determination was made. Salinities are considered correct to within plus or minus 
0.01%,. 
3. Dissolved Oxygen 
Dissolved oxygen determinations were by a modified Winkler method. Each 
sample was subjected to duplicate titrations against sodium thiosulfate. If the differ- 
ence in amount of sodium thiosulfate used exceeded 0.05 ml/I a third determination 
was made. Dissolved oxygen determinations are considered to be accurate to within 
plus or minus 0.03 ml/1. The only exception to this was on four of the Convergence 
stations; on stations 33 through 36, where oxygen values were within plus or minus 
0.05 ml/|. All oxygen analyses were completed within four hours after a sample was 
taken. 
4. Magnetic Total Intensity 
A nuclear resonance total intensity magnetometer, with the sensing unit 
towed 500 feet astern, was used to record total intensity. Data measurements were 
recorded once every two seconds of time on a strip-chart recorder. Total intensity 
data records were scaled and converted to values in gamma (1 gamma equals 10-9 
oersted). 
Measurements were made while hove-to at each oceanographic station by lower- 
ing the sensing unit to a depth of about 400 feet; data recording and processing were 
similar to the procedures for underway observations. 
D. Methods of Data Presentation 
1. Profiles and Cross Sections 
Selected north-south and west-east cross sections of observed characteristics 
are presented for all areas surveyed except the Convergence area, where only one 
line of stations was taken. These characteristics include temperature, salinity, 
dissolved oxygen, and computed values of sigma-t. 
Profiles of corrected regional magnetic gradient are shown along the ship's track. 
In addition, profiles of magnetic and bathymetric observations for crossings of the 
Pacific-Antarctic Ridge are presented. 
2. Dynamic Topographies 
Charts of dynamic topographies were prepared from temperature and salinity 
station data for the Cape Colbeck and Amundsen Sea areas. These charts depict 
