Earth Processes Vol. I

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Earth Processes Vol. I
Internal Forces
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Plate Tectonics The idea that the Earths crust
is made up of large plates that float on top of
the upper mantle.
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They are constantly recycling as magma rises up
and cools and layers of rock are forced downward
and melt.
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Plate Tectonics The idea that the Earths crust
is made up of large plates that float on top of
the upper mantle.
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Plate Boundaries The areas where one plate
stops and another begins.
Marks Plate Boundaries
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Three types of boundaries mark plate movement.
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Divergent Plates move apart or spread. Magma
pushes its way up between them and fills in the
gap.
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Convergent

• Plates collide sometimes causing one plate to
  dive under or
• go over the other plate and sometimes causing the
  plates to fold up.

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Convergent Subduction one plate dives under
another. When an ocean plate collides with a
continental plate, the heavier ocean plate will
dive under the continental plate. This type of
boundary often time creates a volcanic zone.
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Convergent Collision two continental plates
collide and fold up against each other often
forming mountain ranges.
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Transform Plates slide past each other. These
type of boundaries cause earthquakes.
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Fault A fracture or break in the Earths crust
where plates move against each other.
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Continental drift theory A theory developed in
1912 by Alfred Wegener that stated that the
Earths continents are slowly drifting apart and
were once part of a large super continent where
all the Earths land was connected.
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Pangea The term for this super continent. It
comes from a Greek word meaning all Earth.
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It is now believed that the Continents are still
actively drifting and that Pangea has been formed
several times over millions of years.
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Earth Quakes a tremendous amount of pressure
can build up along Transform faults and sometimes
this pressure can release suddenly and violently
in the form of an earthquake.
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Seismograph A tool used to measure the energy
or the force of an earthquake.
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Epicenter

• Epicenter The center of an earthquakes
  destructive force.

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Richter Scale

• a tool that uses information collected by
  seismographs to rank the size of an earthquake.
  A 2 or less would be hardly noticeable and the
  biggest one in history was an 8.9 in 1989 in the
  South Pacific.

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Tsunami when an earthquake occurs in the ocean
it can create a very large and destructive wave
called a Tsunami.
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Volcanoes Natural formations where magma and
gasses are forced from below the Earths surface
to land.
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There are several types of Volcanic Eruptions
ranging from extremely destructive to something
neat to look at.
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Mt. St. Helens - Before
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And after.
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Hotspots Thin areas in the Earths crust where
magma regularly flows to the surface.
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A couple of examples of these are the Hawaiian
Islands and the Mid Atlantic Ridge.
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Ring of Fire A name given to a pattern of
Volcanoes that exist along the boundaries of the
Pacific Plate.
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The pattern of Volcanoes forms a large ring and
therefore it was named The Ring of Fire