Coastal landscapes and systems COPY

Question 1

How can coasts be classified?

Answer 1

• geology (including lithology and structure, concordant and discordant) - sea level changes (submergent or emergent) - level of energy (high or low energy coastline) - the dominant coastal process (landforms of erosion/deposition, sediment inputs)

Question 2

what are the long-term criteria for categorising coasts?

Answer 2

• geology - sea level changes

Question 3

what are the short-term criteria for categorising coasts?

Answer 3

• level of energy - sediment inputs (sediment added through deposition and removed by erosion)

Question 4

explain the structure of the littoral zone including some features

Answer 4

coast backshore (storm beach) foreshore (pebbles + berms) nearshore (runnels and ridges) offshore

Question 5

what is the littoral zone?

Answer 5

the boundary between land and seas and is the area of shoreline where land is subject to wave action. it is subdivided into: back shore, foreshore, nearshore and offshore

Question 6

why does the littoral zone vary?

Answer 6

due to short-term factors and long-term factors

Question 7

what are the short-term factors affecting the littoral zone

Answer 7

individual waves, daily tides, seasonal storms

Question 8

what are the long-terms factors affecting the littoral zone

Answer 8

changes to sea levels, climate change

Question 9

what areas of the littoral experience the most human activity?

Answer 9

the back shore and foreshore experience the most human activity

Question 10

what is the overall word to describe the state of the littoral zone?

Answer 10

DYNAMIC. because of the dynamic interaction between the processes operating in the seas, oceans and on land.

Question 11

what is the coastal system

Answer 11

inputs into process and then to outputs

Question 12

what are inputs in a coastal system

Answer 12

• marine: waves, tide, storm surges - atmospheric: weather and storm surges - land: rock type, tectonic activity - people: human activity and coastal management

Question 13

what are processes in a coastal system

Answer 13

• weathering - mass movement - erosion - transportation - deposition

Question 14

what are outputs in a coastal system

Answer 14

• erosional landforms - depositional landforms - different types of coasts

Question 15

explain Cornwall’s geology

Answer 15

Cornwall bears the worst of the weather from the Atlantic ocean but due to is geology, its rocky coastline can withstand frequent storms. much of Cornwall consists of: - igneous rock (such as basalt and granite) - older compacted sedimentary rocks (sandstone) - metamorphic rocks (slates)

Question 16

explain what rocky coastlines are like

Answer 16

• areas of high or low relief which usually form in areas with resistant geology in high energy environments, where erosion is greater than deposition - destructive waves - tend to be stretches of the Atlantic-facing coast, where waves are powerful

Question 17

explain what coastal plains are like

Answer 17

• (sandy and estuarine coastlines) at low reliefs - where the rate of deposition exceeds the rate of erosion - they result from the supply of sediment from different terrestrial and offshore sources, often in a low-energy environment - constructive waves, form sand dunes, beaches, mudflows and salt marshes - tend to be stretches of the coast where waves are less powerful or where it is sheltered from large waves, can form by sea level changes

Question 18

what is the word for a supply of sediment?

Answer 18

coastal accretion

Question 19

what are terrestrial sources of sediment?

Answer 19

from mass movement or rivers

Question 20

what are offshore sources of sediment?

Answer 20

from waves or currents

Question 21

what is the difference between rocky or cliffed coastlines vs coastal plain landscapes?

Answer 21

rocky or cliffed coastlines: when there is a clear distinction between land and sea, mainly because of the height of the cliffs. mainly in the north west , occupy 1000km of the UK’s coastline coastal plain landscapes: where the land slopes gently towards the sea and there is an almost imperceptible transition form one to the other. these are often maintained in a state of dynamic equilibrium from the sediment coming in and out. the wash is the largest estuary system in the UK, mainly in the east and south fo England.

Question 22

are coastlines always either high or low energy?

Answer 22

no. many coastlines are a mixture of big and low energy environments. for examples, areas such as holderness which hare predominantly low energy can experience short-term high energy erosion through winter storms.

Question 23

explain dynamic equilibrium

Answer 23

where erosion = deposition. there is a continuous flow of energy and material through the coasts but the size of stores (beach, salt marsh) remains unchanged

Question 24

what is geological structure?

Answer 24

refers to how the rock is arranged on a macro-scale and looks at the arrangement of different rock types in relation to each other.

Question 25

what are concordant coastlines?

Answer 25

• this is where rock starts runs parallel to the coast forming bays and coves - example: the souther coast of the isle of purbeck has formed lulworth cove and kimmeridge bay due to its concordant structure

Question 26

what are discordant coastlines?

Answer 26

• this is where the rock starts runs perpendicular to the coast forming headlands and bays - example: the isle of Purbeck’s eastern coast leading to headlands at peril point and durlston head, swanage bay has formed

Question 27

explain the formation of Dalmatian coasts

Answer 27

1) tectonic activity folded limestone layers so that ridges (anticlines) and valleys (synclines) formed parallel to the coast 2) sea level rose following the end of the ice age and drowned the valleys (creating a submergent coastline) 3) the tops of the ridges remained above the surface of the sea running parallel to the coast an example of this is the Croatian Dalmatian coast

Question 28

explain the formation of haff coasts

Answer 28

1) the build up of these sand dunes have created lagoons (haffs) between them and the shore 2) they form where deposition produces unconsolidated geological structures parallel to the coastline 3) this forms long sediment ridges topped by sand dunes that run parallel to the coast an example is chesil beach in Dorset which has formed in this way. shingle ridge reconnected island of portland bill to land (a tombolo)

Question 29

what are half coasts?

Answer 29

they are long spits of sand and lagoons aligned parallel to the coast

Question 30

what is morphology?

Answer 30

the shape of landscape features and is influenced by geological structure (haff and dalmation coasts for concordant, headlands and bays for discordant)

Question 31

explain the formation of headlands on discordant coastlines

Answer 31

1) wave action erodes the less resistant rock quicker due to hydraulic action and abrasion 2) the more resistant rock is left sticking out as a headland, causes waves to refract a water becomes shallower and so waves energy is concentrated on the headlands and waves become higher increasing erosive power on the headland 3) the bay becomes sheltered as wave energy is dissipated, results in the formation of beaches as sediment is deposited in the low energy environment

Question 32

what does the morphology of discordant coasts lead to

Answer 32

the altering of the distribution of wave energy and rate of erosion through wave refraction

Question 33

explain swanage bay

Answer 33

• on the isle of purbeck in east dorset - formed by the erosion of less resistant Wealden clays - resistant limestone forms perril point headland to the south projecting out by 1km and the resistant rock forms the foreland headland which projects 2.5km to the north - structure is not the only factor influencing the indentation of swanage bay. since it faces east it is sheltered from the prevailing south westerly winds and highest energy waves

Question 34

what are cliff profiles influenced by?

Answer 34

• geology, especially the resistance to erosion of the rock - the dip of rock strata in relation to the coastline

Question 35

explain joints

Answer 35

• (vertical cracks), these are fractures caused either by contraction as sediments dry out or by earth movements during uplift - they are fractures created without displacement and occur in most rocks, dividing rock strata up into blocks with a regular shape - jointing increases erosion rates by creating fissures which marine erosion processes such as HA can exploit example: in bantry bay, the limestone is heavily pointed, leading to more rapid fluvial and marine processes in adjacent sandstones

Question 36

explain faults

Answer 36

• formed when he stress of pressure not which a rock is subjected, exceeds its internal strength (causing it to fracture). the faults then slip along fault planes. - it significantly increases erosion since faulted rocks are much more easily jointed - huge forces are involved in faulting and displacing them and therefore either side of the fault line, rocks are often heavily fractured example: in bantry bay in cork in the republic of Ireland there is a major fault which runs SW-NE down the centre of the bays. the limestone is weakened allowing rapid fluvial erosion

Question 37

explain folds

Answer 37

• they are bends in rocks formed by pressure during tectonic activity which makes rocks buckle and crumple - the main two types are anticlines and synclines - folden rock is often more heavily fissured and jolted, meaning they are more easily eroded, also increases erosion by increasing angle of dip and causing joins through the stretching along anticline crests an compressed in syncline troughs

Question 38

explain dips

Answer 38

• refers to the angle at which rock strata lie (horizontally, vertically, dipping towards the sea or dipping inland) - its a tectonic feature, sedimentary rocks deposited horizontally can be tilted by faulting and folding by tectonic forces

Question 39

what is horizontal dipping

Answer 39

a vertical or near-vertical profile, notches reflect weathering

Question 40

what is a high angle of seaward dip

Answer 40

produces a sloping, low-angled profile with vulnerable rock layers

Question 41

what is a low angle of seaward dip

Answer 41

produces a steep profile that may even exceed 90 degrees, creating areas of overhanging rock, vulnerable to rock falls

Question 42

what is landward dipping strata?

Answer 42

produces steep profiles on 70º-80º as downward gravitational force pulls loosened blocks into place, very stable

Question 43

what is a cliff profile?

Answer 43

the height and angle of a cliff face, plus its features such as wave cut notches or changes in slope areas

Question 44

what are micro features?

Answer 44

• small-scale features such a scales and wave-cut notches which form part of a cliff profile - the location of these micro-features are often controlled by the location of faults and/or strata which have a high amount of joints and fissures

Question 45

what is the relief of an area affected by?

Answer 45

the relief or height and slope of land is also affected by geology and geological structure. there is a direct relationship between rock type, lithology and cliff profiles

Question 46

explain the different stages of a cliff profile

Answer 46

Question 47

what is lithology?

Answer 47

refers to the physical characteristics of the rock. igenous, metamorphic, sedimentary and unconsolidated rock each have different characteristics.