COASTS Flashcards
1
Q
what are isostatic sea level changes?
A
When the land rises or falls relative to the sea
2
Q
what are eustatic sea level changes?
A
When the sea itself rises or falls
3
Q
what is a submergent coastline?
A
a coastline with sinking land and rising sea levels
4
Q
what is an emergent coastline?
A
a coastline with rising land and falling sea levels
5
Q
what is means by a strand line?
A
where the seaweed builds up at the high tide mark
6
Q
what is prevailing wind?
A
the most common wind
7
Q
what is dominant wind?
A
the strongest wind
8
Q
what is the climatic climax vegetation?
A
the last vegetation stage in sand dune succesion
in the UK it is deciduous trees
9
Q
how does a bar form?
A
longshore drift creates a spit which then grows and joins a headland, forming a bar
10
Q
how is a tombolo formed?
A
longshore drift creates a spit which then joins to an island, forming a tombolo
11
Q
what is subsidence?
A
the sinking land, it is an isostatic change
12
Q
what are some impacts of sea level rise?
A
- coastal flooding
- infrastructure damage
- loss of towns
13
Q
what are 2 features of an emergent coastline?
A
- raised beaches
- relic cliffs
14
Q
what are 2 features of a submergent coastline?
A
- Rias
- Fjords
15
Q
what are the 4 types of bedding plane?
A
- vertical
- horizontal
- seaward dipping
- landward dipping
16
Q
what bedding plane is this
=====
A
- horizontal
17
Q
what bedding plane is this
[[[[[[
A
vertical
18
Q
what bedding plane is this
/////// sea
A
landward dipping
- slowest erosion
19
Q
what bedding plane is this
\\\ sea
A
seaward dipping
20
Q
How is Porlock managed?
A
MANAGED RETREAT
- shingle ridge was breached and the land allowed to flood forming marshland which would absorb future floods.
21
Q
Why and how is Easington managed?
A
- it has a large gas pumping site, supplies 25% of Britains gas
- a sea wall
22
Q
What rock type is along the Holderness coastline?
A
- boulder clay
23
Q
What management techniques are at Mappleton?
A
- groynes
24
Q
How is Minehead managed?
A
HOLD THE LINE
- curved sea wall
- rock armour
25
why is Minehead protected?
- Butlins is local to minehead, so tourism helped to fund the management techniques
26
what management techniques are at the North of Swanage bay?
NO ACTIVE INTERVENTION as there is low value farmland, the cliffs are eroded so fossils can be found
27
How is Swanage bay managed?
HOLD THE LINE
- groynes
- sea wall
- beach nourishment
- cliff stabilisation
28
what rock types are at Swanage?
- chalk
- clay
- limestone
29
What is the rock type at Walton-on-the-Naze?
london clay
30
How is Walton-on-the-Naze protected?
- short stubb groynes
there is MANAGED RETREAT to protect the settlement, and allow the fossils to be unearthed as it is a SSSI
31
what is a SSSI?
site of special scientific interest
32
What is studland?
- a sand dune in Dorset
33
Who owns studland?
National Trust
34
what problems does Studland face?
- 12-13 tonnes of litter is dropped each week
- up to 30 lost children a day
- fires in the dunes
- naturists can also use the beach
- trampling
35
what is a honeypot site?
an area with all the ammenities so tourists are concentrated in one place
e.g.Knoll Beach at Studland
36
what is HEZE at studland?
H
Education
Zonation
E
37
what is a pioneer species?
the first species in sand dune succession
38
what is a psammosere?
sand dune succession
39
what are the parts of a sand dune?
- embryo dune
- fore dune
- yellow dune
- grey dune
- dune slack
- mature dune
40
what are some characteristics of the embryo dune?
LIMITING FACTORS:
- salty
- windy
- dry
- diurnal tide
- trampling
- lack of soil/nutrients
- pioneer species
e.g. - salt wort
- sandwort
- couch grass
41
what are the characteristics of the yellow dune?
- mobile
- marram grass
- patches of bare sand
42
what are the characteristics of the grey dune?
- fixed
- increased floristic diversity
- soil increases
- gorse
- heather
43
what are the characteristics of the dune slack?
- flooded as is below the water table
- creeping willow
- cotton grass
- reeds
44
what are the characteristics of the mature dune?
- climatic climax vegetation
-
45
what is integrated management?
2 or more managements techniques working together
46
what are examples of hard engineering?
- sea wall
- groyne
- gabion
- shingle ridge
- rock armour
47
what are examples of soft engineering?
- dune regeneration
- beach nourishment
48
what is an ICMZ?
INTERGRATED COASTAL MANAGEMENT ZONE
49
what are subaerial processes?
- mass movement
- weathering
50
what are examples of weathering?
- biological
- chemical
- physical/mechanical
51
what are examples of mass movement?
- soil creep
- landslide
- slumping
- rockfall
52
what are examples of erosion?
- abrasion
- attrition
- corrosion
- hydraulic action
53
what are features of destructive waves?
- weak swash
- strong backwash
- long fetch
- tall
- frequent
54
what are features of constructive waves?
- strong swash
- weak backwash
- short fetch
55
Where do eustatic changes occur?
globally
56
Where do isostatic changes occur?
locally
57
What is an example of a eustatic change?
Ice sheets forming during glacial periods, causing sea levels to fall. When the ice sheets melt sea level will rise.
58
What is an example of an isostatic change?
During glacial periods ice sheets cause land to sink due to their weight. When the ice begins to melt, the weight is reduced, causing the land to readjust and rise.
59
What is isostatic subsidence?
Where land sinks as a result of the weight of ice sheets.
60
What is isostatic recovery
Where land begins to readjust and rise as ice melts, reducing the weight on the land.
61
Where is isostatic recovery evident in the UK?
- North/West of the UK
- the land was once covered by ice sheets during the last ice age, as a result, the land is rising due to isostatic recovery.
62
Where is isostatic subsidence evident in the UK?
- South/East of the UK
63
Why is isostatic subsidence evident in the South/East of the UK?
- Rivers pour water and sediment into the Thames estuary.
- The weight of the sediment causes the crust to sink relative sea levels to rise.
64
How has past tectonic activity affected some coasts in sea levels?
- The Uplift of mountain ranges and coastal land at destructive and collision plate margins causes land to rise
- local land tilting
65
What are the causes of eustatic change?
- changing amounts of ice
- thermal expansion
- tectonics
66
What are the causes of isostatic change?
- post-glacial adjustment
- subsidence
- accretion
- tectonics
67
What is accretion?
The formation of land due to the net deposition of sediment.
68
What are raised beaches
- A feature of emergent coastlines
- Beaches above tide level that appear due to rising land as a result of isostatic recovery.
69
What are relic cliffs?
- A feature of emergent coastlines.
- The remains of eroded cliff lines found behind raised beaches.
70
What are rias?
- The feature of submergent coastlines.
- Form when upland areas are flooded.
71
What are fjords
- A feature of submergent coastlines
- Formed when deep glacial troughs are flooded by rising sea levels.
72
What are Dalmatian coasts?
- A feature of submergent coastlines.
- Where rivers flow almost parallel to the coast rather than at right angles to it
73
Why is Bangladesh at risk of coastal flooding?
- very densely populated
- lies on the floodplain of 3 major rivers
- 46% of people live in places less than 10m above sea level
74
Why is flood risk increasing in Bangladesh?
- subsidence
- removing vegetation
75
How is subsidence increasing flood risk in Bangladesh?
Some esturine islands have sunk up to 1.5m due to the clearing and draining of land for cultivation and building of large earth embankments.
76
How is removing vegetation increasing flood risk in Bangladesh?
70% of Bangladesh's mangrove forested coastline is retreating by up to 200 metres annually as a result of aversion rising sea levels and removal of vegetation.
77
Why are mangrove forests important for Bangladesh?
They provide protection and shelter against storm winds, floods and tsunamis by absorbing and dispersing tidal surges.
78
What are storm surges?
Changes in sea level caused by depressions and tropical cyclones.
79
What is a depression?
- an area of low pressure formed from rising air
80
How do depressions move in the northern hemisphere?
- West to East
- anticlockwise direction
81
Why some short term impacts of storm surges?
- deaths/injuries
- homelessness
- increase in water borne diseases
- buildings/ businesses destroyed
- loss of power
82
Why may climate change increase flood risk?
- Global sea level rise due to warming oceans and melting ice sheets.
- Increased frequency of intense storms.
83
What impact would a 50cm sea level rise have?
- Affect 800 million people worldwide.
- In the UK, 200km of coastal flood defences would be vulnerable, leaving £120 billion worth of infrastructure and resources at risk.
- Coastal flooding would be more frequent
