Fig. 2

Vertical profiles of key environmental parameters in relation to sediment depth and age. Values with error bars are means (± 1 SEM) from six seasonal snapshots. SWC saturated (mass) water content (\({\mathrm{Moi}}_{(m)}\)), TIS total interstitial space volume percent, Temp sediment temperature, ORP redox potential compared to the standard hydrogen electrode (SHE), Cond conductivity, TOC total organic carbon, PDESP percentage of diatoms estimated by sedimentary pigments, DI-TP diatom-inferred total phosphorus, D₅₀ particle median diameter, MGS mean grain size. Gray circles represent the existence of methane bubbles with gas volume (\({\mathrm{VP}}_{(a)}\), %) labeled by the number aside. The dotted line labels the damming event