Landslide/mass wasting/mass movement: interchangeable in eosc114, involves the movement of material down a slope (at any rate) Talus: a sloping mass of rock fragments at the bottom of a cliff. Most slopes outside mountain ranges are gentle and lack a free face. Can be convex, concave, straight, or a combo. Human and economic impacts of landslides are broadly governed by. Landslides are often underestimated, and/or the fatalities are attributed to the landslide trigger (earthquakes, floods, volcanoes, etc. ) B. c. has a mountainous terrain, lots of rain, a complex geology, and many triggers which make it prone to landslides. Return period on large landslides= (>20 million metres cubed of material)= 25-70 years. Debris (mixture of rock, earth, trees, water, and anything else on the slope) Often characterized by a curved scarp above slide. Usually strong material moving on planes of weakness. Cohesive motion of material along a flat surface. Material moves as a coherent mass along a surface of failure.