1. The Earth’s Interior Composed of 4 layers Crust Mantle Outer Core
Inner Core

2. Crust Temperature: Over 175 degrees Celsius Topmost layer of the Earth
Relatively cool
Made of rock
2 types of crust
Oceanic (4-7 km thick)
Continental (20-40 km thick)

3. Mantle Temperature: Over 1250 degrees Celsius
Makes up about 80% of the Earth’s volume
~ 2900 km thick
Outer mantle – rocks
Inner mantle – “plastic”

4. Core Temperature: Over 6000 degrees Celsius Outer core – liquid
Pressure from the mantle & crust do not allow the metals in the outer core to become gasses
Inner core – solid
Pressure from the mantle and crust do not allow the metals to become liquid

5. Plate Tectonics
The Earth’s lithosphere is made up of 7 tectonic plates
Plate tectonics – the movement of these lithospheric plates

7. Why do the plates move?
One theory suggests that plates move due to the convection currents in the asthenosphere (“plastic” inner portion of the mantle)

8. Divergent Plate Boundaries
2 plates move apart
Magma fills the gap created from this movement
Magma cools as it reaches the Earth’s surface creating rift valleys

10. Convergent Plate Boundaries
Oceanic plates dive beneath continental or oceanic plates (called subduction)
Creates deep ocean trenches

11. Wall diving- coral reefs form over time on the “walls” of deep sea trenches. Many are thousands of feet deep.

12. Convergent Plate Boundaries
Mountains form at the convergent plate boundaries as magma from the mantle rises, pushing continental crust upward

13. Convergent Plate Boundaries
Volcanoes form at the convergent plate boundaries as magma rises to the surface and cools

14. Transform Fault Boundaries
Plates move past each other at cracks in the lithosphere (called faults)
Transform fault boundary – horizontal movement between two plates

15. Earthquakes Occur at plate boundaries
Plates slide past each other creating pressure
Rocks break along the fault line
Energy is released, called seismic waves

16. San Andreas Fault

17. Focus = point of earthquake origination
Epicenter = point on the Earth’s surface directly above the focus

18. Energy from an earthquake
Energy is released in the forms of waves
P wave: Primary or longitudinal waves originate from the focus & move quickly through rock. These are the first waves to be recorded
S wave: Secondary or transverse waves originate from the focus & moves more slowly through rock.
Surface waves: move across the earth’s surface, causes building to collapse

19. Earthquake Measurement
Seismograph
Records data about P, S and surface waves
Used to locate the epicenter of an earthquake
Richter scale
Measures energy released at the epicenter of an earthquake (in magnitude)
Each step up in magnitude represents a 30-fold increase in energy released!

21. Volcanoes
Volcanoes result from openings or vents in the Earth’s surface
Magma reaches the surface through these vents
When magma reaches the surface it changes physically and is called lava

22. Shield Volcano Formed from fluid lava, rich in iron
Shield volcanoes are large
Mauna Loa in Hawaii

23. Composite Volcano Made of alternating layers of lava, ash and cinders.
Magma is rich in silica and thick
Large with steep slopes

24. Cinder Cone
Large amounts of gas are trapped in the magma causing violent eruptions
Active for short periods of time

25. Minerals & Rocks Minerals: Rocks:
naturally occurring, inorganic substances
(inorganic = does not contain Carbon)
can be expressed by a chemical formula
Quartz SiO2 (silicon dioxide)
Rocks:
Composed of minerals

26. Types of Rock Igneous Sedimentary Metamorphic
Formed when magma or lava cools and hardens
Magma forms intrusive igneous rock
Lava forms extrusive igneous rock
Sedimentary
Formed when rock particles, plant and animal debris are carried away by water, redeposited, then fused together
Metamorphic
Rock particles are fused together by pressure beneath the Earth’s surface

27. Determining the age of rocks
Two ways to “determine” the age of a rock:
Superposition – determine the age based on layers, older rocks are on the bottom, newer ones on top
Radioactive dating

28. The Rock Cycle

29. Weathering and Erosion
Two types of weathering
Physical
Breaks rocks into smaller pieces, chemical composition does not change
May be caused by ice or plants
Chemical
Changes the chemical composition of rocks
May be caused by oxidation or acid rain

30. Erosion Erosion: the process of loosening and removing sediment
Caused by water, glaciers, wind

31. Deposition Occurs when loose sediment is laid down
Causes river beds to widen and deltas to form.

32. Important Elements Oxygen – most abundant element in the Earth’s crust
Nitrogen – most abundant element in the atmosphere
Iron – most abundant element in the core