- © 2008 by the Seismological Society of America
Crescent City, located in Del Norte County on the California coast about 460 k north of San Francisco (Figure 1), has suffered more impacts 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 this small coastal city (population 7,542) since a tide gauge was established in 1933, including 11 events with maximum peak-to-trough wave range exceeding 1 meter and four that caused damage (National Geophysical Data Center 2008; http://www.ngdc.noaa.gov/hazard/tsu_db.shtml). The most recent damaging tsunami, and the first tsunami to cause significant property damage in the United States since 1964, occurred on 15 November 2006. It was caused by an Mw 8.3 earthquake on the central Kuril trench and produced strong currents in Crescent Harbor that damaged docks in the small-boat basin.
Five tsunamis generated by earthquakes in the Kuril Islands have been recorded at Crescent City since the tide gauge was installed, but only the 2006 event caused damage. The earthquakes were similar in magnitude (7.9 to 8.4) and varied slightly in location relative to Crescent City. This study examines what happened in the 2006 tsunami at Crescent City and why this tsunami was more damaging than other recent events. We use the Method of Splitting Tsunami (MOST) model (Titov and Gonzales 1997; Titov and Synolakis 1998) to simulate three recent tsunamis triggered by similar-sized earthquakes on the Kuril trench and examine which segments of the Kuril-Japan subduction zones have the greatest potential to impact Crescent City.
KURIL ISLANDS–GENERATED TSUNAMIS AT CRESCENT CITY
The Kuril Islands trench in the northwestern Pacific marks the convergent plate boundary between the Pacific and North American plates (Figure 2). The Pacific plate is subducting underneath the Kuril Islands arc in a WNW direction of 81 mm/yr; subduction occurs more rapidly only along …