Global pattern of ocean currents
Rip currents = Strong & relatively narrow currents of water that flow seaward against breaking waves
1.1 . How can coastal landscapes be viewed as systems?
These currents play an important role in the transport of coastal sediment
Caused by tidal motion or by waves breaking at 90° to the shore
1b. Coastal Landscape systems are influenced by a range A cellular circulation is generated by differing wave heights parallel to the shore
of physical factors Water from the top of the of breaking waves with a large height travels further up the shore and
then returns through the adjacent area where the lower height waves have broken
Once rip currents form, they modify the shore profile by creating cusps which help perpetuate the
rip current, channelling flow through a narrow neck
Geology
Cusps = a pointed & regular arc pattern of sediment on a beach
Lithology = the chemical and physical characteristics of rock types
Clay has a weak lithology, with little resistance to erosion, weathering & mass movements (due to weak bonds)
Basalt, dense interlocking crystals, highly resistant, likely to form prominent coastal features such as cliffs &
headlands
Chalk & carboniferous limestone (sedimentary rock) are soluble in weak acids - vulnerable to the chemical
weathering process of carbonation
Structure = the properties of individual rock types such as jointing, bedding & faulting
Structure is also to do with the permeability of rocks
Primary permeability = This is a property where pores absorb & store water e.g. in porous rocks like chalk, tiny air
spaces (pores) separate the mineral particles where these pores absorb and store water Ocean currents = the large-scale horizontal flow of ocean water (at the surface & at depth) driven by
planetary winds and contrasts in water temp and salinity
Secondary permeability = This is a property where there are joints & faults in rocks. E.g. carboniferous limestone is
also permeable, but for a different reason. Water seeps into the limestone because of its many joints. These joints are Generated by the earth’s rotation & by convection
enlarged by corrosion, this is also called pervious Set in motion by the movement of winds across the water surface
Warm ocean currents transfer heat energy from low latitudes towards the poles, they affect
Highly foldable = lots of layers of different rock types, such as hard and soft rock western facing coastal areas when they are driven by onshore winds
Cold ocean currents do the opposite, moving cold water from polar regions towards the equator,
How is structure an important influence on the planform of coasts at a regional scale? they are usually driven by offshore winds, so have less effect on coastal landscapes
Rock outcrops that run parallel to the coast tend to produce The strength of the current itself may have limited impact on coastal landscape systems in terms of
concordant coasts, therefore maybe producing coves geomorphic processes, but the transfer of heat energy can be significant, as it directly affects air
Where rocks lie 90° to the coast, they create a discordant coast; the temp and therefore subaerial processes
more resistant rocks form headlands & the weaker rocks form bays E.g. Labrador current (cold) is in the North Atlantic Ocean and meets the Gulf Stream to the South
Structure also includes the angle of dip of rocks, this can have a
Sub – aerial process = a collective term for weathering and mass movement processes
strong influence on cliff profiles
Horizontally bedded & landward dipping strata support cliffs with
steep vertical profile
Seaward dipping strata tend to support cliffs at the angle of the dip
& bedding planes, more gentle profile & higher sediment supply in
sea
Rip currents = Strong & relatively narrow currents of water that flow seaward against breaking waves
1.1 . How can coastal landscapes be viewed as systems?
These currents play an important role in the transport of coastal sediment
Caused by tidal motion or by waves breaking at 90° to the shore
1b. Coastal Landscape systems are influenced by a range A cellular circulation is generated by differing wave heights parallel to the shore
of physical factors Water from the top of the of breaking waves with a large height travels further up the shore and
then returns through the adjacent area where the lower height waves have broken
Once rip currents form, they modify the shore profile by creating cusps which help perpetuate the
rip current, channelling flow through a narrow neck
Geology
Cusps = a pointed & regular arc pattern of sediment on a beach
Lithology = the chemical and physical characteristics of rock types
Clay has a weak lithology, with little resistance to erosion, weathering & mass movements (due to weak bonds)
Basalt, dense interlocking crystals, highly resistant, likely to form prominent coastal features such as cliffs &
headlands
Chalk & carboniferous limestone (sedimentary rock) are soluble in weak acids - vulnerable to the chemical
weathering process of carbonation
Structure = the properties of individual rock types such as jointing, bedding & faulting
Structure is also to do with the permeability of rocks
Primary permeability = This is a property where pores absorb & store water e.g. in porous rocks like chalk, tiny air
spaces (pores) separate the mineral particles where these pores absorb and store water Ocean currents = the large-scale horizontal flow of ocean water (at the surface & at depth) driven by
planetary winds and contrasts in water temp and salinity
Secondary permeability = This is a property where there are joints & faults in rocks. E.g. carboniferous limestone is
also permeable, but for a different reason. Water seeps into the limestone because of its many joints. These joints are Generated by the earth’s rotation & by convection
enlarged by corrosion, this is also called pervious Set in motion by the movement of winds across the water surface
Warm ocean currents transfer heat energy from low latitudes towards the poles, they affect
Highly foldable = lots of layers of different rock types, such as hard and soft rock western facing coastal areas when they are driven by onshore winds
Cold ocean currents do the opposite, moving cold water from polar regions towards the equator,
How is structure an important influence on the planform of coasts at a regional scale? they are usually driven by offshore winds, so have less effect on coastal landscapes
Rock outcrops that run parallel to the coast tend to produce The strength of the current itself may have limited impact on coastal landscape systems in terms of
concordant coasts, therefore maybe producing coves geomorphic processes, but the transfer of heat energy can be significant, as it directly affects air
Where rocks lie 90° to the coast, they create a discordant coast; the temp and therefore subaerial processes
more resistant rocks form headlands & the weaker rocks form bays E.g. Labrador current (cold) is in the North Atlantic Ocean and meets the Gulf Stream to the South
Structure also includes the angle of dip of rocks, this can have a
Sub – aerial process = a collective term for weathering and mass movement processes
strong influence on cliff profiles
Horizontally bedded & landward dipping strata support cliffs with
steep vertical profile
Seaward dipping strata tend to support cliffs at the angle of the dip
& bedding planes, more gentle profile & higher sediment supply in
sea
