Coasts Flashcards
What is the stages in spit formation
1.long shore drift moves sediment in direction of prevailing wind
Material will continue to be deposited 2.when coastline changes direction creating a spit which overtime will form a permanent feature
3.The river currents in estuary and depth of the water will prevent the spit connecting to the mainland
4.Wave refraction forces material to form a curved end
Mud and silt is deposited behind the spit creating a salt marsh
What is a spit
A spit is a long narrow piece of land joined to the mainland which project out to sea or across a river estuary . It’s a depositional landform made out of sand and shingle
What are the diffract types of mass movement
Soil creep/solifluctuon
Mudflow
Run off
Landslide
Rock fall
Why do waves form
When wind flows over the ocean . The energy from the wind is transferred into the wave via frictional drag . As the wave approaches the shore it breaks as the elliptical motion of the wave is interrupted
What are tides and how are they caused
Tides are the periodic rise and fall in the sea level caused by the frictional pull of the sun and moon
Why are spring tides high
Spring tides are high because the sun and the moon are both pulling the ocean in the same plane . Neap tides are low as the sun and the moon are pulling the ocean in different planes and are working against each other
What is a large and small tidal ranges good for
A large tidal current - Providing energy via tidal currents for the transportation of sediment
A small tidal current - concentrated erosion at cliff base
What are features of a high energy coastline
Rocky coastline
Contains cliffs and headlands
Erosion exceeds deposition
Atlantic facing (for uk)
What are features of a low energy coast
Sandy
Deposition exceeds erosion
Beaches and spits
Less powerful waves
Bays and sheltered areas
What is the process of solifluction ,nature of movement, rate of movement and is it wet or dry
Process- slow Downslope movement of soil due to recurrent freezing and thawing of the ground
Movement-gradual and slow
Wet
What is the process of mudflow , what’s the nature of movement , the rate of movement and is it dry/wet
Process - mud and earth flowing downhill, water gets trapped in mud increasing pressure
Nature and rate of movement- quick
Wet
What is the process of landslides , what’s the nature of movement , the rate of movement and is it dry/wet
When gravity overcomes the forces holding material in place on a slope - can be caused by unconsolidated clays and sands in heavy rain and earthquakes
Very quick
Wet
What is the
What is the process of rockfall , what’s the nature of movement , the rate of movement and is it dry/wet
Rock fragments breaking away from a cliff face
Wuick and sudden
Dry
What is wave quarrying
A braking wave trapping air as it hits a cliff face . The air is compressed into any gaps causing huge pressures
As the water retreats there is an explosive effect of the air pressure being released. This weakens the cliff face .
What are the different types of transportation
Traction
Suspension
Solution
Saltation
What is solution and suspension (transportation)
Solution- soluble materials dissolved in the water and are carried along
Suspension- small particles like silt and clay are carried along in the water
What is saltation and traction(transportation)
Saltation- pebble sized particles are bounced along the sea bed by the force of the water
Traction- large particles like boulders are pushed along the sea bed by the force of the water
Saltation- pebble sized particles are bounced along the sea bed by the force of the water
Traction- large particles like boulders are pushed along the sea bed by the force of the water
What is marine transgression
Erosion during a time of lower sea levels creates materials which is the rolled out towards the coast as sea levels rise
