Download Layers of the Earth

 Once you get past the soil of the earth, you hit the
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bedrock, known as the first layer of Earth called the
crust
Only about 5 miles
thick and 25 miles
at its thinnest part
Found under our feet
and under the ocean
Rocky and solid
Broken into large
segments that move
called plates
Continental Crust
• Thicker crust
• Lighter density material
• Made of granite and
rhyolite
• Place where we live
Oceanic Crust
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Thinner Crust
Heavier density material
Made of basalt and olivine
Under water
 Once you get past the crust,
you end up in the second
layer called the mantle
 Thickest layer of the Earth
 Contains the convection
cells that raise hot mantle material up and allows cool
mantle material to sink
 Creates the motions of mantle plume, ridge push, and
slab pull (TBD)
 Third layer of the Earth is
called the outer core
 This a liquid layer of the
Earth made of iron and nickel
 This spinning outer core is what makes the EM Field
that protects us from the dangerous radiation of space
 It stays liquid because it is the perfect combination of
temperatures and pressures
 The very center of our Earth
is called the inner core
 This is a solid chunk of
iron and nickel that is the
source of our gravity on Earth
 It stays solid because of all of the pressure that is
pressing down on top of it from all the materials above
it.
 The plates are not just made of crust
 The plates of the Earth are made of the crust and a the
top part of the mantle called the lithosphere
 This plates are constantly moving and changing size and
shape
 Under the lithosphere, there is a layer of mantle that is
super soft (like melted plastic) that the plates float on
top of
 This layer is called the asthenosphere
 The plates do not just move in one direction
 3 Types of Movements
 1. Coming together
 2. Moving apart
 3. Sliding past each other
 All plates are moving at all times
 There are two types of plates:
 Continental Plates and Oceanic plates
 Each plate could be doing all three motions, just on
different sides of the plate
 These movements will create the landscapes and
mountain ranges that cover the lands and ocean floors,
and other hazards that we come in contact with
 1. Convergent Plate Boundaries https://www.youtube.com/watch?
 Two plates come together
v=dXDYoCqwSbM
 Where the two plates meet, one is usually subducted
 Subducted means to go beneath
 The plate that is subducted is destroyed in the mantle
 This is why convergent plate boundaries are called destructive
plate margins
 Examples 
 2. Divergent Plate Boundaries https://www.youtube.com/watch?v=2
 Two plates separating
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 When the two plates separate, the crust is pulled thin
and creates a hole in the crust called a rift
 This rift will extend down to the mantle, allowing
mantle material to rise and create new plate material
 This is why divergent boundaries are called constructive plate
margins
 Examples 
 3. Transform Fault Plate Boundaries
 This is where two plates are sliding past each other
 Plates are neither destroyed or created
 This can happen between continental plates or between
oceanic plates
 Where the plates are sliding, they will create a fault,
which is where many earthquakes happen all over the
world
 Most active fault 
https://www.youtube.com/watch?v=tIuk2bl
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 Earthquakes A shaking of the Earth’s crust
 Occurs at all types of plate boundaries, but happens
more often at transform fault boundaries
 Volcanoes  Expulsion of lava and gases from the
Earth’s crust
 At convergent boundaries, they can happen underwater
or on the land
 At divergent boundaries, most of the volcanoes happen
underwater
 There are no volcanoes at transform fault boundary
 If the eruptions or earthquakes happen underwater,
there will be an uplifting of the crust
 That will push the ocean water up and create a tsunami
 This is not a tidal wave because there is nothing this
wave has to do with the tides
 All of these hazards will cause massive amounts of
property damage and loss of life if we are not prepared
for the dangers of nature