Four World Heritage Sites

Throughout history, natural stone has been used to create monuments, build cathedrals, sculpt masterpieces, and build bridges. If you look around your own community today, you may find stone used in many different ways as a building material. Stone can be a very strong material, and may seem to be nearly indestructible, but as you have seen, it can be subject to weathering over time.

The examples in the course text of the Parthenon in Greece, Kilwa Kisiwani off the coast of Tanzania, Mesa Verde in Colorado, and Machu Picchu in Peru demonstrate that stone structures-like natural formations-are inevitably worn down by biological, chemical, and physical weathering. Factors such as rainfall, temperature, rock type, elevation, and vegetation all play a part in the rate of weathering. In this week's Discussion, you will consider the characteristics of the Parthenon, Kilwa Kisiwani, Mesa Verde, and Machu Picchu, and whether or not some sites are more prone to mass wasting and weathering than others.

To prepare for this Discussion:

• Analyze the following four World Heritage Sites listed in figure 9.1 in Chapter 9 of the course text for physical, chemical, and biological weathering. Use Table 9.1 on page 253 to assist you with your analysis.

o Parthenon, Greece
o Kilwa Kisiwani, Tanzania
o Mesa Verde, U.S.A.
o Machu Picchu, Per

• Determine which site is at the greatest risk of weathering. Rank the locations 1 through 4 on their potential for weathering (with 1 being the highest risk).

• Determine which one site is at greatest risk from mass wasting.

With these thoughts in mind:

Post a paragraph with your ranking of the four locations, from the highest risk (1) to the lowest risk (4) from weathering, and explain why you have ranked them this way. Address the type of rock relevant to each location and the type(s) of weathering that impact this site. Then, in a second paragraph, explain the term mass wasting. State which site is most at risk for mass wasting and explain your rationale. If you believe none of the four sites are at risk, explain why.

Be sure to support your ideas by connecting them to the week's Learning Resources, or something you have read, heard, seen, or experienced.

Required Resources

Readings

• McConnell, D., & Steer, D. (2015). The good earth: Introduction to earth science (3rd ed.). Boston, MA: McGraw-Hill.

o Chapter 9, "Weathering and Soils" (pp. 237-266)

In this chapter, you will explore the process of weathering and soil formation. There are scientific equations in this chapter. It is helpful to understand the principles behind these equations, but you are not responsible for memorizing them.

o Chapter 10, "Landslides and Slope Failure" (pp. 267-284)

Each year, there are news broadcasts about landslides engulfing homes and businesses after a big rainstorm. In Chapter 10, you will learn about the factors behind slope failures and landslides that cause millions of dollars in damage annually.

o Chapter 11, "Streams and Floods"

- 11.1 "Humans and Rivers" (pp. 286-287)
- 11.2 "The Hydrologic Cycle" (pp. 287-290)
- 11.3 "Drainage Networks and Patterns" (pp. 290-293)
- 11.5 "The Work of Streams" (pp. 296-303)

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.

• USGS. (2015a). Landslide hazards program. Retrieved from http://landslides.usgs.gov/
• Exploring Earth. (n.d.b). Examine a landscape formed by erosion. Retrieved fromhttp://www.classzone.com/books/earth_science/terc/content/visualizations/es1205/es1205page01.cfm?chapter_no=visualization

Click on various locations on the map to see photographs of well-known eroded landscapes in the United States.

The following animation will help you better understand some of this week's general concepts.

• Exploring Earth. (n.d.j). Observe a raindrop traveling through various paths of the water cycle. Retrieved fromhttp://www.classzone.com/books/earth_science/terc/content/visualizations/es0105/es0105page01.cfm?chapter_no=visualization