details, whenever different interpretations have been applied to parts 

 of the data that seem ambiguous. We have studied these interpretations 

 rather carefully, and evolved our own record of Barney's data in Figure 

 38, indicative of the postquake fluctuations of sea level in Womens Bay. 



Figure 38 is based on the premise that mean lower low water (MLLW) 

 at Kodiak, as a tide level, referenced to mean sea level (MSL), has re- 

 mained unaffected by the earthquake. The only way in which MLLW could 

 be affected would be through a complete change of tidal range in the area, 

 which by all accounts has not occurred. Since astronomical tide level is 

 presijmed unaffected at the time of the earthquake, the record must show 

 the essential continuity of the tide in regard to mean water level at any 

 time. Barney's readings were referenced to a tide staff zero, which from 

 later observation (Bryant, April 6, I96U) is related to sea level as 

 indicated in Figure 38a. 



Barney's data make no reference to any initial recession of the sea 

 from Womens Bay, yet at the time of the earthquake (5=36 p.m. AST, March 

 27) the land level is known to have dropped by 5-5 feet (Bryant, I96U). 

 Barney first noted the water rising rapidly at 6:20 p.m. AST, about ^0 

 minutes after the cessation of the main shock, but since no relative 

 land-sea change had drawn his attention, sea level must have dropped with 

 the land through an approximately equal amount. Accordingly, Figure 38a 

 shows the sudden drop of sea level through 5.5 feet followed by a small 

 hypothetical recession, relative to land, of about 1.5 feet, before the 

 observed rapid rise at 6:20 p.m. AST. 



Figure 38a has question-mark indicators wherever the water level 

 was not definitely established. However, one criterion binding on all 

 the data is that mean sea level at any time must lie at (or close to) 

 the level of predicted tide. By a subjective anal^ysis, we have found it 

 possible to break down the complicated record of Figure 38a into separate 

 components considered to be: Figure 38b, the astronomical tide. Figure 

 38c, the main tsunami, and Figure 38d, the local oscillations. A modu- 

 lated wave system evolves in Figure 38c with the fantastic wave period 

 of about 2.5 hours, upon which is superimposed another beat-system of 

 waves with a period of about 1.3 hours (Figure 38d). 



The first wave system may be shown to correspond to the tsunami 

 envisioned in Figure 3Ta, which applies to the area under consideration. 

 From Figure 37a the half-length (X/2) of the water wave measures approxi- 

 mately 60 nautical miles and the average water depth d about 260 feet. 

 Using the Lagrangian equation for wave velocity 



c = /gd (1+) 



where g is the acceleration due to gravity, the period of the tsunami is 

 found to be 



T = A/c = 2.22 hours (5) 



which is in approximate agreement with Figure 38c. 



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