Partner Reading Take out your spiral notebook. Open your textbook to page 75. Read pages 75-82

1
Partner Reading Take out your spiral notebook.
Open your textbook to page 75. Read pages 75-82

• Pair up with one other person
• Each reads 2 paragraphs
• As you read, write the definitions of the
  following terms in your spiral notebook.
• Salinity
• Density
• Oceanographer
• Name the 3 layers of the ocean divided by
• temperature define each and tell depth of each
  layer. (pg. 79)
• Continental shelf
• Continental slope
• Seamounts
• Mid-ocean ridge
• Sonar
• Satellite imaging

2
3.1 Ocean water covers much of the Earth

• 71 of earth is seawater.
• Earth formed 4.6 billion yrs ago.
• Water vapor condensed making the oceans

3

• Ocean water contains salts and gases
• Every 1000 grams of seawater contains 35 gms. of
  salt.
• Salinity measure of the amount of dissolved
  salt in water.
• Where does the ocean get its salt?
• Rocks and minerals rain wash them into the
  ocean.
• Eruption of underwater volcanoes.

4

• Salt is added and removed but oceans salinity has
  remained the same for 1.5 billion yrs.
• Salt water has greater density than fresh water.
• Density measure of amount of matter packed into
  a given volume.
• Some oceans saltier than others because of
  evaporation, warm climates, and shallow areas.
• Some oceans are less salty being diluted by
  fresh water, rivers, etc.

5
Oxygen and other Gases

• Ocean animals take in oxygen and give off carbon
  dioxide.
• Oxygen and CO2 get mixed into the ocean from the
  air and plants and algae that live near the
  surface.
• CO2 building block of ocean animals shells.

6
Ocean Temperatures Vary

• Oceanographers people who study the ocean.
• Divide the ocean into 3 layers according to
  temperature.
• Surface Layer about surface to 300m. - heated
  by sun, warmest layer, less dense.
• Thermocline 300m to 700m. Middle Temp.
• Deep water below 700m. cold all the time,
  anywhere temp. is barely above freezing.

7
Ocean floor has many features

• Continental Shelf flat or gently sloping land
  underwater that extends from edge to slope of the
  continent.
• Continental Slope land that drops down steeply
  at edge of shelf
• Seamounts underwater mountains.
• Midocean ridge chain of mountains that run
  through an ocean basin.

8
Mapping the Ocean Floor

• Sonar a system that uses sound waves to measure
  distances and locate objects.
• Ships aim waves at oceans bottom and measure time
  it takes to receive the echo
• 1. Fast echo bottom is shallow
• 2. Slow echo bottom is deep

9

• Satellite imaging for mapping large areas of
  the Ocean
• Detect tiny bumps/dips in ocean
• Shape of ocean floor.