A strong earthquake in Del Norte County, California, on November 22, 1873, caused chimney damage in many places as far north as Port Orford, Oregon, and east to Jacksonville, California. The tremor was felt from Portland to San Francisco and onboard ships at sea. Chimneys were damaged (intensity VII) in the Portland area from an October 12, 1877, earthquake apparently centered in the Cascade Mountains.
Another severe shock affected Portland on February 3, 1892. Buildings swayed, and terrified people rushed into the street (VI). The earthquake was felt strongly at Astoria and Salem; the total area affected covered about 26,000 square kilometers. Some damage to buildings at Umatilla (VI-VII) resulted from a March 6, 1893, earthquake. Details on this shock are lacking.
On April 2, 1896, three shocks in succession awakened everyone in McMinnville (VI). The main shock was felt at Portland and Salem. A similar occurrence on April 19, 1906, awakened people at Paisley (V). Three additional shocks followed within 1 1/2 hours. A strong earthquake on October 4, 1913, in the Seven Devils Mountains of western Idaho broke windows and dishes (V) in the area. On May 18, 1915, a sharp local earthquake rattled dishes, rocked chairs, and caused some fright (V) at Portland; three shocks were reported.
Three shocks were felt at Fort Klamath (V) on April 14, 1920. The center was probably in the vicinity of Crater Lake. People in a small area around Cascadia felt an earthquake on February 25, 1921 (V). A shock that was probably rather strong in an unsettled region of southern Oregon occurred on January 10, 1923. Plaster fell at Alturas, California, and the tremor was felt strongly (V) at Lakeview, Oregon. The felt area extended to Klamath Falls. Another earthquake was felt widely over a sparsely settled area in eastern Oregon on April 8, 1927. The center was apparently in eastern Baker County; the maximum intensity (V) was noticed at Halfway and Richland.
A damaging earthquake occurred at 11:08 PM PST on July 15, 1936, near the State line between Milton-Freewater, Oregon, and Walla Walla, Washington. The magnitude 5.75 shock affected an area of about 272,000 square kilometers in the two States and adjacent Idaho. Ground cracking was observed about 6.5 kilometers west of Freewater, and there were marked changes in the flow of well water (VII). Many chimneys were damaged at the roof level in Freewater; in addition, plaster was broken, and walls cracked. Similar damage was reported from Umapine. Total damage amounted to $100,000. There were numerous aftershocks up to November 17; more than 20 moderate shocks occurred during the night, and stronger ones were felt (V) on July 18 and August 4 and 27.
A shock of intensity VI affected about 13,000 square kilometers in the vicinity of Portland on December 29, 1941. A downtown display window was shattered, and a few other windows were broken in other parts of Portland. The earthquake was also felt strongly at Hillsboro, Sherwood (where many were frightened), and Yamhill. The felt region extended into Washington; Vancouver and Woodland experienced minor damage.
On April 13, a major earthquake (magnitude 7.0) caused eight deaths and an estimated $25 million damage at Olympia, Washington, and a broad area around the capital city. The depth of focus was estimated to be slightly greater than normal, which, in part, accounted for the large felt area - 388,000 square kilometers in the United States. In Oregon, widespread damage was observed, several injuries occurred at Astoria and Portland. A maximum intensity of VIII was experienced at Clatskanie and Rainier, where many chimneys twisted and fell, and there was considerable damage to brick and masonry.
Minor damage in the Portland area resulted from a December 15, 1953, shock. There was one report of a cracked chimney and slight damage to fireplace tile (VI). Additional reports of plaster cracking were received from Portland and Roy, Oregon, and Vancouver, Washington. The total felt area covered about 7,700 square kilometers.
Similar damage occurred at Salem on November 16, 1957, from an earthquake felt over a land area of 11,600 square kilometers in northwestern Oregon. The tremor frightened all in the city (VI) and caused some cracked plaster in West Salem.
On August 18, 1961, another earthquake caused minor damage at Albany and Lebanon, south of the 1957 center. The magnitude 4.5 shock was felt (VI) by all in the two cities. Two house chimneys were toppled, and plaster cracked. The felt region extended into Cowlitz County, Washington; the total area was about 18,000 square kilometers. Portland experienced another moderately strong shock on November 6, 1961. Slight plaster cracking (VI) was the principal damage reported. Also, part of a chimney fell, and windows and lights broke. The earthquake was felt over a large area (about 23,000 square kilometers) of northwestern Oregon and southwestern Washington.
A series of earthquakes near the Oregon-California border began on May 26, 1968, and continued daily through June 11. At Adel, old chimneys fell or were cracked, and part of an old rock cellar wall fell (VI) from a magnitude 4.7 tremor on June 3. Some ground fissures were noted in Bidwell Creek Canyon, near Fort Bidwell, California. The total felt area in the two States covered 18,000 square kilometers.
Numerous other shocks located in California, Idaho, Nevada, Washington, and offshore points affected places in Oregon. The 1959 Hebgen Lake, Montana, earthquake was also felt in the State; slight damage was reported at Richland.
Abridged from Earthquake Information Bulletin, Volume 8, Number 3, May-June 1976, by Carl A. von Hake.
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