1. Earth’s Oceans
Chapter 13; Section 1

2. Bellringer
Why does coastal water in places with hotter, drier climates typically have a higher salinity than coastal water in places with cooler, more humid climates?

3. Bellringer
Why does coastal water in places with hotter, drier climates typically have a higher salinity than coastal water in places with cooler, more humid climates?
Coastal water in places with hotter, drier climates has a higher salinity because less fresh water flows into the ocean in drier areas, and because heat increases the evaporation rate.

4. Earth’s Oceans Objectives Describe the history of Earth’s oceans.
Identify the properties of ocean water.
Describe the interactions between the ocean and the atmosphere

5. 1. The history of Earth’s oceans
About 4.5 billion years ago, there were no oceans.
Sometime before 4 billion years ago, water vapor in the atmosphere condensed and fell as rain.
The rain filled the deeper levels of Earth’s surface and the first oceans began to form.

6. 1. The history of Earth’s oceans

7. 2. The properties of ocean water
Dissolved Gases Nitrogen, oxygen, and carbon dioxide are the main gases dissolved in ocean water.
Solids Sodium chloride,
or table salt, is the most
abundant dissolved solid
in the ocean. Other solids
are also found in ocean
water.

8. 2. The properties of ocean water
Salinity is a measure of the amount of dissolved solids in a given amount of liquid.
Changes in Salinity Climate and water movement affect salinity. Costal water in cool, humid places has a low salinity. Slow-moving bodies of water have higher salinity than other parts of the ocean do.

9. 2. The properties of ocean water
Compare Hudson Bay & an Egyptian City
Use page 377 to find salinity levels

10. 2. The properties of ocean water
Temperature Zones The temperature of ocean water decreases as depth increases.

11. 2. The properties of ocean water
Surface Temperature Changes Surface-zone temperatures vary with latitude and the time of year.
Surface temperatures range from 1ºC near the poles to about 24 ºC near the equator.
The surface zone is heated
more in the summer.

12. 3. The interactions between the ocean and the atmosphere
The water cycle is the continuous movement of water from the ocean to the atmosphere to the land and back to the ocean.
The ocean is an important
part of the water cycle
because nearly all of
Earth’s water is in the
ocean.

13. 3. The interactions between the ocean and the atmosphere

14. 3. The interactions between the ocean and the atmosphere
The ocean regulates atmospheric temperatures.
A Thermal Exchange The ocean absorbs and releases thermal energy much more slowly than dry land does.
The circulation of warm water causes some coastal lands to have warmer climates than they would have with the currents.

15. Earth’s Oceans Objectives Describe the history of Earth’s oceans.
Identify the properties of ocean water.
Describe the interactions between the ocean and the atmosphere