Recent tsunami highlights need for awareness of tsunami duration

On Wednesday, 15 November 2006, Crescent City Harbor, in Del Norte County, Calif., was hit by surges resulting from the tsunami generated by the Mw= 8.3 Kuril Islands earthquake. The strong currents caused an estimated US $700,000 to $1 million in losses to the small boat basin at Citizen's Dock, destroying or damaging three floating docks and causing minor damage to several boats (Figure l).The event highlighted a persistent problem for tsunami hazard mitigation: Most people are still unaware that the first tsunami waves rarely are the largest and that the potential for damaging waves may last for many hours.