Paper 1 Coastal Environments

Question 1

2.1a

Abrasion

Marine processes

Answer 1

Stone and sand in the water are forced against the cliff. This wears it down (like sandpaper).

Question 2

2.1a

Attrition

Marine processes

Answer 2

Pebbles hit against eachother and are worn down. Eventually they become smoother and rounder.

Question 3

2.1a

Hydraulic Action

Marine processes

Answer 3

Water is forced into cracks, forcing the rock to weaken. After long periods of time, material breaks away from the cliff face.

Question 4

2.1a

Solution

Marine processes

Answer 4

Acids in the water cause the rocks to dissolve, particularly the soluble minerals. The rocks get smaller over time.

Question 5

2.1a

Erosion

Marine processes

Answer 5

Movement of weathered rock away from the site of weathering by wind, water or ice.

Question 6

2.1a

Wave height and length

Marine processes (Wave action)

Answer 6

1. Strength of the wind (stronger wind = bigger wave)
2. How long the wind has been blowing for (long time = bigger waves)
3. The fetch: the distance over which a wave has travelled (big fetch = big waves)

Question 7

2.1a

Crest

Marine processes (Wave Terminology)

Answer 7

The top of the wave

Question 8

2.1a

Velocity

Marine processes (Wave Terminology)

Answer 8

The speed that a wave is travelling

Question 9

2.1a

Wavelength

Marine processes (Wave Terminology)

Answer 9

The distance between two crests or troughs

Question 10

2.1a

Trough

Marine processes (Wave Terminology)

Answer 10

The low area in between to waves

Question 11

2.1a

Wave height

Marine processes (Wave Terminology)

Answer 11

The distance between the crest and the trough

Question 12

2.1a

Wave frequency

Marine processes (Wave Terminology)

Answer 12

The number of waves per minute

Question 13

2.1a

Why waves break

Marine processes (Wave Terminology)

Answer 13

When a wave approaches the coast its lower part is slowed by friction with the bed, but the upper part continues to move forward. As it is left unsupported, it topples over and breaks forward against the cliff face or surges up the beach, this is called wave break. The water that returns down the beach is called backwash.

Question 14

2.1a

Swash

Marine processes (Wave Action)

Answer 14

Water that rushes up the beach when a wave reaches the shore

Question 15

2.1a

Backwash

Marine processes (Wave Action)

Answer 15

Water from a previous wave returning to the sea

Question 16

2.1a

Constructive Waves

Marine processes (Deposition)

Answer 16

Build up beach by depositing materials brought up by strong swash.
* Strong swash and weak backwash
* Shallow gradient waves (short waves)
* Long wavelength
* Lower frequency
* Spilling breakers

Question 17

2.1a

Destructive Waves

Marine processes (Deposition)

Answer 17

Destroys beach by eroding material with strong backwash.
* Strong backwash and weak swash
* Steep gradient waves (tall waves)
* Short wavelength
* Plunging breakers

Question 18

2.1a

Wave Refraction

Marine processes (Wave Action)

Answer 18

As aves approach a headland they become refracted. This causes wave energy to be concentrated on headlands leading to erosion and to be spread out in bays leading to deposition.

Question 19

2.1a

Suspension

Marine processes (Transportation)

Answer 19

Material carried in the water

Question 20

2.1a

Solution

Marine processes (Transportation)

Answer 20

Dissolved material

Question 21

2.1a

Saltation

Marine processes (Transportation)

Answer 21

Bouncing along the bed: lifted and dropped repeatedly

Question 22

2.1a

Traction

Marine processes (Transportation)

Answer 22

Roll along the bed

Question 23

2.1a

Longshore Drift

Marine processes (LSD)

Answer 23

The transport of and pebbles along the coast is called saltation. The Longshore drift (the direction the prevailing wind usually blows from) causes waves to approach the coast at an angle. The swash carries the sand and pebbles up the beach at the same angle (usually 45°). The backwash however, carries the material back down the beach a 90° as this is the steepest gradient. The pattern repeats over time causing beach material to move along the coast in a zigzag pattern.

Question 24

2.1a

Marin processes

Answer 24

Caused directly by the sea, e.g. erosion, transport and deposition

Question 25

# 2.1a Sub-aerial processes

Answer 25

Take place above the high tide level on the land. e.g. weathering and mass movement

Question 26

# 2.1a Weathering

Answer 26

Breakdown of rock in place and does not involve movement.

Question 27

# 2.1a Mechanical weathering (Freeze-thaw weathering)

Answer 27

Cracks in the rocks get wet and filled with water at night the temperature drops below 0℃. Water in the cracks freezes and as water freezes it expands. The cracks become wide because of this and then the temperature rises above 0℃ causing the ice to thaw and contract. This process is continued (widening the crack) until the rock is broken.

Question 28

# 2.1a Chemical weathering

Answer 28

Chemical weathering occurs when rainwater which contain Carbon dioxide (making it a weak carbonic acid) reactions with Calcium Carbonate in rocks such as limestone and chalk. This dissolves and is washed away in solution, weakening the rock over time.

Question 29

# 2.1a Biological weathering

Answer 29

Living things such as burrowing animals and plants attacking rocks and weakening their structures. Plants roots can grow in cracks. As they get bigger they push open the cracks eventually making the rocks fall apart.

Question 30

# 2.1a Mass movement

Answer 30

All downhill movement of material under the influence of gravity. The process cause the cliff to retreat backwards and provides material for the marine processes.

Question 31

# 2.1a Rockfall

Answer 31

The rapid fall of rocks from the face of a cliff because of the action of gravity. This is made worse by freeze thaw loosening the rock. Bare, well-jointed rock. A scree slope of fallen rock is formed at the bottom of the cliff.

Question 32

# 2.1a Landslide

Answer 32

Blocks of rock detach themselves from the cliff and slide downhill along side a slide plane. The rock accumulates at the bottom of the cliff and is removed by the sea.

Question 33

# 2.1a Slumping

Answer 33

Rapid movements of a mass of earth or rock sliding along a concave slip plane. Undercutting of a steep slope by the seas weakens the rock above making a slump more likely. Can occur after periods of heavy rain.

Question 34

# 2.1c Formation of headlands and bays

Answer 34

The hard and soft rocks determine the geological structure as they are affected by erosion differently from eachother. They form along discordant coastlines.

Question 35

# 2.1c Discordant coastlines

Answer 35

The rocks out crop at 90° to the coastline, and bays and headlands are formed along this coastline due to differential erosion.

Question 35

# 2.1c Concordant coastline

Answer 35

Only have one rock type which is parallel to the coastline.

Question 35

# 2.1c Wave cut platforms

Answer 35

At high tide the power of the sea erodes the bottom of the cliff by processes such as hydraulic action and abrasion. Over time this erosion creates a wave cut notch. As the wave cut notch gets bigger, undercutting occurs and the weight of rock above the notch gets greater. Eventually the cliff cannot support its own weight and it collapses. The process then starts again, with the erosion of the sea making a new wave cut notch. As the process continues the cliff starts to move backwards. Because the cliff is moving backwards a wave cut platform (an expanse of bare rock) is created. Wave cut platforms are only visible at low tide and is smoothed down by the wave action.

Question 35

# 2.1c Cliff erosion

Answer 35

A cliff's shape varies with: 1. The nature of the rock (geology) 2. Its bedding (angle of dip) 3. The presence or absence of bands of weaker rock

Question 35

# 2.1c Formation of caves, arches, stacks and stumps

Answer 35

1. Crack opens up as waves erode a weakness in the rock 2. Cave crack widens tnrough erosion to form a cave 3. Cave ends all the way through the headland to produce an arch 4. Subaerial processes weaken the top of the arch which eventually collapses leaving a stack 5. Stack is eroded and weathered down to a stump 6. More erosion

Question 36

# 2.1c Beach profile

Answer 36

A cross section of a beach from the high water mark to the low water mark.

Question 36

# 2.1c Factors that influence beach profiles

Answer 36

* Sediment size * Wave type (constructive or destructive) * Tidal range

Question 36

# 2.1c Shingle beaches

Answer 36

Coarser, larger material is carried to the top of the beach as the swash is usaully stronger than the backwash. (Constructive waves)

Question 36

# 2.1c Formation of a spit

Answer 36

1. Follows the prevailing wind direction 2. Constructive waves and the swash push sediment up the beach 3. Backwash moves sediment down the beach 4. Sediment moves along the beach in a zig-zag pattern 5. Sand and shingle is moved along the coast by longshore drift 6. Sediment is deposited in sheltered water as the current slows down and there is insufficient energy to carry the sediment 7. Sediment builds up above the level of the sea 8. Sediment comes to a change in the direction of the coastline 9. If a spit grows across the river a bar forms and a lagoon 10. Coast is sheltered and shallow 11. Saltmarsh and sand dunes build up behind the spit

Question 36

# 2.1c Sandy beaches

Answer 36

Backwash carries smaller, finer material back down the beach. (Destructive waves)

Question 36

# 2.1b Metamorphic Rocks

Answer 36

Hard and resistant rocks including granite and basalt. They form headlands in discordant coastlines. Are are tall and steep with rocks at the base.

Question 36

# 2.1b Igneous Rocks | Influence of geology on coastal environments

Answer 36

Hard and resistant rocks including granite and basalt. They form headlands in discordant coastlines. Are are tall and steep with rocks at the base.

Question 36

# 2.1c The difference between a spit, bar and tombolo

Answer 36

A spit cuts across the sea cutting off a lagoon behind it. If a spit joins from mainland to an island it is called a tombolo. A bar is from mainland to mainland and forms similarly to spits.

Question 36

# 2.1b Sedimentary Rocks