Global Landforms

1
Global Landforms

• Chapter 5

2
Section 1 Forces Shaping the Land

• There are internal and external forces shaping
  the the Earths surface
• External Forces
• Rock Weathering
• Water
• Glaciers
• Wind

3
Rock Weathering

• Process of breaking and decaying of rocks
• Very slow process
• All rocks are subject to rock weathering
• How does rock weathering work?
• Can be compared to tooth decay
• Chemicals in the air and water pass through rock,
  slowly eating away at it

4
Rock Weathering

• Can also be compared to breaking or chipping a
  tooth
• Forest fires cause cracking
• Freezing water
• Plant roots
• Rock weathering is the first step in soil
  formation

5
Rock Weathering

• Rocks are broken into sediment
• Mud
• Sand
• Gravel

6
Rock Weathering

• Sediments then move
• Gravity
• Water
• Wind
• Ice

7
Water

• Most powerful force of erosion and sediment
  transportation

8
Water

• Rivers can carry sediments long distances

9
Water

• Rivers erode and shape the valleys into which
  they flow
• Grand Canyon 1 mile deep 18 miles wide