CHAPTER III 



Observations In Physical Oceanography 



Oceanographic Expeditions and Vessels 



The collection of oceanographic data is expensive because it has to be 

 made from vessels whose operation and maintenance are costly. Early 

 oceanographic work was therefore conducted on especially equipped 

 expeditions, most famous among which is the British Challenger Expedi- 

 tion of 1873-1876, the first world-wide deep-sea expedition. In the 

 decades follow^ing the voyage of the Challenger, numerous other expe- 

 ditions have visited most regions of the oceans, but, in the discussion of 

 the water masses and currents of the oceans, use will primarily be made 

 of data from the more recent ones (listed in table 5) because their data 

 are more accurate. It has become customary to refer to most of the 

 oceanographic expeditions and to their observations and results by the 

 name of the vessel. Thus, the terms Challenger or Atlantis cruises are 

 employed. Among recent expeditions only the John Murray Expedition 

 to the Indian Ocean is generally referred to by its name and not by the 

 name of the vessel, the Mabahis. 



In more recent years, deep-sea oceanographic work has also been con- 

 ducted by government organizations in different countries (hydrographic 

 offices and bureaus of fisheries) and by institutions for oceanographic 

 research. In the United States such work has been carried out by the 

 Hydrographic Office of the U. S. Navy (U.S.S. Bushnell, Hannibal, 

 Louisville, and others), the U. S. Coast Guard (Marion and others), the 

 U. S. Coast and Geodetic Survey (Explorer, Oceanographer, and others), 

 and by the Bingham Oceanographic Laboratories, Yale University, the 

 Oceanographic Laboratories of the University of Washington (Catalyst), 

 the Scripps Institution of Oceanography, University of California (E. W. 

 Scripps), and the Woods Hole Oceanographic Institution (Atlantis). 



The present technique of making deep-sea observations and the 

 precision instruments used were developed around 1900, when the Inter- 

 national Council for the Exploration of the Sea was organized, with 

 headquarters in Copenhagen. At that time intensive exploration of 

 the waters adjacent to northwestern Europe commenced because of the 

 important fisheries there. Subsequently, a number of oceanographic 



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