two points on the shoreline at the foot and head of where the Army dock 

 used to be. In Figure 13^, offshore contours indicate the existence here 

 of a submarine spur which by refraction would concentrate wave energy 

 toward its center and the locations mentioned. The two points of land 

 also had the same effect on the wave uprush and this is markedly seen 

 in the manner in which the train of railroad cars was festooned about 

 these shoreline cusps in Figure 1^46, (see also Figure 1U5). 



Generally speaking, the description we have given of wave effects 

 at Seward is in accord with that given by Lemke (1967), though there are 

 differences in detail. The reader is referred to Lemke for an excellent 

 general description of the calamity that beset Seward. 



7. Tsunami Damage at Seward, Alaska 



Seward suffered its greatest damage from the subsidence and 

 disappearance of its entire waterfront facilities (Figures 1U5 and 1U6). 

 This appears to have been a progressive action of the earthquake which 

 could have been assisted by the drawdown of the water table resulting 

 from the initial slide and the subsequent alternate wave loading and 

 suction effect. Shannon and Wilson (196U) point out that in the fan 

 delta prior to the quake, considerable artesian pressures existed and 

 fluctuated with the tide. These pressures would have been generally 

 increased by the regional subsidence of about 5 to 6 feet that affected 

 the entire area during the earthquake. Stability analyses of the soils 

 by Shannon and Wilson (l964) confirmed that reasonable safety against 

 failure for the slopes of the fan delta existed under static conditions 

 but disappeared under accelerations of the order of 0.15 g. Also, the 

 vibration of the earthquake, with a large number of stress reversals, 

 could have reduced cohesion of the soils and promoted liquefaction. The 

 possibility cannot be overlooked that an impulsive shear along a fault 

 plane in the northern part of Resurrection Bay set up a roil of water 

 violent enough to have scoured the toe of the slopes of the fan delta, 

 thus promoting slide failure. We shall not further discuss waterfront 

 damage other than obvious damage that resulted from the seismic sea 

 waves . 



In the switchyard of the Alaska Railroad, yard crews had just 

 finished coupling a freight train when the earthquake started. This 

 train, comprising boxcars, flat cars, gondolas, refrigerator cars, and 

 tank cars, was due to leave for Anchorage early in the evening. As 

 shown in Figures 1U5 and 1U6, the train was swept almost like a con- 

 tinuous string, and festooned around the engine house by the seismic 

 sea waves. It is not certain whether this was a progressive action of 

 the entire sequence of waves or whether it was accomplished by one most 

 powerful wave, probably at 10:00 p.m. (Figure 137). The big-wave con- 

 cept seems likely, because the earlier waves probably lacked enough 

 sustained force to accomplish such total wreckage (see Figures ih'J to 

 151). Evidence exists, nevertheless, that the first and second wave 

 accomplished at least some of this destruction (Lantz and Kirkpatrick, 

 196i+; Chance, I968). 



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