TSUNAMI OF APRIL 1, 1946 — MACDONALD, ET AL. 273 



upward like the spray from a geyser. The water dashed up on shore to 

 a height of only 3 feet except at the place of juncture, where it swept 

 over the top of a sandspit 5 feet above sea level. 



Progressively southward around the shores of Kauai, the average 

 height of the high-water marks gradually decreases, and along much 

 of the southern shore it is 6 to 12 feet above sea level. However, in a 

 zone 3 or 4 miles wide it ranges from 15 to 18 feet. This zone is almost 

 directly across the island from the direction of wave origin, and prob- 

 ably represents the area in which the waves refracted around opposite 

 sides of the island met and reinforced each other. 



DAMAGE BY THE TSUNAMI 



Damage by the tsunami can be divided into structural damage, 

 damage by erosion and deposition, and damage by flooding. The 

 total property damage has been estimated by the office of the Governor, 

 Territory of Hawaii, at about $25,000,000. Space permits only a brief 

 review of the types of damage. The numbers of dwellings destroyed 

 and damaged by the tsunami on the major islands are listed in table 2 

 on page 276. 



Structural damage includes damage to buildings, roads, railroads, 

 bridges, piers, breakwaters, fishpond walls, and ships. Frame build- 

 ings at low altitudes along Hawaiian shores suffered extensive damage. 

 Some were knocked over, by the force of the waves, by cutting away 

 of the sand on which they stood, or by destruction of the foundations. 

 Others were bodily washed away from their foundations. Some had 

 walls pushed in by the force of the water, and in a few residences the 

 water went on through the house and took out the opposite wall. As 

 with earthquakes, there was a tendency to reduce the few two-story 

 buildings to a single story, by destruction of the lower story. It is 

 noteworthy that houses which were well built and tied together in- 

 ternally could be moved for considerable distances without suffering 

 severe damage. Even more striking was the fact that houses elevated 

 on stilts a foot to several feet above the ground survived the waves much 

 more effectively than did those built directly on the ground. Appar- 

 ently the water was able to pass under such houses without greatly dis- 

 turbing them, unless it was deep enough actually to float the house off 

 the stilts. The few reinforced concrete structures in devastated areas 

 suffered little or no damage except that caused by flooding. 



The railroads along the northern coast of Oahu and in Hilo were 

 wrecked, partly through destruction of the roadbed, but largely because 

 the tracks were shifted off the roadbed, either inland or shoreward. 

 Locally rails were torn loose, but more generally the track was moved 

 en masse, a motion probably aided by the buoyancy of the ties. Coastal 

 highways also were partly destroyed, largely by undercutting as the 

 water returned seaward, but partly by the direct force of the waves. 



