Coastal processes

Question 1

What are spring tides?

Answer 1

Spring tides occur after a full moon, where the sun & the moon are alligned. This results in larger tides as the gravity of both the moon and the sun exacerbates eachother.

Question 2

What are neap tides?

Answer 2

Neap tides occur when the sun and the moon are at a right angle to eachother. This results in moderate tides as the sun’s gravity cancells out the moon’s gravity.

Question 3

What are currents?

Answer 3

Currents are the large scale movement of water in the oceans.

Question 4

The thermohaline circulation is a process driven by the different ___________ in water, as _____ water, as well as ______ water, is denser. It moves ______ than currents. It affects ________ by moving hot water to different areas.

Answer 4

densities
cold
salty
slower
climate

Question 5

List five types of mass movement.

Answer 5

1= Rockfall
2= Landslip/slump
3= Soil creep
4= Mudflow
5= Landslide

Question 6

_________ is the sudden collapse and breaking away of rock fragments at a cliff face.

Answer 6

Rockfall

Question 7

What is rockfall.

Answer 7

Rockfall is the sudden collapse and breaking away of rock fragments at a cliff face.

Question 8

What is a landslip? (a.k.a slump)

Answer 8

Where soil / rock fall down a slide surface. It normally involves weak clay or sands, and rain lubricates the curved slip plane. Can create a stepped pattern in the cliff.

Question 9

What is soil creep?

Answer 9

It is very slow movement of soil downhill (1cm a year). Driven by rain and humid environments.

Question 10

What is a landslide?

Answer 10

Rock moving rapidly downhill along a plane, often triggered by an earthquake.

Question 11

What is mudflow?

Answer 11

Flow over unconsolidated material. It is often caused by instability due to wet conditions (link to flooding). Usually fast and via steep slopes.

Question 12

What is corrasion?

Answer 12

Corrasion is the launching of rocks against a cliff face, weakening it.

Question 13

What is abrasion?

Answer 13

Abraison is the sandpapering effect of rocks against a coastline.

Question 14

What is caviation?

Answer 14

Caviation is where bubbles of air are compressed resulting in cracks in a cliff.

Question 15

What is hydraulic action?

Answer 15

Hydraulic action is where waves break against a cliff and forces itself into cracks.

Question 16

What is wave quarrying?

Answer 16

Wave quarrying is where waves break against unconsolidated material and scoop out loose material.

Question 17

What is attrition?

Answer 17

Attrition is the smoothing and reducing of angular rock into pebbles.

Question 18

What is solution (corrosion)?

Answer 18

Soultion is where acids in seawater dissolve alkaline rock.

Question 19

What is weathering?

Answer 19

Weathering is the breakdown of rocks in situ.

Question 20

_________ weathering is the breakdown of rocks due to their interaction with air, water or acid.

Answer 20

Chemical

Question 21

___________ weathering is where rocks are broken down by physcial factors in the environment.

Answer 21

Mechanical

Question 22

__________ weathering is the breakdown of rocks by plants, animals and micro-organisms.

Answer 22

Biological

Question 23

What is freeze-thaw?

Answer 23

This is where water continuously seeps into rocks and expands.

Question 24

What is exfoliation?

Answer 24

This is where cracks develop parallel to the land surface and break off in ‘sheets’.

Question 25

What is crystallisation?

Answer 25

This is where water goes into holes and evaporates, turning into crytsalls which expand the rock.

Question 26

What is transportation?

Answer 26

Transportation is the process of eroded material being moved.

Question 27

What are the four types of transportation?

Answer 27

1= Solution 2= Suspension 3= Saltation 4= Traction

Question 28

What is solution (transportation)?

Answer 28

Solution is where substances that can dissolve are carried along in the water, such as Limestone.

Question 29

What is suspension?

Answer 29

Suspension is where very fine material, such as silt and clay particles, is whipped up by turbulence and caried along in the water.

Question 30

What is saltation?

Answer 30

Saltation is where larger particles, such as pebbles or gravel, are too heavy to be carried in suspension. Instead, the force of the water causes them to bounce along the sea bed.

Question 31

What is traction?

Answer 31

Traction is where very large particles, e.g. boulders, are pushed along the sea bed by the force of the water.

Question 32

Explain the process of longshore drift.

Answer 32

The transportation of sediment along the shore is known as longshore drift. The swash carries sediment up the beach parallel to the prevailing wind and the backwash carries is back down at a right angle to the shore. When the wind is not parallel, it moves sediment along the beach in a zig-zag pattern.

Question 33

What is deposition and what are it's two types?

Answer 33

Deposition is where material being transported is dropped on the coast. It can be marine or aeolian.

Question 34

What is marine deposition?

Answer 34

Marine deposition is when sediment carried by seawater is deposited.

Question 35

What is aeolian deposition?

Answer 35

Aeolian deposition is where sediment carried by wind is deposited.

Question 36

What causes deposition to occur?

Answer 36

Deposition occurs when the sediment load exceeds the ability of the water and/or wind to carry it. This could be because the sediment load increases or the wind or water flow slows down.

Question 37

What are two ways in which wind and water may slow down?

Answer 37

1= When waves enter shallow water or wind reaches land, friction increases slowing it down. 2= If wind or water encounters an obstacle, flow becomes rougher and the overall speed decreases.

Question 38

What is the likely effect of the wind slowing down?

Answer 38

The wave height, speed and energy will decrease as well.