Download ppt wegener

8th Grade Content Statement

The composition and properties of Earth’s interior
are identified by the behavior of seismic waves.

The refraction and reflection of seismic waves as they move
through one type of material to another is used to differentiate
the layers of Earth’s interior. Earth has an inner and
outer core, an upper and lower mantle, and a
crust.

The formation of the planet generated heat from gravitational
energy and the decay of radioactive elements, which are still
present today. Heat released from Earth’s core drives convection
currents throughout the mantle and the crust.
8th Grade Content Statement

Earth’s crust consists of major and minor tectonic
plates that move relative to each other.


Historical data and observations such as fossil distribution,
paleomagnetism, continental drift and sea-floor spreading
contributed to the theory of plate tectonics. The rigid tectonic
plates move with the molten rock and magma beneath them in
the upper mantle.
Convection currents in the crust and upper mantle cause the
movement of the plates. The energy that forms convection
currents comes from deep within the Earth.
8th Grade Content Statement

A combination of constructive and
destructive geologic processes formed
Earth’s surface.
 From
the elaboration - Distinguishing between
major geologic processes (e.g., tectonic
activity, erosion, deposition) and the resulting
feature on the surface of Earth is the focus of
this content statement.
How do the pieces fit together?
• Cut the pieces out.
• Take 5 minutes to work with them.
• Discuss your arrangement with a fellow
scientist.
• As a pair write your claim and provide
evidence on large chart paper.
– CLAIM - How would you put them together?
– EVIDENCE – Explain your reason(s) for
arranging the pieces the way you did.
Scientist Meeting
 Share out claim and evidence
 Can the whole group come to a
common agreement?
What is this?
“Supercontinent”
Pangea
What is this?
By 1570, European explorers had
mapped most of the Earth. People
looked at these maps and began to
notice, what?
What do you think caught their
eye?
What do you notice?
1620
Sir Francis Bacon noticed…
 That the continents
fit together!
Do you agree?
Where do you see it?
Alfred Wegener also noticed…
 Wegener was not the first to notice
the fit of Africa and South America,
but he was the first to collected
evidence to support his theory!
 Let’s look at what he found…
 http://www.ucmp.berkeley.edu/geolo
gy/techist.html
Take a second look…
 Alfred had 3 pieces of evidence to
support his claim…What are they?
 Color the puzzle pieces according to
the key
Wegener’s Evidence
 Natural Fit - Students should understand
that using the shape of the continents to fit
them back together is using one type of
evidence.
 Fossils - Using the presence of the same
type and age fossils is another.
 Rock Type - The presence of the same
rock types is another form of evidence.
Anything else?
 Can you think of other types of
evidence to search for that might be
useful in solving their puzzle.
There are other directions,
but...
 It is far more important to have
students grasp the concept of how
scientists look for clues, or evidence,
and put the pieces together to solve a
problem.
 The conversation the students engage
in is the richest part of the lesson.
• Briefly present background on Wegener. Stress
that although others had recognized the fit of
Africa and South America, it was Wegener who
gathered other scientific data to support his
theory.
• Divide students into groups of two or three.
These small groups allow students to discuss
the significance of different lines of evidence as
they piece together the continental puzzle.
• Each group is given a cut-out sheet containing fossil evidence
(Student Puzzle Pieces), the Key to Wegener's Evidence sheet, the
Student Map of the World Today reference sheet, crayons or
markers, and a pair of scissors.
• Groups label the continents or land mass on each piece. The
students then color each fossil type and the Key to Wegener's
Evidence sheet. Then cut out the land masses from the evidence
sheets.
• Have the students arrange the puzzle pieces using the Key to
Wegener's Evidence to support their arrangement.
• The final puzzle configuration should be attached to paper with glue
or tape.
• When finished, each group will present and defend their
reconstruction.
• You may compare the students' reconstructions with Wegener's Key
to Continental Positions about 250 million years ago (Teacher Copy)
Standing Cube
4 Sides
 Alfred Wegener’s picture and his
contribution to science
 Pangea with explanation/definition
 Wegener’s Claim, Evidence,
Reasoning
 30 years later…
You Tube
• http://www.cleanvideosearch.com/media/a
ction/yt/watch?v=T1-cES1Ekto
Plate Tectonics
•
•
•
•
•
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Foldable - Layers of the earth
Paper Model of sea floor spreading
Transparency Demo
Intranet Resources
Active Art
Models/examples of convection currents
– http://www.youtube.com/watch?v=ft-dP2D7QM4
– http://www.youtube.com/watch?NR=1&v=KCSJNBM
OjJs&feature=endscreen
Heat Up the Floating Plates
• Offers a working model of convection
currents…
Say what?
 The extreme heat in the center of the
earth causes convection currents in
the asthenosphere which is made of
hot molten material on which the
lithospheric plates move.
Break it down
 Have students rewrite and then refine the
statement as new vocabulary is defined
 Example: The center of the earth is very
hot! Heat rises from the center of the earth
and causes the mantel (the hot melted rock
layer of the earth) to move. The crust (the
surface of the earth) is broken into plates
and they move.
Theory
 Their statement:
 The extreme heat
in the center of the
earth causes
convection currents
in the
 Our statement
 Heat rises from the
center of the earth
and causes the
mantel (the hot
melted rock layer of
the earth) to move.
Fact
 Their statement:
 asthenosphere
which is made of
hot molten material
on which the
lithospheric plates
move.
 Our statement:
 The crust (the
surface of the
earth) is broken
into plates and they
move.
 The extreme heat in the center of the
earth causes convection currents in
the asthenosphere which is made of
hot molten material on which the
lithospheric plates move.
Stream Tables
Observe
 Erosion
 Deposition
Investigate
 Standard water source
 Flood water source
 Slope
What evidence could you use to
construct one “Supercontinent”?
CER - Claim, Evidence, Reasoning
 Claim
 The continents were once one large land
mass.
 Using Wegener’s Puzzling Evidence
construct a “supercontinent”
 What evidence can you provide to
support Wegener’s theory that the
continent are moving and were once a
supercontinent?