Coasts Flashcards
Discuss the relative importance of geomorphic processes in forming coastal landforms (16) 2023
Thesis:
define geomorphic (mass movement, erosion + weathering)
Define coastal landform
While other factors such as geology and waves are important geomorphic processes is arguably the most important.
Paragraph 1:
Point-geomorphic processes are the most important…
Explain/evidence-CLS may be formed due to climate change, once weather warms up erosion may occur faster as tropical storms have a higher likelihood of happening. =faster erosion rates, more chance of chemical weathering, mass movement may then occur. This may cause coastal landforms to form such as caves, arches, stacks and stumps. More susceptible to chemical weathering…
(EVIDENCE)
Scale- may start at a local scale then progress globally, as processes are amplified further down the coast, more landforms occur.
Time-long term effect climate change takes a while to occur but maybe irreversible, costal landforms will then form faster and as erosion, MM and weathering occurs faster landforms will build and become more susceptible to strong winds.
Success- N/A
Significance-this is significant because it means landforms are formed in more areas.
It is clear that geomorphic processes are important because they are a significant factor in the formation of coastal landforms.
Paragraph 2:
Point- it could be argued that geology and waves are important in forming coastal landforms.
Explain/Evidence-with weaker geology, landforms are formed quicker. Eg headlands and bays, discordant coastlines.
Waves seem to cause erosion to occur…
EVIDENCE
Scale- this also happens long term as with higher resistant rocks such as limestone erodes at a slower rate, so happens long time but has a significant impact…
Success-N/A
Significance- this is significant because..
Conclusion:
Ultimately geomorphic processes are the foundation for building landforms as they contribute significantly.
Explain how coastal landscapes can be viewed as systems (8) 2022
Define system. It is an o0en system.
Input- sediment, water, energy
Output- sediment carried away by waves, winds (aeolian)
Processes- erosion, transportation, deposition,
Components- beaches , dunes, cliffs
Feedback loop- give examples. Presence of vegetation… High energy environment… low energy environment…
Equilibrium- aim to reach equilibrium, inputs=outputs dynamic equlibrium, if problem equilibrium is restored.
To what extent are long term changes more influential than short term changes on a coastal landscapes system. (16) 2022
Thesis:
Define coastal landscapes system
Example of long term changes and short term
Climate change
Seasonal variation/daily variation
Paragraph 1:
Point- long term changes are very influential on a coastal landscape system
Explain/evidence- climate change. Every 1oC increase in global temperature means sea level rises 2km/year. This means erosion rates may occur quicker due too an increase in wind speed and tropical storm occurrence. Erosion may occur faster
Nile delta
It is currently estimated that there will be a 60 to 100cm rise in sea level by 2100.
It is estimated that the Nile delta will be 25% submerged by 2100.
The constructions of dams such as the Aswan dam has reduced sediment supply, leading to increased coastal erosion. The delta is also experiencing subsidence or sinking high makes the land infertile and more prone to flooding
Scale- global
Time-this long term process may cause the change to be irreversible
Significance- this is particularly significant s the changes become irreversible and the Nile delta economically advantages Egypt as it is used for agriculture and fisheries. Egypt may go into economic instability. It is also vital for food security. Long term impacts and would influence the coastal landscape system negatively.
Paragraph 2:
Point- Short term change is very influential on coastal landscapes system, in the aspect of seasonal and diurnal variation.
Explain/evidence- coastal erosion, storm impact—> winter storms can produce stronger waves leading to higher erosion rates.
Human activities such as the construction of the 50 to 100m groynes mitigate the daily erosion rates and aim to slow LSD
Flamborough head Yorkshire
Scale-local
Time- short term. Daily/seasonal phenomenon.
Significance- this is significant because
Conclusion:
Long term change is significantly more influential that short term change
Explain how geology influences coastal landscapes system (8) 2021
Lithology- less resistant rocks are eroded at a faster rate.
At a discordant coastline, where ands of rock lie perpendicular to the coastline, less resistant rocks eroded faster, forms headlands and bays
Cracks/joints provide weaknesses which are exploited by waves through hydraulic action ,may create arches, stacks and stumps.
This is influential as it…
‘The changes caused by human activity in coastal landscape systems are always negative.’ Discuss. (16) 2021
Thesis:
Define coastal landscape system
While human activity can have a negative on the coast and its stores and processes, it isn’t with every instance that it is negative.
Coastal management strategies such as dredging in sandbanks, Dorset can be seen as a negative intentional impact but sand mining in mangawhai pakiri coastline can be argued differently.
Paragraph 1:
Point- Human activity in a coastal landscape systems can be negative.
Explain/evidence- in Sandbanks Dorset, 3.18 million tonnes of sand is dredged. This removal of sand is to absorbs the impact of waves on the £18 million residential homes and £10 million apartments. Simultaneously, 14 groynes were built to prevent breaching of the peninsular. Groynes aim to…
Success- although this is successful in protection of the residential homes and Poole harbour, the beach would be starved and erosion all processes are amplified further down the coast making the impact of erosion more significant further down.
Significance- this human activity can be argued as negative as it makes the coastal erosion worse down the coast, but from an economic perspective they argue that it protects higher valued areas to sacrifice an area of no value. However, this human activity is seen as positive because it not only protect but sustains the area and creates for economic stability and environmental protection.
Time- the sand will have to keep being dredged… groynes may have to keep being built as sea levels rise…
Paragraph 2:
Point- human activity can be seen as positive and economically advantages lower income areas.
Explain/evidence-in the magawhai pakiri coastline, sand is heavily used in construction,concrete making, glass manufacturing and beach replenishment. This damages ecosystems as it can damage aquatic habitats. It threatens wildlife as vegetation at be destroyed. It is a finite supply, so cannot be renewed unless taken from other parts of the coastline. Around 165,000m3/year between 1994 and 2004 was extracted. The beaches are stave of sediment and become wider and alter and les likely to boil oasis landforms as the sediment budget is seriously depleted. Loss of vegetation makes it susceptible to wind erosion.
Deriding and groyne construction on the mangawhai spit has helped restore some equilibrium after its 28m breach in 1978.
Success- mining has now stopped and the sand is slowly restoring to equilibrium.
Significance- the coastline is only at a sediment deficit due too human activity, as they dredged too much sand causing the area to be at a deficit…
Conclusion:
Overall it is clear that changes caused human activity is mostly negative as there are always negative impacts but perhaps it can be argued that they can sustain the coastline in some ways.
Explain the influence of climate change on raised beaches (8) 2020
A raised beach is an emergent landform.
How it forms?sea levels rise change, emerges, wave cut notch,eave cut platform, flat that emerges out of he sea
Climate change= sea level rise= more rates of erosion more landforms may be formed and wave cut platform will be completely flooded/submerged
Sediment may be deposited as shallower water =more friction so heavier rocks are deposited.
Explain the formation of bays (8) AS 2023
Discordant coastline = perpendicular bands of rock to coast
Less resistant rocks are eroded faster
Erosion=hydraulic action and abrasion (explain)
This material is transported away and a bay is formed
A semi circular indentation in the rock.
Continued erosion means that it will keep getting deeper and may reach the coast.
The most significant influence on coastal landscape systems have occurred during period of warming climate. To what extent do you agree. (14) AS 2023 (answered as if 16)
Thesis:
In warmer climates, sea levels rise and submerging landforms are formed. In cooling climates emergent landforms are formed. (Improve)
Paragraph 1:
Point- Submergent landforms occur when eustatic sea levels change and increase. Fjords, rias and shingle beaches may form.
Explain/evidence- periods of warming climate may increase rates of erosion.
during periods of warming climate, such as inter-glacials, coastal landforms have been shaped significantly by rising sea level; these submergent landforms were originally formed by geomorphic processes during cooler periods, such as glacials, when sea level was lower.in present-day warming climate, submergent landforms are subject to further change due to stormier conditions, high energy wave action at current sea level and current subaerial processes.
S-
Significance-
Time-
Explain the formation of onshore bars. (8) AS 2022
A landform of deposition/sediment accumulation
A bar is formed as a spit grows across a bay joining up two headlands
Explain how a spit is formed briefly. LSD—> recurved
Explain how a bay forms briefly. Continued erosion
As spit grows across bay the bar forms.
It continues to build as sediment is deposited causing the bar to widen
Explain the influence of sea level rise and geomorphic processes in the formation of rias (8) (taster)
A ria is a coastal inlet formed by the partial submergence of an unglaciated river valley.
Rias are formed as sea level rises in a warming climate, it is like to be isolated change that is prominent.
They typically have Etsy sloping sides, variable depth and a winding plan form reflecting the original route of the river and its valley.
Formed by fluvial erosion within the channel and subaerial processes on the valley sides
Increased water depth= larger waves and greater waves energy, thereby increasing rates of erosion ad further modification.
