Washington Public Power Supply System, "WPPSS Nuclear Project No. 2,
Final Safety Analysis Report, Volume 1, Amendment 18"
p. 2.5-120)
September 1981
(RSL comment: this material is extracted from the "WPPSS Nuclear Project No. 2, Final Safety Analysis Report, Volume 1, Amendment 18"
September 1981, Washington Public Power Supply System
p. 2.5-120)
The November 1, 1918 Corfu earthquake had an epicentral
intensity of (MM) V-VI, based on intensity reports from the
town of Corfu, Washington, and on reported landslides in the
vicinity of Corfu. Based on the seismograph record at the
Gonzaga University station (SPO) in Spokane, Washington, it
is estimated that this earthquake had a magnitude (MS) of
approximately 4.4.
The Corfu earthquake and aftershock sequence was reported in
the Bulletin of the Seismological Society of America (1918):
The first shock was on November 1st, between 9:15 and
9:30 a.m. This was the most severe and lasted several
seconds; it shook goods from the shelves and caused
landslides for several miles along the hills. We have
had on an average about three shocks every twenty-four
hours since, but lighter. The intensity is estimated
at IV of the RF Scale.
Bingham et al. (1970) refer to a landslide east of Smyrna
Bench, which they attribute to the Corfu earthquake, but it
was not investigated in detail in their field studies.
Fifer (1966) gathered reports that suggests maximum
intensity (MM) IV at White Bluffs which is located 26 km
northwest of the present plant site and 16 km south of
Corfu. The White Bluffs felt reports ind;Lcate that the
epicenter was probably close to the town of Corfu. This
further suggests that the site intensity was likely to be
less than (MM) IV.
The intensity data are shown in Figure 2.5-43 along with an
arc corresponding to the S-P time of 21.7 seconds measured
from the SPO record of the event. An uncertainty of
approximately 1 second or 8 km is noted for the S-P time.
Based on these data, the most likely location for the 1918
event is considered to be sligntly east of Corfu, within the
central portion of the epicentral region shown in Figure
2.5-43. The coordinates for this point are listed in Table
2.5-5. The 1918 Corfu earthquake is similar in location to
the December 20, 1973, Mc4.4 Royal Slope Event, as
discussed in Appendix 2.5J. The Royal Slope Event had a
focal depth of 2.1 km (Malone, 1979), a maximum intensity of
(MM) V, and was felt to a distance of 30 km (Appendix 2.5I).
Washington Public Power Supply System, "WPPSS Nuclear Project No. 2,
Final Safety Analysis Report, Volume 1, Amendment 18"
p. 2.5-123)
September 1981
(RSL comment: this material is extracted from the "WPPSS Nuclear Project No. 2, Final Safety Analysis Report, Volume 1, Amendm
ent 18"
September 1981, Washington Public Power Supply System
p. 2.5-123)
The only other earthquake larger than intensity (MM) V
within 80 km of the site was the March 5, 1893 shock that
occurred near Umatilla, Oregon, about 62 km south of the
site. Townley and Allen (1939) reported the earthquake as
follows:
1893 March 6 (sic) umatilla. A succession of shocks
were felt here to-night. One of the walls of a large
stone building was thrown down by the force of the
shock (VII? VIII?) .
A VII? to VIII? Rossi-Forel (RF) intensity would correspond
to a (MM) VII? intensity.
The East Oregonian, (1893), Pendleton, newspaper of Monday,
March 6, 1893, had the following headline and article:
Earthquake at Umatilla - the little city in the sand
badly shaken up.
Umatilla, Oregon March 6 - At three minutes past 5
O'clock yesterday afternoon an earthquake shock lasting
several seconds passed over this section of the
country. One side of a large stone warehouse tumbled
down, and the building was so badly cracked on all
sides that it will have to be torn down. D. Harris,
agent for the Union Pacific, who was possessing the
building at the time, barely escaped being buried in
the debris.
This appears to have been an earthquake of very limited
extent, because no felt reports from Pendleton itself nor
any towns in the surrounding area were found in the search
of newpapers in Pendleton and Milton-Freewater, Oregon, and
Yakima, Walla Walla, and Spokane, Washington.
The largest circular area about Umatilla that excludes
Pendleton and Yakima has an area of 7,800 km2. The
intensity-felt-area plot, Figure 2.5-53, is based on data
from Table 2.5-6 and shows that a 7,800 km2 area is
compatible with an intensity (MM) V-VI but is an order of
magnitude less than the felt areas associated with intensity
(MM) VII earthquakes. Consequently, the intensity rating of
this earthquake has been reduced to (MM) VI in Table 2.5-5.
Washington Public Power Supply System, "WPPSS Nuclear Project No. 2,
Final Safety Analysis Report, Volume 1, Amendment 18"
TABLE 2.5-6, page 2.5-386
September 1981
(RSL comment: this material is extracted from theWPPSS Nuclear Project No. 2, Final Safety Analysis Report, Volume 1, Amendment 18",
September 1981, Washington Public Power Supply System)
TABLE 2.5-6
Supplement to
"CHRONOLOGICAL LISTING OF EARTHQUAKES WITHIN 200 MILES OF THE SITE"
Page 1 of 8
Epicentral
Year MOS. Day Location Intensity Remarks Reference*
1833 Jun 29 Fort Nisqually TA
Oregon City, Ore occurred between TA
1846 and 1852
1856 Dec 26 Port Townsend, Wash TA
1857 Sep Birch Bay, Wash Whatcom Co. TA
1859 Apr 1 Olympia, Wash. WG-1
1860 May 7 Port Townsend, Wash TA
1866 Nov 30 The Dalles, Ore. WG-2
1866 Dec The Dalles, Ore. Probably Dec. 1 TA
1868 May 30 Mukilteo, Wash. TA
1868 Jun 20 Mukiltoe-Tulalip, Wash. Slight. R
1869 Feb 18 Port Townsend, Wash Slight. R
1870 Jun 7 Vancouver, Wash. R
1871 Jan 20 Olympia, Wash. R
1871 May 19 mt. Rainier, Wash. R
1871 Jun 20 Seattle, Wash. WG-2
1872 Walla Walla, Wash. Period from Dec. 16, TA
1872 to Jan. 4, 1873
Many light shocks
felt.
1873 Jan 16 Olympia, Wash R
1873 Oct 18 Lake Chelan region, Wash. WG-2
1874 Jan 17 Yakima, Wash. WG-2
*Initials are explained at the end of this table
TABLE 2.5-6(Continued) Page 2 of 8
Epicentral
Year Mos. Day Location Intensity Remarks Reference*
1875 May 6 Yakima, Wash. Two shocks felt at R
at 3:30, 3:35 pm.
1875 May 6 Yakima, Wash. Severe at 4:15 pm. R
1878 Apr 1 Puget Sound region, Wash. R
1880 Aug 22 Northwestern Washington TA
1883 Sep 28 Portland, Ore. TA
1886 Apr 15 Bainbridge Isl., Wash. TA
1887 Apr 29 Walla Walla Valley, Wash. TA
1888 Feb 1 Point No Point, Wash. TA
1889 Mar 16 Point No Point, Wash. TA
1889 Oct 20 Point No Point, Wash. TA
1890 Feb 1 Admiralty Head, Wash. TA
1890 Oct 8 Point No Point, Wash. TA
1891 Dec 11 Mt. Baker, Wash. 11:30 am WG-4
1892 Mar Kalma, Wash. Cowlitz Co. TA
1892 Nov Oregon City, Ore. B & B
1893 Jan 26 Methow Valley, Wash. Near Chelan WG-4
1893 Jul Pleasant Ridge, Ore. Near The Dalles B & B
1893 Jul 7 Wenatchee, Wash WG-2
1894 NOV 21 Mt. Rainier, Wash. TA
1896 Aug 26 Mt. Hood, Ore. Earthquake? TA
1898 Jan Lakeside, Wash. Slight shocks on TA
Jan. 11, 14, 15
1898 Feb 2 Brinnon, Wash TA
1898 Feb 22 Ellensburg, Wash. TA
1898 Jun 3 Lakeside, Wash. TA
1898 Aug 12 Seattle, Wash. Two light shocks TA
during night of
Aug. 12-13
1900 Sep 28 St. Helens, Ore. B & B
1902 Dec 4 Hood River, Ore. TA
1903 Dec 15 Mt. Rainier, Wash. TA
*Initials are explained at the end of this table
TABLE 2.5-6(Continued) Page 3 of 8
Epicentral
Year Mos. Day Location Intensity Remarks Reference*
1905 Dec Chelan, Wash. 2: am. date WG-4
uncertain,
1 or 2 Dec.
1906 Nov 19 Chelan, Wash. 5:30 pm WG-4
1909 May 24 Waterville, Wash. TA
1909 Aug 17 Dayton, Wash. Earthquake TA
1910 Feb 7 Portland Ore. R
1912 Jun 6 Southern Puget Somd, Wash. TA
1912 Nov 24 Seattle, Wash. Three slight TA
shocks,
1914 Feb 1 Lakeside, Wash. TA
1914 Aug 8 Lakeside, Wash TA
1915 Apr 22 Puyallup, Wash. R
1915 Oct 19 Fruita, Ore. TA
1918 Jun 7 West Seattle, Wash. TA
1919 Jun 5 Seattle, Wash. TA
1920 Nov 29 Spokane, Wash. R
1922 Jan 31 Republic, Wash. R
1923 Sep Sultan, Wash. 47.8 121.8
1928 Jul 5 4 8. 1N. , 121. 6 W. R
1930 Jun 17 46.7 N., 122.5 W. R
1930 Jun 17 47.1 N., 122. W. R
1930 Oct 7 Lemanasky Lake, Wash. R
1931 Jan 20 Sultan, Wash. R
1931 May 28 Sultan, Wash. R
1931 Aug 19 Sultan, Wash. R
1931 Sep 18 Lakeside, Wash. R
1931 Dec 29 Sultan, Wash. R
1932 Feu 29 Florence, Wash. R
1932 Jun 13 Sultan, Wash. R
1934 Jan 11 48 N., 117 W.
1934 Feb 8 Sultan, Wash. R
1934 Mar 12 Chelan Falls, Wash. WG-7
1934 Sep 8 Ellensburg, Wash. 8:12 a.m. WG-8
*Initials are explained at the end of this table
TABLE 2.5-6(Continued) Page 4 of 8
Epicentral
Year Mos. Day Location Intensity Remarks Reference*
1934 Sep 17 Ellensburg, Wash. WG-9
1934 Sep 19 Ellensburg, Wash. WG-9
1934 Sep 20 Ellensbury, Wash. WG- 8
1934 Sep 27 Ellensburg, Wash. WG-9,8
1934 Oct 12 Ellensburg, Wash. WG-9
1934 Oct 12 Ellensburg, Wash. WG-9
1934 Oct 20 Ellensburg, Wash. WG-9
1934 Nov 2 Ellensburg, Wash. WG-9
1934 Nov 2 Ellensburg, Wash.
1934 Nov 2 Ellensburg, Wash.
1934 NOV 19 Ellensburg, Wash. WG-9
1934 Nov 27 Ellensburg, Wash. WG-9
1934 Dec 1 Ellensburg, Wash. WG-9
1934 Dec 1 Ellensburg, Wash.
1934 Dec 2 Ellensburg, Wash. WG-9
1934 Dec 2 Ellensburg, Wash.
1935 Jul 24 Shelton, Wash. R
1935 Oct 24 Ellensburg, Wash. R
1935 oct 31 Wenatchee, Wash R
1935 Oct 31 Culdesac, Idaho
1936 Mar 22 Alder, Wash. R
1936 Jun 20 Seattle, Wash. R
1936 Jun 20 Bothell, Wash. R
1936 Jul 15 White Salmon, Wash. R
1936 Jul 15 Mottinger, Wash. R
1936 Jul 15 Walla Walla, Wash. 11:13 pm. After- R
shock of Jul. 15
1936 Jul 15 Walla Walla, Wash 11:23 pm. After- R
shock of Jul. 15
1936 Jul 15 Walla Walla, Wash 11:25 pm. After- R
shock of Jul. 15.
*Initials are explained at the end of this table
TABLE 2.5-6(Continued) Page 5 of 8
Epicentral
Year Day Location Intensity Remarks Reference*
1936 Jul 15 Walla Walla, Wash. 11:56 pm. After- R
shock of Jul. 15
1936 Jul 15 Walla Walla, Wash 11:58 pm. After- R
shock of Jul. 15
1936 Jul 16 Walla Walla, Wash. 00:10 am. After- R
shock of Jul. 15.
1936 Jul 16 Mason City, Wash. 00:25 am. After- R
shock of Jul. 15?
1936 Jul 16 Walla Walla, Wash. 00:27.5 am. After- R
shock of Jul. 15
1936 Jul 16 Walla Walla, Wash. 00:38 am. After- R
shock of Jul. 15.
1936 Jul 16 Walla Walla, Wash. 01:08 am. After- R
shock of Jul. 15.
1936 Jul 16 Walla Walla, Wash. 01:10 am. After- R
shock of Jul. 15
1936 Jul 16 Walla Walla, Wash. 03:00 am. After- R
shock of Jul. 15
1936 Jul 16 Dayton, Wash. 08:30 am. After- R
shock of Jul. 15
1936 Jul 17 Mottinger, Wash. 10:27 am. After- R
shock of Jul. 15
1936 Jul 17 Lowden, Wash. 08:30 am. After- R
shock of Jul. 15
1936 Jul 21 Umapine, ore. Eight aftershocks B & B
1936 Jul 25 Seattle, Wash. R?
1936 Aug 28 Walla, Walla, Wash. Aftershock of R
Jul. 15.
1936 Nov 29 Chelan Falls, Wash. WG-7
1937 Jul 16 Walla Walla, Wash. R
*Initials are explained at the end of this table
TABLE 2.5-6(Continued) Page 6 of 8
Epicentral
Year Mos. Location Intensity Remarks Reference*
1937 Aug 10 Spokane, Wash. R
1937 Sep 20 Walla Walla, Wash. R
1937 Sep 28 Fall City, Wash. R
1937 Nov 26 Darrington, Wash. R
1937 Dec 28 Possession Point, Wash. R
1938 Jan 3 Ariel Dam, Wash. Cowlitz, Co. R
1938 Jan 3 77N R5E Skamania Co., two WG-7, 9
shocks.
1938 Apr 29 Arlington, Wash. R
1938 May 9 Walla Walla, Wash. R
1938 May 24 Walla Walla, Wash. Two shocks. R
1939 Jan 28 Quilcene, Wash. R
1939 Feb 6 Ellensburg, Wash. R
1939 Jul 22 Clinton, Wash. R
1939 Nov 29 Chelan, Wash. v R
1939 Nov 29 Toutle, Wash. R
1939 Nov 29 Chelan Falls, Wash. Three shocks R
1940 Jan 5 Ephrata, Wash. R
1940 Mar 23 Puyallup, Wash. R
1940 Mar 24 Hyak, Wash. R
1940 Nov 18 Tacoma, Wash. R
1940 Nov 25 Tacoma, Wash Three shocks felt. R
1941 Jan 3 Pullman, Wash. R
1941 Apr 6 Republic, Wash. R
1941 Jul 29 Spokane, Wash. R
1942 Feb 2 Pullman, Wash. WG-7
1942 Mar 4 Chelan Falls, Wash. WG-7
1944 Jan 9 Yakima, Wash. R
1944 Jan 28 Chelan Falls, Wash. R
1944 May 9 Mullan, Idaho
1945 May 1 North Bend, Wash. R
1949 Apr 14 Pullman, Wash. R
*Initials are explained at the end of this table
TABLE 2.5-6(Continued) Page 7 of 8
Epicentral
Year Mos. Day Location Intensity Remarks Reference*
1952 Oct 12 47.6 N., 122.6 W. R
1954 Acr 22 South Seattle, Wash. Duwamish Valley. R
1954 Apr 24 South Seattle, Wash. Duwamish Valley. R
1954 Apr 26 South Seattle, Wash. Duwamish Valley R
Two shocks.
1954 Jun 18 47.6N., 122.6W. Seattle. R
1955 Jan- Othello, Wash. T16 N R31 Press reports nearly R
Mar E-31 200 shocks due to
groundwater loading
from irrigation.
1955 Apr 21 46.8 N., 121.9 W.
1959 Jul 11 Deep Lake, Wash. R
1959 Jul 14 Deep Lake, Wash. Water level changes R
noted.
1959 Aug 18 47.9 N., 120.1 W. Chelan. R
1960 May 30 47 53 N., 121 59 W. GMT. Felt?
1960 Jun 15 Longmire, Wash. R
1960 Jul 17 46 35 N., 121 39 W. Longmire. R
1960 Jul 27 47 42 N., 121 59 W. Two shocks. R
1960 Aug 7 48 57 N., 121 17 W. R
1960 Aug 16 46 22 N., 121 29 W. Cougar-Skamania Co. R
1961 Jan 5 46 00 N., 122 10 W. Skamania Co. R
1961 Jan 28 48.07N, 122.4W WG-2
1961 Feb 9 Cougar, Wash. Swift Dam Powerhouse R
1961 Feb 21 Cougar, Wash. R
1961 Apr 1 48 41 N., 121 57 W. GMT WG-2
1961 May 23 47 29 N., 123 19 W. GMT R
1961 Sep 9? Roosevelt, Wash. R
1961 Nov 7 Spokane, Wash. Two shocks felt. R
1961 Nov 15 46 45 N., 121 52 W. GMT. WG-2
1961 Nov 26 Omak, Wash. WG-10
1961 Dec 25 47 04 N., 122 24 W. GMT. WG-2
*Initials are explained at the end of this table
TABLE 2.5-6(Continued) Page 8 of 8
Epicentral
Year Mos. Day Location Intensity Remarks Reference*
1963 Sep 6 44.8N., 117.1 W. GMT.
1964 Jan 15 45.9 N., 120.0 W. GMT.
1964 Jul 30 47.7 122.1 NOAA
1967 Dec 19 South Seattle, Wash.
1972 May 23 43,492, 122.427 NOAA
1974 Jul 14 47.6N 120.7W iv ML = 3.3 WG-3A
1974 Jul 29 45.9N, 122.6W iv ML = 3.0 WG-3A
1974 Dec 13 45.27 121.6 NOAA
1974 Dec 15 48.3 122.08 NOAA
1975 iun 7 46.2N, 122.9W iv ML = 4.5 WG-3A
1975 Dec 3 43.73 118.47 NOAA
1976 Apr 8 45.15, 120.8 NOAA
1976 Apr 13 45-10N, 121.6
1976 Apr 13 45.15N, 120.90W iv ML = 3.4 WG-See 9, IA 10
1976 Apr 13 45-15N, 120.87N iii ML = 3.1 WG-See 9, IA
1976 Air 13 45.18, 121.0 WG
*Initials are explained at the end of this table
(RSL 7/1/1995 - No explanation for the initials is given in my copy of this document)