AS: Coasts
Topic 2
Amy Hannam
,2B.1: Features of the
Coast
The Littoal Ztne – the wider coastal zone including Rtcky Ctasts & Ctastal Plains
adjacent land areas and shallow parts of the sea just ROCKY/CLIFFED COASTAL SANDY COASTS ESTUARINE COASTS
ofshore COASTLINES PLAINS
• Clifs varying in • Sandy • Sand dunes • Found at oiveo
height coastlines (psammtseoes) at mtuths
• Clifs are formed • Estuarine the fringe • Extensive mud fats,
from rock but coastlines • Sandy beach cut by channels,
the hardness of • Ltw eneogy inundated at high inundated at high
the rock is very and ltw- tde, but vegetated tde
variable lying coasts dunes are not • Closer to the
• High eneogy with • Dune vegetaton backshore the mud
ctasts = ctnstouctve plays a crucial role fats are vegetated,
destructve waves and in stabilising the forming a salt
waves with long shtot fetches ctast maosh
fetches causing • This type of coast
erosion along gradually
with weathering transitons from
Backshtoe – only afected by waves during spring tdes and major storms to create mass land to sea
movement
Ftoeshtoe – wave processes normally confned to the foreshore, between
high and low tde marks
E.G. Flambtotugh E.G. Ainsdale, E.G. Lymingttn,
Neaoshtoe – shallow water areas close to land are called the nearshore. Head, Ytokshioe Meoseyside Hampshioe
Intensive human acton (such as fshing and leisure) takes place here. The
nearshore also forms part of the physical system through the transfers of
sediment.
The Classifcattn tf Ctasts
FORMATION Poimaoy Ctasts Sectndaoy Ctasts
PROCESSES Dominated by land-based processes such as depositon at the coast from Dominated by marine erosion or depositon processes
rivers or new coastal land formed from lava fows
RELATIVE SEA Emeogent Ctasts Submeogent Ctasts
LEVEL CHANGE Where the coasts are rising relatve to sea level Coasts being fooded by the sea
TIDAL RANGE Tidal Range varies hugely… Micottdal Ctasts Mesttdal Ctasts Macottdal Ctasts
Tidal Range = 0 – 2m Tidal Range = 2 – 4m Tidal Range = 4m +
WAVE ENERGY Ltw Eneogy High Eneogy
Sheltered coasts with a limited fetch and low wind speeds resultng in Exposed coasts, facing prevailing winds with long wave fetches resultng in powerful waves
small winds
.
, 2B.2: Geological Structure Clif Potfles Aoe Infuenced By Getltgy
Ctnctodant & Disctodant Ctasts
The Resistance tt Eotsitn tf the Rtck
Faults = either side of a fault line, rocks are ofen heavily fractured
Disctodant = forms when diferent rock strata runs peopendiculao to the coast. and broken and these weaknesses are exploited by marine erosion
• These coastlines are dominated by headlands and bays
Joints = occurs in most rocks, ofen in regular paterns, dividing
• The less resistant rock erodes to form bays
rock strata up into blocks with regular shape
• The more resistant geology remains as headlands which protrude into the sea
Fissures = much smaller breaks, only a few cm, cracks in the crust
Folded Rocks = ofen heavily fssured and jointed, meaning they
EXAMPLE: Isle tf Puobeck are more easily eroded
• The sofer Wealden beds have been eroded to form Swanage Bay
• The harder cretaceous chalk and limestone has not been eroded as much and protrudes to
form Ballaod Ptint and Peveoil Ptint
• The strata has a northward (landward) dip
• The eroded Wealden beds have created a valley between 2 ridges of chalk and limestone The Dip tf the Rtck Stoata in Relattn tt the Ctastline
• As waves refract towards the headlands, the wave energy will be concentrated on them and Dip, meaning the angle of the rock strata in relaton to the
through dynamic equilibrium, Swanage Bay and Studland Bay will disappear. horizontal, is a tecttnic featuoe
Sedimentaoy otcks are formed in horizontal layers but can be
Ctnctodant = forms when diferent rock strata runs paoallel to the coast. tlted by tectonic forces
There are 2 types of concordant coast: When this is exposed on a clifed coastline it has a dramatc efect
1. DALMATION on clif profles
2. HAFF
Dalmattn = Dalmata, Cotata (in the Adriatc Sea)
• Drowned by sea level rise during the Holocene period
• Geology = limestone
• Folded by tectonic actvity into antclines and synclines
• The antclines remain above sea level to create a series of long, narrow islands
Haf= Baltc Sea (found on the fringes)
• Long sediment ridges, topped by sand dunes, run parallel to the coast just ofshore
• This creates lagoons, called hafs, between the ridges and the shore
EXAMPLE: Lulwtoth, Dtoset
• The outer layer of rock is Ptotland Sttne (highly resistant limestone)
• The fairly resistant Puobeck Beds protect the sofer Wealden and Gault beds.
• At Lulwtoth Ctve, this protectve layer of rock was penetrated due to fuvial processes
• During the Pleisttcene period, this area experienced periglacial conditons which caused the
inner layer of chalk to become impermeable
• As temperatures rose, surface run of created river networks that breached the Ptotland Sttne
Topic 2
Amy Hannam
,2B.1: Features of the
Coast
The Littoal Ztne – the wider coastal zone including Rtcky Ctasts & Ctastal Plains
adjacent land areas and shallow parts of the sea just ROCKY/CLIFFED COASTAL SANDY COASTS ESTUARINE COASTS
ofshore COASTLINES PLAINS
• Clifs varying in • Sandy • Sand dunes • Found at oiveo
height coastlines (psammtseoes) at mtuths
• Clifs are formed • Estuarine the fringe • Extensive mud fats,
from rock but coastlines • Sandy beach cut by channels,
the hardness of • Ltw eneogy inundated at high inundated at high
the rock is very and ltw- tde, but vegetated tde
variable lying coasts dunes are not • Closer to the
• High eneogy with • Dune vegetaton backshore the mud
ctasts = ctnstouctve plays a crucial role fats are vegetated,
destructve waves and in stabilising the forming a salt
waves with long shtot fetches ctast maosh
fetches causing • This type of coast
erosion along gradually
with weathering transitons from
Backshtoe – only afected by waves during spring tdes and major storms to create mass land to sea
movement
Ftoeshtoe – wave processes normally confned to the foreshore, between
high and low tde marks
E.G. Flambtotugh E.G. Ainsdale, E.G. Lymingttn,
Neaoshtoe – shallow water areas close to land are called the nearshore. Head, Ytokshioe Meoseyside Hampshioe
Intensive human acton (such as fshing and leisure) takes place here. The
nearshore also forms part of the physical system through the transfers of
sediment.
The Classifcattn tf Ctasts
FORMATION Poimaoy Ctasts Sectndaoy Ctasts
PROCESSES Dominated by land-based processes such as depositon at the coast from Dominated by marine erosion or depositon processes
rivers or new coastal land formed from lava fows
RELATIVE SEA Emeogent Ctasts Submeogent Ctasts
LEVEL CHANGE Where the coasts are rising relatve to sea level Coasts being fooded by the sea
TIDAL RANGE Tidal Range varies hugely… Micottdal Ctasts Mesttdal Ctasts Macottdal Ctasts
Tidal Range = 0 – 2m Tidal Range = 2 – 4m Tidal Range = 4m +
WAVE ENERGY Ltw Eneogy High Eneogy
Sheltered coasts with a limited fetch and low wind speeds resultng in Exposed coasts, facing prevailing winds with long wave fetches resultng in powerful waves
small winds
.
, 2B.2: Geological Structure Clif Potfles Aoe Infuenced By Getltgy
Ctnctodant & Disctodant Ctasts
The Resistance tt Eotsitn tf the Rtck
Faults = either side of a fault line, rocks are ofen heavily fractured
Disctodant = forms when diferent rock strata runs peopendiculao to the coast. and broken and these weaknesses are exploited by marine erosion
• These coastlines are dominated by headlands and bays
Joints = occurs in most rocks, ofen in regular paterns, dividing
• The less resistant rock erodes to form bays
rock strata up into blocks with regular shape
• The more resistant geology remains as headlands which protrude into the sea
Fissures = much smaller breaks, only a few cm, cracks in the crust
Folded Rocks = ofen heavily fssured and jointed, meaning they
EXAMPLE: Isle tf Puobeck are more easily eroded
• The sofer Wealden beds have been eroded to form Swanage Bay
• The harder cretaceous chalk and limestone has not been eroded as much and protrudes to
form Ballaod Ptint and Peveoil Ptint
• The strata has a northward (landward) dip
• The eroded Wealden beds have created a valley between 2 ridges of chalk and limestone The Dip tf the Rtck Stoata in Relattn tt the Ctastline
• As waves refract towards the headlands, the wave energy will be concentrated on them and Dip, meaning the angle of the rock strata in relaton to the
through dynamic equilibrium, Swanage Bay and Studland Bay will disappear. horizontal, is a tecttnic featuoe
Sedimentaoy otcks are formed in horizontal layers but can be
Ctnctodant = forms when diferent rock strata runs paoallel to the coast. tlted by tectonic forces
There are 2 types of concordant coast: When this is exposed on a clifed coastline it has a dramatc efect
1. DALMATION on clif profles
2. HAFF
Dalmattn = Dalmata, Cotata (in the Adriatc Sea)
• Drowned by sea level rise during the Holocene period
• Geology = limestone
• Folded by tectonic actvity into antclines and synclines
• The antclines remain above sea level to create a series of long, narrow islands
Haf= Baltc Sea (found on the fringes)
• Long sediment ridges, topped by sand dunes, run parallel to the coast just ofshore
• This creates lagoons, called hafs, between the ridges and the shore
EXAMPLE: Lulwtoth, Dtoset
• The outer layer of rock is Ptotland Sttne (highly resistant limestone)
• The fairly resistant Puobeck Beds protect the sofer Wealden and Gault beds.
• At Lulwtoth Ctve, this protectve layer of rock was penetrated due to fuvial processes
• During the Pleisttcene period, this area experienced periglacial conditons which caused the
inner layer of chalk to become impermeable
• As temperatures rose, surface run of created river networks that breached the Ptotland Sttne
