Coasts and Rivers Flashcards
Common Entrance revision for coasts and rivers.
Define erosion.
The breaking down of rocks over time.
Name the 4 processes of erosion.
-Hydraulic Action
-Abrasion
-Attrition
-Solution
Name the 4 processes of transportation.
-Traction
-Saltation
-Suspension
-Solution
Define fetch.
The distance a wave travels without obstruction.
Name a cause of waves.
Wind.
What is a constructive wave?
A wave that deposits sediment on to a beach.
What is a destructive wave?
A wave that drags sediment into the sea.
Define swash.
The water and sediment flowing on to a beach from a wave.
Define backwash.
The water and sediment going back to the sea from a destructive wave.
In order, state the stages of erosion a headland can become.
- Cracks form on the headland from the erosion.
- The cracks can break and expand, creating caves.
- The erosion can eventually break its way through to the other side of the headland, creating an arch.
- The land above the arch can collapse, with one side forming a stack.
- The hydraulic action can erode at the base of the stack, causing it to fall. What is left is called a stump.
Name 2 features of the upper course of a river.
V-shaped valleys and waterfalls.
Name 2 features of the middle course of a river.
Meanders and river cliffs.
Name 2 features of the lower course of a river.
Floodplains and mouth.
What is the dent where the water falls into in a waterfall called?
Plunge pool.
What is the protruding mass of rock where the water flows in a waterfall called?
Overhang.
How does traction transport sediment?
It rolls larger sediment on the river floor.
What is the 5th process of transportation?
Floatation.
Where is the current fastest in a river?
The lower course.
How are river cliffs formed?
- In the middle course, a river is flowing in an S pattern.
- At the turn of the pattern, water travels fastest, eroding the outer wall faster.
- Eventually, an overhand is created above where the water cut into the wall. That is a river cliff.
Define solution in erosion.
Solution (a.k.a. Corrosion) is when acid in water dissolves softer rock.
Define solution in transportation.
Solution is when sediment has dissolved into the water, and is carried.
Define suspension in transportation.
Suspension is when sediment is floating under the water, and is carried with the current.
Define traction in erosion.
Traction is when the sediment being transported in current hits other rocks, breaking them into smaller pieces which are carried in the current.
