Studies of Coastal Processing Using Radioactive Tracers 



Noshkin, V.E., Jr. 



$50,000 



Lawrence Livermore National Laboratory 



Environmental Sciences Division 



C: 415-422-0931; F: 532-0931 * 



This work is part of the coordinated DOE California Basins Study (CaBS) research program. We will use manmade 

 and naturally occurring radioactive tracers to assess circulation routes of dissolved and particulate materials in the 

 water column and to assess rates and processes depositing (and possibly remobilizing) materials to bottom sedi- 

 ments, and redistributing them within sediments of basins in the Southern California Bight. We will collect water, 



2^ zV) 240 241 90 



particles, and sediment samples to measure concentrations of fallout-delivered Pu, Pu, Pu, Am, Sr, 

 Cs, and natural 210 Pb, thereby determining the supply routes and fluxes of these tracers to the basins and con- 

 tinental slope area. We will investigate: (1) the role of upwelling as a mechanism that transports oceanic tracers in 

 coastal zones; (2) particle-scavenging reactions involved in the transport of these tracers, to determine whether they 

 are element-specific, biological, or abiotic in nature; (3) the effects of upwelling and advective transport on altering 

 the vertical distribution of manmade tracers in the water column; (4) sedimentation rates of particles to different 

 offshore regions; (5) fluxes of specific tracers to the bottom sediments; and (6) redistribution processes in the sedi- 

 ment columns (physical and biological mixing, and pore -water diffusion). These studies will help establish a base of 

 knowledge necessary to evaluate the present and future energy development impacts on Pacific coastal regions. 



Program of Mineralization and Cycling in Marine Systems 



Venketesan, I.; Kaplan, I.R. 



$152,000 



University of California 



Institute of Geophysics and Planetary Physics 



C: 213-825-1805 



Changes in various organic substances that settle to the sea floor are examined. Activities include: (1) evaluating the 

 relative flux of marine photosynthetic carbon to the sea floor versus the importance of terrigenous plant material; 

 (2) determining the rate of decomposition of sedimenting organic matter in the water column; (3) examining the or- 

 ganic matter covering the sediment surface, because this area contains actively metabolizing bacterial forms; and 

 (4) measuring biogenically active organic substances, such as amino acids, sugars, and low molecular weight acids, 

 in pore water and sediments. In conjunction with estimates of inorganic components, controls and rates of organic 

 decomposition in sediments can be estimated 



*"C" indicates the commercial telephone numbers, while "F refers to the numbers for the Federal Telephone Sys- 

 tem (FTS). 



Coastal Ocean Margins Program A19 December 1988 



