scientists now use satellites to track the movements of...name clark science period date there are...
TRANSCRIPT
Do we track plate movement?
• Scientists now
use satellites
to track the
movements of
the Earth’s
plates.
Interesting Fact!• Because of sea-floor spreading, the
distance between Europe and North
America is increasing by a few
centimeters per year.
Theory of Plate Tectonics• States that pieces of
Earth’s lithosphere are in a slow, constant motion, driven by convection currents in the mantle.
• As the plates move, they collide, pull apart, or grind past each other, producing spectacular changes in Earth’s surface. These changes include volcanoes, mountain ranges, and deep ocean trenches.
http://w3.salemstate.edu/~lhanson/gls110/GLS110_BasicConcepts.htm
Convection Currents and Sea-Floor Spreadinghttp://www.absorblearning.com/media/attachment.action?quick=12p&att=2775
Warm-up• Please read
textbook pages 150
– 154 with your
team. When you are
finished, you may
return to your desk
and begin the LAB
• Please be prepared
to share your
answers with your
neighbor.
CAPS
NameClarkScience PeriodDate
Share with your neighbor…
Warm-up
CAPS
• Please read
textbook pages 150
– 154 with your
team. When you are
finished, you may
return to your desk
and begin the LAB
NameClarkScience PeriodDate
There are three kinds of plate boundaries:
• Divergent boundaries, convergent
boundaries, and transform boundaries.
• A different type of plate movement
occurs along each type of boundary.
What are divergent boundaries?
• Divergent Boundary: where two
plates move apart
What happens at divergent boundaries?
• #1 - When two
oceanic plates move
apart, a mid-ocean
ridge is formed. EX:
Atlantic Mid-Ocean
Ridge
• #2 - When two
continental plates
move apart, a rift
valley is formed.
EX: Great Rift Valley
in Africa
We can see this above water in Iceland!
Hydrotherma, vents along mid-ocean ridges!
Black Smoker
Can things live in this superheated environment?
Tubeworms, palmworms,
scale worms and limpets
thrive in warm, diffusely
flowing vent fluids issuing
from the black smoker
chimney "Finn" on the Juan
de Fuca Ridge
Complex
communities
fueled by the
chemicals
dissolved in
the vent
fluids
What is a convergent boundary?
• Convergent
boundary: place
where two plates
come together.
• The result is a
collision where the
density of the crust
determines what
happens.
http://www.divediscover.whoi.edu/images/tectonics-collide.jpg
Convergent Boundary #1• Oceanic plate (more
dense basalt) meets
a continental plate
(less dense granite):
oceanic crust goes
under.
• Volcanoes are
created. Ex: Mt. St.
Helen’s/ Cascade
mountains
Convergent Boundary #2• When continental
plates meet (equal
density): mountains
are created.
• EX: Himalayas
Convergent Boundary #3• When two oceanic plates meet
(more density goes down)
• Trenches are created.
• EX: Mariana Trench between
Japan and New Guinea.
• Deepest part of the ocean but
not closest to the Earth’s core.
What is a transform boundary?• A boundary where two plates grind past each
other without the (no) production or destruction of lithosphere.
• However, earthquakes can occur along the faults. EX: San Andreas Fault
The San Andreas Fault
What does it do to Arizona?
When it comes to the Earth,it’s like a rug…
http://rst.gsfc.nasa.gov/Sect2/Sect2_6.html
• Over millions of years, the forces of plate
movement can change a flat plain into
landforms such as anticlines and synclines,
folded mountains, fault-block mountains, and
plateaus.
Folding Earth’s Crust• This results in
mountains and
plateaus.
• EX: Colorado
Plateau
Rockies were never volcanoes.