Transcript Earth and the Moon

What features of the earth
do you see in this
picture??
What is the burning rock called?
Where does it come from?
What causes such an eruption of
lava from the earth??
From this image showing lava flowing from
dry land into the ocean, what do you think
this chapter might be about??
 Objectives:
› Describe how the continents moved
over the past 250 million years
› Explain the evidence supporting
continental drift
› Make a model of the supercontinent
Pangaea
A
puzzling World
› Look at the map on the next slide and
study the shapes of the continents
closely.
› What do you notice about the shapes
of the continents on the opposite
sides of the Atlantic Ocean?



Hundreds of years
ago, the 1st _________
________ were made
People noticed that
some of the
continents could
___________ like
________ _________
But if the continents
were once joined,
how could they
have moved??

During the 1800’s,
scientists studying
______ ____ ______
found evidence that
seemed to support
the idea of ________
____________

What evidence do
you think this was?




German _____________
Gathered evidence
and proposed the ___
______ ___ _________
__________
Claimed that all
landmasses were once
joined as a
supercontinent –
_____________
Theory not accepted
until the 1950’s
Pangaea Worksheet
 Page 20 of Integrated Resource Book

Scientists have collected large amounts
of _______ on how the continents _______
 They have pieced together a ________ of
the continents


______ ________ ____
___________________

All of the continents
were part of one
___________________
called Pangaea
 Step



1
______ ________years
ago (Mesozoic Era)
Pangaea began to
_______ ___________
across its __________
2 major continents
formed
› __________________
(south)
› __________________
(north)
 Step


2
_____ _________ years
ago
_________________
began to break up
into _________ pieces
that would become
› _______________
› _______________
› _______________
› _______________
› _______________
 Step


3
____ _________ years
ago
_________ breaks apart
forming landmasses
that would become
› ________________
› ________________
› ________________

_________, which has
been drifting north for
100 million years,
collides with ________
 Step
4

Continents as they
_________ _______

Do you think the
continents will keep
moving around??
Watch movie “Plate Tectonics – Our
Restless Planet” from Discovery
Education
 Write down 10 things you learned from
movie and hand in at end of class

Continental Drift Lab
 Page 29 of Laboratory Manual


Scientists have
collected a lot of
evidence supporting 2
related conclusions
› 1.____________________
_____________________
_____________________
_____________________
› 2.
_____________________
_____________________
_____________________
_____________________
A _________ kind of
organism or species
appears on earth only
in ______ _______and
then _________ _____
 Animals that swim and
plants with windblown
seeds can spread
_________ ___ _________
 But, _______ _________
can only spread out
across land


___________________
found fossils of an
ancient fernlike plant
called _____________ in
› _________________
› _________________
› _________________
› _________________
› _________________

What can they infer
from this??

That all of these
continents were
________________
at one time!!
Fossils of several other species have a similar
pattern
 None of these organisms could have
__________ ___ _____________
 How could they end up on different
continents??


Fossils of _____________,
a Triassic land reptile,
were found in Africa,
Antarctica, and India

Fossils of _____________,
a freshwater reptile,
were found in Africa
and South America

Fossils of _____________,
a Triassic land reptile,
were found in South
America and Africa

Fossil evidence also
shows that the
continents have
___________ over the
earth’s surface

Fossils found in
_____________ show it
once was home to
vast ______ _________
and _________ full of
plant and animal life

How could this be??




There are many
___________ between
the rocks and
landforms of _______
and ______ _________
If the 2 continents
are fitted together,
their __________
_______ ______ ____
Also, the mountain’s
rocks are similar in
_____ _____ _______
Were the 2 mountain
ranges once one??
Watch movie “Fossils – Windows into the
Past” from Discovery education”
 Write down 10 fossil facts from movie and
hand in at the end of class.

 Is
it True??
› Recall a time when someone told you
that something you believed to be
true, really wasn’t.
› How did you react?
› Was your reaction similar to the way
scientists reacted to Wegener’s
ideas?



______
are huge
masses of ______ that
move ________ over
land
During the ice ages,
glaciers spread
_________ _____ _____
_________
Glaciers always
move __________
_____________

Rocks that show
evidence of glaciers
at the end of the
_________ ______ were
found in
›
›
›
›

_________________
_________________
_________________
_________________
How could this be if it is
usually hot in these
places??



Rocks can also
show the
________________
in which glaciers
________________
Ice age glaciers
seemed to travel
__________ from
present day ________
This doesn’t make
sense!!

Can only be
explained if the
following continents
were once part of
the _______ _________
› _________________
› _________________
› _________________
› _________________
› _________________





1. Which present day continents were once
part of Gondwanaland?
2. List 2 types of evidence that support the
idea of continental drift.
3. What will happen to the size of the
Atlantic Ocean in the next 50 million years?
4. If you found evidence of glaciers in areas
with warm climates, what would you
conclude?
5. How does evidence of glacier movement
support the idea of a single landmass?

Objectives:
› Describe the process of sea-floor
spreading
› Identify different types of plate
boundaries
› Explain what happens when plates
come together
› Infer from observation of a large surface
feature what kind of plate boundary
produced it
 Moving Plates
› The word plate means “a smooth,
flat, thin piece of material”
› The word tectonic means “having a
strong and widespread impact”
› Does this give you enough
information to get a good idea of
what plate tectonics is all about?

1950’s – Scientists finally got
the tool they needed to
study the ocean floor

_______ __________ – could
bounce ________ waves off
the ocean bottom
› if a sound wave bounced
back _________, the ocean
floor was ___________
› if a sound wave took longer
to bounce back, the ocean
floor was __________

This allowed them to make
a map of the ______________
of the ocean floor



Scientists discovered
long, underwater
____________________
The ranges formed
one long __________
snaking through all
of the oceans
(baseball seams)
This ________________
had a deep valley
running the length of
its crest

Scientists found rocks
from the ocean bottom
were _________ than the
rocks in the ____________

Also the rocks _________
to the mid-ocean ridge
were the ______________

Why do you think this
is??

1960 – American
geologist ______________
proposed the __________
________________________
› 1. Mid-ocean ridge is a
huge ___________ in the
earth’s crust where the
hot _________ pushes up
› 2. The pieces of crust on
either side of the crack
are slowly moving
_______ from each other
› 3. As they move, _______
_______ from the mantle
wells up between them,
forming ______ _________
___________
New ocean crust is constantly being _______
during sea-floor spreading.
 So why doesn’t the earth keep growing
bigger??
 Because at the same time, ________ ocean
crust is being _________ ____ in deep
_______ ___________!
 The ______ _________ of oceanic crust stays
the _______ and it is totally remade every
______ __________years or so.



Other scientists
sampled rocks on
______ _______of the
mid-ocean ridge
They found a pattern
of _________ ________
_________ that was
_________ on each
side



The stripes were
formed when the
earth’s magnetic field
caused ___________ to
line up in the rocks
The stripes were
different because
earth’s magnetic field
___________ itself many
times in the past
Shows that new ocean
crust is added to
______ ________ of the
mid-ocean ridge at
the _________ _________
Watch movie “The Endless Voyage –
Making the Pieces Fit” from Discovery
Education
 Write down 10 new facts that you
learned and hand in at end of class


Magnetic Patterns on the Ocean Floor

Page 98 in Textbook



Earth’s lithosphere is
divided into pieces
called __________
The plates are
_______ ___________,
each at a different
rate and direction
A lithospheric plate
moves as a _______,
floating on top of
the ______________
(like a flat rock on
wet cement)



Each lithospheric
plate is made up
of both ______ ____
___________
________ ________ is
dense and made
up of ______ _____
___________
_________ _______ is
less dense and
made up of
_______ _____
___________



6 of the earth’s 7
major plates are
______________ plates
They carry mostly
continental crust
material
They consist of _____
continent and a
large section of
__________ ________
One major plate and several smaller
plates are oceanic plates
 They are made up entirely of ___________
__________


If plates are moving, what kinds of
interactions are possible??

Demonstration with 2 students
Plates moving ________
from each other
 Places where ________
_______ __ ____ _______
 ______ _____ ______are
divergent boundaries
 Can also occur in
continents and signal
the beginning of the
continent’s ___________




Two plates _______
________ ___ ________
Usually one plate
moves _________
another and crust
material is _________
Produce many
different kinds of
features on earth’s
surface



Two plates ______ ____
________ ___________
beside each other
Crust material is ______
created or destroyed
The break or crack
along which
movement occurs is
called a _____________
____________
Watch first part of movie “Endless
Voyage – World in Motion” from
Discovery Education
 Define the following and hand in at end
of class:
Divergent Boundary
Convergent Boundary
Transform Boundary




__________ of 2 plates
release huge amounts
of _________
Energy causes
important _________
__________ – volcanic
activity or mountain
building
What happens
depends on the ______
___ _______that meet
or converge



The more dense plate is
pushed down under the
other – ______________
Lower plate goes into
_____________, melts, and is
absorbed into ___________
Causes ______ ________to
rise up through other plate
› Volcanoes form on ocean
bottom and build a chain
or _______ ___ ____________
› It also creates a ________
_________ ______ – deepest
parts of the ocean



____________ plate is
always _________ so it
will be pushed down
under the ____________
Oceanic plate melts
into ________________,
causing molten rock
to rise up through
______________ plate
___________ __________
forms, usually
containing ___________




Both plates are the
same __________ and
_____________
Neither can move
___________ the other
They __________ and
_________ each other,
forming _____ ________
Plates become joined
as a _______ _________
Certain instruments measure the slow
movements of earth’s plates, so the _______
and ______________ of most have been
determined – can _______ future movement
 The movement and location of plates
explains many of earth’s features:

›
›
›
›
›
›
_______________________
_______________________
_______________________
_______________________
_______________________
_______________________



___________________
One of the few
transform
boundaries on land
Its movement
causes severe
_______________
(California)

________ ___________

Nazca plate
____________ under
the South American
plate caused this
mountain range

______ _____ _____

New ____________
boundary
beginning to split
Africa in two



_________________
__________ mountains
on earth
Resulted from
____________ of two
continental plates



_________________
Ocean trench
more than _______
_________________
Created by
_____________ of
Pacific plate
under the
Philippine plate
_____ ______ ________ _____________(VLBI)
 Uses ________ signals from distant _______
(stars) to measure plate movement
 Two stations far apart on earth receive
signals from the same quasar
 Get a precise measurement of _________
between the 2 stations
 Make same measurement at a later
date – find out how fast the earth’s
plates are ______________

Hawaii and Japan are moving closer to each other at a
rate of __________________________
The North American and Eurasian plates are moving apart
at a rate of ______________________





1. What happens during sea-floor
spreading?
2. Describe 3 types of plate boundaries,
and give an example of each.
3. Explain how mid-ocean ridges and
subduction zones are similar. How are they
different?
4. Japan is made up of a long chain of
islands formed from volcanoes. What kind
of plate boundary do you think is nearby?
5. What happens at a continentalcontinental plate boundary?

Objectives:
› Describe two models of how convection
occurs in the earth’s mantle.
› Explain how a tectonic plate may move
as part of a convection cell.
› Evaluate models explaining plate
movement by convection.
› Compare and contrast two models for
how convection results in the movement
of plates
 Convey the Concept
› Describe how a conveyor belt works.
› Make a list of where conveyor belts
are used.
› What happens to objects on a
conveyor belt?

Scientists know:
› ___________________
___________________
› ___________________
___________________
› ___________________
___________________

Still don’t know for
sure what the driving
force of plate
movement is!



Driving force for
plate movement
has something to
do with
__________________
__________________
_____________ cells
occur in the
mantle, which are
circular units of
movement
But how exactly
does convection
occur??
Two Models for Convection





First Model - Passive
Plates are _______________
_________ with the
movement of convection
Plates are like ___________
on a giant conveyor belt
________ _____________
form where convection
pushes material up
_______ ______________
form where convection
goes back down into the
mantle





Second Model - Active
Plates themselves
have an _______ ______
in convection
A plate is ________ and
______ _______ than the
asthenosphere
It will sink into a
_________ ________and
pull the rest of the
plate down
This helps _________ the
circular movement of
convection
1. What are two models for convection in
the mantle?
 2. If convection cells in the mantle are like
conveyor belts, what are plates like?
 3. Which model do you think best explains
how convection moves the plates? Explain
the reason for your choice.
 4. What are the similarities and differences
between the two major models explaining
how convection causes plate movement?
