12 - Mass wasting Flashcards
what are landslides
movement or rock, debris or earth own a slope on land, on the sea floor or on another planet
how are landslides classified
by the nature of their movement and their material before displacement
what is a rupture surface
often a bedding plane, fault or joint
what are some natural factors that precondition failure
- slope angle
- bedding and jointing
- sediment characteristics
- saturation of pore spaces
what are some human factors that precondition failure
- removal of vegetation
- dams reducing sediment supply
- effects of coastal defences
what are landslide triggers
- heavy rainfall
- toe erosion
- human activity
- ground shaking
- volcanic activity
what is subsidence
downward movement of material due too removal of underlying support of compression underlaying layers (e.g. leaning tower of Pisa)
what is creep
the slow downslope movement of materials under gravity
what are some marine mass wasting types
- slide
- slump
- flow
- turbidity current
what are debris flows
most commonly occur on the continental slope and extend to a slope failure
what are turbidity currents
gravity driven turbid mixtures of sediment
