RECENT OCEANOGRAPHIC EXPLORATION IN THE NORTH 

 AND EQUATORIAL PACIFIC OCEAN 



By Warren S. Wooster 



Scripps InstiUition of Oceanography 

 La Jolla, California, U.S.A. 



The exploration of the Pacific Ocean may be divided into three 

 major phases. The first phase, that of geographical discovery, was ini- 

 tiated by Magellan and reached its climax in the voyages of James Cook. 

 Early in the nineteenth century the general outline of the shores and 

 the locations of most island groups of the Pacific had been fairly well 

 established. Yet the early explorers were not oceanographers, and in 

 their travels they discovered little about the sea. 



The second phase of Pacific exploration and the science of deep-sea 

 oceanography were both opened by the cruise of HMS CHALLENGER 

 in 1873 to 1876. For the first time a major expedition was devoted to 

 a study of the ocean itself, the physics and chemistry of its waters, the 

 character of its bottom and the nature of its denizens. Expeditions in 

 the great tradition of the CHALLENGER have continued up to the pre- 

 sent day, notable among them being the cruises of the DANA and the 

 CARNEGIE in 1929 and the recent voyages of the ALBATROSS and the 

 GALATHEA, Such studies lead to a general description of the major 

 characteristics of the Pacific Ocean from the physical, chemical, biolo- 

 gical and geological points of view. 



The third phase of exploration can be described as the detailed 

 study of the spatial and temporal changes in conservative and non-con- 

 servative concentrations. The ocean is considered as a dynamic system, 

 and the goal of this phase is the description and understanding of the 

 processes bringing about changes in this system. Much work of this 

 sort has been done already by scientists on both sides of the Pacific, 

 using the classical tools of oceanography. The successful prosecution 

 of this phase, however, requires eventually the development and appli- 

 cation of new tools (such as the bathythermograph, geomagnetic electro- 

 kinetograph or high-speed plankton samplers) which can be used from 

 a moving ship. 



Although the five post-war expeditions of the Scripps Institution 

 of Oceanography have made use of such new tools, their results belong 

 properly to the second phase of exploration. The two expeditions in 

 which the author did not participate differed in purpose from the others 



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