海洋の化学・地球化学における知識空白部

抄録

This article briefly reviews the recent advances in research on the concentration and distribution of the elements in the ocean. Since the last compilation of North Pacific vertical profiles of elements on a periodic table (Nozaki, EOS 78, 221,1997), new data have become available for Nb, Ta, and Os in the literature. Those are shown graphically, and the conservativeness of Os in seawter is examined. We have still lack of knowledge on the fluxes to and out of the ocean for many elements including the above. Chemical speciation and relative importance of complexation with organic ligands in seawater are very obscure as yet for many trace metals. Iron, which plays an important role in the oceanic biogeochemistry of plankton growth and carbon cycling, is not an exemption. Coupling of radionuclide tracers which can provide time-scales and the spatial variations of concentration reflected by the strength of sources and sinks with an isotopic "finger print" should help solve some of the issues generated on the dynamic aspects of elements in the ocean. A case study for Nd by Amakawa et al. (2000) is also briefly outlined.