Coast KQ 1&2 Flashcards

(228 cards)

1
Q

What is a spilling wave ?

A

Steep waves breaking onto gently sloping beaches

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2
Q

What is a plunging wave ?

A

Moderately steep waves breaking onto steep beaches

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3
Q

what is a surging wave ?

A

Low angle waves breaking onto steep beaches

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4
Q

What is a swell wave ?

A

Long wavelength , wave period up to 20 seconds .formed in ocean oceans

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5
Q

What is a storm wave ?

A

Locally generated
Shorter wavelength , greater height , shorter wave period

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6
Q

What is the equation for the amount of energy in a wave ?

A

P= h^2 t

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7
Q

What is a system ?

A

A set of interrelated objects comprising of components and processes that are connected together to form a working unit

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8
Q

What energy types are available to a coastal landscape system ?

A

Kinetic , potential and thermal

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9
Q

What is an open system ?

A

Energy and matter can be transferred from neighbouring systems as an input but also as an output

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10
Q

What are some examples of inputs of a coastal landscape ?

A

Kinetic energy from wind and waves
Thermal energy from heat of sun
Potential energy from the position of material on sloped
Material from marine deposition

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11
Q

What are some examples of outputs of a coastal landscape ?

A

Marine and wind erosion
Evaporation

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12
Q

What are some examples of processes in a coastal landscape system ?

A

Longshore drift

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13
Q

When could equilibrium occur in a coastal landscape ?

A

When the rate at which sediment is bing added to the beach equal the rate at which sediment is being removed from the beach

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14
Q

What is dynamic equilibrium ?

A

When equilibrium is disturbed , the system undergoes self regulation and changes its form in order to restore equilibrium

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15
Q

What is a sediment cell ?

A

Reaches of shoreline which encompass th enter tidal and nearshore movement of sediment

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16
Q

Why are sediment cells closed systems ?

A

No sediment is transferred from one cell to another

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17
Q

How many large sediment cells are there around the coast of England and wales ?

A

11

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18
Q

How are the boundries of sediment cells determined ?

A

By the topography and shape of the coastline

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19
Q

Why is it unlikely that sediment cells are completely closed ?

A

Because of variations in wind direction and the presence of tidal currents

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20
Q

What is a special impact ?

A

From place to place

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21
Q

What is a temporal impact ?

A

Over time

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22
Q

What is the source of energy for coastal erosion and sediment transport ?

A

Wave action

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23
Q

How is wave energy generated ?

A

By the frictional drag of winds moving across the oceans surface

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24
Q

What are onshore winds ?

A

Blow from the sea towards the land , very effective at driving waves towards the coast

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25
How does wind affect landforms ?
Helps to create constructive and destructive Can make small landforms such as sand dunes and blowouts
26
How do waves link to energy ?
A wave posses potential energy as a result of its position above the wave trough, and kinetic energy caused by the motion of the water within the wave
27
What is the formula for the amount of energy in a wave in deep water ?
Power = height ^2 X time interval between wave crests
28
What is the wave period ?
Time interval between wave crests in seconds
29
What is wave frequency ?
The number of waves per minute
30
How do waves affect landforms ?
They deposit sediment for spits and beaches Form wave cut notches Discordant coastline could form due to increased erosion rates
31
What is negative feedback ?
When the process seeks to counter the change and maintain equilibrium
32
What is steady state equilibrium ?
Where variations in energy and the morphological response do nt deviate too far from the long term average
33
What is meta state equilibrium ?
Where an environment switches between two or more states f equilibrium
34
What is positive feedback ?
Where a flow/transfer leads to increase or growth
35
What are the features of constructive waves ?
Low height Longer wavelength Low frequency 6-8 per min Strong swash Weak backwash Surging wave break Deposition
36
What are th features of destructive waves ?
High height Shorter wavelength High frequency 12-14 per min Weak swash Strong backwash Plunging wave break EROSION
37
What is a sediment budget ?
The balance of the sediment volume entering and exiting a particular section of the coast
38
What is a swell wave ?
Long wavelength Wave period of up to 20 seconds Formed in open oceans
39
What is a storm wave ?
Locally generated Shorter wavelength Greater height Shorter wave length
40
What is a tide ?
The periodic rise and fall of the sea surface and are produced by the gravitational pull of the moon and to a lesser extent the sun.
41
How do high tides form ?
The moon pulls water towards it ,creating a high tide , and there is a compensatory bulge on the opposite side of the earth
42
Where will there be a low tide ?
At locations between the two bulges
43
When will the highest tides occur ?
When the moon , sun and earth are all aligned and so the gravitational pull is at its strongest (this happens twice each lunar month and results in spring tides with a high tidal range )
44
How are neap tides produced ?
Twice a month , the moon and sun are a tight angles to each other and the gravitational pull is therefore at its weakness This produces neap tides and low tidal range
45
What does tidal range influence ?
Where wave action occurs Weathering process that happen on land exposed between tides Potential scouring effect of waves along coasts with a high tidal range
46
How is the formation of sand dunes connected to tides ?
The larger the tidal range the more time the sand has to dry so when it is dry it can be blown up the beach to from sand dunes
47
How do tides affect landforms ?
Low tidal range = narrower beach which is prone to more erosion
48
What do tidal currents do ?
Move sediment to and from a beach and are much more consistent than rip currents
49
what is a neap tide ?
Lower than normal tides Occur when the sun and moon are at right angles to the earth so the gravitational pull from both has a reduced impact
50
When do neap tides occur ?
Follows 7 days after a spring tide
51
What is a spring tide ?
Occurs when there’s a new or full moon Happens twice per month The tides on average are slightly larger than usual
52
How are rip currents caused ?
Either by tidal motion or by waves breaking at right angles to the shore
53
What is a rip current ?
Strong and relatively narrow currents of water that flow seaward against breaking waves they are temporary Some last for hours , some last for months
54
How are ocean currents generated ?
By the earths rotation and by convection They are set in motion by the movement of winds across the waters surface
55
What do warm ocean currents do ?
Transfer heat energy from low latitudes towards the poles
56
What do cold ocean currents do ?
Move cold water from the polar regions towards the equator They are driven. By offshore winds so have less effect on coastal landscapes
57
What coastal landforms do rip currents make ?
Remove sediment from the beach Create sand bars , cusps and inshore gutters
58
How do warm ocean currents affect the landscape ?
They increase the rate of sub Ariel processes Warmer the air , the faster the chemical and biological weathering
59
What does lithology mean ?
The physical and chemical composition of rocks
60
What does the structure of the rock mean ?
Properties of individual rock types such as jointing , bedding and faulting
61
What coastal processes are affected by geology ?
Lots of bedding planes and joints encourages weathering , erosion and mass movement lithology affect erosion and weathering rates
62
How does geology affect coastal landforms ?
Affects cliff shape and gradient due to angle of strata Resistant rock - arches , stacks , stumps Less resistant rock - beaches , gentle slopes and cliffs
63
What are some stores in a coastal system ?
Dunes Beaches Sandbank
64
What are some inputs of the coastal system?
Cliff erosion River sediment Longshore drift Wave deposition
65
What are the outputs of the coastal system ?
Aeolian erosion to inland Longshore drift Wave erosion
66
What is freeze thaw weathering ?
Water enters cracks/joints in rock, and freezes causing a 10% expansion. This exerts pressure on the rock Repeated freezing and thawing(to allow more water to enter ), eventually causes rocks to break
67
What is pressure release ? (also called dilation)
When overlying rocks are removed (due to weathering and erosion), the pressure is released , allowing rocks to expand and fracture parallel to the surface
68
What is thermal expansion ? (insulation weathering, or onion skin weathering )
Outer layers of rocks expand and contract when heated and cooled.repeated cycles of heating and cooling can cause the outer layers to crack and flake off
69
What is salt crystallisation ?
Saline water enters pore spaces or cracks in rocks Water evaporates causing the salt to precipitate out forming crystals. The growth of the crystals over time creates stresses within the rocks, leading to break up Particularly effective with sodium sulphate and sodium carbonate around 26-28 degrees .
70
What are the 4 types of physical weathering ?
Freeze thaw Pressure release Thermal expansion Salt crystallisation
71
What are the 5 types of chemical weathering ?
Oxidation Carbonation Solution Hydrolysis Hydration
72
What is oxidation ?
Some minerals in rocks (iron), react with oxygen , either in air or water Causes rocks to crumble easily
73
What is carbonation ?
Weak carbonic acid is formed when rain reacts with CO2 in atmosphere Th acid reacts with calcium carbonate in limestone and chalk creating calcium bicarbonate , which is soluble in water and therefore easily removed
74
What is solution (chemical weathering )?
Some minerals (gypsum), are soluble in water , so are relatively easily dissolved and removed by seawater
75
What is hydrolysis ?
Thi is the reaction between water and a group of rock minerals called silicates (e.g. feldspar found in granite reacts with water to form kaolin
76
What is hydration ?
Certain minerals react wth water creating new minerals of a larger volume Other minerals , e.g. clay , expand when wet and contract when dry Causing many rocks , e.g. shale to flake at their surface
77
What are the two types of biological weathering ?
Tree roots Organic acids
78
What is tree root biological weathering ?
Tree roots grow into cracks in the rocks and exert outward pressure Works in a similar way to freeze thaw When trees fall , the roots can also exert leverage on the rock bringing them to the surface This exposes them to further weathering So rocks break apart
79
What is organic acids biological weathering ?
They are produced during decomposition of plant and animal litter They case soil water to become more acidic and react with some minerals in a process called chelation
80
What does blue-green algae do to rocks ?(weathering )
Produces a shiny film of iron and manganese oxides on rocks
81
What do molluscs do on shore platforms ? (weathering )
May secrete acids which produce small surface hollows in the rock
82
What type of cliffs does rockfall occur on ?
cliffs of 40 degrees or more If the cliff face is bare
83
What happens in rockfall ?
Rocks become detached from slope by physical weathering Then fall off the foot of the cliff under gravity
84
What happens after rockfall occurs ?
Wave processes usually remove the material Or May accumulate as a relatively straight , lower angled scree slope
85
What is hydraulic action ?
When waves break against the cliff face Air and water gets trapped in cracks and become compressed As wave recedes the pressure is released , air and water suddenly expand and the crack is widened
86
What is the average pressure exerted by breaking Atlantic waves ?
11,000kg per m cubed
87
What is pounding ?
When mass of a breaking wave exerts a pressure on the rock causing it to weaken
88
How does hydraulic action affect the coastline ?
Happens in hard rock on a headland Can form wave cut notches
89
How does abrasion affect the coastline ?
Form caves , arches , stacks and stumps Hard rock on headland Destructive waves Requires high energy waves
90
How does attrition affect the coastline ?
Creates more sand and adds to the sediment budget
91
What is suspension ?
Small particles of sand , silt and clay can be carried by currents This is why some sea water is muddy or brown Larger particles can be carries in this way during storms
92
When does deposition occur?
Where rate of sediment accumulation exceeds the rate of removal When wave slows down immediately after breaking At the top of the swash - for a brief moment the water stops moving During the backwash - when water percolates into beach material In low energy environments
93
What is settling velocity ?
Velocity at which sediment particles are deposited
94
Give an example of a rockfall ?
White cliffs of Dover March 2012 Area size of a football pitch fell Rubble fell 300ft downwards
95
Give an example of a landslide ?
Lyme Regis 6th may 2008 Occurred after a long wet period during winter nad early spring Mudslide
96
Give an example of slumping ?
Evans cliff , charmouth , uk 14th January 2006 17 people trapped 200,000 tonnes of mud toppled down
97
Where do rockfalls occur ?
On cliffs of 40 degrees or more Especially if cliff face is bare
98
What is rockfall ?
Rapid free fall of rock from a steep cliff face Rock fragments fall because of gravity and freeze thaw weathering
99
Where doo landslides occur ?
On cliffs previously weakened by weathering
100
What is landslide ?
Downhill movement of large amounts of rock,soil and mud Heavy rain infiltrates soil and percolated down into rock Has a straight slip plane
101
What type of slip plane does slumping have ?
Curved
102
Where does slumping occur ?
Common at clay cliffs , dry weather makes the clay crack allowing water to get into it
103
What is slumping ?
Material is rotated backwards into cliff face as it slips large pieces of rock are pulled downwards
104
How does a cove form ?
1)alternate bands of resistant and less resistant rock are laid paralelé to coastline 2)tectonic pressures cause fault in limestone 3)destructive waves attack fault , eventually limestone eroded through 4)less resistant sands and clays are rapidly eroded to form a cove 5)cove entrance narrows
105
Why do waves “bend”?
When they touch the seabed , friction causes the wave at the headland to slow down ,
106
What is an orthogonal ?
Imaginary lines which show the direction of the waves They are at right angles to the wave crest
107
What effect do converging orthogonal have on the headlands ?
They bring concentrated erosion o the headlands
108
What happens to the orthogonal in the bay ?
They are less concentrated The waves are spread out with less energy - deposition S sediment builds up
109
What happens to horizontally bedded strata ?
Undercutting by wave action leads to rockfall The cliff retreats inland Parallel to the coast
110
What happens to seaward dipping strata ?
Undercutting by wave action removes basal support Rock layers loosened by weathering slide into the sea along the bedding planes
111
What happens to landward dipping strata ?
Rocks loosened by weathering and wave action are difficult to dislodge The slope profile is gradually lowered by mass movement and weathering
112
What is a spit ?
Long , narrow beaches of sand which are attached to land at one end and extend across the bay
113
What 3 pre conditions are required in the formation of a spit ?
Shallow water Supply of sediment Bend in coastline
114
What happens when the coast changes direction ?(spits)
Sediment keeps being deposited in the direction of the prevailing wind
115
Why does a spit hook ?
Prevailing wind or wave refraction changes direction Or secondary wind direction can cause this too
116
What makes a spit permanent ?
Vegetation could grow and the roots fix sediment in place
117
Give 4 facts about spurn point ?
On the Huber estuary Has a road running down it Less than 10m wide in some places
118
Why are spits considered to being balance to a coastal system ?
Deposition which balances out erosion Creates new land
119
How are headlands and bay in dynamic equilibrium ?
Erosion on headlands is counterbalanced by deposition in the bays
120
What is a geo ?
Narrow, steep side clefts within cliffs
121
What processes are included in the formation of a geo ?
Abrasion Weathering Biological weathering
122
What is an example of a geo ?
Huntsman leap
123
How is a geo formed ?
124
What is a blowhole ?
When pressure is in the rock so it explodes out the top
125
What are the processes involved in the formation of a blowhole ?
Pneumatic action Hydraulic action
126
What is an example of a blowhole?
Blowhole in trevone , Cornwall
127
How does a blowhole form ?
May form via hydraulic action and pneumatic action of the waves crashing into the “ceiling” of the cave Eroding upwards to the point where the land above collapses and falls through
128
How do high energy destructive waves affect beach profile ?
Strong backwash drags sediment down beach Beach gets a flatter gradient This means shallower water , more friction and less wave energy
129
How do low energy constructive waves affect beach profile ?
Strong swash adds more sediment onto beach So beach gets steeper gradient So deeper water , less friction and more wave energy
130
What is a salt marsh ?
Areas of periodically flooded low-lying coastal wetland that are found in sheltered areas behind spits
131
What are slat marshes a coastal habitat for ?
Plants , birds and animals
132
What is a mudflat ?
Flat , low lying areas of mud
133
What factors influence the rate of development of a salt marsh ?
Rates of deposition v rates of erosion
134
What is a floc ?
A mass of clay particles formed in a fluid by aggregation of suspended particles
135
What is flocculation ?
Causes the aggregation of minute clay particles into larger masses which are too heavy to remain suspended in the water
136
Why os flocculation important ?
It encourages deposition because the flocs are too heavy
137
What benefits do salt tolerant plants create within the salt marsh environment ?
They encourage deposition because they slow down the flow of water Help to trap sediment
138
What are some slat tolerant plants found at salt marshes ?
Eelgrass Cordgrass
139
What happens to species diversity as you move inland of the slat marsh ?
It increases as conditions are less harsh (salt content decreases )
140
What are creeks ?
Small streams that drain the marsh at low tide allowing water to drain back into the sea
141
What are saltpans ?
Flat area of ground covered with salt deposited by the evaporation of saline water
142
What conditions are required for salt marshes to form ?
No wind or waves Good supply of sediment Low lying flat coast Clay in suspension , which leads to flocculation
143
Which of the 5 physical factors are important in salt marshes ?
Tidal currents - sweep sediment in Tidal range - important as marsh form etween these
144
How do salt marshes form ?
145
What are beaches ?
Sloping areas of deposition between high and low water marks
146
Where does beach material come from ?
Cliff erosion - 5% Offshore(combed from seabed, during periods of rising sea levels)- 5% Rivers - 90%
147
What type of gradient beaches does sand and shingle cause ?
Sand - gentle Shingle - steep
148
Why do sand beaches have a gentle gradient ? (Usually less than 5 degrees)
Small particle size so it becomes compact when wet , allowing little percolation during backwash Little energy is lost to friction , and little volume lost to percolation , material is carried back down beach rather than being left at top
149
What is a ridge ?
Raised area of sediment running parallel to the shore
150
What is a runnel ?
Low trough (or dip)either side of a ridge .parallel to the shore
151
What is a breached ridge ?
Part of a ridge has been eroded away or broken through
152
What is a berm ?
Ridge at the back of a beach created from deposition Found at the mean high tide mark
153
What is a storm ridge/beach ?
Ridge of larger cobbles and pebbles behind the berm that have been throw there by the storm waves
154
What is a cusp ?
Small semi circular depressions at the back of the beach formed by waves reaching the same point at the same time
155
why do shingle beaches have a steeper gradient ?
Saw ash is stronger than backwash so there is a net movement of shingle on shore Shingle may make up the upper part of the beach where rapid percolation due to larger air spaces means that title backwash occurs and so materia is left at the top of beach
156
Why do you need a sheltered bay for a beach to form ?
Because the waves are calmer and constructive so they will deposit more material
157
Why do yo need constrictive waves to form a beach ?
They have a stronger swash than backwash so they deposit more sediment on the beach
158
How does waves affect the formation f a beach ?
Constructive waves = deposit material
159
How does wind affect the formation of a beach ?
Blows dry sand up the beach to form sand dunes
160
Why are beaches in equilibrium ?
Deposition and erosion are in balance with each other
161
What is a tómbolo ?
Beaches that connect the mainland to an offshore island Often formed from spits that have continued until they Jin an island
162
Give an example of a tombolo ?
30km long shingle beach at Chelsie near Weymouth
163
What ae the three theories of how tombolos are formed ?
Wave reaction Longshore drift Seal level change
164
How does longshore drift form a tombolo ?
Carries material along the beach in a zig zag pattern Swash comes in at a diagonal angle and backwash brings sediment back straight into sea
165
How does wave refraction form tombolos ?
Waves bend round island and sediment builds up (ADD 111_
166
How does sea level change form a tombolo ?
In the past there were lower sea levels and low energy waves that have deposited material creating offshore bars Constructive waves pushed this material back toward the shore building up a ridge that attaché to the mainland to the island
167
What is an offshore bar ?
Submerged or partly exposed ridges of sand that os built by waves parallel to the beach
168
What is an onshore bar ?
They can develop if a spit continues to grow across a cove or bay until it joins land at the other side
169
What forms behind a onshore bar ?
A lagoon or brackish water on the landward side
170
What will happen to this lagoon over time ?
Will gradually be infilled by deposition
171
What is an example of an onshore bar ?
100m wide bar , slapton snads , Devon
172
How could have slapton snads be formed ?
By post glacial sea rise Onshore movement of sediment especially flint
173
What is a delta ?
Large areas of sediment found at the mouth of many rivers
174
How do deltas form ?
When rivers an tidal currents deposit sediment at a faster rate than waves and tides can remove it
175
What are the 4 requirements for a delta to form ?
Tidal ranges are low Low energy environment Rivers entering the sea are carrying large sediment loads B-road continental shelf margin exists at the river mouth to provide a platform for sediment accumulation
176
What are the three parts of a delta ?
Upper delta plain Lower delta plain Submerged delta plain
177
What is the uppe delta plain?
Furtherst inland Beyond the reach of tides Composed entirely of river deposits
178
What is the lower delta plain ?
In the inter tidal zone Regularly submerged Composed of both river and marine deposits
179
What is the submerged delta plain ?
Lies below mean low water mark Composed mainly of marine sediments Represents the sea ward growth of the delta
180
How are deltas crisscrossed ?
By a branching network of distributaries
181
What is a distributary ?
Small branching stream channels that flow away from a main stream or river
182
What are the three types of delta ?
Cúlpate Árcate Birds foot
183
What is a cuspate delta ?
Pointed extension to the coastline occurs when sediment accumulates but this is shaped by regular , gentle currents from opposite directions
184
What is an arcuate delta ?
Sufficient sediment supply available for the delta to grow seawards , but wave action is strong nough to smooth and trim its leading edge
185
What is a birds foot delta ?
Distributaries build out from the coast in a branching pattern , with river sediment supply exceeding rates of removal by waves and currents
186
How do deltas and distributes form spits ?
Sediment that is deposited by distributaries at the river mouth forms promontories which are a source sediment for longshore drift
187
What is the case study for the low energy coastline ?
Nile delta , Egypt
188
Where do the summer prevailing winds come from in the Nile delta ?
From north west
189
How much of the time and what is the surface velovcity of prevailing wind ?
60% of the time with a surface velocity of up to 13.5 cm/s in summer
190
How does longshore drift affect the Nile delta ?
Moves sediment from the Rosetta distribritutary brought from the Nile along the delta eastwards
191
What creates many beaches west of Abu air head with crescentic bars ?
Perpendicular wave due to wind approaching the coast directly before the delta , resulting in no longshore drift but a strong rip currentwhich creates the beaches
192
Where does the winter prevailing wind come from and what percentage of the year ?
NE and 8%
193
When was Aswan dam built ?
1964
194
What did the Aswan dam distrust ?
The equilibrium of the delta system - erosion v accretion
195
What has the Aswan dam resulted in ?
Reduction in the amount of deposition from 120 millions t/yr to trace amounts Leading to accelerated erosion rates of up to 148m/yr
196
How much is the meditteranean sea rising per year ?
1.2mm/yr which increases energy levels
197
Where do spits form on the Nile delta ?
East of Abu qir they grow parallel to the delta and extend across the nearshore enclosing sections of the coastline to form lagoons
198
How do lagoons form into slat marshes ?
They fill up with alluvial deposits Due to the facts that lagoons are sheltered areas and low energy environment
199
What type of delta is the Nile delta ?
Arcuate
200
Where do distributaries start at the Nile Ella ?
At Cairo , 160km inland
201
What are the two main distributaries in the Nile delta ?
Rosetta and Damietta
202
Would would happen to the delta pre Aswan dam ?
It would flood every year to deposit silt , the depth of this alluvium is greater than 9m inn the delta
203
How long is the river Nile ?
6650km (largest in world)
204
What is the discharge of the river Nile ?
Low discharge
205
What is the sediment load of the river Nile ?
4.26t/ha/yr
206
Where does water in the river Nile originate from ?
From the Ethiopian summer monsoon rains
207
What will happen to the Nile delta if there is a 50cm increase in sea level
4 million people affected 1,800km squared of land submerged
208
What will happen to the Nile delta if there is a sea level rise of 1.5m ?
8 million people afffected 5,700 Kim squared of land submerged
209
How much will the sea level rise by 2100 (Nile delta )?
A 60 to 100cm rise
210
Name 3 landforms found east of Abu qir headland ?
Bars , spits , lagoons
211
What is the case study of a high energy coastline in the uk ?
Saltburn to flamborough head
212
Where do waves come fro and what is the fetch at subcell 1 d?
North and north east Fetch over 1500km
213
At Whitby bay what are the wave heights like ? sub cell 1d
Can exceed 4m
214
Where is wave energy concentrated at subcell 1d ?
On exposed north facing parts like saltburn Varied energy due to wave refraction creates varied erosion rates
215
What direction does longshore drift move sediment (saltburn - flamborough head )?
From north to south
216
What type of rocks are the north York moors made up of ?
Up to 400 m above sea level Made up og sandstone , shale formed in Jurassic period but also some Carboniferous rock
217
Give some example of Carboniferous rocks on the north York moors ?
Coal measures Millstone grit Mountain limestone
218
What is the geology like at flamborough head ?
Large chalk headland and cliffs topped with till (glacial deposits )
219
What are the erosion rates of shale (weak) and clay ? (Flamborough head )
0.6 m per year
220
What is th erosion rates of sandstone (resistant ) and limestone ? (Sub cell 1 d)
Less than 0.1m per yr
221
What sediment cell is salt burn to flamborough head ?
Sediment cell 1 , sub cell 1d
222
What are the sources of sediment along slatburn to flamborough head ?
Cliff erosion River elk (mouth at Whitby) Nearshore deposits laid dow during ice age and being driven onshore as sea levels rise
223
Where does sediment mainly occur along subcell 1d ?
Filey brigg
224
How do tides affect the coastline at sub cell 1d ?
Weak and low tides result in deposition Waves can attack a larger section of the cliffs
225
Give some examples of coastal landforms at subcell 1d ?
Over 50 geos facing the dominant wave direction Blowholes north of selwicks bay Green stacks pinnacle - stack
226
Why does the coastline of sub cell 1d have so few beaches ?
Deposits of sediment accumulate slowly acrosss coastline due to low input of sediment from rivers and slow erosion of rocks Due to high energy waves from North Sea , sediment removed b4 it has chance to establish a developed beach
227
Give an example of a shore platform on sub cell 1d ?
Robin hoods bay
228
Wha is the height of chalk cliffs at flamborough head ?
20-30 m