EARTH SCIENCEEARTH SCIENCEDirections: Directions: Read each slide Read each slide use theuse the RED RED underlinedunderlined words to words to complete the organizer.complete the organizer.

Tarbuck Lutgens

Chapter

1313Ocean Water

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.

Salinity

13.1 The Ocean’s Composition

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.

Salinity

Where does the Salt come from?

Sources of Sea Salt

a. Chemical weathering of rocks 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.

Salinity Processes Affecting Salinity

Processes Affecting Salinity

• Processes that decrease salinity:

• Processes that increase salinity:

- Precipitation

- Runoff from land - Icebergs melting

- Ice melting

- Evaporation

- Formation of sea ice

Natural Processes Affecting Salinity

Ocean Temperature Variation The ocean’s surface water temperature

varies with the amount of solar radiation received, which is primarily a function of latitude.

13.1 Seawater

• 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.

Temperature Variation with Depth

• The thermocline is a very important structure because it creates a barrier to marine life.

Variations in Ocean Surface Temperature

Variations in Ocean Water Temperature

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.

13.1 Factors Affecting Seawater Density

• Seawater density is influenced by two main factors: salinity and temperature.

Factors Affecting Seawater Density

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The 5 Oceans on Earth

Atlantic

SouthernArticIndian

Pacific

The 5 Oceans on Earth

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;

Technology: Exploring the Ocean Floor1. 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.

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.

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

Draw and label the Topography of the Ocean Floor And circle the deepest feature

Go back to ikeepbookmarksReview a concept then summarize your findings

• Congratulation Oceanographe