Physical Geography and Plate Tectonics

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Physical Geography and Plate Tectonics
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Physical Geography
The study of the natural processes that shape the
surface of the Earth and life on it.
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humanities.ucsd.edu/.../ kuchtahum4/pix/earth.jpg
The Earth is approximately 4.6 billion yrs. old.
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• II. Composition of the Earth
• The Earth is made up of FOUR Parts

INNER CORE
OUTER CORE
CRUST
MANTLE
www.spacedaily.com/ news/carbon-00e.html
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III. Internal Forces
250 million yrs. ago the continents were
one giant landmass called PANGAEA
Continental Drift over time plates drifted
away or collided
wrgis.wr.usgs.gov/docs/ parks/pltec/pangea.html
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bhc.edu/.../study/ Images/platetectonics.gif
Tectonic Plates form the crust layer
(Continents are on these plates) are
constantly moving and cause changes to the
earths surface when they make contact
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Type One Divergent Boundaries
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Boundary
Divergent
Plates spread or move apart
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Formations Created by Divergent Boundaries

• Rift Valleys 2. Mid-Ocean Ridge
• (on land) (under sea)

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• Where a divergent boundary crosses the land,
  rift valleys form, which are typically 30 to 50
  kilometers wide.

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• Great Rift Valley in Africa
• Varies in width from 30 100 km
• Runs north to south for 5000 km

.aucegypt.edu/faculty/ hamroush/images/Geol...
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dataxinfo.com/hormuz/sinai.htm
Red Sea which is between Africa Southwest Asia
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• A mid-ocean ridge is created by plates moving
  away from one another allowing magma to escape
  the Earths core and create a long and narrow
  mountain range underwater.
• These ridges are created as magma cools quickly
  once it hits the water and builds upward.

M I D O C E A N R I D G E
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• Where a divergent boundary crosses the ocean
  floor, the oceanic ridge is much narrower, only a
  kilometer or less across.

Oceanic ridges form a global network tens of
thousands of miles long.
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• Plate separation is a slow process.
• For example, divergence along the Mid-Atlantic
  Ridge causes the Atlantic Ocean to widen at only
  about 2 centimeters per year.

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Type Two
CONVERGENT
BOUNDARIES
Note some convergent plates contain land and
other convergent plates contain water
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CONVERGENT BOUNDARIES
Convergent plate movement occurs when two plates
are headed for each other.
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Convergent Boundary Formations

• 1. mountains (continental continental
  convergence)
• 2. trenches (oceanic oceanic convergence)
• volcanoes (oceanic continental convergence)
• (add 3 to your notes worksheet)

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Continental-Continental Convergence
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Continental-Continental
Himalayas Mountain Range
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Oceanic Oceanic Plate Convergence
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Mariana Trench

• The deepest part of the worlds oceans
• Forms the boundary of two oceanic plates (Pacific
  Plate and Mariana Plate
• 6.78 miles deep

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Continental Plate Converging with an Oceanic
PlateWhen there are different kinds of plate
interaction

• the oceanic plate tends to sink below the
  continental. It then melts into magma in the
  mantle.
• This process is SUBDUCTION
• volcanoes can form.

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Andes Mountains
Add this example to your worksheet
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http//volcano.und.edu/vwdocs/volc_images/southeas
t_asia/indonesia/krakatau.html
Mount St. Helens Washington, USA
Krakatoa, Indonesia
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Convergent Plate Simulation
You can simulate convergent plate motion by
placing your hands together in front of you with
your palms down. Now gently slide your bottom
hand downward and your top hand upward, while
keeping them in contact.
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Type Three

• TRANSFORM

BOUNDARIES
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Transform
Boundaries

• At transform plate boundaries plates grind past
  each other side by side.

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Transform
Boundaries Example

• This type of boundary separates the North
  American Plate from the Pacific Plate along the
  San Andreas Fault, a famous transform plate
  boundary that is responsible for many of
  Californias earthquakes.

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How do transform boundaries impact the areas
where they are located?
Japan 2011
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Kobe Japan 1995
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Oakland, California1989
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Try It!

• You can simulate transformational plate motion
  by placing your hands together in front of you
  with your palms down. Now slide your left hand
  away from you and your right hand toward you.

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Human Impacts
On your notes worksheet, explain how the follow
the following plate boundaries formations impact
humans AND the environment

• Convergent Boundary Formations
• Divergent Boundary Formations
• Transform Boundary Formations