Tsunami damage in Crescent City, California from the November 15, 2006 Kuril event L. Dengler 1 , B. Uslu 2,3 , A. Barberopoulou 2 , S.C. Yim 4 , A. Kelly 5 1 Humboldt State University, Arcata CA 95521, 2 USC, Los Angeles, CA, 90089, 3 NOAA PMEL, Seattle, WA, 98115, 4 Oregon State University, Corvallis, OR, 97331, 5 USGS, Menlo Park, CA, 94301 Abstract - On November 15, 2006, Crescent City in Del Norte County, California was hit by a series of tsunami surges generated by a M w = 8.3 earthquake located in the Kuril Islands. Strong currents generated by the tsunami damaged floating docks and several boats, causing an estimated $9.2 million in losses. Initial tsunami alert bulletins were issued by the West Coast Alaska Tsunami Warning Center (WCATWC) in Palmer, Alaska fifteen minutes after the earthquake. Tsunami Warning and Watch areas were expanded until the alert was cancelled at 6:41 AM PST, about three and a half hours after the earthquake. Crescent City was never placed at an alert level higher than Advisory. An informal dialog between WCATWC, State Warning Centers and the counties resulted in an ad hoc local decision to clear beaches and harbor areas in Humboldt and Del Norte Counties, California before the arrival of the first expected wave at 11:38 AM PST. At the local level, there was confusion about the appearance and duration of a moderate tsunami in a harbor environment. The first surge was observed as a modest rise and fall (38 cm peak to trough) of the water level. No one associated the extremely strong currents several hours later with the tsunami event and two people were on the docks when the largest surges hit the harbor. The largest amplitude wave, 1.76-meter peak to trough, was the sixth cycle, arriving over two hours after the first wave. Strong currents pinned the pile rings against the pilings and the docks were unable to adjust to the rising water level. At least a foot of water flowed over the dock surface pulling the pile rings out of the docks and breaking the slips. Wave activity continued with amplitudes on the order of 0.5 m for more than 8 hours, through the next high tide cycle. Two docks were completely destroyed, a third suffered major damage and cracks were observed in almost all the remaining docks. As a result of the November 15 event, new products were developed by WCATWC that define an Advisory if forecasts indicate that tsunami water heights may approach warning- level thresholds in specific, vulnerable locations. On January 13, 2007 a similar Kuril event occurred and hourly conferences between the warning center and regional weather forecasts were held with a considerable improvement in the flow of information to local coastal jurisdictions. Introduction Crescent City, located in Del Norte County on California’s North Coast about 460 kilometers north of San Francisco (Figure 1), has suffered greater impact from historic tsunamis than any other community on the west coast of the United States (Dengler and Magoon, 2006). Thirty-one tsunamis have been observed at Crescent City since a tide gauge was established in 1933 (Table 1), including eleven events with maximum peak to trough wave height exceeding one meter and four that caused damage. The most recent damaging tsunami occurred on November 15, 2006 as a result of a magnitude M w 8.3 earthquake on the Central Kuril trench that caused significant damage to the floating docks in the small boat basin in Crescent Harbor. The authors visited Crescent City between November 16 – 18, 2006 and conducted interviews with officials and eyewitnesses and continued to follow the damage assessment with County and City officials. This study examines the chronology of events on November 15, Crescent City’s particular vulnerability to a modest tsunami and highlights some of the difficulties of managing a marginal tsunami event. Crescent City Crescent City, population 7,452, is the largest population center and only incorporated city in California’s northernmost coastal county, Del Norte (Figure 2). Traditionally the home of the