| Comments |
P.492 3rd paragraph: "Is the Marine Silica Cycle at Steady State? Because of the large uncertainty in the estimates of input and output fluxes (Table 5), it is difficult to say whether the current silica cycle is balanced, although an increase in continental weathering
due to agricultural expansion and recent changes seen in rivers and the coastal ocean related to damming and eutrophication (Ittekkot et al. 2000, Laruelle et al. 2009) (see above) imply that the cycle is currently perturbed and has been for centuries. [Investigators] take a moment to ponder the strength of the coupling between silicon inputs and outputs, assuming that, in the modern ocean, output fluxes are determined largely by rates of silica production." 1Tmol=1 teramole = 10^12 moles |