Preliminary Report 
EAC #32 
2-11 December 1967 
EGS #18 
3 - 10 December 1967 
Support Ship: USS Tioga County (LST 1158 ) 
Cruise Itinerary: 2 December ( 0800 ) - depart San Diego 
3 December ( 1135 ) - Enter Grid at Pt. Ash 
10 December ( 0910 ) - depart Grid at Pt. Ash 
11 December ( 0900 ) - Arrive San Diego. 
Personnel: R. L. DeLong (BIC) 
T.J. Lewis 
R.L. Brownell 
Methods: 
Diurnal observations were held from the bow, the forward gun mounts, 
and the lee wings of the bridge as weather conditions dictated. No nocturnal 
observations were conducted. The skiff was used for 2 hours on 7 December; 
one storm petrel was collected. No bathythermograph casts were made due to 
lack of equipment. 
Cruise track & conditions: 
The cruise track (Figure l) was altered from the normal on two occasions 
due to heavy weather. The LST class ship is not a satisfactory observation 
platform in the survey area. The ship rolls severely while running in the 
trough; and pounds unceasingly while running into the sea. During this 
survey with prevailing seas from the west severe pounding was encountered on 
all westerly legs. As the ship pounded on a swell and entered a trough it 
"shuddered" with 60-90 vibrations per minute. The constant abnormal ship 
movement did not allow observers to use glasses for scanning, thus the numbers 
of birds observed were certainly fewer than normal. This bias may approach a 
25 percent reduction in observability from the normal conditions. 
Weather during the survey was affected by a number of various sized, fast 
moving fronts. Moderate to heavy seas prevailed through all but two days of 
of the survey. Sea temperatures (recorded as sea water injection tempera¬ 
tures in the engine room) varied only two degrees in the survey area. These 
readings (if accurate) indicate a very flat temperature field throughout the 
Grid, resulting from seasonal cooling at the surface and consequent over¬ 
turning and mixing in the upper layers. The coding and mixing may have been 
accelerated this month because of the several cold fronts passing through the 
area. The N.E. Pacific has been averaging 3 ~ 5 ° F. warmer than normal during 
this past summer and early fall. Rapid cooling would tend to bring tempera¬ 
tures back toward seasonal normal. 
