HR: 1340h
AN: GC13B-1234    [Abstracts]
TI: Dissolved Reactive Phosphorus in Large Rivers of East Asia
AU: * Wu, L
EM: lingling@earth.northwestern.edu
AF: Department of Geological Sciences, Northwestern University, 1850 Campus Drive, Evanston, IL 60208 United States
AU: Huh, Y
EM: yhuh@snu.ac.kr
AF: Department of Geological Sciences, Northwestern University, 1850 Campus Drive, Evanston, IL 60208 United States
AU: Huh, Y
EM: yhuh@snu.ac.kr
AF: School of Earth and Environmental Sciences, Seoul National University, San 56-1, Sillim-dong, Gwanak-gu, Seoul, 151-747 Korea, Democratic People's Republic of
AB: We determined the dissolved reactive phosphorus (DRP) concentrations in the large pristine rivers of East Asia (370 samples) and investigated the effect of phosporites and igneous apatite deposits, temperature, precipitation, runoff, basin area and local relief on riverine DRP concentration. DRP concentrations are distinctly lower (median) than have been observed in North American and European rivers (mean). The locally high DRP coincide spatially with the high-grade phosphorite deposits in the drainage area and suggests that lithology plays a primary role in determining levels of riverine DRP. Factor analysis applied to major elements, Sr and phosphate yielded poor correlation, suggesting cautious employment of proxy such as dissolved silica flux to estimate the contribution of P release from rock weathering. Higher temperature and runoff correspond with higher DRP fluxes. In rivers where seasonal samples are available, DRP flux in summer is about 4 times that in winter. Evidence from statistics does show climate impact on weathering of P-bearing rocks and precipitation may play a more important role than water temperature in influencing the riverine phosphate concentration. Furthermore, no statistical significant correlation exists between basin size, local relief and DRP.
DE: 1615 Biogeochemical cycles, processes, and modeling (0412, 0414, 0793, 4805, 4912)
DE: 1807 Climate impacts
DE: 1886 Weathering (0790, 1625)
DE: 4845 Nutrients and nutrient cycling (0470, 1050)
SC: Global Climate Change [GC]
MN: Fall Meeting 2005