Methane Source and Turnover in the Shallow Sediments to the West of Haima Cold Seeps on the Northwestern Slope of the South China Sea

Table 4

Depth-integrated simulated turnover rates and benthic methane fluxes based on the steady-state modeling.

	CL30	CL44	CL47	Unit
: total POC mineralization rate	18.8	55.2	58.1	mmol m^−2 yr^−1 of C
: sulfate reduction via POC degradation	7.6	23.9	25.1	mmol m^−2 yr^−1 of SO4^2−
: methane formation via POC degradation	3.6	3.7	4.0	mmol m^−2 yr^−1 of CH4
: gas dissolution	28.4	73.3	84.7	mmol m^−2 yr^−1 of CH4
: anaerobic oxidation of methane	30.1	74.3	85.0	mmol m^−2 yr^−1 of CH4
: authigenic CaCO3 precipitation	3.0	2.2	5.6	mmol m^−2 yr^−1 of C
: authigenic MgCO3 precipitation	5.4	7.1	0	mmol m^−2 yr^−1 of C
Sulfate consumed by AOM	79.8	75.7	77.2	%
Benthic flux of CH4 at SWI	0.5	1.9	2.7	mmol m^−2 yr^−1 of CH4
Percentage of CH4 flux from depth	88.0	95.0	95.3	%
Percentage of CH4 consumed by AOM	94.1	96.5	95.8	%