p 



sophisticated a dock wall, pier or jetty design should become. Any- 

 given case would have to he considered on its merits. 



■ The need for proper provision and planning of oil storage tanks 

 is extremely important. These usually are located near the waterfront 

 of ports , whose oil supplies must come from overseas . Invariably oil 

 spillage caused by an earthquake or its tsunami results in fire, which 

 can spread rapidly and make a holocaust of any coastal town or city. 

 Oil tanks caught fire at Seward, Valdez, Whittier and Crescent City as 

 a consequence of the earthquake and tsunami of March 196k. All of these 

 fires were spread by waves. Proper placing and adequate containment of 

 all storage tanks in harbor areas is therefore important. If the tanks 

 cannot be sealed off and recessed below normal ground level or placed 

 on high ground out of reach of tsunami runup, they should be contained 

 by a perimeter wall or dike capable of repelling water and retaining 

 oil. 



5 . Damage from Scour 



Scouring damage from the Alaskan tsunami, on the whole, was not 

 as extensive as expected. The scouring effect was probably most notice- ■ 

 able in the Orca Inlet at Cordova where considerable deepening and shoal- 

 ing occurred in many areas and destroyed many clam beds, and also in the 

 Wear Island channel at Kodiak where the channel was denuded almost to 

 bedrock. 



In downtown Kodiak and at the Kodiak Naval Station there was some 

 minor scouring damage. Roads on Kodiak Island were also heavily eroded. 

 Cases of eroded roads and bridge pile bents have been reported from 

 several places along the Pacific Coast of North America. 



In Seward, railroad fill along the shoreline was partly eroded, and 

 at Valdez the harbor moles undoubtedly sustained erosive damage from the 

 sea waves. Some harbors and entrance channels were affected by scouring, 

 but none too seriously. 



At Kodiak Naval Station a steel sheetpile retaining wall was bowed 

 seawards by hydrostatic pressure and suction from withdrawals of the 

 tsunami waves. Collapse seaward of seawalls from this cause has been 

 frequently noted (cf. Horikawa, I96I ) . 



6. Protective Measures for Ships and Boats in Harbors 



In those harbors hit hardest by the Alaskan tsunami, small boats 

 suffered severely. They were either sunk or carried ashore. Sinking was 

 in many cases caused by direct damage from impact. Other boats capsized 

 when their moorings withheld them from rising with the water level. In 

 Crescent City, it has been reported that strong currents normal to the 

 long axis of boats, moored to anchor-buoys fore and aft, forced the 

 boats to keel so much that they would take in water and sink. There is 



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