An Areal Assessment of Subseafloor Carbon Cycling in Cold Seeps and Hydrate-Bearing Areas in the Northern South China Sea

Figure 3

Sources and sinks of methane and DIC in the shallow sediments. Positive values denote sources of methane or DIC and negative values denote sinks of methane or DIC. OSR: organoclastic sulfate reduction; AOM: anaerobic oxidation of methane; ME: methanogenesis; CP: carbonate precipitation; ES: external methane from the bubble dissolution within modeled sediment columns. ∆ represents difference between fluxes at the lower boundary and fluxes at the upper boundary. Percentages above or below each column represent the contributions of each biogeochemical reaction to the source/sink. denotes the differences between sources and sinks of methane and DIC. Biogeochemical rates (OSR, AOM, ME, and CP) in the three regions and northern SCS are adopted from Table 1. The ES-CH₄ was obtained by assuming a complete mass conservation of methane.