2. Compositional Layers divided into 3 layers based on elements that make up each layer

3. CRUST Continental Crust Oceanic Crust Outermost, solid layer
Made mostly of oxygen, silicon, and aluminum
Divided into two types:
Continental Crust
Less dense
Thicker ( km)
Under continents
Oceanic Crust
Denser (2x more iron, calcium, and magnesium)
Thinner (5-20 km)
Under ocean

4. MANTLE Convection occurs in this layer! Layer between crust and core
2,900 km thick
Contains about 2/3 of Earth’s mass (67%)
Mostly made up of magnesium
Solid but acts like a liquid (like asphalt or chewed gum)

5. CORE Densest layer Made of iron and nickel
Extends from mantle to center of Earth
Radius of 3,430 km (diameter = 6,860 km)
About 1/3 of Earth’s mass (33%)

6. Physical Layers divided into 5 layers based upon different physical properties

7. LITHOSPHERE ASTHENOSPHERE MESOSPHERE Solid, rigid outermost layer
Crust and upper mantle
km thick
Divided into pieces called tectonic plates
ASTHENOSPHERE
Middle mantle
Solid but acts like a liquid (plastic-like)
Convection – allows movement of tectonic plates
250 km thick
MESOSPHERE
Lower mantle, beneath asthenosphere
Solid, liquid-like rock flows slower
2,550 km thick

8. OUTER CORE INNER CORE Between mesosphere and inner core
Only liquid layer!
Made up of iron and nickel
Convection – creates Earth’s magnetic field
2,200 km thick
INNER CORE
Innermost, densest layer
Pressure causes it to be solid
Made up of mostly iron and some nickel
Radius = 1,230 km (diameter = 2,460 km)