Earthquake History of Cascadia (Washington, Oregon, and Southern British Columbia)

Earthquakes in Historic Time: Since 1791

Map of Largest Historic Earthquakes in the Pacific Northwest
1793-1929 Historic Seismicity Catalog and Macroseismic Accounts for Cascadia, 1793-1929: A Database in Microsoft ACCESS format. Selected quakes coming soon in web format!!
- The 1872 North Cascades earthquake: estimated magnitude 7.4
  - The 1872 Earthquake - Significant Data and Conclusions; Weston Geophysical Research, Inc., 1976
    This is a lengthy compilation of newspaper clippings related to the 1872 earthquake and its aftershocks. It is part of the "gray literature" of technical reports, which are published in limited quantities, and are often difficult or impossible to find out about or access.
    - QUICK LINK TO NEWSPAPER ARTICLES ABOUT THE 1872 QUAKE
  - OTHER INFORMATION ABOUT THE 1872 NORTH CASCADES EARTHQUAKE
    - Isoseismal Maps for the 1872 earthquake: Various investigators have proposed different isoseismal maps.
    - Volume 2A of the PSAR for WPPSS Project 1 (1977) (Selected material)
    - Coombs (Selected material)
    - Selected Material from Volume 1, Amendment 18 of the FSAR for WPPSS Project 2 (1981)
  - AFTERSHOCKS of the 1872 North Cascades earthquake, by Ruth Ludwin, 1999
Largest historic earthquakes affecting Puget Sound, 1791-1928

1929-1969 Earthquake information and Isoseismal Maps from United States Earthquakes, U.S. Department of Commerce, Coast and Geodetic Survey

NGDC Earthquake Intensity Database U.S. Intensity Data - 2,500 earthquakes reported from 1638-1928 and more than 18,500 events from 1928-1985.

1970-May 2002 PNSN Catalog of Earthquakes Magnitude 4.0 or larger. Accurate locations and magnitudes became possible after the installation of the PNSN in 1969.

1993-Notable earthquakes recorded by the PNSN since 1993 Large Earthquakes Known Through Ethnographic Evidence

Cascadia Megathrust Earthquakes in PNW Indian Legend Large Earthquakes Known Through Geologic Evidence
- January 26, 1700: Mega-quake on the Cascadia Subduction Zone. Web pages coming soon!
  - Science, 22 May 1987, Vol. 236, pp. 942-944
  - Science, 10 April 1987, Vol. 236, pp. 162-168
  - Nature, 8 February, 1990, Vol. 343, pp. 511-512
  - Science News, 2 February, 1990, p. 104
  - Nature, 12 Sept. 1991, Vol 353, pp. 156-158
  - Science, 5 April 1991, Vol. 252, pp. 101-103
  - Coastal Evidence for Great Earthquakes in Western Washington, USGS Professional Paper 1560, v. 1, 1992
  - Nature, 1996, v. 379, p. 246-249
  - Nature, Oct. 30, 1997, v. 389, p. 922
- 1,100 years ago: Magnitude 7.4 (estimated) crustal earthquake on the Seattle Fault
  - Science, Dec. 4, 1993, Vol. 258; Five articles.
  - Science News, Dec. 5, 1993, p. 388-389.

Earthquake History of Cascadia (Washington, Oregon, and Southern British Columbia)

Earthquakes in Historic Time: Since 1791

Large Earthquakes Known Through Ethnographic Evidence

Large Earthquakes Known Through Geologic Evidence