Question

list three variables that influence mass movement

Answer 1

Mass movements are caused by various conditions:

Volcanic activity many times causes huge mudflows when the icy cover of a volcano melts and mixes with the soil to form mud as the magma in the volcano stirs preceding an eruption.
Mudslides can also develop when water rapidly accumulates in the ground, such as during heavy rainfall or rapid snow melt, changing the earth into a flowing river of mud or "slurry.".
Earthquake shocks cause sections of mountains and hills to break off and slide down.
Human modification of the land or weathering and erosion help loosen large chunks of earth and start them sliding downhill.
Vibrations from machinery, traffic, weight loading from accumulation of snow; stockpiling of rock or ore; from waste piles and from buildings and other structures.
However, the trigger mechanism for mass movement is the gravitational pull of the earth on soil, rocks, and mud.

Types of Mass Movements, Slump and Earthflow.
Pictures from: http://www.geo.duke.edu/geo41/mmo2.htm