Final answer:
Jason witnessed the natural process of harvesting sodium chloride from the ocean via evaporation. This process, often utilized in salt ponds, leaves behind salt crystals as water evaporates, and it's a simple form of desalination.
Step-by-step explanation:
The sight Jason saw was the non-mechanized process of harvesting sodium chloride from the ocean by evaporation of seawater. This process is seen in salt ponds like those near San Francisco, where the high salinity allows for sodium chloride to crystallize.
This is based on the scientific principle that when seawater evaporates, salt crystals such as sodium chloride are left behind because they do not evaporate with the water. This is one method of desalination, which is crucial since most of Earth’s water is not readily usable by plants, animals, or humans due to its salt content. In contrast, magnesium is harvested from seawater using more complex processes involving reactions and electrolysis.