Content Outline for Teaching - Potosi School District - Home

13
Content Outline
for Teaching
Oceans
Underlined words and
phrases are to be filled
in by students on the
Note-taking Worksheet.
Section 1
Ocean Water
A. Oceans are important because they provide homes to many
organisms; provide resources such as food, salt, transportation; provide
water for precipitation; and provide oxygen produced by ocean organisms.
B. Billions of years ago oceans formed from volcanic water vapor that collected in the
atmosphere and then fell as torrential rains.
C. Ocean water contains many dissolved substances that make it taste salty.
1. Salinity—measure of the amount of salts dissolved in seawater
2. Gases enter the ocean from the atmosphere.
a. Oxygen—enters from the atmosphere and photosynthesis of ocean organisms
b. Carbon dioxide—enters from the atmosphere and from respiration of ocean
organisms; forms carbonic acid, which controls ocean acidity
c. Nitrogen—provides nutrients for plants and is used in plant and animal tissues
D. Water temperature and pressure vary with depth.
1. Three layers of water temperature
a. Warm surface layer—found near the equator
b. Thermocline—begins at about 200 m with temperatures rapidly dropping
with increasing depth
c. Deep-water layer—extremely cold
2. Pressure or force per unit area increases about 1 atmosphere (atm) for every 10 m
increase in depth.
Discussion Question
How did the oceans form? Water vapor from volcanoes collected in the atmosphere and
then fell as rain.
Oceans 39