Question

section 5.3 mass movements
this section describes situations in which large amounts of soil are moved naturally.
reading strategy
previewing as you read the section, rewrite the green topic headings as what questions. then write an answer to each question. for more information on this reading strategy, see the reading and study skills in the skills and reference handbook at the end of your textbook.

1. the transfer of rock and soil downslope due to

__________ is called mass movement.
triggers of mass movements

1. what are the factors that commonly trigger mass movements?

1. circle the letter of each sentence that is true about water triggering mass movements.

a. heavy rains and rapid melting of snow can trigger mass movements by saturating surface materials with water.
b. when the pores in sediment become filled with water, the particles slide past one another more easily.
c. if there is sufficient water, sand grains will ooze downhill.
d. saturation of the ground with water makes slopes more susceptible to the force of gravity.

1. is the following sentence true or false? if the steepness of a slope exceeds the stable angle, mass movements become more likely.

1. what are three possible causes of oversteepened slopes?

Explanation:

Answer:

1. gravity
2. saturation of surface materials with water, oversteepening of slopes, removal of vegetation, and earthquakes
3. a. Heavy rains and rapid melting of snow can trigger mass movements by saturating surface materials with water.; b. When the pores in sediment become filled with water, the particles slide past one another more easily.
4. true
5. stream undercutting a valley wall, waves pounding against the base of a cliff, and human activities such as excavating during construction