1. Unit 2: Geosphere Part 1
Lithospheric Plates, Folds, Faults, Earthquakes, Volcanoes, Tsunamis, etc.

2. Structure of Earth The Earth is made up of 3 main layers: Crust Mantle
Core
Mantle
Outer core
Inner core
Crust

3. Structure of Earth – Crust
Two Types of Crust
Continental Crust :
Thick (10-70 km), Buoyant (less dense than oceanic crust), mostly old, made mainly of granite
Oceanic Crust:
Thin (~7 km), Dense (sinks under continental crust), Young, Made mainly of basalt

4. Structure of Earth – Mantle
Mantle between crust and the core.
Made of hot iron-rich silicate rocks; elastic behavior
Mantle moves via convection currents which is when hot material in the mantle rises, cools, and then sinks.

5. Structure of Earth – Core
Core is broken into two parts:
Outer Core:
Made of liquid iron and nickel
Outer core flows slowly creating an electrical current  generates Earth’s magnetic field
Inner Core
Made of solid iron and nickel

6. How do we know what the Earth is made of?
Information gathered from seismographs
Magnetic and electrical anomalies by air
Satellite images of the Earth’s crust
Mining, drilling boreholes in Earth, and Field research

7. What is the Theory of Plate Tectonics?
Explains how and why the surface of Earth is constantly changing.
States that Earth’s outer shell, the lithosphere, is divided into large plates.

8. What is the Theory of Plate Tectonics?
Scientist hypothesized that the continents appear to fit together like puzzle pieces.

9. How many lithospheric plates are there?
Earth’s crust is divided into 15 plates.
7 major & 8 minor
They are slowly moving in different directions.
Plates can collide, pull apart, or scrape against each other.

10. Earth’s Lithospheric Plates

11. What are lithospheric plates made of?
Plates are made of rigid lithosphere.
Lithosphere is the crust and part of the upper mantle.

12. What is below the lithosphere?
The asthenosphere is below the lithosphere.
It is mostly liquid and made up the upper part of the mantle

13. What causes the lithospheric plates to move?
Plate movement is caused by the movement of hot mantle convection cells.

14. What happens at tectonic plate boundaries?
Three types of plate boundaries:
Divergent
Convergent
Transform

15. What happens at divergent boundaries?
Plates move apart and new material from the mantle fills in the gap.