Coastal Processes (Edexcel A Level Geography): Flashcards
Exam code: 9GE0
1/390Still learning
Know0
Define littoral zone.
Was this flashcard helpful?
Cards in this collection (39)
Define littoral zone.
The littoral zone is the part of the coast affected by wave action, where land and sea processes interact and constantly change the coastline.
What are the four sub-zones of the littoral zone?
They are backshore, foreshore, nearshore and offshore.
True or False?
The coast is an open system with inputs and outputs of sediment and energy.
True.
The coast receives inputs from other Earth spheres and loses outputs of sediment and energy, while storing and transferring material.
Define constructive wave.
A constructive wave has a strong swash and weak backwash, causing deposition to dominate and the coastline to advance.
How do high-energy coasts differ from low-energy coasts?
High-energy coasts have destructive waves and dominant erosion; low-energy coasts have constructive waves and dominant deposition forming beaches and coastal plains.
A coast where erosion dominates is , while one where deposition dominates is .
A coast where erosion dominates is retreating, while one where deposition dominates is advancing.
Define rocky coast.
A rocky coast is a coastline of resistant rock with cliffs, where marine and sub-aerial erosion dominate over deposition.
How do high-energy and low-energy settings affect cliff steepness?
In high-energy environments cliffs are usually steep; in low-energy environments cliffs tend to have a gentler slope.
Coastal plains form where deposition exceeds erosion, a process called .
Coastal plains form where deposition exceeds erosion, a process called coastal accretion.
Name two types of coastal plain coastline.
Two types are sandy coastlines and estuarine coastlines.
True or False?
A discordant coast has rock bands running parallel to the shoreline.
False.
A discordant coast has rock types at right angles to the shoreline; concordant coasts have rock bands running parallel to it.
Long-term sea level change is eustatic when changes, and isostatic when moves relative to the sea.
Long-term sea level change is eustatic when sea level changes, and isostatic when land moves relative to the sea.
Define lithology.
The lithology of a rock is its physical characteristics, including strata, bedding planes, joints, folds, faults and dip.
Define strata.
Strata are distinct layers of rock formed over time, often visible as bands in a cliff face.
Define bedding planes.
Bedding planes are horizontal cracks between rock layers created by pauses in sediment deposition during rock formation.
Define joints in rocks.
Joints are vertical cracks in rock caused by tectonic movement or contraction as rocks cool or are uplifted.
How do folds, faults and dip influence cliff profiles?
Folds, faults and dip create weaknesses and control how cliffs are tilted, affecting slope angle, height and where erosion is concentrated.
Name three processes, besides lithology, that shape cliff profiles.
Key processes are hydraulic action, abrasion and subaerial processes such as weathering and mass movement.
Define coastal morphology.
Coastal morphology is the shape and form of the coastline, controlled mainly by geology and geological structure.
What is a discordant coastline?
A discordant coastline has rock bands that meet the coast at an angle, producing alternating headlands and bays.
What is a concordant coastline?
A concordant coastline has rock structures running parallel to the coast, often forming Dalmatian or Haff style coastlines.
True or False?
Lulworth Cove is on a concordant coastline.
True.
At Lulworth Cove, resistant Portland Limestone runs parallel to the sea, with weaker Purbeck Limestone and Wealden Clay behind it.
How did Dalmatian coastlines form?
Tectonic forces created anticlines and synclines parallel to the coast, then post-Devensian sea level rise flooded synclines, leaving island chains of anticlines.
A Haff coastline forms when bars trap water behind them, creating a lagoon called a .
A Haff coastline forms when bars trap water behind them, creating a lagoon called a Haff.
How does wave refraction affect discordant coastlines?
Wave refraction concentrates wave energy on headlands, increasing erosion there while reducing energy and encouraging deposition in bays.
Define pioneer species.
Pioneer species are the first plants to colonise a harsh coastal environment, stabilising sediment and improving conditions so other, less tolerant plants can establish.
How does vegetation help stabilise coastlines?
Plant roots bind sand or soil, while vegetation reduces wind speed, traps sediment, and adds organic matter, gradually forming more stable soil.
A succession in a sandy environment is called a and in a salty environment a .
A succession in a sandy environment is called a psammosere and in a salty environment a halosere.
Describe embryo dunes in sand dune succession.
Embryo dunes form where wind-blown sand is trapped by debris; they are low, alkaline, fragile, and colonised by halophytic pioneers like lyme grass.
How do fore dunes differ from embryo dunes?
Fore dunes are higher, more sheltered, and stabilised by deep-rooted marram grass, which adds organic matter and creates more hospitable conditions.
As dunes develop from yellow dunes to grey dunes, exposed sand falls below and soil increases.
As dunes develop from yellow dunes to grey dunes, exposed sand falls below 10% and soil acidity increases.
Define climax community in dune succession.
A climax community is the final, most stable stage of succession, where mature soil supports long-lived species such as oak and alder.
True or False?
Salt marshes often begin with algae colonising deposited sediment.
True.
Early algae bind fine sediment, add organic matter, and trap more sediment, allowing later colonisers like cord grass to establish.
Define coastal recession.
Coastal recession is the retreat of the coastline inland due to erosion, sea level rise, or submergence.
How does mineral composition affect coastal erosion rates?
Reactive minerals like calcite weather quickly, so rocks containing them erode faster than rocks rich in inert minerals like quartz.
Rock formed by lithification of sediment is rock, while rock formed by cooling magma is rock.
Rock formed by lithification of sediment is sedimentary rock, while rock formed by cooling magma is igneous rock.
True or False?
Metamorphic rocks are usually less resistant than sedimentary rocks.
False.
Metamorphic rocks are generally more resistant than sedimentary rocks but less resistant than igneous rocks.
Define differential erosion.
Differential erosion is when different rock types erode at different rates, creating varied cliff profiles and coastal landforms.
How does differential erosion create headlands and bays?
On discordant coastlines, resistant rocks erode slowly to form headlands, while less resistant rocks erode faster, forming bays.
Sign up to unlock flashcards
or