Figure 2. Times series plots of methane ¹³C values from PCS cores at Site 995. Each panel shows data from a single PCS core. Gases were evolved sequentially from the PCS, with the first gas sample released and collected labelled as Sample 1 (see text and Paull, Matsumoto, Wallace, et al., 1996, for details). The scale of the vertical axes is the same in all panels. Error bars show analytical uncertainties of 2 standard deviations (±0.4). For each core, the average ¹³C value calculated by weighting the individual measurements by the volume of CH₄ released is shown by a horizontal line (±2 uncertainty shown as dashed line). Average ¹³C values could not be calculated for Cores 164-995A-45P and 60P because the volume was not measured for all gas aliquots.