1. Unit 1: Land and Water Forms
World Geography
Unit 1: Land and Water Forms

2. The Earth’s Surface and It’s Shape
Looking at Earth from the moon what would we see?
If we could put what we see on fast forward what would we observe?
What could we explain about the earth from our observations?

3. The Structure of Earth Earth is not simply a ball of rock
There are distinct layers that have different qualities.
It is difficult to study the inside of the earth because we cannot simply gaze into the earth.
One method for studying the inner structure of the planet is to study earthquakes
The study of earthquakes is known as Seismology

4. The Structure of Earth

5. The Structure of Earth Inner Core 2700 km in diameter Solid
Made mostly of iron but with some nickle
Temperature of 40000C to 60000C

6. The Structure of Earth Outer Core 2300 km
Liquid, molten iron and nickel
Temperature above 40000C

7. The Structure of Earth Mantle 2900 km in thickness
Divided into two layers, upper and lower
Lower layer is mostly solid
Upper layer is called asthenosphere
The asthenosphere is in a plastic state, sometimes solid sometimes liquid.
Made mostly of magnesium and iron silicates.

8. The Structure of Earth Mohorovicic Discontinuity
The boundary between mantle and lithosphere
This is where earthquake waves abrubtly change speed

9. The Structure of Earth Lithosphere 1-100km thick
Made up mostly of lightest elements, magnesium, aluminum, and iron silicates such as granite
Can be divided into two layers, one under ocean basins and one making up continents
Rocks of continents are known as the crust
Crust is 6-70km thick

10. Types of rock that make up the planet
Igneous: Rock that forms when molten substances cool down and harden.
Sedimentary: Rock that forms when small pieces of other rocks merge together.
Metamorphic: Rock that undergoes some physical or chemical change due to the application of heat or pressure

11. Igneous Rock: Obsidian
Sedimentary Rock
Metamorphic Rock

12. Forms that make up Earth’s surface
The different forms that make up the earth’s surfaces are generally known as its Topography.
Relief is the differences in elevation and slope between the higher and lower parts of the land surface of a given area.
Plains: Large flat expanses found at low elevations.
Plateaus: Large flat expanses that are at higher elevations.
Mountains: Described as elevations of more that 300m; Hills would be elevations less than 300m.

13. A World in Constant Change
The world did not always appear as it does today
225 million years ago all of the continents were actually connected!!!
We called this super continent Pangea, and the super ocean surrounding it Panthalas
Overtime the continents eventually drifted into the positions they occupy today.

15. The Forces at Work
The forces that continental drift create are responsible for many of the features we see on the surface of the earth.
Mountains, volcanoes, and earthquakes are all a result of continental drift.
Plate tectonics: the movement of plates

16. Forces at Work
Compressional force: The force created when two plates move toward each other.
Causes rock layers to bend, warp, and move upward.
Tensional force: Forces of tension are created where two plates are moving away from each other.
Causes large trenches where plates move appart.
1.1.1 Explain how compressional forces are
caused. (k)
1.1.2 Explain how tensional forces are caused.
(k)

17. Activity 1: Mapping the Plates
On the provided map sketch, and label a map detailing the continental plates.
Indicate with arrows in which direction the plate is moving.
Complete the chart attached to the map
Your map should include the following map elements.
Legend
North arrow
Title
1.1.3 Relate selected plate movements to
compressional and tensional forces. (a)

19. Compressional Forces
What features are created by compressional forces?
Fold mountains
Reverse Faults
Overthrust Faults

20. Compressional Forces: Fold Mountains
Fold mountains: Occur where compressional forces cause the land to lift upwards, creating some of the worlds most spectacular mountains.
1.1.4 Explain how compressional forces create
fold mountains. (k)

22. Compressional Forces: Fold Mountains
Fold mountains take on a wave like appearance.
The peak of these waves is called the anticline
The trough of the wave is called the syncline
1.1.5 Differentiate between the terms anticline
and syncline. (k)

23. Anticline and Syncline Folds

24. Compressional Forces: Reverse Faults
Reverse Fault: When two plates push against each other one side can be pushed up over the other.
1.1.7 Explain how compressional forces create
reverse and overthrust faults. (k)

25. Compressional Faults: Overthrust Faults
Overthrust Faults: When folded rock gets pushed together and thrust over other layers we get an overthrust fault
1.1.7 Explain how compressional forces create
reverse and overthrust faults. (k)

26. Tensional Forces What features are created by forces of tension?
Normal Faults

27. Tensional Forces: Normal Fault
Normal Fault: occurs when a plate on one side of a fault drops down lower than the other.

28. How Are Mountains Formed
Mountains are formed in three main ways
Tensional forces
Compressional forces
Volcanoes

29. How Do Volcanoes Build Mountains?
There are three types of volcanoes that all have distinctive characteristics
Ash-and-cinder cones
Shield cones
Composite Cones

30. Volcano Terms
Volcano: most common landform that is associated with extrusive volcanic activity
Vent: area of the volcano through which volcanic products erupt
Magma: Super heated melted rock below the surface
Lava: Liquid rock that has reached the surface
Ash: Small molten rock fragments

31. Volcano Forms
Ash-and-cinder cones: Typical form is symmetrical with steep sides and a large crater at the top
They form from bits of cinder and ash being ejected from the vent and building up to form a cone
These volcanoes can grow rapidly, forming mountains within a few years.
1.1.9 Describe the characteristics of an ashand-
cinder cone, a shield cone, and a
composite cone. (k)

32. At the start

33. Ash-and-Cinder Volcanoes: Paricutin

34. Ash-and-Cinder Volcanoes: Paricutin

35. Present day

36. Volcano Types Shield Cones: Broad flat cones Liquid lava
Mild eruptions
Little or no ash
1.1.9 Describe the characteristics of an ashand-
cinder cone, a shield cone, and a
composite cone. (k)

37. Types of Volcanoes Composite Volcano
Layers of ash and cinders intermixed with layers of lava
Weak points may develop along outer walls
Periods of explosive activity, and relative quiet
1.1.9 Describe the characteristics of an ashand-
cinder cone, a shield cone, and a
composite cone. (k)

38. Composite Cone Volcano

39. What Causes Volcanoes to Erupt
Heat is the major factor in Volcanic eruptions
Where plates meet there is a great amount of heat
When plates are pushed together one slides under another
This heat present causes rock to melt, forming magma
The pressure from the weight of the heavier rock drives the magma up through cracks in the earths crust
Forming volcanoes.
1.1.8 Explain what causes a volcano to erupt.
(k)

40. Global Distribution of Volcanoes
Given what we know about what causes volcanoes to erupt we may say that volcanoes occur where plates meet
The most famous region of volcanoes on earth is know as the Pacific Ring of Fire
The Pacific Ring of Fire circles the Pacific Ocean.
The west coast of north and south america.
The east coast of Asia, and South toward The southern ocean.
Conclude how the location of active
volcanoes is related to places where plates
meet. (a)

41. The Pacific Ring of Fire
Describe global patterns in the location
of landforms. (k)