1. Earth’s Structure

2. Layers of the Earth
CRUST
MANTLE
CORE

3. LAYER 1 CRUST outer most layer thinnest layer
consists of loose rocks and soil
2 types of crust
continental-dry land
oceanic- ocean floor

4. LAYER 2
MANTLE
thickest layer
carries the most mass
hot solid rock

5. LAYER 3 and 4 CORE inner or center layer 2 parts
outer core liquid layer that contains melted iron and nickel
inner core solid layer that contains solid iron and nickel

6. RESTLESS CONTINENTS

7. ALFRED WEGENER THEORY OF CONTINENTAL DRIFT
The idea that the continents were once part of a giant land mass.
The one giant land mass is called “PANGAEA.”

8. WEGENER’S EVIDENCE Fossil Evidence
fossils are remains of living things that lived long ago.
similar fossils have been discovered in matching coastlines on different continents.

9. Mountain Evidence
some mountain ranges on different continents seem to match.
mountain range in eastern Canada seems to match one found in Norway and Sweden.

10. Rock Evidence
The age and kind of rocks and minerals along the edge of one continent match rocks and minerals along the edge of another continent.

11. THEORY OF PLATE TECTONICS
Earth’s lithosphere is divided into tectonic plates that are in constant, slow motion, driven by convection currents in the mantle.

12. CONVECTION CURRENTS
The movement of a gas or a liquid caused by differences in temperature.
Hot material from deep within the Earth rises while cooler material near the surface sinks

13. Sea-Floor Spreading
The proof of sea-floor spreading supported Wegener’s original idea.

14. Takes place at Mid-ocean ridges.
Sea-floor spreading is the process by which new oceanic lithosphere is created as older materials are pulled away.
Takes place at Mid-ocean ridges.
Mid-ocean ridges are underwater mountain chains that run through Earth’s ocean basins.
Mid-Atlantic
Ridge.

15. TECTONIC PLATES
Pieces of the lithosphere that move around on top of the asthenosphere.
Carry the continents, parts of the ocean floor, or both.

17. MAJOR TECTONIC PLATES NORTH AMERICAN SOUTH AMERICAN PACIFIC INDIAN
AUSTRAILIAN
ANTARCTIC
EURASIAN

19. plate movement
As the plates move, they produce changes in Earth’s surface, including volcanoes, mountain ranges, and deep-ocean trenches.

20. The edges of different pieces of the lithosphere meet at lines called plate boundaries
FAULTS
edges of different pieces of the lithosphere
form at these boundaries

21. DIVERGENT BOUNDARIES
When two tectonic plates move away from one another.

22. Sea-floor Spreading
When the plates pull apart, magma rises and fills in the gap.
At mid-ocean ridge, the rising magma cools to FORM NEW OCEANIC LITHOSPHERE.

23. Continental Rift When two continental plates pull away.
The continents form a RIFT.

24. Divergent Boundaries
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Diverging Africa

25. Diverging Iceland

26. CONVERGENT BOUNDARIES
When two tectonic plates push into one another.

27. Continental vs. Continental
When two continental crustal plates collide, the continents buckle upward and form mountains.

28. Himalayas- Asia

29. Oceanic vs. Continental
The oceanic plate slides under the continental plate.
The continental crust crumbles and forms new mountains.

30. Oceanic vs. Continental
Ex: Andes mtn in S.
America
Cascade Mtns. in N. America- Mt. St. Helens

31. Oceanin vs. Oceanic
Two oceanic plates collide, one of the oceanic plates slides under the other.
also called a subduction zone

32. Oceanic vs. Oceanic
Hawaiian Islands

33. TRANSFORM BOUNDARIES
When two tectonic plates slide past each other horizontally.
Produce EARTHQUAKES.

34. San Andreas Fault

35. New Madrid Fault

36. WHICH TYPE OF BOUNDARY? Rift forming in Iceland San Andreas Fault in
California

37. WHICH TYPE OF BOUNDARY?