Triple Oxygen Isotopic Compositions of Ocean Water from the Mariana Trench

High-precision triple oxygen isotope data on 40 water samples (5–10 923 m in depth) collected at the Challenger Deep of Mariana Trench are reported this study. The analyses Laboratoire des Sciences du Climat et l’Environnement yield mean values δ18O = −0.084 ± 0.224‰, δ17O −0.061 0.117‰, and 17O-excess −17 5 per meg, with standard deviations 1σ. range (from −0.480 to 0.544‰) falls within records Global Seawater Oxygen-18 Database Trench. average value is more negative than −5 4 (1σ) meg only prior set including deep ocean samples. slope (λ) three-isotope plot 0.521 0.003 (1σ), lower λ 0.528 0.001 for new matches prediction mass balance model, suggesting that it may represent a appropriate endmember thermometry. respect Vienna Standard Mean Ocean Water (VSMOW) recognized be necessary correction quantifying gross productivity euphotic regions relative humidity moisture source regions.