The oceans cover about 70 percent of the Earth's surface. Ocean water contains salts and we say that ocean water has a certain salinity. You are very familiar with a salt: NaCl But there are other salts in the oceans. Scientists estimate that if the salt in the
oceans could be removed and spread evenly over the Earth's land surface it would form a layer more than 500 feet thick, about
the height of a 40-story office building (NOAA). Scientists also believe that the amount of salt in the Earth's oceans remains
pretty constant. Salt water - fresh water. Where did the salt in the oceans come form?
Salts dissolve in water. Look at the image of the water cycle. Hypothesize as to the original source of the salts in the oceans on
Earth
A)
Water collecting on Earth chemically erodes the continental crust.
B)
Elements found within the Earth, dissolve in water, enter the water cycle,
and return to the oceans.
Elements in the atmosphere fall back to Earth when combined with water
in some form of precipitation
D)
Evaporation leaves behind salts that eventually combine with the water
that covers the oceanic plates.