SURVEYING THE OCEANS (HYDROGRAPHIC) 



37 



earth's crust. Also, because of the experience gained in 

 developing this airborne capability, Navy geophysicists have 

 helped improve techniques for magnetic detection of submarines 

 and have assisted in resolving magnetic anomaly problems of the 

 Strategic Air Command. 



To supplement Project MAGNET's collection of magnetic data, 

 nearly all Navy deep-water survey ships tow magnetometers, 

 allowing a direct comparison of magnetic data with the bathy- 

 metric and gravity measurements taken simultaneously. These 

 efforts have not only added considerably to the amount of data 

 describing the sea's magnetic field, but have also proved valuable 

 in developing techniques for locating submarines and sunken ships, 

 as demonstrated in finding the remains of the THRESHER. 

 Recent experiments aboard the ALUMINAUT indicate the 

 feasibility of similar operations close to the sea floor, using under- 

 water vehicles. 



READING CIRCUIT AMPLIFIER 



ZERO SERVO AMPLIFIER , CORRECTION SERVO AMPUBER 

 ACCELEROMETER AMPLIFIER 



CONTROL BOX 



POWER SUPPLY 



GRAVITY METER 



Shipboard equipment used in measuring the force of gravity. 



