Transcript Plate Tectonics

TLW identify convergent,
divergent, and transform
plate boundaries
For the purpose of
understanding the different
landforms formed by these
plate boundaries
As measured by naming the
three types of plate
boundaries correctly
Plate Tectonics
Why do we have
earthquakes?
Is the earth’s crust solid?
• No, the earth’s crust is broken into
many plates.
Do the plates move?
• At one time, there was only one
continent called Pangaea.
• Yes, the plates move slowly
over time.
Why do they move?
Heat from the inner earth creates
convection currents that move the
magma.
Driving Forces of Plate Tectonics
 Divergent Boundary 
Two Tectonic Plates That Separate
 Divergent Boundary 
Sea-floor spreading
Magma rises up and
new crust is formed
Divergent Boundary 
MidAtlantic
Ridge
Indian
Ridge
 Divergent Boundary 
Divergent Boundary
Iceland
Rift Valley
 Divergent Boundary 
Rift Valley in Africa
The East African Rift Valley is land that
has sunken by divergent boundary
(Land Subsidence = sinking land)
 Transform
Boundary 
Two tectonic plates slide past each other.
 Transform
Boundary 
 Transform
Boundary 
Convergent  Boundaries
Two tectonic plates collide.
Ocean-Continent
Convergent Boundary
Rising magma
forms new crust
in the form of
mountains and
volcanoes
Sea Trench
Melting of
old crust
Andes Mountains
Visualizing Physical
Geography
Copyright © 2008 John
Wiley and Sons
Publishers Inc.
Ocean-Ocean
Convergent Boundary
Aleutian Trench
Old crust is melted and recycled.
Aleutian Islands
21
Continent-Continent
Convergent Boundary
No new crust is formed or created
TLW identify convergent,
divergent, and transform
plate boundaries
For the purpose of
understanding the different
landforms formed by these
plate boundaries
As measured by naming the
three types of plate
boundaries correctly