SMOW
SMOW stands for Standard Mean Ocean Water. It is a reference material used in stable isotope geochemistry to express the isotopic composition of hydrogen and oxygen in water samples. SMOW represents the average isotopic composition of the Earth’s oceans and serves as a defined standard for calibrating measurements, rather than a single physical specimen.
The concept provides a scale for reporting the ratios of heavy to light isotopes, specifically D/H for
SMOW originated in the mid-20th century as a practical ocean-water standard, providing a stable baseline for
Applications of SMOW and its derivatives include hydrology, climatology, paleoclimatology, and geochemistry. By comparing isotopic compositions