Coastal Systems and Landscapes

Question 1

What are some examples of inputs into a coastal system

Answer 1

● sediment
● energy - from wind, waves, tides, currents

Question 2

What are some examples of stores/components in a coastal system

Answer 2

landforms such as beaches, dunes and spits

Question 3

What are some examples of flows/transfers in a coastal system

Answer 3

Processes such as erosion, weathering, transportation and deposition can move sediment within the system

Question 4

What is an example of negative feedback in a coastal system

Answer 4

As a beach is eroded, the cliffs behind it are exposed to wave attack. Sediment eroded from the cliffs is deposited on the beach, causing it to grow again

Question 5

What is an example of positive feedback in a coastal system

Answer 5

As a beach starts to form it slows down waves, which can cause more sediment to be deposited, increasing the size of the beach

Question 6

What are different sources of energy in coastal systems

Answer 6

● Wind
● Waves
● Tides
● Currents

Question 7

How are winds a source of energy for coastal systems

Answer 7

● Winds are created by air moving from areas of high pressure to areas of low pressure
● During events such as storms, the pressure gradient (the difference between high and low pressure) is high and winds can be very strong
● Strong winds can generate powerful waves

Question 8

How are waves formed

Answer 8

Waves are created by the wind blowing over the surface of the sea. The friction between the wind and the surface of the sea gives the water a circular motion

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● Winds move across the surface of the water, causing ​frictional drag (resistance to the wind by the water) which creates ​small ripples and waves​. This leads to a ​circular orbital motion of water particles​ in the ocean
● As the ​seabed becomes shallower towards the coastline, the ​orbit of the water particles becomes more elliptical​, leading to ​more horizontal movement of the waves
● The ​wave height increases, but the wavelength (distance between two waves) and wave velocity both decrease
● This causes ​water to back up from behind the wave​ until the ​wave breaks (collapses) and surges up the beach