Figure 5. Graphs showing model results for Site 995 data. A. Sulfate concentrations (Paull, Matsumoto, Wallace, et al., 1996) and methane concentrations (Hoehler et al., Chap. 8, this volume) measured at Site 995. A cubic spline function was used to fit the methane concentration profile. Inflections in the methane concentration trend are highlighted with arrows. The dashed line associated with sulfate concentrations is not a linear regression fit to the data like that in Figure 2B, but was calculated by the numerical model by increasing methane oxidation rates seen in Figure 2B by approximately three times. B. Zones for methane production (P) and consumption (C) predicted by the model, and calculated methane reaction rates (R) are in units of mM yr^-1 (or mmol cm^-3 yr^-1). ¹³C values of the dissolved CO₂ (CO₂) pool are plotted for comparison.