1. Ocean Composition Chapter 13, Sect. 1

2. The Adventures of Huckleberry Finn by Mark Twain
Summary: This famous story recounts the
adventures of a young boy and a runaway slave
on a raft floating down the Mississippi River.
Excerpt:. . . It’s lovely to live on a raft Once or
twice a night we would see a steamboat slipping
along in the dark and by and by her waves
would get to us, a long time after she was gone,
and joggle the raft a bit . . .
Questions: Would it be easier to float a raft on salt water or fresh water? Did the egg float more easily in salt
or fresh water?

3. The total amount of dissolved salts in water.
Salinity
The total amount of dissolved salts in water.

4. Variations in Salinity
Near the surface, rain, snow, and melting ice add fresh water to the ocean, lowering the salinity.

5. Variations in Salinity
Salinity is also lower near the mouths of large rivers, since they empty fresh water into the ocean.

6. What increases Salinity?
Evaporation - salt is left behind as the water evaporates.
Freezing – salt is left behind as the surface water freezes.

7. Effects of Salinity
Freezing – ocean water doesn’t freeze until the temperature drops to about –1.9 degrees C.

8. Effects of Salinity
Density – The mass of 1L of salt water is greater than 1L of fresh water. Example Egg Experiment.

9. Buoyancy – Salt water lifts less dense objects. Floating is easier.
Effects of Salinity
Buoyancy – Salt water lifts less dense objects. Floating is easier.