23 
In Hawaii, it was recorded on the instrument 
of the U. S. Coast and Geodetic Survey lo¬ 
cated on the campus of the University of 
Hawaii in Honolulu, and on those of the 
Hawaiian Volcano Observatory at Kilauea 
on Hawaii. The epicenter of the earthquake 
has been located by the Coast and Geodetic 
Survey at latitude 53.5° N. and longitude 
163° W., and the time established as l h 
59 m a.m. Hawaiian time (12 h 29 m Greenwich 
time) (Bodle, 1946: 464). It may be as¬ 
sumed that the tsunami originated at the 
same place and time as the earthquake. The 
place of origin was thus 2,241 miles N. 8.5° 
W. of Honolulu, and 2,375 miles N. 12° W. 
of Hilo (Fig. 1). 
Fig. 1 . Map of the Pacific basin, showing the position of the Hawaiian Islands, the place of origin 
of the tsunami of April 1, 1946, and the distribution of seismically active belts around the Pacific in 
which tsunamis are likely to originate. 
Tsunami of April 1, 1946 — Macdonald et al. 
near the coast of South America and one in 
the Aleutian area, and one was of local 
origin. One tsunami of moderate intensity 
came from near Kamchatka, and another 
probably from South America. 
GENERAL FEATURES OF THE APRIL, 1946, 
TSUNAMI: ORIGIN AND NATURE 
OF THE WAVES 
The tsunami of April 1, 1946, was caused 
by a movement of the sea bottom on the 
northern slope of the Aleutian Deep, south 
of Unimak Island. The same crustal move¬ 
ment gave rise to a violent earthquake, re¬ 
corded on seismographs all over the world. 
