CASE STUDY- Landslide State US, Washington

Question 1

What are the 6 causes of landslides in Washington?

Answer 1

1) Steep Slopes
2) Glacial sediments
3) heavy precipitation
4) Timber industry
5) Earthquakes
6) Building

Question 2

How do glacial sediments lead to landslides?

Answer 2

• As the glaciers retreated they left Sand, silt and loose material which are porous and weak
• Water within the pores of sediments act as ball bearings allowing soil movement
• As the glaciers retreat they take enormous weight off the terrain which then rises over thousands of years, this increases slopes (Isostatic rebound)