1. Chapter 7-Section 1 Earth’s Moving Plates

2. Layers of the Earth
List the layers of the earth in order from the exterior to the interior- in your notebook
Crust
Lithosphere
Asthenosphere
Mantle
Outer core
Inner core

3. Clues to Earth’s Interior
Geologists must use indirect observations
Geologists also study-
to gather clues about what Earth’s interior is made of
earthquakes and rocks that are exposed at Earth’s surface
the speed of waves and the paths they take
Certain rocks from different places on the Earth’s surface

5. Earth’s Layers Earth’s interior has at least 4 distinct layers
inner core, outer core, mantle, and crust

6. Inner Core Inner core Innermost layer
Solid-dense-composed mostly of solid iron
Hottest part
Experiences the greatest amount of pressure

7. Outer Core Outer core Lies above the inner core
Composed mostly of molten metal
liquid

8. Mantle Mantle Above the outer core Largest layer
Flows slowly-similar to putty
82% of Earth’s total volume

9. Crust Crust Earth’s outermost layer Thin compared to other layers
Contains all features of the Earth’s surface

10. Earth’s Plates-Lithosphere
rigid, upper part of Earth’s mantle and the crust
broken into about 30 sections, or plates
Sections of Earth’s crust and rigid, upper mantle that moves slowly around on the asthenosphere

11. Plate tectonics Tectonics – Theory of plate tectonics –
structural deformation of the Earth's crust (Note: prefix “de”
means to undo)
scientific theory explaining how the plates move on the Earth’s surface

12. Tectonic Plates

13. Scientific fact, law, theory
Scientific law –
Scientific theory –
statement that is accepted as being true.
statement that describes an observed phenomenon but
does not explain how or why it occurs.
statement that explains a complex idea.

14. Plate Movement

16. Plate Boundaries Plate boundaries-
Boundaries can form-
Faults-
Where the edges of different plates meet
mountains, huge rift valleys with volcanoes, or faults (which cause earthquakes)
large fractures in rocks along which movement occurs

18. Plates that move apart When plates move apart-
New lithosphere and mid-ocean ridges form
Volcanic activity
Rift valleys
Divergent boundary

19. Divergent Boundary

20. Ocean Basin Ocean basin
a great depression in the surface of the lithosphere occupied by an ocean
are below sea level.
The Atlantic Ocean has an actively growing ocean basin where as the Pacific Ocean has a actively shrinking ocean basin.

24. Plates that collide When plates collide Convergent boundary

25. 3 types of convergent plate boundaries
Mountains/shallow earthquakes
Continental-continental collisions may cause-

26. 3 types of convergent plate boundaries
Continental-oceanic collisions (subduction) may cause-
Earthquake activity, volcanic eruptions, volcanic mountains, tsunamis, ocean trench

27. 3 types of convergent plate boundaries
Oceanic-oceanic collisions (subduction) may cause-
 earthquakes, oceanic trench, a chain of volcanic islands

28. Plate Subduction Plate subduction-
At a convergent boundary-when one plate sinks underneath another plate

29. Plates that slide past When plates slide past each other
transform boundary
Causes faults-which leads to earthquakes

30. Ring of Fire

31. Why do plates move?
Scientists suggest
Convection currents

33. Here is a simulation of convection in the mantle of the earth
Here is a simulation of convection in the mantle of the earth. Hot rock (yellow) rises and cool rock (blue) falls. The rock is at 1000 to 2000o C and creeps slowly; the rate of motion is a few centimeters per year (the simulation shows millions of years). The convection occurs because of the slow change of density with depth in the upper mantle, and between the 700 and 400 km discontinuities. As a result, a hot zone of rock at the bottom of one of these zones expands enough so its density becomes less than that of the surrounding rock and it rises, or floats, toward the surface of the earth. 

34. Earth in the Past and Future