VSMOWSMOW
VSMOWSMOW is not a distinct standard in itself; it is best understood as a reference to the pair of closely related isotopic standards used for hydrogen and oxygen in water analyses: SMOW (Standard Mean Ocean Water) and VSMOW (Vienna Standard Mean Ocean Water). Both are central to the way scientists report stable isotope ratios in water, but they serve different historical and practical roles within the same calibration framework.
In isotope geochemistry, two isotopes are routinely measured in water: hydrogen-1 (protium) and deuterium (hydrogen-2), and
SMOW, established in mid-20th century practice, was the original standard against which natural waters were compared.
Applications of these scales span hydrology, climatology, paleoclimatology, and forensic science, where isotope ratios reveal water