Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

coasts > eqi3 & 4 > Flashcards

eqi3 & 4 Flashcards

(87 cards)

Start Studying
1
Q

what is eustatic change?

A

a change in sea level relative to the land becaues of:
- melting of glaciers and ice caps
- thermal expansion of oceans
- tectonic change

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what is isostatic change?

A

a change in the land relative to the sea due to
- tectonic uplift
- subsidence
- accretion
- post glacial adjustment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what are facts on melting of glaciers and icecaps?

A
  • most pronounced effects of climate change has been metling of masses of ice around the world
  • they hold 66% of world’s freshwater
  • it is the melting of land based uce that causes sea level rise as the water based ice is just displacing the volume
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what are some facts on thermal expansion?

A

as oceans are heated, the volume of the water increases as the particles move further away from each other
- risen 25mm since 1961 due to this

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

how does isostatic rise occur?

A

the greenland ice cap is very thick and heavy and if it melts, the land will slowly rise as the pressure is lifted.
- this is glacial rebound

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

how does isostatic fall occur?

A

caused by accretion of sediments resulting in subsidence.
- fluvial flood flows does thames could rise by 40% by 2080 because of increased rainfall
- increased discharge will result in increased erosion and deposition
- accretion will also occur as sediment accumulates through the flooding of the banks and natural levees

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what are landforms of emergence?

A

comes from eustatic fall and isostatic rise

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what are landforms of submergence?

A

come from eustatic rise and isostatic fall

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what is created by emerging coastlines?

A
  • raised beaches
  • abandoned coastlines and relic cliffs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what is created by submerging coastlines?

A
  • rias
  • fjords
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what are fjords?

A

fjords are submerged glacial valleys. they have steep, cliff-like sides and the water is uniformly deep. these were formed when glaciers eroded below sea-level. when the ice metled the valleys were flooded
- an example of a fjord can be seen in norway

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what are rias?

A

submerged river valleys
- the lowest part of the river’s course and the floodplains alongside the river may be completely drowned but the higher land remains exposed
- an example is milford haven

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what landforms are on emergent coastlines?

A

emergent coastlines are evident through raised beaches that are backed by relict cliffs
- rasied beaches are areas of former wave cut platforms
- relict beaches are identifiable through their steep cliff face however they may not be as steep as they have been due to subaerial processes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what are the landforms on submergent coastlines?

A

on submergent coastlines we can find rias, fjords and dalmatian coastlines

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what are dalmatian coastlines?

A

formed from tectonic forces produced by the collision of african and eurasian plates, creating folded ridges and fown folded valleys called ANTICLINES and SYNCLINES aligned parallel to the coast

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

which areas are most as risk from sea level change?

A

asian cities will be worst affected by sea level rise with 4/5 people affected
- shanghai = 17.5 mn people affected
pacific region which is home to 59% of world’s population

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what are the local influences on coastal flooding?

A
  • storm surges
  • loss of ecosystems e.g. salt marshes and mangrove forests
  • land reclamation
  • secretion of sediment leading to subsidence
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what are the global influences of coastal flooding?

A
  • glaciers melting
  • thermal expansion
  • melting of greenland and antarctics ice caps
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what are the local influences along the Nile that causes flooding?

A
  • the delta area is home to 95% of egypt’s pop
  • erosion rates jump from 20 mm per year to 200mm a year because of the Aswan dam
  • changes in sediment volume from the river nile caused by water withdrawals for industry and farming
  • following the construction of the dam on the river nile - discharge from 35 bn m3 to 10 bn m3
  • building of aswan dam reduced terrestrial sediment supplies
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what are the global influences along the Nile that causes flooding?

A
  • there is salt intrusion into the delta due to sea level rise and more frequent coastal flooding
  • the meditteranian was rising by 1.8 mm to 2.1 mm
  • along the egyptian coast, rising sea levels have combined with a sinking landmass
  • if sea level rise by 1 mm by end of century at least 6 million people will be displaced
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what are storm surges and their causes?

A

a rise in the ocean as the result of strong winds which is caused by:
- very high wind speeds
- large fetch
- very low atmospheric pressure
- high spring tides
- high waves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what are the physical reasons for erosion on holderness coast?

A
  • geology = mass movement
  • weather = low pressure depression which lead to storms and big wind leading to high energy waves
  • transportation of sediment = LSD and no beach
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

how does geology affect erosion?

A

bedrock (underlying rock) is chalk eroding at 0.3m p/yr and above that there is boulder clay eroding at 2m p/yr
glacial outwash - deposited glacial sediment - fine sediment - extended the coastline outwards to form holderness.
boulder clay has very little resistance to erosion especially when wet = erosion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

how does fetch affect erosion?

A

holderness is exposed to wind and waves from the north-east which has a small fetch of 500-800 km
- currents from the atlantic with a fetch of 5000km are added into the north sea as the waves refract around the top of the UK leading to more powerful destructive waves
- small enclosed spaces like north sea often generate huge waves during storms . waves move within the sea but cannot disperse their energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
how does sediment and LSD affect erosion?
boulder clay erodes to produce mainly clay particles which are easily transported out to sea, rather than accumulating - without a beach the waves can attack the cliff freely
26
what are the economic impacts of erosion on the holderness coast?
- numbers of visitors to areas along the coastline has dropped - some settlements cannot keep enough of a pop to warrant shops - money must be spent on coastal management - gas terminal at easington (supplies 25% of britain's gas) is at risk
27
what are the social impacts of erosion on the holderness coast?
- many settlements rely on tourism - around 30 villages have been lost since roman times - properties under threat lose their value and cannot be sold and the owners cannot have compensation
28
what are the social impacts of coastal flooding?
typhoon haiyan - powerlines were damaged - communication was down - roads were blocked by debris - 90% of tacloban was destroyed
29
what are the economic impacts of coastal flooding?
- 1.1 mil homes were badly destroyed and 4.1 million people became homeless - infrastructure was damaged - ~ 1.1 mil tonnes of crops were destroyed - 3/4 of farmers and fishers lost their income
30
what is hard engineering?
involves manmade structures along the coast usually at the base of cliffs or along the beach. - they are designed to stop erosion and mass movment
31
what are the different types of hard engineering?
- groynes - rip rap - revetments - sea wall - off shore breakwater
32
what are groynes and how much are they?
timber or rock structures built at right angles to slow LSD - £150-2500 per m
33
what are advantages and disadvantages of groynes?
advantages: - builds up beach which increases tourist potential and protects the land - not too expensive - do not affect access to each disadvantages: - terminal groyne syndrome - unnatural and can be unnatractive - reduces sediment going further up the coast - needs regular maintainance
34
what are sea walls and how much are they?
run parallel to the backshore and have steel reinforcements and deep piled foundations - they are often steeped or have a recurved top - £6000-10,000 per m
35
what are the advantages and disadvantages of sea walls?
advantages: - effective - creates a clapotis waves (reduces the energy of new waves) - creates a promenade for people to walk along disadvantages: - does not blend in - expensive to maintain - recurved - energy focuces on the base - only reflects waves does not absorb them
36
what are rip rap and how much are they?
large igneous boulders. their large surface area breaks up the wave and can be used to protect scouring at the base of sea walls or to hold back mass movement on unstable cliffs - £1350 - 6000 per m
37
what are the advantages and disadvantages of rip rap?
advantages: - quite cheap and easy to construct - used for fishing and sunbathing disadvantages: - dangerous - home to vermin - don't fit into natural geology
38
what are revetments and how much are they?
sloping wooden, concrete or rock structures placed at the foot of the cliff or top of beach - £500 - 3000 per m
39
what are the advantages and disadvantages of revetments?
advantages: - does not affect access to beach - cheap - not intrusive disadvantages: - short lifespan - not attractive - destroys habitats
40
what are off shore breakwaters and how much are they?
igneous boulders aligned in short lengths in shallow nearshore parallel to shore line - £1750 - 4300 per m | `
41
what are the advantages and disadvantages of off shore breakwater?
advantages: - provides a sheltered beach - low maintainance disadvantages: - ugly - expensive - effectiveness is reduced in high tide - can be desroyed in storms
42
what are the different types of soft engineering?
- beach nourishment - cliff regrading and drainage - dune stabalisatoin - marsh creation
43
what is beach nourishment and how much is it?
the addition of sand or pebbles to an existing beach to make it higher or wider - £300,000 for 100 m
44
what are the advantages and disadvantages of beach nourishment?
advantages: - cheap and easy to maintain - looks natural - increases tourism disadvantages: - needs constant maintainance because of LSD - takes sand from somewhere else
45
what is cliff regrading and drainage?
cliff regrading reduces the angle of the cliff to help stabalise it cliff drainage removes water to prevent landslides and slumping
46
what are advantages and disadvantages of cliff regrading and drainage?
advantages: - regrading can work on clay or loose rock - drainage is cost effective disadvantages: - regrading effectively caues the cliff to retreat - drained cliffs can dry out and lead to collapse
47
what is dune stabilisation and how much is it?
marram grass can be planted to stabilise dunes. areas can be fenced in order to keep people off them - £200 - 2000 per 100m
48
what are the advantages and disadvantages of dune stabilisation?
advantages: - maintains a neutral coastal environment - provides important wildlife habitats - relatively cheap and sustainable disadvantages: - time consuming - people may react negatively to being kept off certain areas
49
what is marsh creation?
a form of managed retreat, by allowing low lying coastal areas to be flooded by the sea
50
what are the advantages and disadvantages of marsh creation?
advantages: - relatively cheap - creates natural defense - creates important wildlife habitat disadvantages: - agricultural land is lost - farmer's or landowners need to be compensated
51
what are shoreline management plans?
the development of shoreline management plans is because the environmental agency base their strategy for flood and coastal defences on sediment cells and if there is a disruption there will be consequences elsewhere.
52
what are the 4 options of shoreline management plans?
1) no active intervention 2) hold the line 3) managed realignment 4) advance the line
53
what is sustainable coastal management?
a long-term approach that considers future threats such as sea level rise and storm surges. this may mean to abandon the coastline, low lying area. - these plans may conflict with the wishes of local people who may lose their land
54
what are the aims of sustainable management?
1) monitoring coastal change and adapting to unexpected trends 2) educating communities 3) adapting to rising sea levels 4) managing flood and erosion risks 5) managing natural resources to ensure longevity
55
what is coastal squeeze in Abbotts hall farm?
occurs when beaches and salt marshes are trapped between rising sea level and hard defences such as sea walls. - on natural coastlines, beaches and salt marshes would simply migrate in land, but the presence of hard defenses make this impossible. instead the sea rises over the salt marshes and removes them.
56
what is managed realignment on Abbotts hall farm?
a sustainable coastal management solution. it usually occurs in low lying esturaries and often involves the flooding of land that has at some point been claimed from the sea. - it involves the breaching of an existing coastal defence and allowing land behind to be flooded
57
how much of essex salt marshes have been lost to coastal squeeze?
40% over the last 25 yrs.
58
what were the positive changes of managed realignment at Abbotts hall farm?
- salt marsh is flourishing - pressure on sea walls elsewhere along the blackwater estuary have been reduced - £500,000 has bgeen saved in sea defences - a natural defence agaisnt flooding has been created - new wildlife habitats have been created - valuable sediment sinks have been restored.
59
what are the drawbacks of managed realignment in Abbotts hall farm?
- land is lost to the salt marsh and beaches - settlements, farmland and other property is destroyed - need for compensation for land owners - there may be the need for new roads and pipes to be laid
60
what is a polder?
a tidal areas enclosed by wooden fencing that is designed to regulate tidal flow - it reduces erosion and encourages deposition of sediment - encourages salt marsh creation
61
how many polder sites are in the Essex estuaries?
26
62
what is an advantage of polder sites?
- a natural defnece against coastal flooding - salt marsh traps sediment and stabilizes the sites - provides feeding and breeding grounds for important species of birds
63
what is an ICZM?
intergrated coastal zone management - a holistic approach
64
what does and ICZM aim to do?
establish sustainable levels of economic and social activity in coastal areas while protecting the enviornment - plan for long term - involve all stakeholders - work with natural processes
65
who are the winners of ICZMs?
- people whose property of businesses are protected - farmers whose land will be protected
66
who are the losers of ICZMs?
- people who have to move - habitats will be destroyed
67
where is hold the line occuring along the Holderness coast?
- bridlington - hornsea - mappleton - withersea - esaington (only short term)
68
where is no active intervention occuring along the Holderness coast?
- bridlington - hornsea - hornsea - mappleton - mappleton - withernsea - easington (medium -->)
69
where is management realignment occuring along the Holderness coast?
- easington - spurn point
70
why is coastal management needed aong the holderness coast?
- coastline is made of boulder clay - no wide sandy beaches to protect the cliffs so the clay is transported away - coast has little protection from waves from the north east which have a long fetch - between Flambourough and spurn head an average of two metres of coast is lost each year - need to protect important settlements
71
what strategies are used along Holderness coast?
bridlington - 3.6 km of sea wall and groynes to stabilise the beaches hornsea - 1.6 km of sea wall, groynes and rock armor mappleton - only allowed defences after an economic case was made by the people that the road was threatened (450m of cliff are protected with groynes, revetment) withernsea - 2.3 km of sea wall, groynes and rock armor easington has gas terminals located to the north - 1 km of revetment
72
how sustainable is the management
- limiting erosion along th Holderness coast = less material travelling south to humber estuary (~50,000 people live there) where it is deposited on mudflats - most land is farmland which has limited value - policy of protection = protect larger setllements but elsewhere do nothing
73
where is slapton?
- barrier beach on the south devon coast - seperates slapton ley (freshwater lagoon) form the sea - prone to coastal erosion and flooding
74
what are the causes of coastal erosion at slapton?
natural: - high energy waves from the South west atlantic - LSD moves sediment along the coastline - storm events accelerate erosion human: - coastal management elsewhere disrupts sediment supply - increased traffic on A376 puts pressure on coastline
75
what is conflict around SMP in holderness?
1) local residents and businesses = depend on A379 for commuting and tourism and fear loss of property value 2) environmental groups = concerned about the impact of hard engineering 3) devon council = concerned about cost of road repairs 4) tourism sector = coastal erosion threatens attraction and local businesses
76
what are the short and long term solutions to erosion in slapton?
short: - shingle replenishment - emergency repairs to A379 long: - a379 may be relocated - focus on sustainable coastal management
77
what are environmental refugees?
someone forced to move because their environment have changed, places have storm surges, etc...
78
why are there environmental refugees in the maldives?
- pop. of 340,000 - highest point is 2.3 m above sea level - 50cm sea rise by 2100 would mean losing 77% of land - areas above water would be vulnerable to storm surges - they have sea walls (3m) and built an artificial island from coral and sediment dregded which cost 32 mil
79
why are there environmental refugees in the bangladesh?
+1m sea level rise = 15 mil affected +1.5m sea level rise = 18 mil affected - 45% of pop lives less than 10m above sea level - bangladesh lives on floodplain of 3 major rivers - mangroves help combat cyclone in 2007 but 71% of the mangrove coastline is retreating ~200cm a year
80
why are there environmental refugees in the kiribati?
- low lying and only one metre or less above sea level - many islands will disappear in the next 50 years - some places, sea level is rising by 1.2 cm
81
why is odisha's coastal zone important?
- rich in minteral deposits - huge potential for offshore wind, tidal and wave power - cultural and archaeological sites
82
who are the main players in odisha's ICZM?
- climate change - gov of india - world bank - anyone affected
83
what are SGH's?
self help groups which are helping provide alternative livlihood activities to reduce the pressure on depleting marine resources and dependancy on fisher communties
84
what are the alternate livlihoods?
- intergrated physiculture - dairy - poultry - dry fish - product preparation
85
why were erosion control measures put in place?
to combat a long term solution to erosion at Pinto. an example would be the installation of geotextile tube embankment at Pinto which was to save the life and properties
86
how many people have benefitted from erosion control measures?
41,222 people are benefitted from 6883 hectares of highly productive crop fields have been protected
87
has the ICZM been successful?
it has been attempting to adress several challenges faced by coastal regions. some initiatives are: - cyclone prepardness - through construction of cyclone shelters and enhancement of cyclone warning systems - ecosystems restoration - protect coastlines from erosion, storm surges and sea level rise - community engagement - local stakeholders are involved in decision making

coasts (3 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions