1. 8th Grade Earth Science
Name
Date

2. The Earth is Made of 5 Physical Parts
Lithosphere
Asthenosphere
Mesosphere
Outer Core
Inner Core

3. Lithosphere The cool, outermost layer of the earth.
The Lithosphere consists of:
Crust
Rigid, uppermost part of the mantle.
The Lithosphere is divided into 2 huge pieces called Tectonic Plates.

4. Asthenosphere
The solid, soft layer of the mantle below the lithosphere.
The Asthenosphere is made up of mantle rock that flows very slowly, allowing the tectonic plates to move on top of it.

5. Mesosphere Middle Sphere
The Mesosphere is the solid lower part of the mantle below the asthenoshpere.

6. Outer & Inner Core Outer Core Inner Core
The outer shell of the Earth’s core
It is made of liquid iron and nickel.
Inner Core
A sphere of solid iron and nickel.

7. Plate Tectonics
Plate Tectonics is the theory that the lithosphere is divided into tectonic plates that move around on top of the Asthenosphere.
There are 3 types of Tectonic Plate Boundaries:
Convergent
Divergent
Transform

8. Convergent Boundary
The boundary that is created when two tectonic plates collide.
There are 3 types of Convergent Boundaries:
Continental/Continental
Continental/Oceanic
Oceanic/Oceanic

9. Continental/Continental
When two tectonic plates with continental crust collide, they buckle and thicken, pushing the continental crust upward.

10. Continental/Oceanic
When a tectonic plate with continental crust crashes into a tectonic plate with oceanic crust, the oceanic plate slides under the continental plate.
The region where oceanic lithosphere sinks into Asthenosphere is called a subduction zone.

11. Oceanic/Oceanic
When two oceanic plates collide, one of the oceanic plates is subducted, or sinks, under the other.

12. Divergent Boundary
The boundary that is created when two tectonic plates separate.
Also called rift zones.
As the two tectonic plates move apart, magma rises to fill the gap.
At a mid-ocean ridge, the rising magma cools to form new oceanic lithosphere.

13. Transform Boundary
The boundary that is created when two tectonic plates slide past each other horizontally.
As the two tectonic plates slide past one another, they are not smooth, they grind and jerk as they slide, producing earthquakes.