THE TSUNAMI OF APRIL 1, 1946, IN THE HAWAIIAN 



ISLANDS^ 



By G. A. Macdonald 



TJ. 8. Geological Survey 



F. P. Shepaed 



Scripps Institution of Oceanography 



and 



D. C. Cos 



Haicaiian Sugar Planters' Association Experiment Station 



[With 6 plates] 

 INTRODUCTION 



The tsunami which struck the shores of the Hawaiian Islands on 

 the morning of April 1, 1946, was the most destructive, and one of 

 the most violent, in the history of the Islands. More than 150 persons 

 were killed, principally by drowning, and at least 161 others were in- 

 jured. Property damage reached about $25,000,000. 



The wave attack on Hawaiian shores was far from uniform. The 

 height and violence of the waves at adjacent points varied greatly, 

 and not always in the manner which would have been expected from 

 superficial inspection and a study of the existing literature on tsunamis. 

 Therefore, a detailed study of the effects of the tsunami has been 

 made, in an effort to understand the observed variations, and in the 

 hope that the principles established may help lessen the loss of life 

 and property in future tsunamis. Space is not available in the pres- 

 ent short paper to discuss findings in detail, or even to present all the 

 evidence for all the conclusions. These matters will be treated in 

 detail in a longer paper (Shepard, Cox, and Macdonald, in prepara- 

 tion). 



Acknowledgments. — We wish to thank the many persons who fur- 

 nished information during the course of the field study. We are also 

 especially grateful to M. H. Carson, H. S. Leak, H. W. Beardin, and 

 W. K. Sproat, who supplied measurements of the highwater level in 

 areas not visited by us ; H. W. Iversen and J. D. Isaacs, who supplied 

 additional measurements on Oahu ; A. F. Robinson and Dexter Fraser, 



1 Reprinted by permission from Pacific Science, vol. 1, No. 1, January 1947. 



257 



