Submarine Topography South of Hawaii 1 
K. O. Emery 2 
Geomorphic and structural evidence 
strongly suggests that the center of volcanism 
in the Hawaiian Islands has migrated slowly 
from northwest to southeast. This movement 
is reflected in a progression from the eroded 
and reef-covered volcanic platform of Mid- 
way Island to the periodically active volcanoes 
of Kilauea and Mauna Loa on the island of 
Hawaii. From the general age relationships 
of the islands it might be supposed that a 
still younger center of volcanism may now be 
building one or more new cones on the sea 
floor southeast of Hawaii, eventually to form 
new islands at that end of the chain. 
Soundings shown on charts of the area 
south and southeast of Hawaii prior to 1954 
were taken mostly by various ships that hap- 
pened to be passing through the area. They 
are too sparse and poorly positioned to reveal 
many details of the topography; however, 
several single isolated soundings on U. S. 
Coast and Geodetic Survey Chart No. 4179 
suggested the presence of as many separate 
submarine mountains. At the request of the 
Office of Naval Research the Commander 
Service Forces Pacific made available a ship 
for a brief bathymetric survey of these areas. 
This ship was U.S.S. Patapsco, AOG 1, a 
16,000 barrel 10-knot oil tanker that carried 
a NMC-2 echo-sounder. The great stability 
of the ship permitted routine sounding opera- 
tions to be carried on in spite of the fact that 
most of the sounding traverses paralleled the 
1 Allan Hancock Foundation contribution No. 156. 
University of Hawaii Marine Laboratory contribution 
No. 72. Manuscript received January 12, 1955. 
2 Department of Geology, University of Southern 
California. 
trough of waves produced by winds of up to 
Force 6. 
Appreciation is due Ft. J. W. Downing, 
commanding officer, and Ft. j.g. C. J. Kelly, 
navigator, for their cooperation and interest 
in the work. The Hawaiian names for the five 
seamounts were kindly supplied by Mrs. 
Mary K. Pukui and Mrs. Martha Hohu of 
the Bernice P. Bishop Museum in Honolulu 
and by Dr. Gordon A. Macdonald, director 
of Hawaiian volcano observatory. Dr. Mac- 
donald kindly read the manuscript, suggest- 
ing several improvements. The study was 
made possible by funds provided by Office 
of Naval Research contract Nonr 228 (06). 
METHOD 
Between 0100 June 29 and 1000 July 2, 
1954 about 800 miles of sounding traverses 
were run in the area of Figure 1. Soundings 
were read visually at one-minute intervals by 
crew-members but only alternate soundings 
were plotted on the base chart for Figure 1. 
Index error and motor speed error were con- 
stant within the accuracy of their measure- 
ment. Accurate positions were obtained with- 
in 4 miles of shore by visual pelorus bearings. 
Radar fixes to 15 miles from shore proved less 
reliable. Only star fixes could be used farther 
off-shore because the area is one of base line 
extension for Foran. Accordingly, the survey 
was set up in such a way that sounding in the 
nearshore areas was done during the daytime, 
and the long radial traverses were started from 
a land fix at dusk and ended with a landfall 
after dawn. Errors in the dead-reckoning posi- 
tions at the ends of traverses were pro-rated 
over the entire traverses, taking into account 
286 
