Question

What is the main reason for rapid mass movement?
A. Rockfalls
B. Landslides
C.Land subsidence
D. All of the above

Answer 1

Hint: Mass movements is the soil moving in bulks due to the pull in gravity or the rapid sinking of the earth’s ground surface in a vertical direction.

Complete answer: Mass movements are also called mass wasting and it is a continuous erosional process.This is a geomorphic process in which rock,solid moves down as a solid under the force of gravity with a characteristic flow as in debris flow and mud flows. The main reasons for mass movements are rock falls, landslides,land subsidence. The downslope movements are a result of several factors such as: weathering, erosion. The pull of the gravity causes sections from the cliffs of the hills to move down. These mass movements can be dangerous because they occur very fast and include the entire area.The four types of mass movements are: creep, falls, slides and flows.These classifications are based on how fast the rock and sediments move and how much water it contains. The material of the slope is also another factor.The slopes which are made up of clay and shale are more prone to mass wasting.

Therefore, The correct answer is Option D.

Note: Gravity is the major factor that causes mass movements. This is not under human control. The stability of the slope is also determined by the amount of water it contains.Hydro Compacting soils expand and they contain high amounts of clay minerals. When they get wet they expand and increase the volume of the mineral.When this clay dries out they lose water and become compact.This process is called hydro compaction.