1. Setting the stage The water disasters of 1964 Crescent City – early April 1964 Klamath – late December 1964 Lori Dengler, HSU Geology lori.dengler@humboldt.edu

2. The tsunami - March 27 & 28, 1964 Caused by a magnitude 9.2 earthquake in Alaska Took about 4 hours to travel to Calfiornia Warning issued one hour before wave arrival

3. Four major surges Water levels causing inundation ~ 5 hours Currents persisted for days The 1964 tsunami

4. In comparison, 1964 flood water levels were above flood stage for days to weeks FLOOD STAGE Eel River at Scotia

5. Flooded ~ 30 blocks in Crescent City Damage to the Noyo harbor and river in Mendocino County Damage in San Francisco Bay The 1964 tsunami Est. $17 million losses (1964 $$)

6. In comparison, the 1964 flood caused flooding throughout Northern California Est. losses ~$195,000,000 (1964 $$) Army Corps Eng. SF District Destroyed Klamath Pepperwood Weott Myers Flat Orleans Shively Stafford South Fork Manhattan Almost every community in Humboldt and Del Norte County suffered damage

7. Harbor unbusable Destroyed one bridge Impeded traffic on 101 for a day The 1964 tsunami – impacts on transportation

8. In comparison, the 1964 flood: destroyed/damaged 27 bridges on State/Fed. Hwys destroyed/damaged 132 county bridges disrupted the transportation system throughout Northern California for years Bridges damaged/destroyed

9. Debris – Debris - Debris Crescent City Harbor after the tsunami Crescent City Harbor after the flood If the flood had happened first tsunami might have been worse