What is a significant source of dissolved solids in seawater?

Dissolved solids in seawater primarily consist of various salts, with sodium chloride being the most abundant component. Salinity concentration, which is the measure of the amount of salts in seawater, is a direct result of the natural processes such as evaporation and the inflow of freshwater from rivers, which carry dissolved minerals from land. As seawater evaporates, the salts remain, increasing the salinity and thereby the concentration of dissolved solids. This is noteworthy because while freshwater inflow contributes to the overall composition of water systems, it typically dilutes salinity rather than being a significant source of dissolved solids.

Atmospheric deposition also adds some dissolved materials to seawater, but this is usually a minor contribution compared to the directly derived salts from evaporation and mineral composition of the Earth. Similarly, while mineral leaching from rocks contributes to dissolved substances in freshwater systems, the ocean's vastness means that the majority of its dissolved solids come from processes concentrated in salinity dynamics rather than direct input from freshwater sources or atmospheric contributions.