landscapes in the UK Flashcards
how is rock broken down?
by mechanical and chemical weathering
what is mechanical weathering?
the breakdown of rock without changing its chemical composition
give an example of mechanical weathering
freeze-thaw weathering
explain what happens in freeze-thaw weathering
water enters cracks in rocks then freezes, this expands and puts pressure on the rock .when the water thaws it contacts wich realizes pressure. this is repeated and widens the cracks
what is chemical weathering?
the breakdown of rock by changing its chemical composition
what is mass movement?
the shifting of rocks down a slope
what is a scarp
a steep cut in the side of a slope
what are the two types of waves?
constructive and destructive
the greater the fetch of a wave the …
..more powerful the wave
when waves erode the coast what are they called?
destructive waves
what wave has a high frequency, and is high and steep?
destructive waves
what type of waves deposit material?
constructive waves
what is a destructive wave backwash like?
the backwash is more powerful than swash so the material is removed
what is constructive waves backwash like?
swash is more powerful than backwash so the material is deposited
what wave is low frequency and is low and long?
constructive waves
what three types of erosion are used to wear away coasts?
hydraulic, abrasion, and attrition
how does hydraulic power work?
waves crash against rock and compress the air in the cracks, this puts pressure on the rock .repeted compression widens the cracks and causes bits of rock to break off.
how does abrasion work?
eroded particles in the water scrape and rub against the rock, removing small pieces
how does attrition work?
eroded particles in the water collide, break into smaller pieces and become more rounded
what is a trick to distinguish the waves?
destructive waves destroy and constructive waves create beaches
when does deposition occur?
when water carrying sediment loses energy and slows down
what does prevailing mean?
most common
what are the two types of coastline?
concordant and discordant
what are discordant coastlines made up of?
alternating bands of hard and soft rock at right angles to the coast
what are concordant coastlines made up of?
alternating bands of soft and hard rock parallel to the coast
when a Headland and bays formed?
where there are alternating bands of resistant and less resistant rock along the coast, less persistent rock is eroded faster forming a bay, the resistant rock sticks out forming a Headland
what is Headland eroded to form?
caves, arches, and stacks
give two case studies of headlands
Durdle Door in Dorset and old Harry in Dorset
how is a cave formed?
waves crash into the Headland in and large the cracks so repeated arrangement causes a cave form
how is an arch formed?
continued erosion deepens the cave into a breakthrough the headlamp to form an arch
how is a stack formed?
erosion continues to wear away the rock supporting the arch until it eventually collapses
what happens when waves erode Cliffs?
wave-cut platforms are formed
how are beaches formed?
through deposition
where do spits form?
at sharp bends in the coastline
how are sand dunes formed?
when to sand deposited by longshore drift is moved up the Beach by wind
name two types of dunes
embryo dune and mature dune