Week 4: Weathering, Erosion, and Mass Movement 1
Weathering, Erosion, and Mass Movement
Have you ever built a sand castle? You start with a small pile of sand and continue to build and shape it until it forms into a
castle. Then, you stand back in awe of what you built. But wait! A wave comes and washes it away and you are again left
with a small pile of sand.
Just like a sand castle, mountains and other land forms are continually built up, and then worn down through different
processes. This week, you will learn about the forces of change, such as mass wasting, slope failure, the hydrologic cycle,
and weathering that wear down the mountains.
By the end of this week, you should be able to:
Evaluate a location’s risk for damage from weathering, mass wasting, landslides, and flooding
Describe the interrelationship of the hydrologic cycle, streams, floods, and landslides
Understand the concepts and terminology related to weathering and soils, landslides and slope failures, and the
hydrologic cycle and streams
The Good Earth
Chapter 9, “Weathering and Soils” (pp. 243–271)
In this chapter, you will explore the process of weathering and soil formation. There are scientific equations in
this chapter. It is good to understand the principles behind them, but you are not responsible for memorizing
Chapter 10, “Landslides and Slope Failures” (pp. 273–289)
It seems like every year the news broadcasts landslides engulfing a person's house after a big rain storm. In
Chapter 10, you will learn about the factors behind slope failures and landslides that cause millions of dollars in
damage each year.
In Chapter 11, “Streams and Floods” read "11.1 Humans and Streams" (pp. 292-293), "11.2 The Hydrologic
Cycle" (293-295), "11.3 Drainage Networks and Patterns" (pp. 296–299); "11.5 The Work of Streams" (pp. 302–
309); and "Floods" (pp. 309–311)
What is the most valuable substance on Earth? Gold, platinum, diamonds? These may be valuable monetarily,
but water is essential for life on Earth. Without fresh water, you could not survive and many of the plants and
animals would perish. In this chapter, you will learn about the hydrologic cycle that helps to cleanse our water
supply, the path water takes from land to the ocean, and the factors responsible for floods.
LANDSLIDE HAZARDS PROGRAM
Landslides constitute a major geologic hazard because they are widespread, occur in all 50 states and U.S.
territories, and cause $1-2 billion in damages and more than 25 fatalities on average each year. Expansion of urban
and recreational developments into hillside areas leads to more people that are threatened by landslides each year.