2. Material Transfers and Transformations at the Land/Sea Boundary. Research 

 at this interface is focused on displacement of heterogeneous equilibria and on chemical fluxes in 

 the upper sediment and porous crust. Major scientific breal^throughs have occurred in this area 

 in recent years as a result of joint efforts with Biological Oceanography and Marine Geology and 

 Geophysics. An example is the discovery of and follow-on work concerning hydrothermal vents. 



Activity has increased in the recent past, and with new vents being found (e.g., hydrothermal 

 methane plumes in the North Fiji Basin in February 1986), this trend is likely to continue. 

 Moveover, bottom landers and other similar instrument packages will provide a technology 

 whereby heretofore impossible studies on chemical processes and mechanisms at the ocean 

 bottom boundary will begin. Core resources required for studies in this component will 

 increase somewhat in the immediate future, including associated ship and submersible time and 

 construction of samplers and analytical instrumentation for deployment from ships or from 

 Alvin. 



3. Fluxes of Material to, Transport Through, and Alteration in Ocean Basins. This 

 component is aimed at understanding and measuring fluxes in ocean basins, including sources and 

 input from the troposphere to the ocean surface, lateral injection of material from the coastal 

 boundary, and transport through the water column to underlying sediment. The state of the art 

 for following particles through the atmosphere to the ocean surface and for quantifying fluxes of 

 particulate material by collection and analysis of material in sediment traps has increased 

 notably over the past several years. 



Major programs have contributed to this understanding during the last decade (e.g., Sea-Air 

 Exchange Program, Vertical Exchange Program, and ADIOS). Several other National Science 

 Foundation Programs also have contributed to support of this research, either through joint 

 support of individual awards or of major thrusts in atmospheric, biological, geological, and 

 physical sciences. 



Progress has been significant, but for the most part it has remained within specific disciplinary 

 areas. The coupling of rates and characteristics of material passing between the troposphere and 

 the ocean must now be considered. Some material falling through the ocean depends upon how 

 particles are packaged by marine organisms and the stability of these biogenic containers as they 

 pass through domains of varying temperature, oxygen content, and acidity. Metals capable of 

 being adsorbed on particles, for example, can be scavenged from and then released to the water 

 several times during their descent. 



These same particles could have originated from desert regions and been carried aerially 

 through tortuous paths in the lower atmosphere before beginning their equilibration with 

 seawater. Investigators are now relating rates of input to the surface with fluxes carrying 

 material to the bottom. Clearly, significant complementary biological and physical 

 oceanographic information is required to understand the entire process fully. 



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