Download Notebook #4 Earths layers gt

The Earth’s Layers
Notebook #4 January 22, 2016
8.E.5A.3 Following these notes you will be able to obtain
and communicate information about the relative
position, density, and composition of Earth's layers to
describe the crust, mantle, and core.
The Earth is ~ 4,000 miles (6,400 km) from
surface to center.
Earth has layers that have specific
conditions and composition
The 3 layers of Earth
* Crust
*Mantle
*Core
Crust Position
 *Outermost
layer
 * Thinnest under the ocean
 * Thickest under continents
 * Crust & top of mantle called the   
lithosphere
Mantle Position
* Middle layer
 * Thickest layer
  
 * Top portion called the   
asthenosphere
Core Position
 *
Inner layer
 * Consists of two parts
 – outer core and   inner core
Density
* Measures how heavy an object is for its size
* Formula is mass
 
volume 
* If an object's density is >1, it will sink
* If an object's density is <1, it will float
Crust Density
 *
Least dense layer
 *Oceanic crust (basalt) is more dense than
continental crust (granite)
Mantle Density
 *
Density increases with depth because of
increasing pressure
Core Density
 *
Heaviest material
 
 * Most dense layer
Crust Composition
* Solid rock –
 mostly silicon and oxygen
* Oceanic crust  basalt
* Continental crust  granite
Mantle Composition
 * Hot softened rock
 * Contains iron and magnesium
Core Composition
* Mostly iron and nickel
 * Outer core –
 slow flowing liquid
 * Inner core  spinning solid
* Scientists have been able to identify the
composition of inner and outer core based
on the movement of seismic waves through
the Earth's layers
* Scientists have been able to identify the
composition of the mantle based on the
movement of seismic waves through the
earth's layers as well as materials ejected
from volcanic activity. Most lava that erupts
during volcanic activity is actually just
melted crust and is not material from the
mantle and/or the core.
* The reason that the inner core is solid,
despite being at very high temperatures, is
because of the weight of all of the other
materials above it (crust, mantle, and outer
core). The pressure of these layers keeps
the inner core solid
* The movement of the inner and outer core
results in Earth's magnetic field.