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Quiz/Review. Get out a small piece of paper and put your name on it. When the bell rings, the quiz will begin. Question 1. Name two types of floods?. Question 2. What is the difference between a warning and a watch. Question 3.
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Quiz/Review • Get out a small piece of paper and put your name on it. • When the bell rings, the quiz will begin.
Question 1 • Name two types of floods?
Question 2 • What is the difference between a warning and a watch.
Question 3 • Why should you or should you not travel through flooding water?
Answers • Flash floods, coastal, urban, ponding, River • Warning is possible and a watch is probable. • Unknown depth, water is strong.
What are mass movements • When large areas begin to flow like a liquid do to gravity. • Commonly called a landslide or landslip.
When and how • Usually after a rain event, but sometimes after shaking or volcanic activity. • Think of a sand castle at the beach, what happens over time? Why?
Where do these occur? • Anywhere that has steep slopes and potentially high quick rainfall.
Types Slides Flows When the ground becomes saturated (full) of water. Very wet and muddy. • Large chuck or blocks of soil and rock loosens and is pulled down slope. • Much drier than other movements. Slump Fall • Gravity pulls land down vertical. • Usually very dry on steep slope. • Slow movement over seasons. • Freezing and thawing causing slope failure in small steps.
Causes • Increase in water in the ground. • Alterations to the slope. • Loss of vegetation. • Vibrations • Volcanic eruptions