Lesson 6  Sea Floor Spreading
Learning Outcomes <ul><li>You will be successful if you can:   </li></ul><ul><li>Know  that sea-floor spreading causes the...
Compare and contrast <ul><li>How is the model like &quot;real-life&quot; - i.e. the seafloor  </li></ul><ul><li>How is the...
Evidence for sea floor spreading Since the Earth was formed the north and south poles have periodically “________ ____”.  ...
<ul><li>Fact </li></ul><ul><li>Seafloor drilling in 1969 found that sediments further away from oceanic ridges are thicker...
How far does the Atlantic spread in a lifetime? (100 years) How far has it spread in all of human history? (10 000 years) ...
Review Radioactive Decay Continental plate Magnetic reversal pattern Earthquakes Subduction High Density Fossils Oceanic P...
Upcoming SlideShare
Loading in …5
×

E&U L5

603 views

Published on

Published in: Education, Technology
0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total views
603
On SlideShare
0
From Embeds
0
Number of Embeds
27
Actions
Shares
0
Downloads
3
Comments
0
Likes
0
Embeds 0
No embeds

No notes for slide

E&U L5

  1. 1. Lesson 6 Sea Floor Spreading
  2. 2. Learning Outcomes <ul><li>You will be successful if you can: </li></ul><ul><li>Know that sea-floor spreading causes the continents to move </li></ul><ul><li>Describe how magnetic field reversals led to the acceptance of continental drift. </li></ul><ul><li>Explain how the movement of tectonic plates leads to unpredictable earthquakes. . </li></ul>
  3. 3. Compare and contrast <ul><li>How is the model like &quot;real-life&quot; - i.e. the seafloor </li></ul><ul><li>How is the model different from what really happens under the sea? </li></ul><ul><li>What simplifications have we made? </li></ul>
  4. 4. Evidence for sea floor spreading Since the Earth was formed the north and south poles have periodically “________ ____”. When tectonic plates move apart and _____ fills the gap the iron particles in the magma orientate themselves in line with the Earth’s ________ field. This means that the rock formed on the sea floor contains a “magnetic __________” of the changing field: These magnetic patterns can be used to prove that sea floor spreading does happen, and at a rate of about 2 to 10 cm per _____. Words: impression, magma, swapped over, magnetic, year
  5. 5. <ul><li>Fact </li></ul><ul><li>Seafloor drilling in 1969 found that sediments further away from oceanic ridges are thicker </li></ul><ul><li>1) How do you think this is linked to the age of the rock </li></ul><ul><li>a) close to the ridge </li></ul><ul><li>b) far away from the ridge? </li></ul><ul><li>2) How is this evidence for sea floor spreading? </li></ul>
  6. 6. How far does the Atlantic spread in a lifetime? (100 years) How far has it spread in all of human history? (10 000 years) How far has it moved in 100 million years?
  7. 7. Review Radioactive Decay Continental plate Magnetic reversal pattern Earthquakes Subduction High Density Fossils Oceanic Plate Rock types S America Africa Tectonic plates Low density Heat Core Mantle Crust

×