The Layers of EarthThe Layers of EarthAnd And
Plate TectonicsPlate Tectonics
How do we know what the How do we know what the Earth is made of?Earth is made of?
How do we know what the How do we know what the Earth is made of?Earth is made of?
• Geophysical surveys: seismic, gravity, magnetics and electrical
Earth LayersEarth Layers
• The Earth is divided into four main layers.
*Inner Core*Outer Core*Mantle *Crust
The CrustThe Crust• The Earth’s crust is
like the skin of an apple. It is very thin compared to the other three layers.
• *The crust makes up 1% of the Earth.
* The crust of the Earth is broken into many pieces called plates.
The MantleThe Mantle• The mantle is
the layer below the crust.
• The mantle is the largest layer of the Earth.
• The mantle is divided into two regions: the upper and lower sections.
Outer CoreOuter Core•The core of the
Earth is like a ball of very hot metals.
* The outer core is liquid.
* The outer core is made up of iron and is very dense.
Inner CoreInner Core* The inner core of
the Earth has temperatures and pressures so great that the metals are squeezed together and are not able to move.
* The inner core is a solid.
LithosphereLithosphere
• The lithosphere
consist of the crust plus the very upper part of the mantle
AsthenosphereAsthenosphere
• Layer of the mantle directly below the Lithosphere.
• Upper Mantle that is soft and bendable like plastic (but still solid).
ReviewReview1) What are the four layers of the
Earth?
2) The Earth’s crust is very ______?
3) The mantle is the largest layer of the Earth? True or False
4) Is the Outer Core a liquid or a solid?
Answers!Answers!
1) Crust, Mantle, Outer Core, Inner Core
2) Thin3) True4) Liquid
Plate TectonicsPlate TectonicsIf you look at a map of the world, you may notice that some of the continents could fit together like pieces of a puzzle.
Plate TectonicsPlate Tectonics•The Earth’s crust is divided
into 12 major plates which are moved in various directions.
•This plate motion causes them to collide, pull apart, or scrape against each other.
•The word, tectonic, refers to the deformation of the crust as a consequence of plate interaction.
Plate TectonicsPlate Tectonics
• How Plates Move
Earth’s Lithospheric Earth’s Lithospheric PlatesPlates
Three types of plate boundaryThree types of plate boundary
• Divergent
• Convergent
• Transform
• Plate Tectonics in Action Video
Divergent BoundariesDivergent BoundariesThis map shows the age of the oceanic crust. The red coloring shows the youngest ages, while the dark blue shows the oldest ages (around 200 million years old). The divergent boundary runs
straight through Iceland….
Divergent BoundariesDivergent Boundaries
• Spreading ridges
–As plates move apart new material is erupted to fill the gap
Convergent BoundariesConvergent Boundaries
• There are three styles of convergent plate boundaries
1. Continent-continent collision
2. Continent-oceanic crust collision
3. Ocean-ocean collision
Continent-continent Continent-continent Collision make mountainsCollision make mountains
Himalayas
Continent-Oceanic Crust Continent-Oceanic Crust CollisionCollision
Also called subduction form volcanoes
Ocean-Ocean Plate CollisionOcean-Ocean Plate Collision
• Forms deep ocean trenches
Mariana Trench is 11km deep!
Transform BoundariesTransform Boundaries
Where plates slide past each other
San Andreas Fault
Color Code Plate BoundariesColor Code Plate Boundaries
• You will need this map to complete future assignments
