Download plates

Bell Work: 10/24/13
Write the question, full answer, and justify
why you chose your answer.
Work on your Earth’s Layers Foldable when
you are finished with bell work.
Objectives
27. Movements of Earth’s Major Plates
►Can
I differentiate among the characteristics of earth’s
three layers? (SPI 0707.7.4)
►Can
I recognize that lithospheric plates on the scale of
continents and oceans continually move at rates of
centimeters per year. (SPI 0707.7.5)
►Can
I describe the relationship between plate
movements and earthquakes, mountain building,
volcanoes, and sea floor spreading. (SPI 0707.7.6)
►Shifting
Plates Choice Boards
Think, Pair, Share …
Come up with an explanation to the
following question, pair up with your
elbow partner, & share:
►How
do we know so much about
the mantle and the core?
Question…
How do we know so much about the
mantle and the core?
►We
can study magma on the Earth’s surface
from volcanic eruptions. Also, seismic waves, or
vibrations produced from earthquakes, travel at
different speeds through the Earth. Their speed
depends on the density and composition of the
material they pass through.
 Traveling through a solid will go faster
than through a liquid. How did this
knowledge help scientists figure out what
state each layer is in?
Restless Continents
► Look
at pg. 400!
► In the early 1900s, ___________
___________
Alfred
Wegener
wrote about his hypothesis of ____________
continental
______,
drift arguing that all the continents were once
joined together in a single landmass and have
drifted apart.
► He proposed that the continents plowed through
ocean floor, driven by the spin of the Earth.
► Continental drift is the hypothesis that states that
continents once formed a single
the _____________
______________,
broke up, and drifted to their
landmass
present locations.
Pangaea
► Wegener
thought that
all of the present
continents were once
joined in a
__________
single, huge continent
called
Pangaea
______________.
► Pangaea is Greek for
“all Earth”
______________.
You try it!
Make Pangaea with the
pieces of continents at
your group.
Look at the map. At your group, discuss
the following questions. You have 2
minutes.
1.
What evidence supports
Wegener’s theory?
2.
Since all dinosaurs
cannot swim, explain
how the same fossil can
be found on all
continents.
Challenging Question…
Think, Pair, Share…
► Based on what you know about the plates,
how would you prove Wegener’s theory to
be true today?
Tracking Tectonic
Plate Motion
► Today,
scientists use a system of satellites
called global positioning system or GPS.
► Radio signals are continuously beamed from
satellites to GPS ground stations, which
record the exact distance between the
satellites and the ground stations.
► Over time, these distances change slightly.
**The movement is measured in centimeters
per year.
Composition of Earth’s Plates
► Wegener
thought that more than continents were
plate
moving. According to the theory of _________
_________,
tectonics Earth’s lithosphere is divided into
tectonic plates that move around on the
asthenosphere.
boundary is a place where tectonic plates
► A ___________
touch.
► ____________Convergent
boundary formed by the collision of two
lithospheric plates
Divergent
► ____________boundary between two tectonic plates that are
moving away from each other
Transform
► ____________boundary between tectonic plates that are
sliding past each other horizontally
Proving Wegener Wrong
► The
older term "continental drift" is not quite
accurate -- both continents and oceanic crust
move.
► We now know that Wegener's theory was wrong
in one major point: continents do not plow
through the ocean floor. Instead, both continents
and ocean floor form solid plates, which "float"
on the asthenosphere, the underlying rock that is
under such tremendous heat and pressure that it
behaves as an extremely viscous liquid.
2 Minute Journal
Write a two minute journal giving
evidence on how Wegner’s
Continental Drift theory could possibly
be true, but also discuss the flaws
behind his theory.
Events associated with movements of
earth’s major plates:
► Sea-floor
spreading
► Mountain building
► Earthquakes
► Volcanoes
Bell Work: 10/25/13
Please write the question,
answer, and explain why you
chose that answer (justify). Have
your Earth’s Layers foldable open
on your desk & turn in your
questions to the inbox.
Objectives
27. Movements of Earth’s Major Plates
►Differentiate
among the characteristics of earth’s three
layers. (SPI 0707.7.4)
►Recognize
that lithospheric plates on the scale of
continents and oceans continually move at rates of
centimeters per year. (SPI 0707.7.5)
►Describe
the relationship between plate movements
and earthquakes, mountain building, volcanoes, and sea
floor spreading. (SPI 0707.7.6)
►Shifting
Plates Choice Boards
Events associated with movements of
earth’s major plates:
► Sea-floor
spreading
► Mountain building
► Earthquakes
► Volcanoes
Sea-Floor Spreading
►
►
►
Mid-ocean __________,
ridges
____________
or underwater mountain
Sea-floor
spreading takes
chains, are where ____________
___________
place. Divergent boundaries are formed when
plates move away from each other.
Sea-floor spreading is the process by which new
magma
Lithosphere (or crust) forms as __________
oceanic ____________________
rises toward the surface and solidifies.
tectonic __________
plates
As ___________
move
away from each other, the
sea floor spreads apart and
magma fills the gap.
Draw a picture of Sea Floor Spreading.
Mountain Building
Mountains
► ______________
exist because tectonic plates are
continually ______________
around and
moving
colliding with one another.
___________
► The Andes Mountains in South America formed
where two tectonic plates converge or collide.
compression
► When tectonic plates undergo ________________
tension
or ____________,
they form mountains.
Volcanoes
►
►
►
►
►
Tectonic plate boundaries are likely places for
volcanoes to form.
_____________
________
_____
which are
The _________
Ring
of _________,
Fire
plate boundaries surrounding the Pacific Ocean,
contains nearly _____
75% of the world’s active
volcanoes.
About _____
80% of active volcanoes on land form where
plates ______________,
and about ______
collide
15% form
where plates ____________.
separate
At these plate boundaries it is possible for
magma
_____________
to form and travel to the surface.
What about the volcanoes that do not form at plate
boundaries? How do they form? Look at page 466.
Earthquakes
►
►
►
►
►
►
►
The study of earthquakes is called ________________.
seismology
Most earthquakes take place near the edges of
tectonic ___________.
plates
__________
As tectonic plates push, pull, or slip past each other, stress
increases along breaks in the Earth’s crust, or
faults
___________.
In response to this stress, rock in the plates
_______________.
deforms
Elastic _______________
deformation
__________
leads to earthquakes.
It’s like a stretched rubber band, you can only stretch rock
so far before it breaks. When the rock breaks, it releases
energy
________________.
This energy is released in the form of seismic waves.
2 Minute Journal
“Why is it important to me and to the
future of our planet to learn as much
as we can about the movement of
plates and what effects they have?”
Shifting Plates Choice Board
► You
and a partner will complete one mandatory
topic and one topic of choice from the Shifting
Plates Choice Board.
► Along with researching these topics, you and your
partner will choose a product to create for each
topic.
► You may only use each product once.
You must use the sites on my portaportal to
research your topics.