effect produced by the large shallow lagoon between the island and its 

 encircling reef. This record shows five large waves with crests separated 

 by about one hour and forty minutes as noted in Table III. The records 

 from Hilo, Honolulu, and Kahului all begin with wave crests 23 minutes 

 apart. At Kahului, this appears to be near to a natural resonance and 

 three large crests occurred before an incoming crest and cycle of a 

 natural mode of oscillation were out of phase and destructive inter- 

 ference occurred. The case for Hilo has already been discussed in 

 Section II-6 and will not be further referred to here except to note 

 that a greater interference effect at Hilo seems to account for the 

 greater amplification at Kahului than at Hilo. 



The tidal range in the Hawaiian Islands is normally less than 2 

 feet (cf. Figures 5Tb, 58b, 59b). The initial resonance at Hilo caused 

 by the tsunami occurred on fairly low tide. Had it occurred on the high 

 tide, maximum elevations would have been increased about 1.5 feet. 



134 



