I. INTRODUCTION 



A. Pxirpoae 



The primary objective of the U, S. Navy Antarctic Cruise 19^k-19^S 

 was a reconnaissance survey of the general regions of the Ross and 

 Weddell Seas to select sites for future bases for the International 

 Geophysical Year program. As secondary projects carrying lower 

 priority, investigations were carried out in such fields as distri- 

 bution and intensity of cosmic rays, radio reception, meteorology, 

 snow compaction for airstrips, and oceanography, Oceanographic 

 investigations were carried out on a not-to-interfere basis on the 

 trip to the Antarctic and on the return voyage. In the area of 

 operations, oceanographic observations were undertaken whenever it 

 was possible to stop the ship for periods of two hours or more. 

 Bottom sediment cor-es were obtained when it was possible to stop 

 the ship for half -hour periods, ice conditions permitting. 



The first U, S. Navy icebreaker venture into the Antarctic was 

 in 19lj.6-19[t7 in connection with Operation HIGHJUMP. On the expedi- 

 tion the icebreakers USS BURTON ISLAND (AGB-l) and the USCGC NORTH- 

 WIND (WAGB-282) took bathythermograph observations and, along with 

 other vessels of Operation HIGHJUMP, occupied a few scattered oceano- 

 graphic stations in the area extending from the Ross Sea westward to 

 the Hunger Lakes area. The following year the U. S. Navy icebreakers 

 USS BURTON ISLAND (AGB-l) and USS EDISTO (AGB-2) made a survey from 

 the Bunger Lakes area to Marguerite Bay in the Palmer Peninsula, 

 Some oceanographic work was accomplished, consisting mainly of 

 bathythennograph casts. The Navy icebreaker USS ATKA (AGB-3) was 

 the first United States vessel to enter the Antarctic regions since 

 19^8. 



B. Summary of Oceanographic Operations 



The USS ATKA (AGB-3) left Boston on 1 December 19$h enroute to 

 New Zealand and the Antarctic (fig. l). The ATKA returned to Boston 

 on 12 April 1955 after steaming over 28,000 miles during a period of 

 almost four and a half months. 



Bathythermogrsfih casts were made every h hours from Boston to 

 Panama. Upon leaving Panama, bathythermograph casts were increased 

 (on 12 December) to one cast hourly, a schedule that was maintained 

 throughout the cruise except when the ship was in shoal water or in 

 ice, BT casts were made at U-hotirly Intervals when conditions per- 

 mitted while in ice. Hourly BT casts were resumed when open water 

 was reached on the return trip north from Antarctica and were con- 

 tinued as far north as 20° N. During the remainder of the trip casts 

 were made every 1* hours until near Boston, Near the Antarctic 



