III. DATA PROCESSING 



The magnetic data were converted from magnetometer counts 

 to absolute values of total magnetic intensity in gammas. These 

 values were then plotted on a 1:500,000 scale survey track chart. 

 A magnetic total intensity contour chart was constructed from 

 this plot using a contour interval of 50 gammas (Figure 3) . A 

 bathymetrlc contour chart (Figure 4) was also constructed on a 

 1:500,000 scale using a contour interval of 100 fathoms. Total 

 magnetic intensity and bathymetrlc charts were prepared in a 

 similar manner for each of the development areas. Because the 

 development-area magnetic charts were prepared Independently of 

 the large area chart, there are some differences in the contouring, 



No corrections to the magnetic data were made for temporal 

 variations of the magnetic field. Honolulu Magnetic Observatory 

 records show that the daily fluctuation rarely exceeded 25 gammas 

 during the survey period. No major magnetic disturbances were 

 noted. 



To more clearly identify the trends and character of the 

 magnetic anomalies, a Residual Magnetic Intensity Contour Chart 

 was constructed (Figure 5). This residual chart was prepared 

 by subtracting the regional magnetic Intensity values from the 

 observed total intensity values. 



