A similar instance of errors in interpretation and translation 

 occurred in the reports of an 1840 event at Santa Cruz, California. 

 Heavy rain and high waves caused by a storm resulted in considerable 

 damage. The collapse of buildings caused by flooding from the rain was 

 misinterpreted as an earthquake, and the waves as a tsunami. Holden 

 (1898) reported this as an earthquake and tsunami, when in fact neither 

 occurred. 



Consideration must also be given to the fact that records based on 

 visual observations may not include all tsunamis which occurred. The 

 observers probably gave special notice only to those waves which caused 

 substantial flooding or large, rapid variations of the water level in 

 bays and harbors. At a location where the normal tidal range was of the 

 same order as the tsunami height, a tsunami occurring at a low tide stage 

 may have been given only passing notice, if noticed at all, while the 

 same tsunami occurring at a high tide stage would have been recorded as 

 a major tsunami. Likewise, the occurrence of a tsunami in conjunction 

 with high storm waves would have caused more flooding, and therefore, 

 may have been given more significance in the records than a tsunami 

 occurring during a relative calm. 



Records of tsunamis in the Mediterranean and Middle East include 

 theories on the eruption of Thira (also known as Santorini) and the 

 tsunami on the coast of Crete that destroyed the Minoan Empire circa 

 1400 B.C. Factual accounts of tsunamis extend back at least 2,000 

 years. Accounts of tsunamis in Japan extend back at least 1,300 years. 

 In contrast, records of tsunamis originating in the Chile-Peru coastal 

 areas only cover about 400 years (from 1562 to present), those originat- 

 ing in Alaska about 200 years (from 1788) , and those occurring in Hawaii 

 slightly more than 150 years (from 1813). Few records are available of 

 tsunamis occurring on the California-Oregon-Washington coastline. Holden 

 (1898) indicates tsunamis occurred at points on the California coastline 

 in 1812, with various occurrences at later dates, mainly recorded or 

 observed at San Francisco. Townley and Allen (1939) provide similar 

 information. 



Knowledge of the action of more recent tsunamis can be helpful in 

 evaluating historical information. Although no record exists of major 

 tsunamis on Puget Sound in Washington State, the Puget Sound Weekly (1866) 

 reported that a tide, the highest ever recorded, occurred at Port Townsend. 

 Washington, on 20 December 1866. The report stated, "The main street was 

 filled with drift logs, and the dwellers on lower floors were compelled 

 to elevate to the next story." Camfield's (1975) article on historical 

 accounts gives the date as 27 December 1866. Kelly (Seattle, Washington; 

 personal communication, 1979) also gives the year as 1866. Neither 

 Holden (1898) nor Townley and Allen (1939) report a tsunami occurrence 

 in 1866; both list a 26 December 1856 date, with no additional details, 

 which was probably an incorrect report of the 1866 event. The historical 

 accounts describing a gradual rise in water level indicate this was prob- 

 ably a tsunami, but the origin is unknown. 



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