Pore fluid constraints on deep ocean temperature and salinity during the Last Glacial Maximum

Pore water records of δ 18 O and [Cl] from ODP Site 1063A on the Bermuda Rise constrain the change in seawater δ 18 O and salinity from the Last Glacial Maximum (LGM) to the Holocene to be 0.75±0.05‰ and 2.5±0.1% respectively. Coupled with a measured benthic foraminiferal δ 18 O change, this result means that bottom waters were 4.6±0.8°C cooler than the Holocene at the LGM and therefore at or near the seawater freezing point. Coupled δ 18 O and chlorinity results give an extrapolated mean ocean LGM to Holocene change in δ 18 O of 0.95±0.09‰. These data also constrain the past southern source deep‐water salinity to be 35.76±0.04 psu, which is within error of the mean deep ocean value for this time.