Transcript Lab 3&4 PowerPoint

LAB 3:
FORCES THAT CAUSE
EARTH MOVEMENTS
Key Question: Does the rock
of the Earth’s mantle move?
Plasticity
Today, you will see what happens to a
material that has plasticity (the ability to
flow) when it is heated from below
Observations
The corn syrup warmed & bubbled on the
bottom of the pan in the center.
The warmed corn syrup rose causing the
cardboard to move apart very slowly.
This is a model of convection.
*CONVECTION CURRENT*
Convection Animation
CONVECTION:
• When a substance moves because it is
heated from below and cooled from above.
Warm less dense material rises while cooler
more dense material sinks.
Convection in the Mantle:
Mid-Ocean
Ridge
Earth vs. Model
When comparing our model to the earth, what do the
following parts of your model represent?
• The heat source (candle): Core
• The moving syrup: Mantle Convection
• The cardboard pieces: pieces of the Earth’s crust
Plate Tectonics
Sea Floor Spreading
Mid-Ocean Ridge
Iceland
LAB 3:
FORCES THAT CAUSE
EARTH MOVEMENTS
Key Question: Does the rock of
the Earth’s mantle move?
Yes, the rock of the earth’s mantle is a solid
but it has plasticity (or the ability to flow)
The outermost layer of the Earth is
the crust.
The Earth’s crust (lithosphere) is like a
puzzle.
It is made up of a series
of plates (Lithospheric
plates) that move around
the earth slowly due to
convection in the mantle
(more specifically the
asthenosphere)
Plate Tectonics
Is the theory that the earth’s crust
is broken into plates that move and
interact with each other
These plates interact with each
other at
Plate boundaries
(areas where plates meet)
There are 3
main types
of plate boundaries:
•Divergent
•Convergent
•Transform
Plate Boundaries
animations
along plate
boundaries.
Plate Boundary
Map GEOLOGY.COM
Divergent Plate Boundaries
Where lithospheric plates move
away from each other and new
crust is formed
Convergent Plate Boundaries
Where lithospheric plates move
toward each other and collide
Transform Boundaries
Where lithospheric plates
slide/grind past each other sideby-side
LAB 4:
Movement of the
earth’s lithospheric
plates
Key Question: What happens where
lithospheric plates meet?
Divergent Plate Boundaries
Where lithospheric plates move away
from each other and new crust is
formed
CAUSES SEA-FLOOR
SPREADING
Convergent Plate Boundaries
Where lithospheric plates move
toward each other and collide
3 Types
Ocean – Ocean Convergence
Ocean – continent Convergence
continent – continent Convergence
Continental Crust
Thicker, less dense lithospheric plate
Vs.
Oceanic Crust
Thinner, more dense lithospheric plate
Ocean – continent Convergence
•Ocean plate is subducted below continent.
Subduction: The movement when one plate (oceanic
crust) dives below another plate
•A trench forms above the subduction zone in water
•A volcanic mountain chain forms on land
Ocean – Ocean Convergence
•One Plate Subducts
•Subduction: The movement when one plate (oceanic
crust) dives below another plate
•A trench forms above the subduction zone in water
•A volcanic island arc forms on the plate that is not
subducted
Ring Of Fire
continent – continent Convergence
•No subduction because continents are less
dense than the mantle
•Continents collide and fold up (crunch) to form
mountains
Ocean – Continent Convergence
1. A. When an ocean plate converges with a
continental plate, what happens?
(Which plate subducts?) Explain.
B. What is a subduction zone?
C. What feature is found on the earth
directly above the subduction zone?
D. What feature forms on land? Explain.
Ocean – ocean Convergence
2.A. When two ocean plates collide, what
happens?
B. What feature is found on the earth’s
surface directly above the subduction
zone?
C. What feature forms on the ocean plate
that is not subducted? Explain.
Continent– Continent Convergence
3.A. When two continents collide, what
happens?
B. What feature forms on the earth’s
surface because of the collision?
C. Why don’t continents go down at the
subduction zones?
Transform Boundaries
Where lithospheric plates slide/grind
past each other side-by-side
The San Andreas
Fault is a
TRANSFORM Fault