ABSTRACT 



Results of oceanographic operations during ttie U.S. Navy Antarctic Expedition 1954-1955 

 are presented. In the Ross Sea area water temperatures off Kainan Bay were markedly 

 different because of the relatively thin layer of fast ice as compared with the thick shelf ice at 

 Little America. Low salinities were found near the shelf ice at Little America while at Kainan 

 Bay low salinity water was pushing in from the north. 



In Bransfield Strait water mass characteristics observed in the eastern part of the strait 

 showed marked differences from those observed in the western portion of the strait. 



In the Weddell Sea observations near the shelf ice along the eastern edge of the sea dis- 

 closed warmer high salinity water from the Indian Ocean striking the Antarctic Coast. After 

 being cooled over the shallow continental shelf this water sinks along the continental slope 

 and flows out to the north as a deep, strong, cold-water current of high salinity. 



Shallow water sound channels found in the Ross Sea compare favorably with similar shallow 

 water sound channels found in the Bering Sea and eastern Arctic region. In Bransfield Strait 

 both depth of the axis and velocities found along the axis indicate a transition between con- 

 trasting water masses. In the Weddell Sea sound channels were not discernable. 



The Antarctic Convergence is depicted by horizontal plots of air temperature, and water 

 temperature, salinity, and density obtained from bucket samples. Vertical water temperature 

 sections constructed from bathythermograph observations across the convergence are pre- 

 sented. The zone of convergence was found farther north in the South Atlantic Ocean than in 

 the South Pacific Ocean. Also, greater mixing was apparent in the surface layer to the north 

 of the convergence on the Atlantic side. 



Analyses of bottom samples show marked differences on the Atlantic side of the Antarctic 

 Continent as compared to the Pacific side. Magnetic grains were most prevalent in the 

 Bellingshausen Sea and Bransfield Strait, but were not abundant in the Antarctic area. Radio- 

 activity appeared to be nonexistent, and organic carbon content was low. 



Occurrence and depth of the deep scattering layer were observed throughout the cruise. 

 Characteristics of the layer are compared with those observed by the USS HENDERSON in 

 1946-1947 and the French Ship COMMANDANT CHARCOT in 1948-1949. 



Observations of snow temperature, density, and hardness and of snow stratigraphy at 

 locations on the fast and shelf ice are presented and discussed. 



The names of the following geographic features are not 

 officially approved by the United States Board on 

 Geographic Names: Admiral Byrd Bay, Atka Bay, 

 Observer's Ice Tongue, and Penguin Bay. 



