Marine Science Affairs 



scope never before possible. Scientists in submersibles and aqualungs can 

 make direct observations in surface layers as well as deep within the oceans. 

 Improved geophysical tools such as seismic profilers, magnetometers, and 

 gravimeters enable us to "see" geological features in greater detail and at 

 greater distances below the bottom. Continuous recording devices make 

 possible the automatic determination of many ocean parameters. Improved 

 satellites, ships, aircraft, buoys, navigation systems, computers, and other 

 devices have greatly increased our ability to collect and analyze data from 

 the oceans. 



Recent Scientific Advances ^ 



Recent technological advances have enabled us to obtain a new under- 

 standing of fundamental marine geological and geophysical phenomena. 

 A striking achievement was the discovery of a ridge-rift system throughout all 

 ocean basins, with its associated magnetic reversals and high heat flow. From 

 this discovery has evolved the important new concept of sea floor spreading, 

 which provides an important key for finally solving the problem of the origin 

 and development of ocean basins and continents as well as for unraveling 

 the earth's structural history and continued evolution on a global scale. Also, 

 the recently developed capability to drill through the complete sedimentary 

 column wherever it is relatively thin into underlying basement rock in the 

 deep ocean basins adds a new and important dimension to our understanding 

 of the geology and resource potential of ocean basins. 



In physical oceanography, investigations of fluid dynamics in rotating 

 frames are providing a basis for eventual development of numerical models 

 of oceanic circulation. Also, an array of new devices — expendable bathy- 

 thermographs, salinity-temperature-depth recorders, and thermistor chains — 

 is being used to obtain rapid and more detailed observations of the physical 

 characteristics of the ocean. We can forecast temperatures in the oceans; 

 we have discovered strong subsurface currents; we are able to observe tides 

 in the deep ocean ; we have increased our understanding of the overall energy 

 budget of surface gravity waves in the ocean; and we have made many 

 advances in our understanding of the physical processes that govern water 

 contamination in estuaries and coastal regions. 



In biological oceanography, a major achievement has been the develop- 

 ment of a mathematical model, still undergoing refinement, which pre- 

 dicts phytoplankton, zoopl^nkton, and nutrient salt concentrations in the 



^ Prepared with assistance of the Committee on Oceanography of the National 

 Academy of Sciences. 



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