Hajime Obata, Dia Sotto Alibo, Yoshiyuki Nozaki
Dissolved aluminum, indium, and cerium were measured in seawater from the Sea of Japan and the Sea of Okhotsk. Surface maxima of Al in the eastern Japan Basin indicate a signature of atmospheric mineral dust deposition resembling that of In. Data from all stations in this study show that Ce was markedly high in well-oxygenated bottom waters. The Ce:A1 ratios of settling particles and surface sediments implicate the benthic flux of Ce as its cause. The In:A1 ratios found in this study are not as high as those of the South China Sea and Sulu Sea, suggesting the minor influence of atmospheric deposition on the In:A1 ratios in seawater. Fractionation between In and A1 during scavenging processes, in addition to input from the bottom sediment, might contribute to the In enrichment of seawater. Apparent differences between In and Ce distributions in the marginal seas show that the benthic supply mechanism of In is not merely a simple redox-related process. Copyright 2007 by the American Geophysical Union.
Marine Inorganic Chemistry Group, Ocean Research Institute, University of Tokyo, Nakano-ku, Tokyo 164-8639, 1-15-1 Minami-dai, Japan; Department of Chemistry, University of San Carlos, Cebu City 6000, Philippines
