| Comments |
P.490 5th paragraph: "This estimate is conservative for at least three reasons. First, the full extent of the opal belt may extend northward well beyond the limits of Lisitzin’s opal belt (Geibert et al. 2005), which would increase the size of the estimates. Second, the contribution of the seasonal ice zone is incomplete (because there are no 230Th-normalized data available from the Indian sector). Third, opal burial in the coastal and continental zone has not been included, as uncorrected 230Th data are available only for the Ross Sea (0.04 Tmol/m^2/year, primary source), an exceptional region. The resulting revised estimate for silica burial in the world ocean (Table 4) is FB = 6.3 ±
3.6 Tmol Si/year (Figure 1). This is nearly identical to DeMaster’s (primary source) estimate of 6.35 ± 1.05 Tmol Si/year." See note beneath table. 1Tmol=1 teramole = 10^12 moles |