S6E3. Students will recognize the significant role of water in earth processes.
Explain that a large portion of the Earth’s surface is water, consisting of oceans, rivers, lakes, underground water, and ice.
c. Describe the composition, location, and subsurface topography of the world’s oceans.
2. Chapter
Ocean Water
13
S6E3. Students will recognize the significant role of
water in earth processes.
a.Explain that a large portion of the Earth’s surface is
water, consisting of oceans, rivers, lakes, underground
water, and ice.
c. Describe the composition, location, and
subsurface topography of the world’s oceans.
3. 13.1 The Ocean’s Composition
Salinity
Salinity is the total amount of solid
material dissolved in water.
Because the proportion of dissolved
substances in seawater is such a small
number, oceanographers typically express
salinity in parts per thousands.
Most of the salt in seawater is sodium chloride,
common table salt.
4. Where does the Salt come from?
Salinity
Sources of Sea Salt
rocks
a. Chemical weathering of
on the
continents is one source of elements found in
seawater.
b. The second major source of elements
found in seawater is from Earth’s interior.
5.
6. Processes Affecting Salinity
Salinity
Processes Affecting Salinity
• Processes that decrease salinity:
- Precipitation
- Ice melting
- Icebergs melting
- Runoff from land
increase salinity:
• Processes that
- Evaporation
- Formation of sea ice
8. 13.1 Seawater
Ocean Temperature Variation
The ocean’s surface water temperature
varies with the amount of solar radiation
received, which is primarily a function of
latitude.
Temperature Variation with Depth
• The thermocline is the layer of ocean water
between about 300 meters and 1000 meters where
there is a rapid change of temperature with depth.
• The thermocline is a very important structure
because it creates a barrier to marine life.
11. 13.1
Factors Affecting Seawater Density
Ocean Density Variation
Density is defined as mass per unit volume.
It can be thought of as a measure of how
heavy something is for its size.
Factors Affecting Seawater Density
• Seawater density is influenced by two main factors:
salinity
and
temperature.
12. The 5 Oceans on Earth
Aunt
Patty
Seldom
Ate
Inchworms
What?
Atlantic
Pacific
Southern
Artic
Indian
14. The 5 Oceans on Earth
• The continents divide the 5 major oceans
and the equator subdivides these oceans
into the North Atlantic Ocean and South
Pacific Ocean
On average, the Atlantic is the saltiest of the world's
major oceans;
15. Technology: Exploring the
Ocean Floor
1. How can scientists study the ocean floor?
2. What did they find?
3. With state of the art technology, scientists
have discovered a wide variety of landforms
and sea life on the ocean floor.
16. Underwater Explorer
• Some parts of the ocean are too deep for
humans and so they must use special
underwater equipment.
• One piece is a minisub called Alvin.
• Alvin has been used to
search for sunken
ships, recover lost hydrogen bombs, and
explore landforms on the ocean floor.
17. Viewing the ocean floor with sonar
• SONAR (sound navigation and ranging) is a technology
based on the echo-ranging behavior of bats.
• We can measure the ocean’s depth with SONAR by
sending high frequency sound waves to the ocean floor.
• The sound bounces off the ocean floor and back
to the boat.
• The time it takes to get back to the boat can be use to
find the depth. Depth = t/2x1500m/s
18. Draw and label the Topography of
the Ocean Floor And circle the
deepest feature
