Claire Chadwick; Lauren Maurizio; Robin Humphreys; and Vijay Vulava
In this section, we focus on how the process of erosion slowly changes mountains and also leads to mass wasting. Earth’s surface environments have a significant impact on landscapes. Forces such as water, wind, ice, gravity, and biological organisms sculpt and shape these landscaped by the process of weathering and erosion. The sudden movement of land and soil in mountainous environments due to erosion can result in mass wasting events such as landslides. In this section, we will investigate the causes of mass wasting events and focus on the Oso Landslide – one of the deadliest landslides that occurred in the US in recent times.
Exercise 2 – Erosion and Mass Wasting
Use the following resources to answer the questions in this section:
- 5 Weathering, Erosion, and Sedimentary Rocks – An Introduction to Geology (opengeology.org)
- 10 Mass Wasting – An Introduction to Geology (opengeology.org)
- Define erosion.
- Of the three mountain ranges studied previously, which range has undergone the most erosion?
- The age of a mountain range correlates positively with the amount of erosion. T/F
- What geographic feature is common to the areas of elevated risk of landslides and other types of mass wasting?
- Why does this feature have a higher landslide risk?
- List the seven most common triggers that cause landslides.
- Identify the natural triggers from the list.
- Identify the anthropogenic triggers from the list.
Oso, Washington 2014 Landslide
In 2014, a major landslide occurred near Oso, Washington wiped out a rural community and taking the lives of 43 people. We will investigate why this landslide occurred and if humans may have contributed to this disaster.
Exercise 3 – Oso Landslide
Use the following resources to answer the questions in this section:
- Watch the video to learn about the triggers and evidence of past landslides in the area.
- Causes of Deadly Washington Mudslide Revealed in Scientific Report (nationalgeographic.com)
- A PDF version of the above article is available on OAKS
- 10 Mass Wasting – An Introduction to Geology (opengeology.org)
- What type of landslide was this?
- List the three natural factors that contributed to the landslide.
- What anthropogenic factors may have contributed to the landslide?
- What landslide triggers can you identify that could have helped predict that a landslide might occur in this area?
- Was there evidence for past landslides in this area?
- How is the LIDAR technique used to identify evidence of past landslides?
- How are computer models being used to predict the possibility of another landslide?
Climate Change and Natural Disasters
The rapidly changing climate on Earth is increasing extreme weather events as well as shifts in global climate patterns. These changes may contribute to increasing the intensity and frequency of natural disasters.
Exercise 4 – Climate Change and Natural Disasters
Use the following resources to answer the questions in this section:
- List two reasons how the risk of landslides is likely to get worse as the climate changes.
- According to this article, how does climate change reduce landslide risk?
