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A Level Geography > Coasts > Flashcards

Flashcards in Coasts Deck (277):
1

Input-What?

Material or energy moving into the system from outside the system

2

Output-What?

Material or energy moving from inside the system to outside the system

3

Energy-What?

A power or driving force

4

Dynamic Equilibrium-What?

A state of balance within a constantly changing system

5

Stores-What?

The individual elements or parts of a system

6

Flows/Transfers-What?

The links or relationships between the components

7

Positive Feedback-What?

When a flow/transfer leads to increase or growth

8

Negative Feedback-What?

When a flow/transfer leads to decrease or decline

9

Erosion-What?

The gradual destruction of the coasts by waves

10

Landforms-What?

A naturally created thing on the coast

11

Landscape-What?

The area as a whole

12

Deposition-What?

When sediment is deposited on a beach

13

Open System-What?

A system with inputs and outputs

14

Coastal System-What?

The way the coast works

15

Links between the coast and other systems-Urban Pollution

Pollution in towns and cities causes water pollution, which leads to animals dying

16

Links between the coast and other systems-Farms near rivers

The fertilizers used runs into the water-causes water pollution and eutrophication

17

Links between the coast and other systems-Global Warming

Causes sea levels to rise. Increase in coastal flooding

18

Links between the coast and other systems-Marine Ecosystem

Small fish in river estuaries-more coastal biodiversity

19

Links between the coast and other systems-Forests

They provide food for the coastline when they erode. Mangroves are known as the "nurseries of the sea"-provides habitat

20

Energy Sources at Coast-Wind

Wind is the movement of air. Strong winds can create powerful winds

21

Energy Sources at Coast-Wind-Prevailing Wind

The prevailing wind is the direction in which the wind consistently comes from. In the UK, it is the South West

22

Energy Sources at Coast-Factors that influence wave height

-Fetch
-Wind Strength
-Seismic Movement-Tsunami
-Asteroids colliding with water
-Atmospheric Pressure

23

Fetch-What?

The distance the wave has travelled. High fetch=more energy=Strong Wave

24

Types of Atmospheric Pressure-High Pressure

-Dry
-No wind
-Low energy waves/No waves

25

Types of Atmospheric Pressure-Low Pressure

-Storms
-Strong Winds
-Strong Waves

26

Wave Formation-How?

-The water becomes shallower and the circular orbit of the water particles change to a elliptical shape
-The wavelength and the velocity decreases, wave height increases-Causes water to back up behind and rise to a point where it starts to topple over
-Water rushes up the beach as Swash, and moved back down the beach as Backwash

27

Wavelength-What?

The distance between the crest (top) of two waves

28

Types of Wave

There are two different types of wave:
-Constructive
-Destructive

29

Differences between Wave Types-Formation

-Constructive-Distant weather systems generate waves in the open ocean
-Destructive-Local storms create these waves

30

Differences between Wave Types-Wave Form

-Constructive-Low,surging waves with a long wavelength
-Destructive-High,plunging waves with a short wavelength

31

Differences between Wave Types-Wave Break

-Constructive-Strong Swash, Weak Backwash
-Destructive-Strong Backwash, Weak Swash

32

Differences between Wave Types-Beach Gain/Loss

-Constructive-Beach gain
-Destructive-Beach loss

33

Differences between Wave Types-Beach Profile

-Constructive-Gentle beach that will over time will become steeper
-Destructive-Steep beach, over time it will become flatter

34

Sources of Energy at Coast-Tides-What

Tides are the periodic rise and fall of the ocean surface, caused by the gravitational pull of the Moon, and to an extent the Sun

35

Sources of Energy at the Coast-Tides

Tides affect the position at which waves break on the beach. The area between maximum high tide and minimum low tide is where most landforms are created and destroyed

36

Sources of Energy at the Coast-Currents-What?

The general flow of water in one direction.

37

Sources of Energy at the Coast-Currents

Currents move materials along the coast

38

Types of Coastlines

There are two types of coastline:
-High Energy
-Low Energy

39

Types of Coastlines-High Energy Coasts

-Has large powerful waves
-Sandy Coves
-Rocky Landforms
-High rate of erosion
-Low rate of deposition

40

Types of Coastlines-Low Energy Coasts

-Has small,gentle waves
-Has offshore reefs or islands
-Has saltmarshes and tidal mudflats
-High rate of deposition
-Low rate of erosion

41

Types of Coastline-Causes

On a local scale, the cause of high and low energy coastlines is Wave Refraction

42

Wave Refraction-What?

Wave refraction is the distortion of wave fronts as they approach a indented coastline

43

Wave Refraction-How?

Wave refraction causes energy to be concentrated at headlands (on high energy coasts) and dissipated in bays

44

Sediment-What?

Any material which can be eroded,transported or deposited. Sediment can vary in size from large boulders to microscopic particles

45

Sources of Sediment-Rivers

Sediment that is transported in rivers often account for the majoirty of coastal sediment. The sediment will be deposited in river mouths and estuaries, where it will be reworked by waves, tides and currents

46

Sources of Sediment-Cliff Erosion

Important in areas of relatively soft or unconsolidated rocks. Soft rock cliffs erode much quicker than hard rock cliffs

47

Sources of Sediment-Longshore Drift

Sediment is transported from one stretch of coastline to another stretch of coastline

48

Sources of Sediment-Wind

In glacial or hot environments,wind blown sands can be deposited in coastal erosion. Sand dunes are both a acclamation of sand and a potential source of sand

49

Sources of Sediment-Glaciers

Ice Sheets break off and fall into the sea, depositing sediment trapped within the ice

50

Sources of Sediment-Offshore

Offshore sediment can be transformed into the coast by waves,tides and currents. A rise in sea level means that a large amount of sediment being bulldozed to form landforms. Storm surges and Tsunami waves can also be responsible for inputs of sediment to the coastal system

51

Sediment Cell-What?

A stretch of coastline, usually boarded by two prominent headlands, where the movement of sediment is more or less contained within the cell

52

Sediment Cells in the UK-How many

There are eleven major sediment cells in the UK. These can be divided into smaller subcells

53

Sediment Budget-What?

The difference between the amount of sediment that enters the system and the amount of sediment that leaves the system

54

Sediment Budget-Positive Budget

Occurs when more sediment enters the system than leaves. This builds the coastline

55

Sediment Budget-Negative Budget

Occurs when more sediment leaves than enters the system. This causes the coastline to retreat

56

Weathering-What?

The breakdown or disintegration or rock in situ (original place) at or close to the ground

57

Types of Weathering

There are three types of weathering:
-Physical (Mechanical) Weathering
-Biological Weathering
-Chemical Weathering

58

Weathering-Physical-What?

The break down of rocks without any chemical changes taking place

59

Weathering-Physical-Types-Frost Shattering

Occurs when water enters a crack or joint in the rock when it rains and then freezes. When water freezes, it expands. This expansion exert pressure on the rock, which makes the cracks widen. Once this process repeats,rock fragments break away

60

Weathering-Physical-Types-Salt Crystallization

When salt water evaporates, it leaves salt crystals behind. These grow over time Nd exert pressure in the rock,causing it to break up. Salt can also corrode rocks

61

Weathering-Physical-Types-Wetting and Drying

Frequent cycles of wetting and drying are common on the coast. Rocks rich in clay expand when wet and contract as they get dry. This can cause them to crack and break apart

62

Weathering-Biological-What?

The breakdown of rocks by organic activity

63

Weathering-Biological-Types-Plant Roots

Thin plant roots grow into small cracks in a cliff face. These cracks widen as the roots grow,causing rocks to be broken up

64

Weathering-Biological-Types Water

Water running through decaying vegetation becomes acidic, leads in increased chemical vegetation

65

Weathering-Biological-Types-Birds and Animals

Birds and animals dig burrows into cliffs

66

Weathering-Biological-Types-Marine Organisms

They can also burrow into rocks and/or secreting acids

67

Weathering-Chemical-What?

A chemical reaction where salts are dissolved and the rocks becomes easily erodeable

68

Weathering-Chemical-Types-Carbonation

Rainwater absorbs carbon dioxide from the atmosphere to form a weak carbonic acid. This reacts with calcium carbonate in the rock to form calcium bicarbonate, which can easily dissolved

69

Weathering-Chemical-Types-Oxidation

The reaction of rock minerals with oxygen to form a powder, leaving rocks vulnerable to erosion

70

Weathering-Chemical-Types-Solution

The dissolving of rock minerals

71

Mass Movement-What?

The downhill movement of material under the influence of gravity

72

Mass Movements-Types-Soil Creep-Rate and Nature

Rate of movement:Imperceptible
Nature of movement: Creep/Flow

73

Mass Movements-Types-Soil Creep-How?

When sediment expands, individual particles are lifted up at right angles to the slope. Sediments can expand when they freeze, get wet or heated up. When sediment shrinks, the particles fall straight back down. Soil creep takes a long time because each participant might move a millimetre each time

74

Mass Movements-Types-Soil Creep-Case Study

Launceston

75

Mass Movements-Types-Mudflow-Nature and Rate

Nature of movement: Flow
Rate of movement: Quite rapid

76

Mass Movements-Types-Mudflow-How?

After a period of heavy rain, water gets trapped within the rock, increasing water pressure. This forces rock particles apart and leads to slope failure. Mudflows are often sudden and fast flowing

77

Mass Movements-Types-Mudflow-Case Study

California

78

Mass Movements-Types-Landslides-Nature and Rate

Nature of movement-Slide
Rate of movement- Usually rapid

79

Mass Movements-Types-Landslides-How?

A landslide involves a block or rock moving very rapidly down a slide plane. Landslides are frequently triggered by earthquakes or very heavy rainfall, when the slip surface becomes lubricated and friction is reduced. Landslides tend to be very rapid and pose a threat to people and property

80

Mass Movements-Types-Landslides-Case Study

Holbeck Hall

81

Mass Movements-Types-Rockfall-Nature and Rate

Nature of movement-Fall
Rate of movement-Rapid

82

Mass Movements-Types-Rockfall-How?

A rockfall involves the sudden collapse or breaking away of rock at cliff. They are associated with steep or vertical cliffs and resistant rocks. A rockfall is often triggered by freeze thaw or a earthquake. Once broken away from the source, rocks fall or bounce down the slope to form scree at the foot of the slope

83

Scree-What?

Scree is a temporary store in the coastal system, with material being removed and transported. Scree is a store and a input into a sediment cell

84

Mass Movements-Types-Rockfall-Case Study

Cornwall

85

Mass Movements-Types-Landslide/Slope-Nature and Rate

Nature of movement-Slide
Rate of movement-Rapid

86

Mass Movements-Types-Landslide/Slump-How?

A landslide/Slump differs from a landslide in the the slide surface is curved rather than flat. Landslips occur in weak clays and sands, often when permeable rock overlays impermeable rock, which causes pore water pressure to build up. Landslips are characterized by a sharp break of slope and the formation of a scar

87

Mass Movements-Types-Landslips/Slumps-Case Study

The Holderness Coastline

88

Mass Movements-Types-Runoff-Nature and Rate

Nature of movement-Flow
Rate of movement-Rapid

89

Mass Movements-Types-Runoff-How?

When overland flow occurs down a slope/cliff face, small particles are moved downslope to enter the littoral zone. Runoff can be considered a type of flow that transfers both water and sediment from one store to another

90

Mass Movements-Types-Runoff-Case Study

Any river

91

Mass Movements-Types-Solification-Nature and Rate

Nature of movement-Creep
Rate of movement-Imperceptible

92

Mass Movements-Types-Solification-How?

Solification is similar to soil creep, but it only happens in cold periglacial environments. In the summer, the surface layer of soil thraws out and becomes extremely saturated because it lies on top of impermeable frozen ground called permafrost.

93

Mass Movements-Types-Solification-Case Study

The Arctic

94

Types of Movement-Slides

Material shifts in a straight line

95

Types of Movement-Slumps

Materials shifts with a rotation

96

Types of Movement-Flow

Materials flow downslope

97

Transportation of Sediment

Coastal transportation plays a major role in the coast system as it transfers sediment from one store to another

98

Transportation of Sediment-Types

There are 4 types of coastal transportation:
-Saltation
-Suspension
-Solution
-Traction

99

Transportation of Sediment-Types-Traction

The rolling of course sediment along the seabed that is too heavy to be picked up and carried by the sea

100

Transportation of Sediment-Types-Saltation

Sediment is "bounced" along the seabed. Sediments is light enough to be picked up or dislodged but too heavy to remain in the water flow

101

Transportation of Sediment-Types-Suspension

Smaller (lighter) sediment is picked up and carried within the water flow

102

Transportation of Sediment-Types-Solution

Chemicals dissolved in the water , transported and precipitated elsewhere

103

Transportation of Sediment-Longshore Drift

Longshore drift is an important transfer mechanism as it is responsible for moving vast amounts of sediment along the coastline

104

Transportation of Sediment-Longshore Drift-How?

The waves approach the beach at an angle, in the direction of the prevailing wind. The waves are refracted before reaching the beach. When the wave reaches the beach, it picks up sediment and advances up the beach. Backwash then carries the sediment down the beach at 90° to the swash. This is due to gravity. The sediment is either moved by traction, saltation or suspension. This repeats until the sediment has reached the end of the beach, or a curve in the beach, where a spit would be created

105

Ways to erode the coast-Abrasion

Bits of rock and sediment transported by the waves smash and grind against rocks and cliffs, breaking bits off and smoothing surfaces

106

Ways to erode the coast-Hydraulic Action

Air in cracks in the cliffs is compressed when waves crash in. The pressure exerted by the compressed air breaks off rock pieces

107

Ways to erode the coast-Cavitation

As waves recede, the compressed air expands violently, again exerting pressure on the rock and causing pieces to break off

108

Ways to erode the coast-Wave Quarrying

The energy of a wave as breaks against a cliff is enough to detach bits of rock

109

Ways to erode the coast-Solution

Soluble rocks get gradually dissolved by the sea water

110

Ways to erode the coast-Attrition

Bits of rock in the water smash against each other and break into smaller bits

111

Factors affecting coastal erosion-Waves

The size and type of wave can affect the rate of coastal erosion on a stretch of coastline. Most erosion occurs during winter storms when destructive waves are at their largest and most powerful

112

Factors affecting coastal erosion-Rock Type

Tough and resistant rock erode at very slow rates compared to weaker rocks

113

Factors affecting coastal erosion-Geological Structure

Cracks, joints, bedding planes and faults create weaknesses in a cliff that can be exploited by erosion

114

Factors affecting coastal erosion-Beach

Beaches absorb wave energy and reduce the impact of waves on a cliff. If a beach is not there, a cliff may experience increased erosion as it is more vulnerable to wave attack

115

Factors affecting coastal erosion-Subaerial Processes

Weathering and mass movement will weaken cliffs and create piles of debris that are easily eroded by the sea, increasing the rate of erosion

116

Factors affecting coastal erosion-Coastal Management

The presence of coastal management can affect erosion rates. When the sediment is trapped by groynes, beaches further down the coast are affected, as they will not have a beach. A sea wall may deflect wave energy elsewhere along the coast, exacerbating erosion in those localities

117

Coastal Deposition-What?

When sediment is put down on to a beach by constructive waves

118

Beach-What?

A accumulation of sand and shingle, known as a store. A beach is formed between high and low tide marks. They are a temporary store

119

Erosion Based Landforms-Wave Cut Platform-Formation

At high tide, the waves attack the cliff. This is done by hydraulic action. This creates a wave cut notch between the high and low tide marks. As the notch gets bigger due to more erosion, the cliff is undercut and the rock above it becomes unstable, eventually collapsing due to gravity. This causes the cliff to move inland, leaving a gently sloping wave cut platform, which can only be seen at low tide

120

Cliff Profile-Steep Cliffs

Steep cliffs occur when the rock is strong and resistant to erosion. They tend to have no beach, but a wave cut platform

121

Cliff Profile-Gentle Cliffs

Gentle cliffs occur when the rock is weal or unconsolidated rocks that are prone to slumping. They are sloped towards the sea and tend to have a big beach

122

Factors affecting the rate of retreat of cliffs

-Rate of weathering
-Geology-Rock Type
-Fetch
-Wave type
-Energy levels
-Size of Beach
-Rate of erosion

123

Costal Morphology-What?

Not just the geology of the cliff, but also the cliffs lithology

124

Lithology-What?

The geological structure

125

Strata-What?

Layers of rock

126

Costal Morphology-Strata

Horizontal strata produces steep cliffs

127

Bedding Planes-What?

Horizontal, natural breaks in the strata, caused by gaps in time during periods of rock formation

128

Joints-What?

Vertical fractures caused by either contraction as sediments dry out, or by earth movements during uplift

129

Costal Morphology-Joints

Rocks dip gentle towards the sea with almost vertical joints. The joints are opened by weathering and pressure release

130

Folds-What?

Formed by pressure during tectonic activity which makes rocks buckle and crumble

131

Faults-What?

Formed when the stress or pressure to which a rock is subjected to exceeds its internal strength causing it to fracture. The faults then slip or move along fault planes

132

Dip-What?

Refers to the angle at which rock strata lie

133

Costal Morphology-Steep Dip

A steep dip towards the sea makes rocks slabs slides down the cliff along bedding planes

134

Costal Morphology-Inland Dip

Rocks dip inland producing a stable steep cliff profile

135

Costal Morphology-Inland dip with joint

Rocks dip inland but with a well developed joint at right angles to bedding planes. The joints act as slide planes

136

Headland Erosion-How?

The erosion of rocks like limestone tends to exploit ant lines of weakness. Joints and faults are eroded by hydraulic action and abrasion to create caves. If two caves join up, or a single cave is eroded though a headland, an arc is formed. The gap is enlarged by erosion and weathering. The top of the arc then collapses due to gravity and erosion. This creates a stack. As the stack continues to be eroded by hydraulic action, the stack collapses to leave a stump, which may only appear above the surface at low tide

137

Depositional Landforms-Beaches

Beaches are the most common landform of deposition and represent the accumulation of material. Beach material in the form of sand, shingle, pebbles and cobbles come from three sources

138

Sources of Beach Material

-Cliffs
-Offshore
-Rivers

139

Types of Beaches

There are two types of beaches. They are:
-Swash Aligned Beaches
-Drift Aligned Beaches

140

Types of Beaches-Swash Aligned Beaches

Formed in low energy environments, this type of beach may consist of either sand or shingle, depending on factors like the nature of the sediment and the power of the waves. High energy waves will transport sand, leaving behind coarser shingles whereas low energy waves will deposit sand or mud

141

Types of Beaches-Drift Aligned Beaches

Formed when the waves approach the coast at a angle. Long shore drift moves the sediment along the beach, Finer shingles are likely to be carried further and also become increasing rounder as they move

142

Beach Profile-Beach Zones

-Backshore Zone
-Forshore Zone
-Nearshore Breaker Zone
-Offshore Zone

143

Berm-What?

A ridge made of the biggest boulders thrown by large waves, found above the high tide mark

144

Cusp-What?

Semi circular shaped depressions which form when waves break directly on thee beach

145

Runnel-What?

Developed on the sand by wave action or tidal currents

146

Spit-What?

A long narrow accumulation of sand or shingle with one end attached to land and the other projecting out to sea or to a river estuary

147

Depositional Landforms-Spit-Formation

Long shore drift continues to deposit material across the river mouth, leaving a bank of sand and shingle sticking out into the sea. Occasional changes to the dominate wind and wave direction may lead to the spit having a curved end. Over time, the curved ends may be abandoned as they waves return to their original direction. The area behind the spit is sheltered from the waves and often develops into mudflats and saltmarshes

148

Offshore Bar-What?

Elongated ridges and mounds of sand or gravel deposited beyond a shoreline by currents and waves

149

Tombolo-What?

Beaches formed between an islands and the sea

150

Depositional Landforms-Offshore Bar-Formation

Bars are formed when a spit joints two headlands together. A lagoon formed behind the bar. Bars can also form off shore when material moves towards the coast

151

Depositional Landforms-Tombolo-Formation

A bar is formed that connects the shore to an island

152

Barrier Beach-What?

When a beach extends across an indentation in a coastline to join two headlands

153

Depositional Landforms-Barrier Beach-Formation

We are not shore how they formed, but scientists think they formed after the ice age ended, when ice melted caused sea levels to rise. The rising waters flooded the land behind beaches and transported sediment offshore, where it was deposited in shallow waters, forming the barrier beaches

154

Salt Marshes-What?

A salt marsh is a coastal ecosystem in the upper coastal tidal zone between land and open salt water or slack water that is regularly flooded by tides

155

Factors associated with salt marsh development

-A sea shore with very little wave action
-Shelter from the waves
-A source of mud

156

Depositional Landforms-Salt Marshes-Formation

The low energy coast allows the negatively charged mud particles to become neutral and stick together, to be transported. The shelter protects the area and allows the mud to build up, forming the salt marsh

157

Sand Dunes-What?

Sand dunes are accumulations of sand shaped into mounds by the wind. They are dynamic ecosystems called Pasammoseres

158

Sand Dunes Equation

Wind+Sand+Water+Beach Grass (Marram Grass)=Sand Dunes

159

Depositional Landforms-Sand Dunes-Formation

Sand trapped by driftwood or berms is colonised by plants and grasses. The vegetation stabilises the sand and encourages more sand to accumulate there. Over time, the oldest dunes migrate inland as newer dunes are formed

160

Wind Transportation Methods-Creep

Creep is similar to Traction

161

Wind Transportation Methods-Saltation

Saltation is similar to saltation of sediment

162

Wind Transportation Methods-Suspension

Suspension is similar to suspension of sediment

163

Types of Sand Dunes-Embryo and Fore Dunes

-High water mark
-Poor water retention
-Sand builds up against pioneer plants
-Seaweed deposits humus

164

Types of Sand Dunes-Yellow Dunes

-Above high tide
-Reduced water speed
-Surface continuously blown away, replaced with new sand
-More water retentive

165

Types of Sand Dunes-Grey Dunes

-Shelter by higher dunes
-No longer gaining sand
-Has a closed vegetation community

166

Types of Sand Dunes-Dune Slack

-Occurs in low lying hollows between dune ridges
-High water table
-Relief intersects the water table

167

Types of Sand Dunes-Heath/Woodland

-Well sheltered from wind
-High organic soil
-Rich in nutrience
-Minimal maritime influence

168

Types of Sea Level Change

There are two types of sea level change:
-Eustatic Change
-Isostatic Change

169

Eustatic Change-What?

When the sea level rises or falls

170

Eustatic Change-Features

-A global change
-A lot of Ice in the water- Low sea levels
-Sea levels rise when Ice sheets melt- More water in sea

171

Isostatic Change-What?

When the land rises or falls, relative to the sea

172

Isostatic Change-Features?

-A local change
-Caused by vertical movements of the land, due to uplift, depressions, drainage or tectonic plate movement

173

Isostatic Change-Case Study-Isle of Arran

On the Isle of Arran, they have caves and a raised beach. This is caused by land rising

174

Isostatic Change-Case Study-Turkakirae Head, New Zealand

In this place, there is multiple wave cut platforms

175

Landforms Created by Sea Level change

There are two types of landforms created by sea level change:
-Emergent Landforms
-Submergent Landforms

176

Emergent Landforms-What?

Occurs when Isostatic change occurs more than Eustatic change. In simple terms, the land rises quicker than the sea does

177

Emergent Landforms-Types

-Raised Beaches
-Wave Cut Platforms
-Relic Stacks

178

Raised Beach-What?

When a beach is above the current sea level

179

Relic Stacks-What?

The remains of eroded cliffs lines

180

Submergent Landforms-What?

Occurs when Eustatic change occurs more than Isostatic change. In simple terms, the sea rises quicker than the land does

181

Submergent Landforms-Types

-Fjords
-Rias
-Dalmatian Coasts

182

Fjord-What?

A fjord is a flooded glacial valley

183

Fjord-Case Study

Fjords can be seen in Norway

184

Rias-What?

A ria is a flooded river valley

185

Rias-Case Study

A ria can be seen in Kingsbridge

186

Dalmatian Coast-What?

A Dalmatian coast is a set of offshore islands. These islands are the tops of valleys, and run parallel to the coastline

187

Dalmatian Coast-Case Study

A example of a Dalmatian Coast can be seen in Croatia

188

Sea Level change and Tectonics-Japan

The earthquake caused the land to drop 2 metres. The sea level essentially rose 2 metres, flooding the area

189

Sea Level change and Tectonics-Banda Ache

The earthquake caused the sea level to rise

190

Sea Level change and Tectonics-The Indian Ocean

The rising of the sea bed caused the Indian ocean to have less water in it, causing a permanent rise in sea level by 0.1mm

191

Sea Level change and Tectonics-Tsunamis

Tsunamis cause a short term increase in sea level

192

Sea Level change and Tectonics-Fold Mountains

The creation of fold mountains causes sea levels to drop

193

Sea Level change and Tectonics-Thermal Expansions

Causes more warm water in the sea

194

Sea Level Rise-Case Study-Tuvalu

Tuvalu is a island that was created on a old coral reef. They are incredible vulnerable to sea level change

195

Sea Level Rise-Case Study-Tuvalu -Why are they Vulnerable

-Waves have a large fetch-More powerful
-Width of land is thin
-Land is flat
-Ocean is on both sides of Island
-Everything is close to the sea
-Protected by a small beach
-No flood Defences

196

Sea Level Rise-Case Study-Tuvalu Responses

Tuvalu has sued the US and Australian Governments for producing a lot of Carbon dioxide, which help to cause sea level rise

197

Coastal Management-Types

There are many types of Coastal Management:
-Hard Engineering
-Soft Engineering
-Shoreline Management Plan
-Integrated Coastal Zone Management Plans

198

Hard Engineering-What?

Hard engineering is man made structures that protect the coastline

199

Types of Hard Engineering

There are many types of Hard Engineering Techniques:
-Groynes
-Sea Walls
-Rip-Rap
-Reventments
-Offshore Breakwater

200

Types of Hard Engineering-Groynes-Description

Wood or rock structures at right angles to the coast. They trap sediment being moved by long shore drift

201

Types of Hard Engineering-Groynes-Cost

£10,000 each

202

Types of Hard Engineering-Groynes-Advantages

+Works with natural processes to built up beaches-Leads to more tourists
+Protects land behind beach
+Not too expensive

203

Types of Hard Engineering-Groynes-Disadvantages

-Deny beaches of sediment-Causes increased erosion
-Unnatural
-Unattractive

204

Types of Hard Engineering-Sea Walls-Description

Stone or concrete walls that normally have a curved face which reflects waves back to the sea

205

Types of Hard Engineering-Sea Walls-Cost

£6000 per metre

206

Types of Hard Engineering-Sea Walls-Advantages

+Effective protection of erosion
+Often have a promenade for people to walk across

207

Types of Hard Engineering-Sea Walls-Disadvantages

-Does not absorb wave energy
-Intrusive
-Unnatural
-Very expensive to build and maintain

208

Types of Hard Engineering-Rip-Rap-Description

Large rocks that form a permeable barrier to the sea-breaking up the waves, but allowing some water to pass

209

Types of Hard Engineering-Rip-Rap-Cost

£100,000 to £300,00 per 100 metres

210

Types of Hard Engineering-Rip-Rap-Advantages

+Relatively cheap
+Easy to construct and maintain
+Used for recreational activities

211

Types of Hard Engineering-Rip-Rap-Disadvantages

-Rocks can look out of place with local geology
-Can be dangerous for people clambering over them

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Types of Hard Engineering-Revetments-Description

Sloping wooden concrete or rock structures that break up the waves energy

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Types of Hard Engineering-Revetments-Cost

£4500 per metre

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Types of Hard Engineering-Revetments-Advantages

+Cheap

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Types of Hard Engineering-Revetments-Disadvantages

-Unnatural looking
-Needs high levels of maintenance

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Types of Hard Engineering-Offshore Breakwater-Description

A partly submerged rock barrier, designed to break up the waves before they reach the coast

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Types of Hard Engineering-Offshore Breakwater-Cost

£100,000 to £300,000

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Types of Hard Engineering-Offshore Breakwater-Advantages

+Effective Permeable barrier

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Types of Hard Engineering-Offshore Breakwater-Disadvantages

-Visually unappealing
-Potential navigation hazard

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Soft Engineering-What?

Techniques that use the natural environment

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Types of Soft Engineering

There are a few types of soft engineering:
-Beach Nourishment
-Cliff regrading and drainage
-Dune Stabilization
-Marsh Creation

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Types of Soft Engineering-Beach Nourishment-Description

The addition of sand or pebbles to an existing beach to make it higher or wider. The sediment is normally drained from the nearby seabed

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Types of Soft Engineering-Beach Nourishment-Cost

£300,000 per 100 metre

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Types of Soft Engineering-Beach Nourishment-Advantages

+Cheap
+Easy to maintain
+Natural looking
+Helps build bigger beach

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Types of Soft Engineering-Beach Nourishment-Disadvantages

-Needs constant maintenance

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Types of Soft Engineering-Cliff Regrading and Drainage-Description

Cliff regrading reduces the angle of the cliff to help stable it. Drainage removes water to prevent landslides and slumping

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Types of Soft Engineering-Cliff Regrading and Drainage-Cost

Variable

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Types of Soft Engineering-Cliff Regrading and Drainage-Advantages

+Effective on clay or loose rock cliffs
+Drainage is cost effective

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Types of Soft Engineering-Cliff Regrading and Drainage-Disadvantages

-Causes cliff retreat
-Drained cliffs can dry out, leading to rock fall

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Types of Soft Engineering-Dune Stabilization-Description

Marram grass can be planted to stableise dunes. Areas can be fenced in to keep people off the dunes

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Types of Soft Engineering-Dune Stabilization-Cost

£200 to £2000 per 100 metres

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Types of Soft Engineering-Dune Stabilization-Advantages

+Maintains natural environment
+Provides habitats for wildlife
+Cheap
+Sustainable

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Types of Soft Engineering-Dune Stabilization-Disadvantages

-Time consuming to plant Marram grass
-People may respond negatively to being kept off areas

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Types of Soft Engineering-Marsh Creation-Description

A form of managed retreat, by allowing low lying coastal areas to be flooded by the sea. The land then becomes a salt marsh

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Types of Soft Engineering-Marsh Creation-Cost

Variable depending on the size of the area

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Types of Soft Engineering-Marsh Creation-Advantages

+Cheap
+Natural buffer created
+Habitat created

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Types of Soft Engineering-Marsh Creation-Disadvantages

-Agricultural land is lost
-Farmers or landowners will need to be compensated

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Sustainable Coastal Management-Shoreline Management Plan

A SMP is a extremely detailed document that decides what to do with the sediment cell. There are 4 options:
-Hold the Line
-Advance the Line
-Managed Retreat
-Do Noting

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Shoreline Management Plan Options-Hold the Line

Maintain the current position of the coastline ,often using hard engineering

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Shoreline Management Plan Options-Advance the Line

Extending the coastline out to sea, by encouraging the build up of a wider beach

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Shoreline Management Plan Options-Managed Retreat

Allowing some areas to flood in a planned and manged way. Normally, this is low quality land

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Shoreline Management Plan Options-Do Noting

Let nature take its course, allowing sea to erode cliffs, flood the land and allow existing defenses to collapse

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Sustainable Coastal Management-Integrated Coastal Zone Management

This form of management involves splitting the area up into zone, which each zone for a certain purpose

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Integrated Coastal Zone Management-Case Study-St Lucia

The coastline of St Lucia has been divided into zones
These zones are:
-Marine reserves
-Fishing priority area
-Recreational Areas
-Multi Use Areas

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Integrated Coastal Zone Management-Case Study-St Lucia-Economic Reasons

-Provides people with jobs
-More income for people

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Integrated Coastal Zone Management-Case Study-St Lucia-Social Reasons

-Provides people with jobs
-Increases tourism

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Integrated Coastal Zone Management-Case Study-St Lucia-Environmental Reasons

-Some areas are protected
-Allows area to be regenerated if damaged
-Protects wildlife

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Case Study-Holderness-Where?

The Holderness coast is on the east coast of England, close to Hull

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Case Study-Holderness-Rate of Erosion

Since Roman times, about 3.5 km has been eroded. It is the fastest eroding coastline in the UK

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Case Study-Holderness-Coastal Issues

-Landslides
-Slumping
-High Cliff Erosion-Due to boulder clay
-Houses Destroyed
-Roads Destroyed

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Case Study-Holderness-Fetch

The fetch is very long. This means that powerful waves hit the soft rocks, causing lots of erosion

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Case Study-Holderness-Coastal Features

-Flamborough Head-North of Holderness, eroded headland with a wave cut platform
-Spurn Head Spit-A spit on the south of Holderness

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Protection Methods on Holderness-Hornsea-Uses

The town of Hornsea is used for tourism

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Protection Methods on Holderness-Hornsea-Methods Used

-Wooden Groynes
-Beach Nourishment

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Protection Methods on Holderness-Hornsea-Conflict and Issues

Mappleton did not receive any sediment. This lead to major cliff erosion there
The sand that was added can be removed in a year, it has to be replaced every year

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Protection Methods on Holderness-Mappleton-Uses

The village of Mappleton has a main road going through it

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Protection Methods on Holderness-Mappleton-Methods Used

-Rock Groynes-Groynes of Norwegian Granit laid out and work like wooden Groynes
-Re graded cliff face

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Protection Methods on Holderness-Mappleton-Conflicts and Issues

Erosion increased past the last groyne. Erosion rate increased from 2.5 metres a year a 3.8 metres a year

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Protection Methods on Holderness-Easington-Uses

Easington has a gas terminal, which provides gas for the north

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Protection Methods on Holderness-Easington-Methods Used

-Rock Revetments

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Protection Methods on Holderness-Easington-Conflicts and Issues

-Expensive but long lasting
-Some people think they are unattractive

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Protection Methods on Holderness-Withernsea-Uses

Withernsea is one of the largest towns in the area, It has hospitals, lifeboat station and schools

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Protection Methods on Holderness-Withernsea-Methods Used

-Sea Wall
-Rip Rap

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Protection Methods on Holderness-Withernsea-Conflicts and Issues

-Cost £6.3 million- justified using cost-benefit analysis
-Smaller Promenade
-Views from hotels have been damaged
-Rip Rap is expensive and unattractive

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Case Study-Odisha-Location

Odisha is a province on the east coast of India. It is on the eastern coastal plain of India

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Case Study-Odisha-Factors that make the area unique

-Between 0-1500 metres above sea level
-Mostly Depositional Landforms
-Six major deltas on the coast
-Has 1435km of Mangrove Forest
-Chillika Lake-Salty Lagoon-increases in area during monsoon season
-Beaches are important sediment stores
-Region is a significant sediment store
-Rivers transfer sediment from the Bay of Bengal
-Majority of inputs are rivers
-Coastal and River based landforms
-Relatively low energy coastline
-Concordant coastline
-A multi hazard area

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Case Study-Odisha-Factors that disrupt the sediment cell

-Storm surges that erode the sediment
-Tsunami Waves
-Sea Walls-Prevent transportation
-Mangroves-Natural defence,- if taken away, it affects the sediment cell
-Breakwaters
-Rock Armour
-Shoreline Change

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The Opportunities and Risk of the Odisha Coastline-Economic

-Offshore oil, natural gas and seabed mining
-Cultural and archaeological sites, drawing visitors from around the world-Money into area
-Tourism-Beaches, Wildlife sanctuaries
-35% of the coast is laden with substantial sediment minerals and heavy metal deposits. They are important clay and limestone resources in the north of Odisha
-Huge potential for offshore wind, tidal and wave power
-Many local people are employed in coastal fishing and in aquaculture

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The Opportunities and Risk of the Odisha Coastline-Environmental

-Large stocks of fish, marine mammals, reptiles, sea grass meadows and seaweed
-Wide variety of marine and coastal flora and fauna including mangroves, sea grasses, salt marshes, sand dunes, estuaries and lagoons
-The Chilika Lake Bird Sanctuary has over 150 migratory and resident species of bird

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Risks of Coastal Development on Odisha

-Cyclones create storm surges-flooding
-Flooding causes erosion
-Flat land-easily flooded
-Rising sea levels-Flooding
-Locals are forced to adapt
-Could built on flood plains

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Risks of Coastal Development on Odisha -Types of Risk

There are both human and physical risks to developing the Odisha coast

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Risks of Coastal Development on Odisha -Types of Risks-Human

-Infrastructure Destroyed
- Homes destroyed
-Flooding of buildings
-Jobs lost due environmental destruction
-Economic loss
-Loss of life

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Risks of Coastal Development on Odisha -Types of Risk- Physical

-Storm Surges
-Tsunami
-Coastal erosion
-Disruption to sediment cells
-Areas destroyed
-Rising sea level

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Management of Odisha-Technique used

They used a ICZM project. This project is a joint venture between organisations

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Odisha- ICZM- Aims

-Establish sustainable levels of economic and social activity
-Resolve environmental, social and economic challenges and conflicts
-Protect coastal environment

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Odisha- ICZM- Issues Identified

-Coastal erosion
-Assessing vulnerability to disaster
-Biodiversity conservation
-Livelihood security
-Pollution and environmental quality management
-Conservation of cultural assets

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Odisha- ICZM- What have they done?

-Planted mangrove trees
-Built cyclone shelters