Glacier, Whatcom Co.; Okanogan, Okanogan Co.; and at Victoria, B. C., and Seattle. At Marblemount an aftershock was felt at 10 a.m.-MWR, 43, 416; BSSA, 5, 157; Reid's Scrapbook, 4, 81.
 
Source ID Publication Pub Date Pub Details
310  Bradford, Donald C., 1935, Seismic History of the Puget Sound Basin, BSSA, V. 25, No. 2, pp. 138-153  1935   
Transcription: 1915 August 18, 10:00 a.m.; 48 degrees 32' north and 121 degrees 26' west; felt from Seattle to Laurier and from Victoria to Okanogan; felt area approximately 30,000 square miles.
 


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