On your paper, answer the following question of the day:

1
Welcome to Science 9/13

• On your paper, answer the following question of
  the day
• In the Liquid Layers Lab, the coldest liquid
  was the most dense. In class you learned that the
  core is the most dense as well as hottest layer
  of Earth. Typically the colder a substance, the
  more dense it is. Why do you think the core is so
  hot yet is still the most dense layer.
• Todays Schedule
• ? Of the Day
• Review Liquid Layers Lab
• Reconstructing Pangaea Lab

2
What was Pangaea?

• Has the world always looked as it does today?
• Continents of the Past. Animation.

3
What was Pangaea?

• Pangaea means all land in Greek
• 245 million years ago Earths continents were
  joined together to form a supercontinent known as
  Pangaea.

4
Reconstructing Pagaea Lab

• 1. Label the 7 continents, including Greenland
  and India, before cutting them out.
• 2. Outline the edge of each continent with a
  different color.
• 3. When you are cutting, cut as close to the edge
  of the continents as possible. Dont cut out the
  islands.
• 4. Ask Questions if you are confused or need
  help.
• 5. Follow the procedure on the Lab Sheet.

5
Welcome to Science 9/14

• Immediately find your partner for the
  Reconstructing Pangaea Lab and continue working
  on it. You have about 20 minutes to complete the
  lab.
• Todays Schedule
• 1. Conclude Pangaea Lab
• 2. Begin Ch. 7 Section 2 Notes/Discussion

6
Evidence from Mountains
7
Evidence from Glaciers and Mountains
8
Pangaea Model
9
Reconstructing Pangaea Lab

• Question of the Day
• Besides the shape of the continents, what other
  evidence shown in the map below supports the
  Pangaea theory?

10
Welcome to Science 9/15

• Have a seat. Get your Reconstructing Pangaea Lab
  out. Open your book to page 173 and begin
  completing your notes for Ch. 7 Section 2.
• Todays Schedule
• 1. Notes/Discussion Ch. 7 Section 2
• 2. Review Reconstructing Pangaea Lab

11
Ch. 7 Section 2 Restless Continents

• What do we mean when we say Restless Continents?
• Continental drift- theory that continents can
  drift apart and have done so in the past.

12
I. Drifting Continents

• What did Alfred Wegener observe that led him to
  believe in continental drift?
• 1. continents fit together like a puzzle
• 2. Fossils of the same species were found on
  different continents
• 3. evidence of rocks and climatic conditions were
  found on the same continents.

13
II. Breakup of Pangaea

• What did Wegener infer based on his evidence?
• Millions of years ago there was one
  supercontinent that over time slowly broke apart

14
(No Transcript)
15
III. Wegeners Theory Rejected

• Why?
• Wegener could not conclude how or why the
  continents moved.
• What discovery provided clues that Wegener was
  right?

16
III. Mid-Ocean Ridge

• 1960s underwater worldwide mountain chain was
  discovered
• What happens at the mid-ocean ridge that moves
  the continents?
• Sea-floor spreading

17
III. What is sea-floor spreading?

• As plates diverge magma rises up to form a
  mid-ocean ridge. As more magma continues to rise
  and harden it spreads the sea-floor apart .
• animation

18
III. Evidence of Sea-floor Spreading

• How do we know sea-floor spreading is happening?
  Seafloor Spreading Interactive
• Rock samples taken from the sea-floor show that
  the oldest rocks are further from mid-ocean
  ridges.

19
IV. Magnetic Reversals

• Throughout history Earths magnetic fields will
  switch. Meaning the north pole goes to the south
  pole and vice versa.
• Magnetic minerals in magma align with Earths
  magnetic field. When the poles switch this
  creates stripes or bands that can be seen on the
  sea-floor.
• animation