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 (249Kb)
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52,373,000 Yen
Carbon in the settling particle conveys the net flux of carbon from the surface ocean to the deep. The settling process is the necessary knowledge to understand the global carbon cycles . In this program, sediment trap experiment to measure the net carbon flux in the pelagic ocean and the deep trench was planned. The degradation process of the settling particle in the deep sea, lateral transport of particulate having terrestrial origin were studied from chemical analysis. Samples collected by sediment traps moored in Japan Trench, where the bottom depth was 9200m, were analyzed to asses the lateral flux of particulate matter from coastal area to the pelagic ocean through continental shelf. Adsorption of clay particle of terrestrial origin to larger biogenic particle and also scavenging of dissolved Mn and Cu with settling particle were observed. An in situ dissolution experiment of calcareous tests was done using the sediment trap mooring. The dissolution of calcitic tests increased with depth, which is consistent with the thermodynamic stability. However, the dissolution in the deep ocean was extremely slow compared with the results of laboratory experiment. To asses the lateral flux of organic carbon from coastal area to pelagic ocean through continental shelf, techniques for the estimation of the ages of the organic carbon in the trapped materials were developed. From 14C measurement of surface sediment, suspended particle and settling particle, the transportation model of organic matter from continental shelf to the pelagic ocean, which consist of degradation of organic matter and scavenging of suspended particulate, was described.
ocean, sediment trap experiment, ocean particulate, organic carbon, flux