CO2, S, As flux

Previous studies demonstrated that the CO2 fluxes by hydrothermal solution and volcanic gas from midoceanic ridges play an important role in the global CO2 cycle and affect the CO2 concentration in the atmosphere (e.g., Javoy, 1988). However, submarine volcanism and hydrothermal activity occur not only at midoceanic ridges but also at island arc and back-arc basins as already noted. 

The CO2 concentrations of present-day hydrothermal solutions venting from back-arc basins and midoceanic ridges are summarized in Table 3.2. The data show that the CO2 concentrations of hydrothermal solution from back-arc basins and midoceanic 

The CO2 concentrations of hydrothermal solutions at Guaymas Basin vary widely and some data show high CO2 concentrations. These high CO2 concentrations and low of fluids (—10.5%o) are considered to be caused by the effect of decomposition and dissolution of organic matters and carbonates in the sediments overlying basalt (Simoneit et al., 1984). 

In order to estimate hydrothermal CO2 flux, fluxes of hydrothermal solution into the ocean have to be estimated. 

---