Extended Data Fig. 7: Best fit scenario with different CH4 14C bottom boundary conditions.
From: Deglaciation drove seawater infiltration and slowed submarine groundwater discharge
To match the observed offset towards more 14C-depleted DIC, near radiocarbon-free methane is required. The 71 pMC is the in-situ 14C content of the POC and therefore the highest possible methane 14C content. These model experiments support that the methane must have a near radiocarbon-free precursor and therefore likely originates from much deeper in the sediments.
