Sub Aerial Processes Flashcards
What is a sub aerial weathering?
slowly breaks down a coastline, weakens the underlying rocks and allow sudden movements or erosion to happen more easily
What are the types of weathering?
mechanical/physical
biological
chemical
What is mechanical/physical weathering?
in a climate which has temperature fluctuations above and below freezing(freeze thaw is common)
water enters the cracks,expands when frozen by 10% widening the rock, eventually breaking.
Biological weathering?
breaking down of rocks By action of vegetation and coastal organisms.
piddock have adapted shells that can drill into hard rock
Chemical weathering?
occurs where rocks are exposed to air and moisture so chemical processes can breakdown the rocks
solution is the main chemical process
What is hydration?
makes rocks more susceptible to further chemical weathering ,although it involves the physical addition of water to minerals in rocks.
What is mass movement?
What are the factors?
lvl of cohesion within the sediment
height if the slope and slope angle
graim size withing the sediment
temp and lvls of saturation
Types of mass movement?
landslides rockfall mudflows rotational slumping soil creep run off
What are landslides?
cliffs made of soft rock slip as a result of failure within when lubricated, usually following heavy rainfall
Rock fall?
occur from cliffs undercut by the sea or on slopes affected by mechanical weathering like frost action
mudflows?
heavy rainfall cause a large quantities of fine material to flow downhill.