| pub | pubpl | pubde | smem | pubda |
|---|---|---|---|---|
| Milne, W.G., 1956, Seismic Activity in Canada, west of the 113th meridian 1841-1951: Canada Dominion Obs. Pub., V. 18, No. 7, pp. 119-146 | 1928 FEBRUARY 9. 3:04 a.m. IV. The Victoria seismograph indicates an epicentre about 100 miles northwest of the city. Alberni, Bamfield, and Pachena Point felt the tremor most severely. At Alberni it was like a loud report, and near Bamfield small tidal waves were reported. Vancouver and Nanaimo reported the tremor as very slight. It was also felt at Abbotsford, Duncan, Cowichan, Victoria, Port Renfrew, Tatoosh and Destruction Islands. The epicentre was probably in the region of the Alberni canal. D, Prov. | 1957 | ||
| Rasmussen, Norman, 1967, Washington state earthquakes 1840 through 1965, BSSA V. 57, No. 3, pp. 463-476 | 189 1928 Feb. 9 11:05 48.5 N, 125.0 W V 1,5 At Sea | 1967 | ||
| U. S. Dept. of Commerce, 1973, Earthquake History of the United States, V. 41-1, revised ed., pp. 89-96 | 1928. February 9. Vancouver Island, B.C. Strong. Fairly strong at Tatoosh Island; loud roar. Felt at Port Townsend, Wash. | 1973 | ||
| U. S. Dept. of Commerce, 1973, Earthquake History of the United States, V. 41-1, revised ed., pp. 89-96 | Feb. 9 03:05 Vancouver Island, B.C. 48.5 125.0 10,000 V(4) 27 | 1973 | ||
| Woodward Clyde Consultants, unpublished | Woodward-Clyde Consultants (1981), Historical Catalog (1841-1980) for the Pacific Northwest Region, unpublished catalog prepared for the Washington Public Power Supply System. Copy provided to UW in 1993. | 192802 91105000 48500-125000 NO 01 | 1981 | |
| Garry Colin Rogers, Seismotectonics of British Coulmbia, PhD Thesis | PhD Thesis, Dept. of Geophysics and Astronomy, University of British Columbia, pp. 19-27 and p. 228 | TABLE Il Larger Historic Vancouver Island - Puget Sound Earthquakes Their Felt Area (In square KM -RSL 6/95) and Resulting Magnitude FELT PREVIOUS(1) FELT AREA (2) DATE COORDINATES AREA MAGNITUDE MAGNITUDE 1872 DEC 14 48.6 121.4 1010,000 - 7.3 1903 MAR 14 47.7 122.2 26,000* 4.3 4.9 1904 MAR 17 47.8 123.0 50,000* 6.0 5.3 1909 JAN 11 48.7 122.8 150,000 5.6 6.0 1911 SEP 29 48.8 122.7 8,000 4.3 4.1 1913 DEC 25 47.7 122.5 20,000* 4.3 4.7 1915 AUG 18 48.5 121.4 77,000* 5.5 4.6 (This magnitude is a typographic error in Roger's thesis correct magnitude should be 5.6, based on the felt area given here RSL 6/95) 1918 DEC 06 49.5 125.9 650,000 7.0 7.0 1920 JAN 24 48.6 123.0 70,000 5.0 5.5 1923 FEB 12 49.0 122.7 8,000 4.3 4.1 1926 DEC 04 48.5 123.0 30,000 4.3 5.0 1928 FEB 09 49.0 125.3 120,000 3.7 5.8 (List continues through 1965 - RSL 6/1995) *Felt area from "Earthquake History of the United States" by Coffman and von Hake (1973). 1)Magnitude in the Canadian Earthquake Data File. 2)Calculated using Toppozada's (1975) relationships 5) Comments on Revisions of Some Key Earthquakes (Figure 6) a) March 16, 1904 In the Canadian Earthquake Data File the epicentre for this event was located on the west side of the Olympic Peninsula and it was assigned a magnitude of 6. in "Earthquake History of the United States" it is given the location of Victoria, B.C. and assigned an intensity value of V. A study of felt levels from newspaper reports suggests the earthquake has an epicentre along the west side of Puget Sound, south of Port Townsend and that the magnitude is about 5. The confirmation that this earthquake was not near the west coast of the Olympic Peninsula is important as no large earthquakes have yet been located along the coast. b) January 11, 1909 Felt reports from newspapers limit this epicentre to the San Juan Islands region where several instances of damage occurred. Felt information also clearly shows that the size of the isoseismal maps is between that for the 1965 Seattle earthquake and the 1976 Gulf Islands earthquake (Figure 7). The magnitude is about 6 according to Toppozada's (1975) felt area relationship. Lack of aftershocks and lack of higher intensities in the epicentral region suggest this event belongs to the deeper suite of earthquakes. This event is significant because it points out that large earthquakes in the deeper suite can also occur north of Puget Sound. c) December 6, 1918 This earthquake has several epicentres in the literature which are shown in Figure 8. Investigations with the set of P arrival times listed in the ISS place the epicentre on Vancouver Island near the west coast, south of the present town of Gold River which did not exist in 1918. Because of the quality of 1918 arrival times this epicentre has an uncertainty of the order of + 50 km. Felt information collected by Dennison (1919) and supplemented by newspaper investigations suggest the magnitude of 7 (Ms) calculated by Gutenberg and Richter (1949) is correct. d) February 9, 1928 Felt information and a 100 mile distance issued from the Victoria seismograph station (VGZ), presumably from the S-P interval, indicates the earthquake was in the vicinity of Barkely Sound and had a magnitude of about 5-3/4. This event was in the Canadian Earthquake Data File but was located in the Strait of Juan de Fuca with a magnitude of 3.7. It is significant that an earthquake of this size occurred in the Barkely Sound region as there have been no events above magnitude 4 in that region since 1928. e) September 17, 1926 and May 7, 1927 Both of these events were assigned epicentres by the ISS at the location previously calculated for the epicentre of the December 6, 1918 earthquake (Figure 8). Because of the proximity of the cities of Nanaimo and Victoria and the distribution of population close to the ISS epicentral region, these earthquakes could not have been located there as they would have been felt. With the data listed in the ISS and felt reports they were located elsewhere. The 1927 event occurred in the vicinity of Brooks Peninsula on Vancouver Island and the 1926 event occurred on the mainland north of Vancouver (see Appendix 1). APPENDIX 1 - Revised parameters fir earthquakes in the Vancouver Island-Puget Sound Region 1900-1950 ( P 128. - Included here are 1900-1928; Times apparently GMT -RSL 5/95) YEAR DATE TIME LAT LONG MAG 1903 Mar. 14 02:15 47.7 122.2 4.9 Location from "EQ Hist. of the US.", mag. from felt area 1904 Mar. 17 04:21 47.8 123.0 5.3 Location from "EQ Hist. of the US.", mag. from felt area 1909 Jan. 11 23:49 48.7 122.8 6.0 Location based on felt reports, mag. from felt area 1911 Sept. 29 02:39 48.8 122.7 4.1 Location from "EQ Hist. of the US.", mag. from felt area 1913 Dec. 25 14:40 47.7 122.5 4.7 Location from "EQ Hist. of the US.", mag. from felt area 1915 Aug. 18 14:05 48.5 121.4 4.6 Location from "EQ Hist. of the US.", mag. from felt area (Note - the magnitude of 4.6 is due to a typographical error in Table 1 of Roger's thesis. The correct magnitude, based on a felt area of 77,000 square km is 5.6 RSL 6/95) 1918 Dec. 06 08:41:05.8 49.62 125.92 7.0 Recalc. from ISS data. Mag. from Gutenberg and Richter (1949) and felt area. 1919 Oct. 10 01:07:16.5 48.63 127.15 5.5 Recalc. from ISS data. Mag. estimated from the number of P arrivals. 1920 Jan. 24 07:10 48.6 123.0 5.5 Location from "EQ Hist. of the US.", mag. from felt area 1923 Feb. 12 18:30 49.0 122.7 4.1 Location from "EQ Hist. of the US.", mag. from felt area 1926 Sept. 17 23:14:40 50.0 123.0 5.5 Recalc. from ISS data. Mag. estimated from the number of P arrivals. This event was previously identified as occurring on Sept. 7 at 22:14:36 1926 Dec. 4 13:55 48.5 123.0 5.0 Location based on felt reports, Magnitude from felt area 1927 May 7 21:56 50.15 127.85 5.5 Gonzales (VGZ) S-P and felt reports are similar to 1978 Brooks Peninsula events, thus this epicentre is used. Magnitude from felt area. This event was previously identified as occurring on May 8 at 14:00. 1928 Feb. 9 11:05 49.0 125.3 5.8 Location on the basis of Gonzales (VGZ) S-P and felt reports. Magnitude from felt area. |
1983 |