Transcript Continental Drift through Plate Tectonics

Continental Drift
through
Plate Tectonics
Warm Up
• Carefully tear one page out of your
magazine to use.
• Rip up your page into exactly 7 pieces.
• Pile your 7 pieces into one pile.
• Rotate one table clockwise and choose a
new seat. Do not touch the piles.
• Piece together the magazine into a full
page on the desk.
• What evidence did you use to piece
together the magazine?
Kontinentalverschiebung
Drifting Continents?
500 Years Ago
-World thought to be flat
Who is the most famous person that
challenged this?
Drifting Continents Notes
500 Years Ago
-World thought to be flat
Alfred Wegener: 1910
-Made a hypothesis that all the continents
had once been joined together in a single
landmass, and have since drifted apart.
-Named this supercontinent “Pangaea”
(meaning “all lands”)
Theory of Continental Drift
-10 million years ago, the continents began
to slowly move apart from Pangaea and
into their present locations.
Wegener’s Evidence
-Landforms- mountains matched across
continents
-Fossils- fossils matched across oceans
-Climate- fossils and landforms created in
climates that do not match today’s climate
Missing Evidence
-Wegener could not come up with an
explanation for what caused continents to
move
-Theory was rejected by geologists and
other scientists because no force could be
found.
Continental Drift Notes: Page 28-32
Read the section in the book, and then answer
the following questions in your notebook:
1. What was Alfred Wegener’s theory of
Continental Drift?
2. Explain the three types of evidence Wegener
used to support his theory that continents
move.
3. What is the main reason scientists rejected
Wegener’s theory of continental drift?
4. Use Wegener’s theory of continental drift to
explain why we find coal deposits in
Antarctica? (Coal deposits can only form in
warm swampy climates).
Warm-Up
1/20/14: What was the main reason
scientists rejected Alfred Wegener’s
theory of Continental Drift?
The main reason that scientists rejected
Wegener’s theory of Continental Drift is
because…
New Evidence!
Seafloor Spreading Notes
• Chain of mountains discovered at the
bottom of the sea after WWII.
• Longest (continuous) chain of mountains
in the world!
• The idea was proposed that material from the
mantle rises up and erupts in underwater
volcanoes.
• Molten material spreads out, pushes older rocks
to both sides
To understand “seafloor spreading,” we first
have to know mantle convection.
http://classzone.com/books/earth_science/te
rc/content/visualizations/es0903/es0903pa
ge01.cfm?chapter_no=visualization
Why don’t oceans keep getting
wider and wider?
• As older rocks cool, they become more
dense.
• Dense basalt oceanic crust “sink” under
less dense continental crust made of
granite
• (figure 23, page 38)
Event
1. Use of Sonar in
WWII
2. Harry Hess’s
theory
3. Alvin deep sea
dive
4. Magnetic stripes
5. Glomar Challenger
Contribution to
Seafloor
Spreading
Sonar used to find
Mountains in middle
submarines,
of Atlantic ocean
mapped ocean floor
discovered
Describe the
event
Seafloor Spreading Questions
1. Fill out the table of evidence for seafloor
spreading using the book (page 33-39)
2. Define Subduction.(Page 38)
3. Explain why this information provides
strong evidence for Alfred Wegener’s
continental drift.
4. Draw figure 23 from page 38 into your
notes.
Plate Tectonics Notes
• The geological theory that states that
pieces of Earth’s lithosphere are in
constant, slow motion is the theory of
Plate Tectonics.
• Pieces of Earth’s lithosphere called
“plates” are in constant motion.
• Plates can’t move without interacting with
one another.
• Plate motion
is powered
by Mantle
Convection
Convergent, Divergent, Transform
Convergent
Divergent
Transform
Convergent, Divergent, Transform
Convergent:Island arc
or folded mountain range
Divergent: Mid-ocean ridge
or rift valley
Transform: Transform boundary
Use given sheet of paper to draw diagram of
plate tectonics on bottom of page 44-45.
Color, fold, then glue into science
notebook.
Warm-Up
1/22/14: With a partner at your table,
practice the science handshake for
Plate Boundary Types
(Converging, Diverging, Transform).
Plate Tectonics Rock Paper Scissors
Two types of crust: Oceanic and Continental
• C+C= folded mountain range / rift valley
• O+C= subduction zone / volcanic
mountain range
• O+O= island arc / midocean ridge
Option 1: Plate Boundary Rock Paper
Scissors Rulebook
Create a rulebook for the game. You must
include:
• Describe how to play the game
• List all the different combinations you and
the other player can make
• Describe why each landform is created.
(Example: A Subduction zone is created
by a continental crust and ocean crust
converging because the denser ocean
crust will be pushed under the less dense
continental crust.)
Option 2: Letter to Alfred Wegener
Alfred Wegener never discovered the force that was able to move
the continents. Later, that force was discovered at the bottom of
the oceans. Write a letter to Alfred Wegener telling him that he
was right about the moving continents, and that his missing
evidence was found!
Include:
• A description of the missing force (Sea Floor
Spreading)
• A description of the new theory, Plate Tectonics, which
includes his theory of Continental Drift and the theory
of Seafloor Spreading. Include the different plate
boundaries that can be formed.
• An excited voice (Alfred Wegener would be VERY
happy to learn this news!)