Geography EQ 1 (Coast)

Question 1

Define coast

Answer 1

A coast is a zone where the land meets and interacts with the sea.

Question 2

what are the parts on a coast?

Answer 2

1. foreshore
2. backshore
3. offshore
4. berm
5. cliff
6. wave-cut platform

Question 3

Factors that affect coastal environmental dynamics

Answer 3

1. waves
2. tides and sea level changes
3. currents
4. geology
5. types of ecosystem
6. human activites

Question 4

define wave

Answer 4

a wave is a rising and falling movement of the water surface that is usually produced by winds blowing across the sea

Question 5

what does tides affect

Answer 5

processes like coastal erosion, sediment transportation and deposition

Question 6

define current

Answer 6

a large scale, continuous movement of water in seas

Question 7

define geology

Answer 7

the arrangement and composition of rocks found in the area

Question 8

how are waves formed

Answer 8

formed when wind blows over the surface of the ocean . teh friction from the wind causes the water particles near the surface to move in an orbit

Question 9

crest (parts of a wave)

Answer 9

highest part of a wave

Question 10

trough (parts of a wave)

Answer 10

lowest part of a wave

Question 11

wave height (parts of a wave)

Answer 11

verticle distance between the crest and the trough

Question 12

wavelength (parts of a wave)

Answer 12

the horizontal distance from crest to crest, trough to trough

Question 13

wave steepness (parts of a wave)

Answer 13

the ration of wave height to wavelength (height/wavelength)

Question 14

wave period (parts of a wave)

Answer 14

the time waves take to travel through 1 wavelength

Question 15

wave frequency (parts of a wave)

Answer 15

the no. of wave crests and troughs that pass a fixed point in 1 second

Question 16

Factors affectig wave energy

Answer 16

1. wind speed
2. length of fetch
3. wind duration

Question 17

wind speed (Factors affectig wave energy)

Answer 17

greater the wind speed, greater the wave energy

Question 18

length of fetch + define fetch (Factors affectig wave energy)

Answer 18

fetch - lenth of open water over which the win can blow unobstructed

longer fetch = more energy can be transferred as wind will be able to blow over for a longer period of time

Greater the fetch, the more energy the wave has

Question 19

wind duration (Factors affectig wave energy)

Answer 19

the longer the wind blows, the more energy waves have

Question 20

characteristics of waves in the open ocean (Movements of waves)

Answer 20

• long wavelength and low wave height
• water particles move in an orbit
• there is less orbit motion in deeper water

Question 21

characteristics of waves approaching the store (Movements of waves)

Answer 21

• water gets shallower
• friction between the water particles and sea bed causes base of the wave to slowdown
• wave height will increase
• wavelength will decrease
• wave becomes so steep that the crest topples over

Question 22

define Swash and Backwash

Answer 22

swash - the water rushing up the slope of the shore

backwash - swash looses energy due to gravity and friction with the land and returns back to the sea as backwash

Question 23

wat are the 2 types of waves?

Answer 23

constructive wave
destructive wave

Question 24

characteristics of constructive waves
Points:
gradient
wave height
wave length
frequency
wave period
swash vs backwash
energy of waves
which process is more prominent

Answer 24

• gentle gradient
• low wave height
• long wavelength
• low frequency
• wave period is high
• swash is more powerful than backwash
• low-energy waves
• deposition process more prominent

Question 25

characteristics of destructive waves Points: gradient wave height wave length frequency wave period swash vs backwash energy of waves which process is more prominent

Answer 25

- steep gradient - high wave height - short wavelength - high frequency - wave period is low - backwash more powerful than swash - high energy waves - erosion process is more prominent

Question 26

4 types of erosion

Answer 26

1. hydraulic action (agent - waves) 2. attrition (agent - rocks) 3. abrasion (agent -rocks/sediment) 4. solution (agent -soluble materials e.g. sea water)

Question 27

Define hydraulic action

Answer 27

air in the cracks are compressed by the oncoming waves exerting pressure on the cracks

Question 28

Define attrition

Answer 28

rock particles break down and become smaller, smoother and rounder as they hit against each other

Question 29

Define abrasion

Answer 29

as waves break, sediments are hurled against the coast, weakening the cliffs

Question 30

Define solution

Answer 30

soluble minerals dissolve in the sea water

Question 31

Define longshore drift

Answer 31

- longshore current flows parallel to the coast and is generated by wind, tides and waves approaching at an angle - Swash and backwash motion is repeated and causes a zig-zag movement of sediments along the coast

Question 32

Cliff definition

Answer 32

steep and near- vertical rock surface found along coasts.

Question 33

How is a wave-cut platform formed?

Answer 33

1. Wave erosion is concentrated along a line of weaknesses, forming a notch. 2. Prolonged erosion of the notch causes it to become deeper, forming a cave. 3. Further erosion of the cave causes the roof to collapse, and a steep cliff is formed. 4.Further erosion causes the cliff to retreat inland. A wave cut platform is formed at the foot of the cliff.

Question 34

What are wave-cut platforms

Answer 34

the cliff will retreat inland and a gentle sloping platform appears at the base where the cliff used to be. This platform is called a shore platform/ wave-cut platform, which is submerged during high tides.

Question 35

headlands definition

Answer 35

resistant rocks are less easily eroded by the waves and they remain as headlands,

Question 36

bays definition

Answer 36

less resistant rocks are more easily eroded and are eroded away to form bays.

Question 37

why id it that wave erosion along such coastlines cannot carry on indefinitely?

Answer 37

The rate of erosion in the bay will eventually decrease as wave energy decreases with the refraction of the wave front by the headlands.

Question 38

Wave Refraction definition

Answer 38

the process by which waves change direction as they approach a coast.

Question 39

Alittle bit abt wave refraction

Answer 39

Water waves travel faster on the surface of deep water than they do on shallow water ● The change in speed of the wave will cause refraction. ● Refraction = bend or a change of direction

Question 40

relating wave refraction to coasts [converge and diverge]

Answer 40

On a coastline with alternating headlands and bays, waves tend to converge on headlands. This gives rise to increased wave height and greater erosive energy. However, when waves approach bays, they diverge, resulting in decreased wave height and reduced erosive energy.

Question 41

how are caves arches and stacks related to headlands

Answer 41

Caves, arches and stacks are erosional features commonly found on a headland.

Question 42

How are headlands and bays fromed?

Answer 42

Waves attack an exposed discordant coast where alternate bands of resistant rocks and less resistant rocks occur at right angles to the coast. 2. The coast is eroded unevenly due to the different resistance of the rocks. The more rapid erosion of the less resistant rocks forms the bay. The less rapid erosion of the resistant rock forms the headlands.

Question 43

formation of caves

Answer 43

1. Waves attack a line of weakness to form a notch at the headland. Continued erosion forms a cave.

Question 44

formation of arches

Answer 44

2. An arch is formed when the cave cuts through the headland or meets with another sea cave on the other side of the headland.

Question 44

formation of stacks

Answer 44

3. Weathering may cause the arch to become unstable and collapse. This leaves behind an isolated pillar of rock called a stack. Continual erosion of the stack reduces the height of the stack, forming a stump.

Question 45

how are spits formed (simplified)

Answer 45

the accumulation of materials will appear above the surface of water, resulting in a long narrow ridge of sand or pebbles with one end attached to the mainland. This coastal feature is known as a spit.

Question 45

define beach

Answer 45

a zone of sediment deposition, usually formed from loose sand, gravel, pebbles, broken shells and corals or a mixture of these materials.

Question 45

how are beaches formed

Answer 45

Wave refraction causes waves to converge at the headlands. ● Erosion is concentrated at the headland. ● Wave refraction causes wave energy to be dissipated at the bay ● Materials eroded at the headlands as well as other materials carried by the waves are deposited at the bay. ● The materials on the beach may be sorted, with the larger materials being deposited inland.

Question 46

how are spits formed (extended)

Answer 46

2. Overtime, the accumulation [1] of materials will appear above the surface of water, resulting in a long narrow ridge of sand or pebbles with one end attached to the mainland. This coastal feature is known as a spit. [1] 1. The longshore drift transports material in a zig-zag fashion parallel to the coast [1]. Even when the coastline changes, longshore drift continues to transport material in the original direction [1]. 3. Wave refraction or changes in wind direction may cause the free end of the spit to curve to form a hooked spit. [1]

Question 47

define tombolo

Answer 47

the spit extends seawards and joins an offshore island nearby to form