Erosion- the process and landforms Flashcards
factors that influence erosion
human intervention lithology wave type location discordant vs concordant coastlines
types of transportation
traction (large particles pushed along)
suspension (small particles carried in the water)
saltation (small particles bouncing along sea bed)
solution (dissolved in water)
two factors that influence transportation
energy and size
groynes create a ___ feedback
positive
why do groynes create a __ feedback?
positive because they increase erosion downwind as groynes starve the beach downwind of sediment
sea walls create a _____ feedback … because…
positive, as they deflect the waves backward keeping the energy and transferring elsewhere – increasing erosion downwind
what is a high energy coastline
small particles easily transported whilst larger and heavier material is deposited, forming shingle beaches
what is a low energy coastline
even the smallest matter is deposited forming mudflats and salt marshes
what is wave quarrying (type of erosion)
a breaking wave traps air as it hits the cliff face
the air is compressed into any gaps causing large pressure
as wave retreats there is an explosive effect of the air pressure being released
weakens cliff face- removes large chunks
concordant coastline definition
rocks on these coastlines run parallel to the sea
discordant coastline definition
rocks on these coastlines run perpendicular to the sea
formation of a stump IN DEPTH EXPLAIN
headland is attacked by wave quarrying, HA and solution. erosion begins where waves find a line of weakness in the rock and erode laterally and backwards , forming a cave
if the weakness runs through the headland two caves may form back to back, forming an arch
waves continue to erode the base and sub-aerial processes attack the roof of the arch- roof collapses- leaves a headland and a stack
attacked by biological, physical and chemical weathering and erosion until it collapses leaving a stump which is covered at high tide
how does a wave cut platform reduce erosion in the future
although they rarely extend more than a few hundred metres WCPs slow down the waves as they have further to travel in shallow water. so they tend to break earlier and dissipate their energy before they can erode the cliff reducing the rate of erosion.
– note that WCPs are made out of hard rock
a cliff profile refers to …
how steep the cliff face is at its meeting point with the sea
if the bedding planes (the layers of rock that make up the cliff) are HORIZONTAL then…
the cliff profile will be stable with a steep cliff face
