Calcium Carbonate Saturation in the Ocean

A procedure and a nomogram are presented for the determination of the calcium carbonate saturation of seawater at in situ pressures. This procedure was applied to data from the eastern South Pacific Ocean, and results show that these waters are generally undersaturated below the first few hundred meters. This undersaturation suggests that sinking calcareous tests will partly dissolve and that the specific alkalinity should increase with time.