essay flashcards p2
1
Q
Explain how the littoral zone is a dynamic system influenced by both marine and terrestrial processes.
A
2
Q
What marine processes influence the littoral zone’s morphology?
A
Wave action, tides, and longshore drift (LSD).
3
Q
How does wave action influence the littoral zone’s morphology?
A
Waves in the nearshore zone distort due to friction with the seabed, leading to erosion (e.g., cliffs) or deposition (e.g., beaches).
4
Q
How does the interaction of waves impact littoral zone morphology?
A
Destructive waves erode rocky coastlines, creating cliffs, while constructive waves deposit sediment, forming beaches on low-energy coasts.
5
Q
What is the overall impact of these marine processes on the littoral zone?
A
They cause continual morphological change, with simultaneous erosion and deposition in different parts of the littoral zone.
6
Q
What terrestrial processes contribute to littoral zone dynamics?
A
Weathering, mass movement, and sediment supply from rivers.
7
Q
How does weathering impact the littoral zone?
A
Weathering in the backshore zone leads to rockfalls and landslides, particularly during storms, adding sediment to the nearshore and foreshore zones.
8
Q
How does sediment supply from rivers affect the littoral zone?
A
Sediment from rivers accumulates in estuaries, causing deposition and forming features like mudflats and salt marshes.
9
Q
How does interaction between marine and terrestrial processes affect the littoral zone?
A
It creates a continually changing environment, influenced by short-term factors (tides) and long-term factors like sea-level rise due to climate change.
10
Q
Explain how coasts can be classified based on long-term and short-term criteria.
A
11
Q
What are examples of long-term criteria for classifying coasts?
A
Geology (rock type and structure) and sea-level change.
12
Q
How does geology classify coastlines?
A
Through rock type (resistant or soft) and structure, creating rocky, sandy, concordant, or discordant coasts.
13
Q
What coastal features does a discordant coastline produce?
A
Features like headlands and bays due to differential erosion of alternating rock types.
14
Q
How does sea-level change classify coasts?
A
It classifies coasts as emergent (due to uplift or falling sea level) or submergent (due to sinking land or rising sea level).
15
Q
What features characterize submergent coastlines?
A
Drowned valleys, rias, and estuaries caused by rising sea levels flooding river valleys.
16
Q
What are short-term criteria for coastal classification?
A
Energy inputs (wave and tidal strength) and sediment inputs.
17
Q
What features occur on high-energy coastlines?
A
Erosional features like cliffs and wave-cut platforms due to powerful waves.
18
Q
How does the balance between erosion and deposition influence coastal change?
A
When erosion exceeds deposition, coastlines retreat; when deposition dominates, coastlines advance, forming features like deltas.
19
Q
Explain how geology influences the formation of rocky coasts and coastal plain landscapes.
A
20
Q
What geological conditions typically form rocky coasts?
A
High-energy environments with resistant rock types like granite or basalt.
21
Q
How do geological structures influence rocky coast erosion?
A
Joints, faults, and folds influence erosion patterns, creating features like cliffs.
22
Q
Give an example of a high-relief rocky coast.
A
Conachair cliffs (Isle of Hirta) with resistant rocks leading to slow erosion and steep cliffs.
23
Q
How do low-relief rocky coasts form?
A
Formed from softer, easily eroded rocks like clay, resulting in gentle slopes (e.g., Chapel Porth, Cornwall).
24
Q
What geological conditions form coastal plains?
A
Low-energy environments with softer sedimentary rocks (sand and silt) where deposition exceeds erosion.
25
What are common features of coastal plains?
Beaches, mudflats, and salt marshes due to sediment accumulation from rivers and offshore currents.
26
Why do coastal plains have low-relief landscapes?
Continuous sediment deposition without significant erosion allows gradual accumulation, creating flat landscapes.
27
Summarize how geology influences rocky coasts and coastal plains.
Resistant rocks slow erosion, creating rocky coasts with cliffs; softer sediments enable sediment accumulation, forming low-relief coastal plains.
28
Explain how geological structure leads to concordant and discordant coastlines.
29
How does geological structure define concordant coastlines?
Rock strata run parallel to the coast, creating smoother coastlines with uniform erosion rates.
30
Give an example of a concordant coastline.
The Dalmatian coast in Croatia, characterized by parallel islands formed due to folded rock strata.
31
Why do concordant coastlines have fewer pronounced erosional features?
Uniform resistance to erosion causes the coastline to erode evenly, limiting the formation of headlands and bays.
32
What defines discordant coastlines?
Rock strata intersect the coastline at an angle, leading to differential erosion and irregular coastlines.
33
Example of a discordant coastline and its features?
Cork coastline in Ireland, with softer rocks forming bays and harder rocks forming headlands.
34
How does faulting and folding influence discordant coastlines?
Faults and folds create zones of weakness that erode quickly, enhancing the formation of bays.
35
How does the angle of rock layers (dip) affect coastline formation?
Tilted strata in discordant coasts form distinct headlands and bays; horizontal strata in concordant coasts maintain smoother coastlines.
36
Summarize the difference between concordant and discordant coastlines.
Concordant coasts have parallel strata, smoother shorelines; discordant coasts have angled strata, forming irregular headlands and bays.
37
Explain how geological factors influence the morphology of headlands and bays.
38
What geological factors primarily shape headlands and bays?
The rock type and its resistance to erosion along discordant coastlines.
39
Provide an example of geology forming a headland and bay.
Swanage Bay (soft Wealden Clay eroded) and Peveril Point (resistant Portland Limestone headland), Dorset.
40
How do erosion rates vary between headlands and bays?
Headlands erode slowly due to resistant rocks; bays erode quickly due to softer rocks, creating an uneven coastline.
41
How does wave refraction influence headland erosion?
Waves refract around headlands, concentrating wave energy, accelerating erosion at headlands while dissipating energy in bays.
42
What structural geological features influence headland and bay formation?
Bedding planes, joints, faults, and the angle (dip) of rock layers.
43
How do joints and faults affect coastal morphology?
They create zones of weakness, enhancing erosion in bays, while resistant rocks form headlands.
44
How can concordant coastlines form bays or coves despite their structure?
Faults or joints breaching outer resistant layers (e.g., Lulworth Cove), allow rapid erosion of weaker inner rocks.
45
Summarize how geological factors shape headlands and bays.
Rock resistance and geological structures (faults/joints) influence differential erosion, shaping distinct headlands and bays.
46
Explain how geological structure affects cliff profiles and the formation of micro-features such as caves, arches, and stacks.
(Essay 1)
47
What aspects of geological structure influence coastal landscapes?
Dip of rock strata, joints, faults, and folds.
48
How do joints influence cliff erosion?
Joints increase vulnerability to marine erosion processes like hydraulic action, accelerating cave formation.
49
Provide an example of joint-influenced coastal micro-features.
Purbeck Limestone at Lulworth Cove, where intense jointing created caves and arches, eventually forming stacks like Old Harry Rocks.
50
How does the dip of strata affect cliff profiles?
Steep seaward dips (>45°) create sloped cliffs vulnerable to rock slides and mass movements, e.g., Carboniferous Limestone at Bantry Bay.
51
How does faulting affect coastal erosion?
Faults weaken rock, increasing erosion rates, forming headlands, bays, and eventually stacks.
52
Example of fault-influenced coastal landscape?
Bantry Bay, where fault lines in Carboniferous Limestone increase erosion, forming distinct coastal features.
53
What is the overall impact of geological structure on coasts?
Determines cliff shape, erosion rates, and the formation and evolution of micro-features through interplay of joints, dip, and faults.
54
Explain how different rock types influence rates of coastal recession.
(Essay 2)
55
What determines the rate of coastal recession?
Rock lithology including mineral composition, rock structure, and presence of weaknesses such as joints or fissures.
56
Why are igneous rocks resistant to coastal recession?
Composed of interlocking crystals, minimal jointing, weather slowly (e.g., granite at 0.1 cm/year).
57
Give an example of resistant igneous rock coastlines.
Granite coastlines erode slowly due to their minimal jointing and crystalline structure.
58
Why are sedimentary rocks more susceptible to erosion?
Clastic composition, presence of bedding planes, weaker cement binding sediment particles together.
59
Examples of erosion rates in sedimentary rocks?
Limestone (1 cm/year), sandstone (up to 10 cm/year).
60
How does chemical weathering affect sedimentary rocks?
Chemical dissolution (e.g., limestone dissolving calcite) accelerates coastal recession rates.
61
Overall, how does lithology influence coastal landscapes?
Determines rate of coastal recession by influencing how quickly marine processes and weathering break down rock.
62
Explain how alternating layers of resistant and less resistant rock influence coastal landforms.
(Essay 3)
63
How do alternating rock layers affect coastal erosion?
Differential erosion, softer rocks erode faster, creating uneven cliff profiles and features like wave-cut notches.
64
Which landforms develop where softer rock erodes rapidly?
Wave-cut notches, receded cliffs, and unstable overhangs due to rapid erosion.
65
How do resistant rocks influence cliff morphology?
Resistant rocks form stable landforms like rock benches/platforms and overhangs, eventually collapsing due to undercutting of softer rock.
66
What geological phenomenon is caused by permeable overlying impermeable rock layers?
Groundwater accumulates, creating springs and increasing cliff erosion through mass movements like slumping and sliding.
67
Provide examples of rock types for resistant and less resistant layers.
Resistant: limestone, granite; Less resistant: sandstone, clay.
68
Which geographical theories connect to differential erosion?
Principle of selective erosion and groundwater dynamics in mass movement theories (slumping, sliding).
69
Summarize the significance of alternating rock layers on coasts.
Influences rate of cliff recession and coastal morphology due to differing erosion rates between resistant and less resistant rock types.
70
Explain how vegetation stabilises coastal landscapes such as sand dunes and salt marshes.
(Essay 4)
71
How do pioneer plants stabilise sand dunes?
Root systems bind sediment, reducing wind erosion; organic matter builds nutrient-rich soil promoting further vegetation growth.
72
Examples of pioneer dune plants?
Sea couch grass, lyme grass, marram grass.
73
How does marram grass specifically stabilise dunes?
Deep roots reaching water table, waxy leaves resist wind abrasion and water loss, trapping sediment effectively.
74
What process describes dune stabilisation through vegetation succession?
Dune succession; vegetation promotes sand accumulation, increasing stability over time.
75
How do halophytic plants stabilise salt marshes?
Roots bind sediment, reduce erosion from tidal currents, and encourage deposition of organic matter.
76
Name examples of salt marsh plants.
Cord grass, glasswort.
77
How do halophytes influence sediment deposition?
Reduce wave energy and facilitate sediment accumulation through flocculation (clay particles clumping).
78
Overall importance of vegetation on coastal stability?
Vegetation stabilises sediment, reduces erosion, promotes landform growth, creating buffer zones protecting inland areas from flooding/storm surges.
79
Explain how different wave types influence beach morphology and sediment profiles.
(Essay 5)
80
Characteristics and impact of constructive waves?
Low-energy waves; strong swash deposits sediment up beach, forming berms and gentle beach slopes.
81
Example location of constructive waves influencing beach profiles?
Swanage Bay, Dorset – summer profiles with sorted sediment (coarse at back, finer at shoreline).
82
How do constructive waves sort sediment?
Depositing larger material at high tide (berms) and finer sand closer to waterline, creating distinct sediment profiles.
83
Characteristics and impact of destructive waves?
High-energy waves; strong backwash removes sediment offshore, reducing beach gradient and width.
84
What features result from destructive waves?
Storm ridges, offshore bars, reduced beach width, and steeper beach profiles.
85
Example location of destructive wave impacts?
St Ives Bay, Cornwall – significant sediment loss and reshaping shoreline during winter storms.
86
Seasonal influence on wave types?
Constructive waves dominate in summer (building beaches), destructive waves dominate in winter (eroding beaches).
87
Summarise how wave types influence beach morphology.
Wave energy and seasonality shape sediment distribution, gradient, and beach stability, continuously altering beach morphology.
88
Explain how marine erosion creates distinctive coastal landforms such as cliffs and wave-cut platforms.
(Essay 1)
89
What coastal landforms does marine erosion primarily shape?
Cliffs and wave-cut platforms.
90
How is a wave-cut notch created?
Between high and low tide marks, destructive waves use hydraulic action and abrasion to erode rock at the cliff base, forming a notch.
91
What occurs when a wave-cut notch deepens?
The overlying rock becomes unstable, collapses due to mass movement, creating a steep cliff face.
92
What forms when the cliff retreats inland due to repeated notch formation and collapse?
A flat, seaward-sloping wave-cut platform below low tide level, exposed at low tide.
93
Why don't wave-cut platforms typically extend far?
Shallow water dissipates wave energy, limiting erosion beyond a certain point.
94
Describe the role of joints and faults in coastal erosion.
They are structural weaknesses eroded more rapidly by hydraulic action, forming features like caves.
95
Outline the cave-arch-stack-stump sequence linked to cliffs/platform formation.
Weaknesses erode to caves, connect forming arches, arches collapse to stacks, stacks eroded further become stumps.
96
How does wave refraction influence cave formation?
Concentrates wave energy on headlands, accelerating erosion and feature formation.
97
Explain how hydraulic action, abrasion, attrition, and corrosion contribute to coastal erosion.
(Essay 2)
98
Define hydraulic action and explain its erosion mechanism.
Force of water compressing air in cracks; air explodes upon wave retreat, creating fractures, weakening rock over time.
99
Example of hydraulic action erosion and its effect on coastline retreat.
Holderness Coast—boulder clay rapidly eroded during storms, causing significant coastline retreat.
100
Explain abrasion (corrasion) and how it contributes to erosion.
Waves hurl sediment at rock surfaces, physically chipping away at rock, especially effective with destructive waves.
101
Describe the ideal conditions for abrasion.
High-energy, destructive waves carrying large sediment loads hitting soft rock types (e.g., mudstones/clays).
102
Example of coastline erosion significantly influenced by abrasion.
Holderness Coast—soft sedimentary rocks rapidly worn down, speeding up coastal retreat.
103
Why does sediment availability enhance abrasion?
Presence of shingle/hard sediment at cliff base increases abrasion efficiency and erosion rates.
104
Explain the processes of attrition and corrosion briefly.
(Note: Original essay focused only on hydraulic action and abrasion extensively; attrition/corrosion implicitly included as secondary processes contributing to sediment breakdown.)
105
Explain how the cave-arch-stack-stump sequence is formed.
(Essay 3)
106
What structural weaknesses facilitate the cave-arch-stack-stump sequence?
Joints or faults in headlands targeted by hydraulic action and abrasion.
107
Initial stage of the cave-arch-stack-stump sequence?
Sea cave formation by concentrated wave erosion on structural weaknesses.
108
How does a sea cave evolve into an arch?
Continuous erosion deepens caves from both sides of a headland until they connect through.
109
Role of wave refraction in arch formation?
Focuses wave energy, intensifying erosion on headland sides, accelerating cave-to-arch formation.
110
What causes an arch to collapse into a stack?
Further erosion (hydraulic action, abrasion) and weathering weaken the arch structure, causing roof collapse by blockfall.
111
How does a stack eventually become a stump?
Marine erosion forms notches at stack bases, leading to collapse through blockfall, leaving stumps visible at low tide.
112
What key coastal processes are demonstrated by this sequence?
Continuous erosion, wave energy dynamics, mass movement, coastal recession, and evolving landforms.
113
Overall significance of the cave-arch-stack-stump sequence?
Demonstrates progressive erosion-driven retreat of headlands, linked to wave-cut platform formation and coastal morphology evolution.
114
Explain how longshore drift influences the formation of depositional landforms.
(Essay 4)
115
Define Longshore Drift (LSD).
Lateral sediment transport along drift-aligned coastlines, driven by waves approaching at an angle to prevailing wind.
116
Describe sediment transport mechanisms in LSD.
Swash moves sediment diagonally up beaches; backwash moves it perpendicular down slope—resulting in net lateral sediment transfer.
117
Formation process of a spit due to LSD.
LSD transports sediment beyond coastline breaks (river mouths/bays), sediment deposits in low-energy zones, forming spits extending into open water.
118
How does wave refraction or secondary winds influence spit shape?
Curves spit ends landward, forming recurved spits (e.g., Poole Harbour).
119
How can double spits form and what features result?
Opposite spits from dual-directional LSD partially enclose bays, forming salt marshes or lagoons stabilised by vegetation deposition.
120
Describe cuspate foreland formation influenced by LSD.
Opposing LSD currents converge, depositing sediment in triangular formations (e.g., Dungeness).
121
Explain sediment characteristics changes along drift-aligned coastlines.
Grain size, roundness, sorting progressively change due to abrasion/selective transport by wave action.
122
Summarise LSD’s overall coastal impact.
Fundamental in depositional landform formation within sediment cells, influenced by wave refraction, tides, vegetation stabilisation, and human intervention.
123
Explain how different types of coastal deposition lead to formation of spits, tombolos, and barrier beaches.
(Essay 5)
124
Key factors influencing coastal deposition and landform formation?
Wave energy variations, sediment supply, transport processes like longshore drift.
125
Describe spit formation on drift-aligned coastlines.
LSD moves sediment past a coastline direction change (>30°), deposition creates a linear ridge extending into the sea (e.g., Spurn Head).
126
Conditions forming a recurved or hooked spit?
Secondary currents (river outflows) interrupt sediment extension, causing spit ends to curve inward.
127
Explain tombolo formation via drift-aligned coasts.
LSD extends spits until reaching an island, connecting island and mainland (e.g., Chesil Beach).
128
Explain tombolo formation via swash-aligned coasts.
Wave refraction around islands causes sediment deposition behind island in calm water, forming tombolo (e.g., St Ninian’s, Shetland).
129
Barrier beach (bar) formation explained.
LSD extends spits across bays, enclosing lagoons behind sediment barriers (e.g., Slapton Ley).
130
Alternate process forming barrier islands?
Rising sea levels move offshore sediment landward, creating barrier islands (e.g., coastlines in the Netherlands).
131
How do plant succession processes stabilise depositional features?
Vegetation roots bind sediment, enhancing stability and deposition, securing landforms long-term.
132
Explain how sediment cells operate as systems of dynamic equilibrium.
(Essay 1)
133
Define sediment cells and their main components.
Closed systems of sediment movement along a coastline with sources (e.g., cliff erosion, rivers), transfers (e.g., longshore drift, waves, tidal currents), and sinks (e.g., beaches, spits, offshore bars).
134
How is dynamic equilibrium maintained within sediment cells?
Sediment inputs balance outputs, preventing net loss or gain; equilibrium is maintained through negative feedback mechanisms.
135
Give an example of negative feedback restoring equilibrium.
Storm erodes beach sediment, forming an offshore bar that dissipates wave energy, allowing sediment redeposition onshore.
136
What can disrupt dynamic equilibrium in sediment cells?
Positive feedback (e.g., reduced sediment supply from coastal defenses like groynes, causing increased erosion downstream).
137
How do human activities impact sediment cells?
Coastal management (e.g., seawalls) reduces sediment availability, disrupting sediment supply and equilibrium.
138
Explain climate change's role in sediment cell disruption.
Increasing storm intensity accelerates sediment redistribution, causing long-term equilibrium shifts.
139
Summarize sediment cell functioning and equilibrium concept.
Operate as self-contained systems with inputs, transfers, sinks, maintaining equilibrium through feedback, though vulnerable to human and climatic disruptions.
140
Explain how weathering processes influence rates of coastal erosion and landform development.
(Essay 2)
141
How does weathering influence coastal erosion?
Weakens rock structure, preparing material for erosion by hydraulic action, abrasion, and attrition.
142
Name three main types of weathering influencing coastlines.
Mechanical (freeze-thaw, salt crystallization), chemical (carbonation), and biological weathering.
143
Explain mechanical weathering's coastal impact.
Fragmentation of porous/jointed rock accelerates cliff retreat (e.g., freeze-thaw in cliffs).
144
Describe chemical weathering and provide examples.
Dissolves calcium carbonate, forming features like limestone pavements and caves, especially in limestone cliffs.
145
How does biological weathering contribute to erosion?
Plant roots and burrowing animals weaken cliffs, increasing susceptibility to erosion and mass movement.
146
Example contrasting soft/hard rock coastlines impacted by weathering.
Holderness Coast: rapid erosion (soft rock), Dorset Coast: slower erosion, preserving arches, stacks, stumps (hard rock).
147
Weathering interaction with mass movement processes?
Triggers rockfalls and slumping, changing cliff profiles; can form protective talus slopes that reduce further erosion (negative feedback).
148
Summarize weathering's role in coastal landscapes.
Prepares rock for erosion, shapes landforms, increases sediment supply, interacts dynamically with erosion and mass movement processes.
149
Explain how mass movement contributes to the development of distinctive coastal landforms.
(Essay 3)
150
Define mass movement and its significance to coastal landforms.
Downslope movement of sediment altering cliff profiles, creating depositional landforms.
151
Explain blockfall and its role in landform formation.
Occurs on steep, jointed cliffs (>40°) like chalk or limestone, cliff base undercut by marine erosion; destabilized rock collapses suddenly (e.g., St Oswald’s Bay 2013).
152
What coastal features result from blockfall?
Cliff retreat, wave-cut notches, talus scree slopes, sediment reworked by LSD forming spits/tombolos.
153
Explain rotational slumping and ideal conditions for occurrence.
Unconsolidated material (e.g., boulder clay/sand) over impermeable clay; water infiltration reduces friction causing cliff sections to slump downslope.
154
Provide an example location of rotational slumping.
Barton-on-Sea, Hampshire—permeable sands over clay slumping due to heavy rainfall and wave undercutting, causing rapid coastal retreat.
155
Short-term and long-term impacts of slumped material?
Temporarily protects cliffs, but wave action eventually removes it, maintaining instability.
156
Overall significance of mass movement to coastal systems?
Interacts dynamically with marine and sub-aerial processes, significantly altering coastal morphology and landform development.
157
Explain how eustatic and isostatic changes influence sea levels over time.
(Essay 4)
158
Define eustatic sea level change with historical examples.
Global sea level changes linked to water volume; Devensian Glacial: sea levels fell 120m; Holocene Interglacial: rose 100m over 1,000 years, forming rias (Kingsbridge Estuary) and fjords (Sognefjord).
159
Explain isostatic sea level change.
Vertical land movement due to ice addition/removal; post-glacial rebound in Scotland/Scandinavia (rising 2mm/yr) causes emergent coastlines (raised beaches, fossil cliffs).
160
Example of emergent coastal landforms due to isostatic rebound?
Isle of Arran—raised beaches, fossil cliffs.
161
Describe isostatic sinking and its coastal impact.
Southern Britain sinking, causing marine transgression and submergent coastal landforms.
162
How do eustatic and isostatic changes interact?
Together shape global coastlines, illustrating interplay between global water volume changes and local land adjustments.
163
Summarize the importance of eustatic and isostatic processes.
Both significantly alter coastal geography, shaping coastlines through submergence/emergence over geological timescales.
164
Explain how emergent coastal landforms such as raised beaches and fossil cliffs are formed.
(Essay 5)
165
What causes emergent coastal landform development?
Post-glacial isostatic rebound after ice sheet retreat raises previously ice-depressed land.
166
Specific example of emergent landforms in northern Britain?
Isle of Arran—5m raised beaches forming as land rises at ~2mm/year, exposing former shorelines.
167
Explain formation of raised beaches.
Former high tide level left stranded above current sea levels due to uplift; flat platforms of sand and pebbles exposed inland.
168
Define fossil cliffs and their formation.
Abandoned cliffs formed by past marine erosion, now inland due to uplift; often contain relict wave-cut notches, caves, and arches.
169
Example location and features of fossil cliffs.
Lendalfoot, Ayrshire—40m fossil cliff now located 200m inland, evidence of former wave erosion processes.
170
Explain episodic nature of isostatic rebound.
Periods of stability allow marine erosion/deposition before uplift exposes relict landforms rapidly.
171
Overall significance of emergent coastal landforms.
Illustrate historical sea-level changes due to isostatic processes, provide evidence of past marine erosion, and demonstrate dynamic nature of coastal environments.
172
Explain how submergent coastal landforms such as rias and fjords and their characteristics are formed.
(Essay 1)
173
What causes submergent coastal landforms?
Sea-level rise (eustatic changes) flooding landscapes, submerging terrestrial landforms.
174
Define rias and their formation process.
Drowned river valleys formed during Devensian Glacial; rising sea levels flood V-shaped valleys creating estuarine systems, submerging tributaries (e.g., southern England).
175
Provide an example of a ria and describe its features.
Kingsbridge Estuary, Devon—sinuous, dendritic submerged river valleys with multiple submerged tributaries.
176
Define fjords and explain their formation.
Deep, steep-sided submerged valleys formed when glaciers erode valleys, truncating interlocking spurs, creating steep, straight-sided profiles.
177
Example of a fjord and distinctive features.
Sognefjord, Norway, steep-sided, 1.3 km deep due to intense glacial erosion; deeper than surrounding seas.
178
Key difference between fjords and rias.
Fjords have straighter, steeper sides due to glacier erosion; rias more sinuous/dendritic due to river erosion.
179
Explain the effect of sea-level rise on submergent landforms.
Rising sea levels flood valleys and glacial features, shaping coastlines dramatically and creating distinctive submergent features like rias and fjords.
180
Explain how contemporary sea-level rise increases coastal risks.
(Essay 2)
181
How does eustatic sea-level rise increase coastal flooding and erosion?
Thermal expansion (40% of sea-level rise) and glacial melt raise sea levels, causing coastal flooding, erosion, and habitat loss.
182
Impact of rising sea levels on low-lying coastal communities.
Flooding, erosion, loss of agricultural productivity, increased saltwater intrusion, creating climate refugees (e.g., Bangladesh, Maldives).
183
Role of tectonic activity in contemporary sea-level rise.
Causes 10% of sea-level change through uplift/subsidence; earthquakes can drastically alter sea levels locally (e.g., 2004 Indian Ocean tsunami).
184
Example of tectonic activity impacting sea levels and human settlements.
Indonesia (2004): earthquake-induced seabed uplift and subsidence caused sudden local sea-level changes, increasing coastal flooding risks.
185
How do natural and anthropogenic factors amplify coastal vulnerability?
Human activities (building sea walls, groynes) and natural processes (subsidence, earthquakes, storms) combine to amplify coastal vulnerability.
186
Specific impact of sea-level rise on human populations.
Increased flooding, reduced agricultural productivity, forced climate migration, emergence of climate refugees (e.g., Bangladesh).
187
Summarize the combined impacts of eustatic and tectonic sea-level rise.
Natural and human factors interact, amplifying coastal vulnerability, increasing risks to ecosystems and human populations.
188
Explain how physical and human factors influence the rate of coastal recession.
(Essay 3)
189
Physical factors influencing coastal recession rates.
Geology (rock strength, structure), marine processes (wave energy, longshore drift), and storm frequency.
190
Example illustrating geological impacts on recession rates.
Holderness Coast: weak boulder clay geology rapidly eroded by strong longshore drift and storm waves (over 2m/year erosion).
191
How do destructive waves influence recession rates?
Higher wave energy and frequency increase erosion through hydraulic action and abrasion, rapidly eroding soft coastlines.
192
Role of human activity in accelerating coastal recession.
Disrupting sediment budgets via dams, coastal defences (groynes, seawalls), and dredging starve coasts of sediment, intensifying erosion downstream.
193
Example of human-induced rapid coastal recession.
Aswan Dam, Egypt: reduced Nile sediment increased coastal recession from 20m to 200m/year, damaging downstream coasts.
194
How does dredging influence coastal recession?
Removes sediment from beaches/estuaries, disrupting equilibrium, intensifying erosion rates and coastline retreat.
195
Summarize interaction between physical and human factors.
Both natural processes (geology, waves) and human interventions (groynes, dredging, coastal management) significantly accelerate coastal recession.
196
Explain how mass movement and subaerial processes influence rates of coastal retreat.
(Essay 4)
197
How do weathering processes affect coastal recession?
Weaken rock structure, making cliffs more susceptible to erosion and mass movement (mechanical, chemical, biological).
198
Example of subaerial processes intensifying erosion despite coastal defenses.
Overstrand, North Norfolk: subaerial weathering (chemical, biological) continues behind seawalls, causing repeated slumping and rapid retreat.
199
Explain rotational slumping's role in coastal retreat.
Rainwater infiltration increases pore pressure, causing cliff collapse along curved planes, especially in boulder clay areas like Holderness.
200
Role of wave-cut notches in mass movement.
Marine erosion undercuts cliff base, destabilizing cliffs, triggering collapse and accelerating coastal retreat.
201
Specific example of mass movement accelerating recession.
Holderness Coast, slumping contributes significantly to rapid recession (>2m/year).
202
Explain how mass movement and weathering interact dynamically.
Weathering weakens rock, mass movement transfers sediment downslope, creating rapid, unpredictable coastal recession.
203
Summarize the combined impact of these processes on coastal landscapes.
Weathering and mass movement significantly enhance erosion, altering coastal landforms rapidly, creating unstable landscapes.
204
Explain how different timescale factors influence coastal recession.
(Essay 5)
205
Immediate short-term physical factors causing rapid coastal recession.
Prevailing winds (onshore) generate powerful waves; e.g., North Norfolk coast (1,600 km fetch), recession rates up to 8m/year.
206
Why do prevailing wind directions significantly affect erosion rates?
Onshore winds increase wave energy, heightening erosion intensity on exposed coastlines. Offshore winds reduce erosion potential.
207
Explain the impact of tidal variations on recession rates.
Higher tides allow deeper water, waves retain more energy, reach further inland, accelerating backshore erosion.
208
How do storm events influence long-term coastal recession rates?
Winter storms produce higher wave energy, rapidly eroding coastlines; storm surges significantly increase erosion rates temporarily.
209
Provide examples illustrating storm and tidal impacts.
Holderness: storm events and spring tides rapidly erode cliffs (2–6m quickly), compared to 1.25m average annually.
210
Long-term impact of climate change on recession rates.
Increasing storm frequency/intensity due to global warming likely to further accelerate coastal erosion significantly.
211
Summarize short-term vs long-term influences on coastal recession.
Short-term (winds, fetch) cause rapid recession events, while long-term (storms, tides, climate change) produce sustained erosion trends over years or decades.
212
Explain how local and global factors influence coastal flood risk.
(Essay 1)
213
Identify local factors that increase coastal flood risk.
Low-lying coastlines, subsidence, vegetation removal (mangroves).
214
Example illustrating local vulnerability to flooding due to elevation.
Maldives (highest point 2.3m), vulnerable to flooding, especially storm surges and rising sea levels.
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Impact of vegetation removal on local flood risk.
Removal of mangroves (natural buffers absorbing wave energy) increases flood vulnerability, e.g., Bangladesh’s Ganges-Brahmaputra delta.
216
How does subsidence affect flood risk locally?
Human-induced subsidence from groundwater abstraction/agriculture drainage compounds flood risk, particularly in Bangladesh.
217
Outline global factors influencing coastal flood risk.
Climate-change-driven sea-level rise (IPCC prediction: 18-59cm by 2100) significantly increasing flood risk globally.
218
Examples illustrating global sea-level rise impacts.
Maldives losing 77% of land (50cm rise); Bangladesh could see 11% submerged with a 40cm rise, displacing millions.
219
Summarize interaction between local and global factors in coastal flooding.
Global sea-level rise intensifies local risks, especially in densely populated, low-lying agricultural/tourist-dependent areas, highlighting interconnectedness.
220
Explain how storm surges increase the risk of coastal flooding.
(Essay 2)
221
Define storm surges and their cause.
Temporary sea-level rise caused by low-pressure systems (tropical cyclones/depressions), strong winds pushing water onto coasts.
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Example of significant storm surge impact.
Tropical Cyclone Sidr (2007, Bangladesh): 6m storm surge intensified by Bay of Bengal funnel shape and mangrove loss, causing 15,000 deaths, 1.6 million homes destroyed.
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Physical factors amplifying storm surge effects.
High tides (especially spring tides) combined with geographical features (e.g., funnel-shaped bays) increase flooding severity.
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Impact of storm surges on erosion and infrastructure.
Increased sea-level combined with destructive waves worsens coastal erosion, infrastructure damage (e.g., Storm Xavier, UK, 2013, 1,400 homes flooded).
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Example showing mitigation of storm surge impacts.
UK’s Thames Barrier reduced Storm Xavier impacts, protecting 800,000 homes, highlighting effectiveness of flood defenses.
226
Contrast storm surges historically and currently.
Advances in defenses and forecasting reduced storm surge impacts since 1953 storm, though underlying threat remains severe.
227
Summarize how storm surges amplify flood risks.
Temporary extreme sea-level rise and wave energy significantly increase coastal flooding, erosion, infrastructure damage, and human risk.
228
Explain how climate change increases coastal flooding risks.
(Essay 3)
229
How does climate change cause rising sea levels?
Thermal expansion (40% of rise) and glacial melt, IPCC predicting 18-59cm rise by 2100.
230
Consequences of sea-level rise for coastal flooding.
Increased storm surge frequency/severity, inundation of low-lying deltas, severe flooding (e.g., Bangladesh, Maldives).
231
Impact of more intense tropical cyclones.
Predicted cyclone intensity increase (2-11%) raises storm surge risk, resulting in heavier rainfall, dramatic flooding events.
232
Example illustrating climate-change-increased storm intensity.
Thames Barrier constructed due to increased storm surge risks, showing impacts on coastal defenses planning.
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Future coastal risk projections due to climate change.
50% more coastal land at risk globally by 2100; increased wind speeds, waves, storm frequency/intensity.
234
Explain cumulative impacts of climate change on coasts.
Sea-level rise and intensified storms interact, amplifying future flooding risks, requiring effective mitigation/adaptation strategies.
235
Summarize climate change's impact on flooding.
Climate change dramatically increases coastal flooding risks via sea-level rise, intense storms, storm surges, demanding urgent action.
236
Explain how coastal recession and flooding lead to economic/social losses.
(Essay 4)
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Economic impacts of coastal recession and flooding.
Loss of homes/businesses/agricultural land; high land/property value loss (e.g., residential land in Dorset: £2.1 million/hectare).
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Specific example of costly infrastructure damage.
South Devon Main Line Railway (2014) collapse, costing £35 million repairs, £60 million business losses, highlighting significant economic impacts.
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Social impacts of coastal recession and flooding.
Forced relocation, community breakup, livelihood loss for those dependent on local businesses/agriculture/tourism.
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Example illustrating social costs of coastal flooding/recession.
East Riding of Yorkshire: Coastal Change Pathfinder scheme (£1.2 million) relocated 43 homes, highlighting social disruption.
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Broader social consequences of relocation and flooding.
Financial burden, disruption to social networks, stress, hardship, community disintegration.
242
Summarize economic and social interconnectedness.
Damage to property/infrastructure cascades into local economy/social structures, amplifying long-term community challenges.
243
Explain how sea walls and groynes protect coastlines.
(Essay 5)
244
How do sea walls function to protect coastlines?
Concrete barriers (curved shape) reflect wave energy back to sea, preventing cliff erosion (e.g., Bridlington).
245
Advantages and disadvantages of sea walls.
Effective cliff protection but expensive construction/maintenance (£2,000 per meter), potential wave damage requiring ongoing maintenance.
246
Define groynes and their purpose.
Wooden/rock structures perpendicular to coast, interrupt longshore drift, trap sediment, build beaches (e.g., Hornsea, Withernsea).
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Benefits of groynes for coastal protection.
Beach sediment accumulation buffers wave action, supporting tourism and natural coastal defense.
248
Negative impacts associated with groynes.
Down-drift sediment starvation increases erosion elsewhere along coastline.
249
Cost-effectiveness of groynes as coastal defenses.
Relatively low-cost compared to sea walls, effective sediment management, popular coastal protection choice despite limitations.
250
Integration of sea walls and groynes as coastal protection.
Combination methods (Hornsea, Withernsea) manage erosion and sediment effectively, highlighting combined approach effectiveness.
251
Summarize how sea walls and groynes protect coasts.
Both structures effectively manage erosion and sediment movement, though each has advantages and limitations, best used in combination.
252
Explain how local and global factors influence coastal flood risk.
(Essay 1)
253
Identify local factors increasing coastal flood risk.
Low-lying coastlines, subsidence, vegetation removal.
254
Example illustrating vulnerability due to low elevation.
Maldives (highest elevation: 2.3m), vulnerable to flooding during storm surges and sea-level rise.
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Impact of vegetation removal locally.
Loss of mangroves reduces natural wave buffers, increasing flood vulnerability (e.g., Bangladesh’s Ganges-Brahmaputra delta).
256
How does subsidence increase flood risk locally?
Human-induced subsidence from groundwater abstraction and agricultural drainage exacerbates flooding (60% of Bangladesh <3m elevation).
257
Global factors influencing coastal flood risk.
Climate-change-driven sea-level rise predicted by IPCC (18-59cm by 2100), threatening low-lying deltas/islands (e.g., Bangladesh, Maldives).
258
Example of global sea-level rise impacts.
Maldives: 77% land loss from 50cm rise; Bangladesh: 11% submerged by 40cm rise, displacing millions.
259
Summarize how local and global factors interact.
Global sea-level rise amplifies local flood risks, showing interconnectedness, especially in densely populated low-lying coastal areas.
260
Explain how storm surges increase the risk of coastal flooding.
(Essay 2)
261
Define storm surges and their cause.
Temporary sea-level rises caused by low-pressure systems (cyclones/depressions), pushing seawater toward coasts.
262
Conditions intensifying storm surges.
Combination with high tides (spring tides), funnel-shaped coastlines intensifying surge heights (e.g., Bay of Bengal).
263
Example illustrating severe storm surge impact.
Tropical Cyclone Sidr (2007): 6m storm surge in Bangladesh causing 15,000 deaths, destroying 1.6 million homes.
264
Storm surge impacts on coastal erosion and infrastructure.
Elevated sea levels and destructive waves increase erosion and infrastructure damage, e.g., Storm Xavier (UK, 2013), flooding 1,400 homes.
265
Role of improved defences in mitigating storm surges.
Thames Barrier protected 800,000 homes during Storm Xavier (2013), showing effectiveness of enhanced coastal protection.
266
Comparison between historical/current storm surges.
Advances since 1953 reduced fatalities and damage, but underlying threat remains high.
267
Summarize storm surge flooding risk.
Temporary elevated sea levels significantly amplify coastal flooding, erosion, infrastructure damage, human vulnerability.
268
Explain how climate change increases coastal flooding frequency and severity.
(Essay 3)
269
How does climate-driven sea-level rise increase flooding risk?
Thermal expansion and glacial melt raise global sea levels (18-59cm by 2100), inundating low-lying areas more frequently and severely.
270
Influence of rising sea levels on storm surge severity.
Higher baseline sea levels intensify storm surge impacts, increasing flooding in low-lying deltas/coastal zones (e.g., Bangladesh).
271
Predicted change in tropical cyclone intensity due to climate change.
Cyclone intensity may increase 2-11%, exacerbating storm surge magnitude and flooding (IPCC, 2014).
272
Consequences of intensified cyclones and heavier rainfall.
Storms carry more moisture, heavier rains, and stronger winds, amplifying coastal flooding damage.
273
Example of increased storm surge risks in developed countries.
Thames Barrier, UK, built to protect from increased storm surge frequency/intensity.
274
Future risk projections due to climate change.
By 2100, 50% more delta land at flooding risk; cumulative effects of storms, waves, sea-level rise magnify flood risks significantly.
275
Summarize climate change impact on flooding.
Climate change significantly increases flooding frequency/severity through sea-level rise and intensified storms, demanding mitigation/adaptation strategies.
276
Explain how coastal recession and flooding can lead to economic and social losses for communities.
(Essay 4)
277
Economic impacts of coastal recession/flooding.
Property loss (homes, businesses, agricultural land); infrastructure damage incurring substantial repair costs.
278
Example illustrating economic losses.
2014 South Devon Railway collapse: £35 million repairs, £60 million lost businesses; residential land values up to £2.1m per hectare in Dorset.
279
Social consequences of recession/flooding.
Forced relocation, community breakup, loss of livelihoods dependent on tourism, agriculture, or local businesses.
280
Costs associated with social displacement.
Coastal Change Pathfinder scheme (East Riding of Yorkshire): £1.2 million to relocate 43 homes, highlighting displacement costs.
281
Wider social impacts.
Community fragmentation, stress, financial hardship, disruption of social networks, employment instability.
282
Interconnectedness of economic/social losses.
Economic impacts (property/infrastructure) trigger cascading effects on social structures, intensifying community vulnerability.
283
Summarize overall impact of coastal recession and flooding.
Extensive economic/social losses interconnected, amplifying long-term community challenges from coastal erosion/flooding.
284
Explain how sea walls and groynes protect coastlines.
(Essay 5)
285
Function and advantages of sea walls.
Concrete structures (e.g., Bridlington), reflect wave energy, physically prevent cliff base erosion, immediately protect inland areas.
286
Disadvantages of sea walls.
High construction costs (£2,000-£10,000/m), expensive ongoing maintenance; wave energy damages structures over time.
287
Groynes: definition and coastal protection role.
Structures perpendicular to coast (e.g., Hornsea, Withernsea), trap sediment, interrupt longshore drift, building protective beaches.
288
Advantages of groynes.
Effective sediment accumulation builds beaches, natural buffers, enhances tourism due to maintained beaches.
289
Disadvantages of groynes.
Cause sediment starvation downstream, increasing erosion elsewhere along the coast, transferring erosion risk.
290
Economic considerations of groynes.
Relatively low cost, popular for protecting beaches economically, despite negative downstream impacts.
291
Integration of sea walls and groynes.
Combined methods (e.g., Hornsea, Withernsea) effectively manage erosion and sediment movement, highlighting strategic integration value.
292
Summarize coastal protection by groynes and sea walls.
Both structures offer effective localized protection but carry environmental, financial trade-offs, requiring balanced management approaches.
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