Transcript The Changing Earth

The Changing Earth
A Science Lesson for
5th Grade
http://www.dc.peachnet.edu/~pgore/students/w97/lehrer/
http://www.geo.utexas.edu/outreach/Barker%20lecture/barker.htm
Earth’s Layers
• The three layers of Earth are the
crust, the mantle, and the core. (see
diagram to the right)
See the cutaway view and learn
more about the Earth's layers.
• Crust: the thin, outer layer of Earth
• Mantle: A thick layer of rock
between the crust and the core of
Earth
• Core: the innermost layer of Earth,
which consists of a molten outer
part and a solid inner part.
• Want to learn more? Click here!
http://www.geog.ouc.bc.ca/physgeog/contents/i
mages/earthcut.jpg
Text B19
THE THEORY OF PLATE
TECTONICS
• Plate Tectonics is the theory of
continents drifting from place to
place breaking apart, colliding,
and grinding against each other
• See Pangaea split into the seven
continents
• Alfred Wegener discovered
fossil remains on separate
continents that proved the
continents were once one giant
landmass called PANGAEA
• Click on the map for a closer
view of the Earth's plates.
http://www.exploratorium.edu/faultline/earthquakescience/images/pangea_lrg.gif
THE THEORY OF PLATE
TECTONICS (CONTINUED)
• Now you try it...see the plates move.
http://www.lr.k12.nj.us/ETTC/archives/platetectonics2.jpg
TECTONIC PLATE
MOVEMENT
• Plate boundaries are places
where plates interact and
many earthquakes and
volcanoes occur. The three
main boundaries are:
1. Convergent boundaries where plates move together
2. Divergent boundaries where plates move away
from one another
3. Transform-fault boundaries where plates move past one
another
http://www.mrd.gov.fj/gfiji/geology/educate/platect.html
Mountains
• Mountains form as the
result of four basic
processes:
1. Folding – when masses of
rock are squeezed from
opposite sides (two plates
collide).
2. Faulting – when blocks of
rock move up or down
along a fault.
3. Doming – when the
surface is lifted up by
magma.
4. Volcanic Activity
http://www.anamericandream.net/testimonials.html
Earthquakes
• View a globe showing
where earthquakes
have occurred over a
five year period.
• Do you have questions
about earthquakes?
Find the answers here!
• See these animated
faults in motion!
http://pubs.usgs.gov/gip/earthq1/san_andreas.gif
EARTHQUAKES (CONT.)
http://www.ga.gov.au/news/images/GA1117.gif
• The instrument used to
record the intensity,
duration, and nature of
earthquake wakes is a
seismograph.
• The Richter scale is a
scale of numbers by
which the magnitude
of earthquakes is
measured.
Volcanoes
• A volcano is any opening
in Earth’s crust through
which hot gases, rocks,
and melted material
erupt.
• The melted material that
erupts is called magma.
• Want to learn more about
volcanoes? Click here!
http://rwor.org/i/volcano.gif
VOLCANOES
(CONT.)
• A volcano erupts in certain steps:
1. High temperatures and pressures
deep within Earth cause rock to
melt.
2. Magma makes its way toward the
Earth’s surface melting
surrounding material to form a
central pipe.
3. Hot melted material moves
through the volcanic vent.
4. Magma turns to lava.
• Watch this animation of a
volcanic eruption!
http://www.geo.mtu.edu/volcanoes/hazards/primer/image
s/volc-images/puuoo.jpg