Mass movements Flashcards
To learn the processes of mass movement (27 cards)
Soil creep has what type of movement…
Slow
What is the precise mechanism of movement in soil creep?
The particles rise towards the surface
Why do the particles rise towards the surface?
Wetting or freezing.
The particles rise….. to the …. in response to ….. as the soil … … or ….
The particles rise vertical to the surface in reponse to gravity as the soil dries out or thaws.
The zig zag movement that happens is similar to what other coastal process.
Longshore drift
Can soil creep be seen?
No
What occurs that suggests soil creep has happened?
Formation of shallow terracetes as well as, build up of soil on the upslope and the bnding of tree trunks.
A mudflow involves?
Earth and mud flowing downhill.
Normally over wich type of surface?
unconsolidated/weak bedrock usually clay.
What will often happen after heavy rainfall?
Water gets trapped within the rock which increase the water pressure.
What does the pore water pressure decide?
How instable the rock is.
How quick are mudflows?
Quick and fast-flowing.
What does it represent?
A natural hazard.
What does a landslide involve?
Block of rock moving rapidly downhill.
What is a difference between a landslide and a mudslide?
The material that moves during the landslide remains largely intact.
What type of surface is a landslide likely to occur on?
A slide plane, often parallel to the ground surface.
Landslide are triggred after what event?
Earthquakes or very heavy rainfall.
How does heavy rainfall cause a landslide to take place?
Lubrication between the two surfaces.
How fast are landslides and do they pose threat to human life?
Rapid and can pose as a natural hazard?
What does a rock fall involve?
Sudden collapse or the breaking away of individual rock fragments.
What shape cliff is this most associated with?
Steep and vertical cliffs.
What is the typical geology of this cliff face?
Impemeable/ resistant rock, as well as heavily jointed meaning fractture are apparent in the rock.
What triggers rockfall?
Mechanical weathering and earthquaes?
What type of mecahnical weathering is likely to occur the most?
Freeze-thaw mainly because the cliff face is heavily jointed meaning it has vertical cracks within the surface.
