The maximiim tsunami runup at Zaikof Bay, Montague Island, was about 

 33 feet above postquake MLLW. 



At a place, for the time being unknown, on Montague Island, 5 waves 

 at about 5 minute intervals were observed travelling parallel to the 

 shore; the first one, with a height of 12 feet, arrived at about 6:05 

 p.m. (Van Dorn, 1966). 



2. Tsunami Waves in Port Valdez , Prince William Sound 



The disaster that befell Seward had something of a parallel at 

 Valdez, situated in Prince William Sound, at the head of a long fjord 

 comprising the Valdez Arm and the Port of Valdez (Figure l6o). The 

 similarity of earthquake and tsunami effects is rendered the more in- 

 teresting because of a similarity of location of the towns with respect 

 to bays of very similar shape and size. In fact, the schematic repre- 

 sentation of a coupled system of basins shown in Figure 133b, applies 

 in the same sense to the Valdez fjord, which is seen to comprise two 

 basins connected by a constricted channel of shallower water (Figure 

 l60). Even the dimensions are quite similar. What is different in the 

 relative situations of Valdez and Seward, is that Valdez Bay opens on 

 Prince William Sound, a virtually closed basin, whereas. Resurrection 

 Bay opens on the sea. Valdez, much closer to the epicenter of the 

 earthquake than Seward, is located close to the hinge line of zero 

 vertical earth motion (Figure l60, inset). 



We investigate the oscillating properties of Valdez Arm and Port 

 Valdez as the chain-basin system represented schematically by Figure 

 133b. In this case basins I, II, and III have the approximate dimensions 

 given in Table VIII. By the impedance principle of Rayleigh as employed 

 by Neumann (19^8), we find the eigenperiods Tn (n=l,2,3 ,i+. . . ) for the 

 first four modes of free oscillation of the system to be 



T„ = 39; l8; 11; 7; minutes (i+8) 



TABLE VIII 



Dimensions of Interconnecting Rectangular Basins 

 Simulating Valdez Arm and Port Valdez 





Length 



Breadth 



Depth 



Basin 



L(n. mi. ) 



b 



(n. mi . ) 



d (ft) 



I 



11.35 





2.01 



TOO 



II 



2.00 





0.t6 



6oo 



III 



10.52 





2.66 



1100 



254 



