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1 September 2012 The March 2011 Tōhoku Tsunami and Its Impacts along the U.S. West Coast
Jonathan C. Allan, Paul D. Komar, Peter Ruggiero, Robert Witter
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Allan, J.C.; Komar, P.D.; Ruggiero, P., and Witter, R., 2012. The March 2011 Tōhoku tsunami and its impacts along the U.S. West Coast.

The March 11, 2011, magnitude 9, Tōhoku earthquake off the coast of Japan generated a tsunami that crossed the Pacific Ocean and impacted the shores of the U.S. West Coast. Analyses of the arrival times, wave heights, periods, and total water levels from the tsunami waves and the tides have been undertaken for 17 tide gauges along the length of the West Coast. Significant along-coast variations in wave heights were found, with the highest waves having been recorded at Crescent City (maximum height of 4.23 m) in northern California and in San Luis Obispo Bay (maximum 4.25 m) in southern California. It was concluded that similar to the Kuril Island tsunami in 2006, the particularly large wave heights that impacted the California–Oregon border region, including Crescent City, California, were the result of wave refraction that focused tsunami energy into a relatively narrow band as it crossed the ocean from Japan, followed by local shelf resonance that further enhanced the wave heights and determined the dominant wave periods recorded by tide gauges. Detailed analyses of the tsunami waves at Crescent City, California, and nearby at Port Orford, Oregon, documented the differences in their heights and periods and in the profiles of the maximum measured waves. The effects to developments along the coast varied in response to the local wave conditions, moderated by the largest waves having arrived during a low tide. Undoubtedly, damage to infrastructure would have been greater had the waves arrived a few hours earlier, at the time of the Higher High tide. The resulting damage occurred almost entirely within the harbors, brought about mainly by the strong to-and-fro currents that alternately filled and then emptied the boat basins, capsizing boats and damaging docks.

Jonathan C. Allan, Paul D. Komar, Peter Ruggiero, and Robert Witter "The March 2011 Tōhoku Tsunami and Its Impacts along the U.S. West Coast," Journal of Coastal Research 28(5), 1142-1153, (1 September 2012).
Received: 24 June 2011; Accepted: 23 September 2011; Published: 1 September 2012

coastal hazards
Crescent City
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