The salinity of the oceans is the result of all the fresh water rivers running into them. This rivers carry minute amounts of salt with them. But once in the oceans thecsalt remains . The rivers just keep adding to that salt. read more
Throughout Earth's history, certain processes have served to make the ocean salty. The weathering of rocks delivers minerals, including salt, into the ocean. Evaporation of ocean water and formation of sea ice both increase the salinity of the ocean. read more