380 
PACIFIC SCIENCE, Vol. XXII, July 1968 
No. 6 
0 200 400 600 800 I Km 200 400 600 800 2 Km 200 400 600 800 3 Km 
- ' i - i i i i i i i i 1 1 1 1 1 
^,3 Km 200 400 600 800 4 Km 200 400 600 800 5 Km 200 400 600 800 
bL 1 i i i i i n i i i i i i i 
Fig. 3b. Bathymetric profiles Nos. 6-10. See Figure 1 for locations. 
(3) A deep level extending from about the 
diving limitation of the "Asherah” (180 
meters) seaward. These marine terraces ob- 
served from the "Asherah” correspond fairly 
well with the submarine terraces recorded by 
Ruhe et al. (1964) in their careful analysis of 
the shorelines and submarine terraces of Oahu. 
It is known from work done by Stearns (1966) 
and by Ruhe et al. (1964) that a shoaler terrace 
also exists in the depth range of 5-18 meters, 
but this terrace was above the general working 
range of the "Asherah” during the present in- 
vestigation. 
It is not the purpose of this paper to attempt 
to refine on the depth limitations computed by 
Ruhe for each of the submarine terraces around 
Oahu. Interested readers should refer to his 
work cited above or to several of H. T. Stearns’ 
works on the same subject. However, it is our 
purpose to describe certain features of these \ 
terraces that lay beyond the ability of these j 
earlier workers because of the previous lack of j 
means for direct visual observation. 
The most striking feature of the submarine 
geomorphology off northwestern Oahu as ob- 
served by the "Asherah” was the escarpment I 
between the lower and intermediate terrace 
levels (here equated to the Lualualei and 
Mamala shelves, 247-932 meters and 75-124 ! 
meters, respectively, of Ruhe et al., 1964). j 
After viewing firsthand this major escarpment 
and the submarine terraces it separates, it seems 
no wonder that the depth determinations for j 
the various shelves around Oahu have such a 
wide range: the near vertical nature of this j 
escarpment prevents accurate determinations of 
its features by echo sounding, it is cut in many ! 
places by wide sand channels that grade gently 
J 
