Download Name:______________________________ o ___________________ Samples

Name:______________________________
Chapter 5 Notes: Plate Tectonics
Earth’s Interior

Scientists learn about the ___________________ of Earth in 2 ways
o ___________________ Method
 ___________________ Samples
 ___________________
 ___________________
o ___________________ Method
 Seismic ___________________
 Speed of waves and paths shows the ___________________ of the planet
o Show that the earth is made up of several ___________________
The Layers of the ___________________ vary in several ways
 Temperature
o Gets ________________ as you descend toward the _________________ of the earth
 Temperature ___________________ 1oC for every 40 meters descended
 Pressure
o Pressure ___________________ as you descend
The Layers of the Earth

The Crust
o ___________________ Layer
 Includes ___________________ land
 Includes the ___________________ floor
 Includes ___________________ and soil
o Thinner than other layers
 Thinnest under ___________________
 Called ___________________ crust
o Composed of ___________________
 ___________________ under mountains
 Called ___________________ crust
o Composed of ___________________

The Mantle
o 40 Km ___________________ surface
o Hot ___________________ Rock
o About 3000 km ___________________
o Divided into ___________________
 Lithosphere
 Upper part of ___________________
 ___________________ Layer



Asthenosphere
 Below lithosphere
 ___________________
 Increasing ___________________
 Softer but still ___________________
Lower Mantle
 Under Asthenosphere
 Solid- extends to the ___________________
The Core
o Made of ___________________ and Nickel
o Has ___________________ parts
 ___________________ Core
 ___________________
 Molten(melted) ___________________ surrounding inner core
 ___________________ Core
 ___________________ ball
 ___________________ metal
o Creates a Magnetic Field
 Due to movement in the ___________________
 ___________________ poles
Convection and Mantle
Types of ___________________ transfer
 Radiation: transfer of energy through ___________________
o No direct ___________________ between heat source and object
o Examples
 The ___________________
 ___________________
 Conduction: heat transfer ___________ a material or between materials that are _________
o Responsible for some of the ___________________ transfer within the Earth
o Example: metal ___________________ in a hot pot
 Convection: heat transfer by the movement of ___________________ in a fluid
o Caused by ___________________ in temperature and densities in a fluid
o Examples
 Convection zone in the ___________________
 Deep currents in ___________________
Convection Currents in Earth


Mantle
o Heat from the ___________________ causes convection current
 Moves the ___________________ of the lithosphere
Core
o Heat in the ___________________ (liquid) core causes a convection current
 Causes Earth’s ___________________ field
Continental Drift

Alfred Wegner
o Thought all ___________________ formed Pangaea at one time
 Pangaea: a ___________________ land mass
 Evidence
 ___________________ of the continents
 ___________________
o Glossopteris
 ___________________
o Wegener’s theory was ___________________
 He could not explain the ___________________ that push and pull the
 continents
Sea Floor Spreading
Mid Ocean Ridges
 Tall ___________________ ridges hidden under the oceans
o ___________________ around the world
 In a few places the ridge or mountain is ___________________ the surface of
the ocean
 Example: ___________________
 Mapped using ___________________
o Sonar is a device that ___________________ sound waves off underwater objects
and then records the ___________________ of the sound waves
Sea Floor Spreading
 Sea floor spreads ___________________ along both sides of the mid ocean ridge
o Adds New ___________________
o ___________________ floor like a conveyor belt
 Carries ___________________

Evidence of Sea Floor Spreading
o ___________________ material
 Submarine Alvin finds pillow shaped rocks
 These rocks only form when molten material cools
 ___________________
o Magnetic strips
 The earth’s magnetic poles have ___________________ many times
 Evidence in the ___________________ on the ocean floor
o Drilling Samples
 The samples far from the ridge are ___________________
 The “youngest” rocks near the ___________________ of the ridge
Subduction at Trenches
 Process by which ocean floor ____________
under the trench and ___________________
into the mantle
o Crust near ridge moves
___________________ from ridge
 Like a giant conveyor belt
 The ___________________ floor
o Pacific Ocean is ___________________
 Lots of deep ___________________
 Trench ___________________ more of the floor faster than its made
o ___________________ Ocean expanding
 Oceanic crust ___________________ to the continental crust
 Continents ___________________
Theory of Plate Tectonics
J. Tuzo Wilson
 Scientist who discovered the ___________________
o Plates: a section of the lithosphere that slowly ___________________ over the
Asthenosphere ___________________ pieces of the continental and oceanic crust
 Combined continental drift and sea floor spreading into a ___________________ theory
o Scientific Theory: well ___________________ concept that explains a wide range of
observations
 Ideas that are ___________________ by data.
How Plates Move
 Theory of Plate Tectonics
o Earth’s lithosphere is in ___________________ , slow motion driven by the convection
currents in the ___________________ .

3 ways of moving
o ___________________ (convergent)
o Pull ___________________ (divergent)
o ___________________ past each other (transform)
 Each ___________________ the earth’s surface
Plate Boundaries

Extend ___________________ into the lithosphere
o Faults: breaks in Earth’s crust where rocks have ___________________ past each
other
 Move ___________________
3 kinds of Boundaries
 Divergent Boundaries
o Plates move ___________________ from each other
o Most occur ___________________ the mid ocean
ridge
 Where sea floor ___________________
occurs
o Can occur on land
 Forms a Rift ___________________
 A ___________________ valley

Convergent Boundaries
 Two plates that ___________________ together or _________________
 Density of the plates determine which plate is on ___________________
o ___________________ crust vs. continental crust
 ___________________ .
o Continental crust vs. ___________________ crust
 ___________________ are squeezed from the crust

Transform Boundaries
o 2 plates slip ___________________ each other
 ___________________ are common
o Crust is neither ___________________ or
___________________