Term
|
Definition
| Waves are the result of wind blowing the sea. Waves break as they reach the coast. |
|
|
Term
|
Definition
| A thin sheet of water that moves up the beach face after a wave of water breaks on the shore according to the direction of the prevailing wind. |
|
|
Term
|
Definition
| A sheet of water that flows back to the ocean perpendicular to the coast because of gravity. |
|
|
Term
|
Definition
| Formed at anticyclones meaning there is little wind and no precipitation. The beach builds up since swash > backwash and hence there is more deposition. The slope is shallow. |
|
|
Term
|
Definition
| Formed with depressions, meaning the weather is wet and stormy. Backwash > Wash meaning the beach is eroded and the effect is amplified since the waves are more frequent. The slope is steep. |
|
|
Term
|
Definition
| Distance of water over which winds have blown (e.g. UK= Highest in SW and NE) |
|
|
Term
|
Definition
| The process by which waves break. The bottom of the wave touches the sand and is slowed down by friction and the wavelength decreases whilst wave height increases. The wave topples forward due to gravity since the crest travels faster than the base. |
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
| Distance between 2 crests |
|
|
Term
|
Definition
| Time taken for wave to travel 1 wavelength |
|
|
Term
|
Definition
| Ratio of Wave height to wavelength. Cannot be greater than 1:7 |
|
|
Term
|
Definition
| E is proportional to Wavelength * Waveheight^2. |
|
|
Term
|
Definition
| Waves caused by storms faraway and not by local winds. They can travel thousands of miles. |
|
|
Term
|
Definition
| Regular Rising and Falling of the Sea caused by the gravitational pill of the moon and sun. |
|
|
Term
|
Definition
| The point where the tidal range is greatest (i.e. highest spring tide, lowest low tide) since the gravitational pull of the sun and moon are combined. |
|
|
Term
|
Definition
| The earth sun and moon form a right angle and the gravitational pull is interfered. The tidal range is smallest (Lowest High Tide, Highest Low Tide) |
|
|
Term
|
Definition
| Spinning Motion of the Earth which affects tide patterns. |
|
|
Term
|
Definition
| A factor which affects tidal paterns. E.g. English Channel= Narrowed Channel, and therefore tides can be high. In landlocked seas (e.g. Mediterranean) tidal range can be as low as 0.01m. |
|
|
Term
|
Definition
| Area between the spring high and spring low where almost all landforms are created. |
|
|
Term
|
Definition
| Ridges parallel to the cliff formed as spring tides are unable to reach them. |
|
|
Term
|
Definition
A stretch of coastline within which sediment is sourced, transported, and deposited. Sediment is largely self-contained and sediment cell boundaries are defined by headlands and bays.
Inputs= Erosion, Rivers, Wind, Beach renourishment, Biogenic material
Transportation= Longshore Drift, Waves, Currents, Wind, Tides
Output= Wind, Tides,Deposition, Removal |
|
|
Term
|
Definition
| Rocks and pebbles collide and smooth each other down into smaller sediment. |
|
|
Term
|
Definition
| Rocks and pebbles scrape along surface of the beach and sea bed. |
|
|
Term
|
Definition
| Chemical Reactions dissolve the rock |
|
|
Term
|
Definition
| The coastal equivalent of Hydraulic Action. The force of waves against the beach and cliffs. |
|
|
Term
|
Definition
| The force of water pushing air into cracks. |
|
|
Term
|
Definition
| The combination of an angled swash and right angled backwash causes material to shift in one direction |
|
|
Term
|
Definition
A long, narrow accumulation of sand or shingle, with one end attached to the land, and the other projecting at a narrow angle either into the sea or across a river estuary. Many spits have a hooked or curved end. They form when the coastline suddenly changes direction and longshore drift carries sediment out of land and into the sea. A change in the prevailing wind direction causes sediment to be pushed inland forming a hooked end. A marsh is often created behind. Spits are cut off by the flow of the river.
E.g. Spurn Head, Yorkshire
Dawlish Warren, Devon |
|
|
Term
|
Definition
A protrusion of land which connects an island to mainland. These are formed by continuous build-up of spits.
E.g. Chesil Beach, Dorset |
|
|
Term
|
Definition
| A 'bar' of land which crosses between two sides of land forming a wetland behind. They are formed when a spit connects two areas of land. |
|
|
Term
| Offshore Bar/Barrier Island |
|
Definition
A series of sandy islands detached from the mainland running close to parallel to the mainland. One theory suggests that they are formed as bars which are later disrupted and broken from the mainland. Another theory suggests that they are formed when the returning water loses energy and collides with the oncoming wave causing deposition build up.
E.g. Mississippi-Alabama Barrier Islands, Gulf of Mexico |
|
|
Term
|
Definition
| The bending of the waves which focus their energy at headlands. On the headland side, the sea becomes shallower and there is more friction than on the other side. This causes the waves to turn towards the headlands as they reach the bay. |
|
|
Term
|
Definition
| Lines drawn at right angles to the crest. |
|
|
Term
|
Definition
| Weathering involving and caused by live organisms. |
|
|
Term
|
Definition
|
|
Term
|
Definition
| Where the diurnal range hovers around 0 degrees, water freezes and melts. As water freezes, it expands by 9% and exerts pressure and causes frost shattering. |
|
|
Term
|
Definition
| Acidic rain can cause chemical reactions to occur causing the rock to be eroded. |
|
|
Term
|
Definition
| Land mass slips down the cliff and slumps creating an uneven step-like formation. Slumps have a curved rupture surface and involve a rotational element. |
|
|
Term
|
Definition
| Rainfall causes splashing of soil and expansion of soil. Expansion upon freezing and contract upon drying causes the particle to roll downhill. |
|
|
Term
|
Definition
| Weathering and erosion triggers rapid rare movements downhill where slopes exceed 40 degrees. |
|
|
Term
|
Definition
| A faster version of soil creep, loose particles travel downhill following rainfall. |
|
|
Term
|
Definition
| Water flowing overland can carry small particles downhill. |
|
|
Term
|
Definition
| A pronounced change in gradient where the land meets the sea. |
|
|
Term
|
Definition
| Appears as a protrusion of land outwards and are formed where less resistant rock exists even though wave energy is concentrated at headlands due to wave refraction. |
|
|
Term
|
Definition
| A curved beach between headlands formed since the rock is less resistant even though wave energy dissipated. |
|
|
Term
|
Definition
| A crack in the cliff is exploited by weathering (e.g. Freeze Thaw, Hydraulic Pressure) forming a cave. |
|
|
Term
|
Definition
Further erosion on either side of the cave wall breaks the backwall forming an arch.
E.g. Durdle Arch |
|
|
Term
|
Definition
| As the arch grows higher a pillar is formed. |
|
|
Term
|
Definition
| A pillar is eventually cut off by aerial weathering often chemical or wind. This leaves behind a tall column known as a stack. |
|
|
Term
|
Definition
| The continued aerial weathering and pressure of gravity causes the stack to become smaller until it is below 50% of height of mainland. |
|
|
Term
|
Definition
| The stump collapses due to gravity forming a reef. |
|
|
Term
|
Definition
| Bands formed of rock of varying resistance are perpendicular to the coast. Headlands and Bays can only form on a discordant coastline. |
|
|
Term
|
Definition
| The layers of rock are parallel to the sea. |
|
|
Term
|
Definition
| The roof of a cave is weakened along a joint by hydraulic pressure forming a narrow vent when the roof collapses. Water may spit out from the blowhole |
|
|
Term
|
Definition
| A steep sided inlet formed when erosion exploits a weakness (joint, crack, fault, bedding plane) largely by hydraulic pressure. |
|
|
Term
|
Definition
| A ledge at the base of a cliff which is gently sloped and protrudes outwards to sea. Waves attack the cliff base by wave pounding and abrasion creating a wave-cut notch. The cliff becomes unstable and falls due to gravity causing the notch to recede and platform to extend. Dissipation of wave energy prevents long wave-cut platforms from forming. |
|
|
Term
|
Definition
| Appear like an ohm sign with a narrow neck. Coves form on concordant coastlines where a weakness in a hard layer of rock is exploited by hydraulic pressure, abrasion and hydraulic action which is then widened when the water meets a band of less resistant rock. |
|
|
Term
|
Definition
| An area of flat land formed between the sea and land along a coastline. |
|
|
Term
|
Definition
| Area of foreshore that is raised above the adjacent shore. |
|
|
Term
|
Definition
| Tiny valleys between ridges. |
|
|
Term
|
Definition
A pattern of horns and embayments. Horns are made of coarser material and embayments are made of finer material.
E.g. Southern Worbarrow Bay, Dorset |
|
|
Term
|
Definition
| A flat area of sand formed by wind transportation near oceans. |
|
|
Term
|
Definition
| A young dune which is highly unstable and infertile for most species unless they are salt tolerant. E.g. Sandwort, Marram Grass |
|
|
Term
|
Definition
| A more stable dune with wider range of flora. Plants begin to stabilise dune. |
|
|
Term
|
Definition
| Damp, low lying hollows where the land is below the water table. Dune slacks are home to water loving plants. E.g. Rushes |
|
|
Term
|
Definition
| Much more nutrient rich soil where acid-loving plants co-exist with woody perennials such as Heather. |
|
|
Term
|
Definition
| The removal of dune vegetation to extract sand for production of titanium and glass. |
|
|
Term
|
Definition
| Pressure placed on vegetation through trampling and vehicular pressure can compact the soil and reduce oxygen content forming blowouts and allowing weed infestation. |
|
|
Term
|
Definition
| An area of a dune where there is no vegetation even though the surrounding area is rich in vegetation. Sand is picked up forming a bowl shaped depression with a flat bottom. |
|
|
Term
| Foreign Influences- Dunes |
|
Definition
Foreign species may be introduced to increase stability and/or biodiversity, but some species can become invasive.
E.g. Bitou Bush, Australia |
|
|
Term
|
Definition
| An are of flat terrain dominated by short grasses with many creeks. Where seawater is largely still, sediment is deposited through flocculation and forms an unvegetated mud flat. Vegetation such as eelgrass an halophytes begin to grow. As the conditions become increasingly suitable for vegetation, other plants can grow. E.g. Manna Grass. The marsh continues to rise above sea level until it is only covered at times of high tide. Creeks receive increasingly less water and dry out allowing trees to form. |
|
|
Term
|
Definition
A triangular beach formed by deposition where longshore drift conflicts at sediment and sub-sediment cell boundaries.
E.g. Dungeness, Kent, Uk |
|
|
Term
|
Definition
LANDFORM OF EMERGENCE
An elevated area of sloping ground above the current tide level. A sudden relative rise in land pushes the original beach considerably above sea level.
E.g. Hudson Bay, Canada |
|
|
Term
|
Definition
LANDFORM OF SUBMERGENCE
A relative rising of sea level causes former river valleys to be drowned forming what looks like a deep inlet of water into land.
E.g. Georges River, Sydney, Australia |
|
|
Term
|
Definition
LANDFORMS OF SUBMERGENCE
A partly inundated glacial trough which appears as a large lake. They appear somewhat like rias but are deeper and have steeper sides with a flatter base.
E.g. Sognefjord, Norway
Loch Torridon, Western Scotland |
|
|
Term
|
Definition
| A rise of water inland associated with low pressure weather systems. Low pressure causes warm air to rise. Air quickly rushes into these gaps causing windy conditions while there is frontal rainfall. |
|
|
Term
|
Definition
| A technique by which defences are maintained and upgraded to restrict any further erosion. |
|
|
Term
|
Definition
| The process by which certain areas are left unprotected whilst other areas are chosen to be protected. |
|
|
Term
|
Definition
| Decision not to invest and existing defences are exposed. |
|
|
Term
|
Definition
| Schemes to manage coastal flooding through means which work in harmony with the environment. |
|
|
Term
|
Definition
| Schemes which involve the construction of a physical structure to limit coastal flooding. Hard Engineering tends to be expensive but more effective. |
|
|
Term
|
Definition
SOFT
Placing sand back on the beach to provide a physical barrier and absorb wave energy.
+ Retains natural beauty
+ Can help boost tourist industry and revitalise local economy (e.g. Miami Beach, Florida)
- A single storm can remove vast amounts of sediment
- Only lasts 1-10 years
- Damaged ecosystem
- Only mitigates effect
E.g. Miami Beach, Florida |
|
|
Term
|
Definition
SOFT
Natural processes to build up dunes and increase vegetation to strengthen dunes and prevent excessive coastal retreat.
+ Increased Biodiversity
+ Little Maintenance
+ Leaves interrupt windflow to encourage further deposition
+ Once fully established, vegetation will colonise the area
- Vegetation can be placed under physical pressure
- A major storm can destroy dune
- Maintenance is labour intensive
- Turf stripping and excavation are expensive
E.g. Sefton Coast, Merseyside, UK
Studland Bay, Dorset, Uk |
|
|
Term
|
Definition
SOFT
Allowing water to flow into one area forming a marsh to reduce erosion either side of the marsh.
+ Increased Biodiversity
+ Encourages beach creation either side
+ Little/No Cost
+ Can provide flood defence by absorbing large volumes of water
- Loss of land and potentially services and housing
- Only a long-term solution
- Will reach a maximum capacity which, when passed renders the defence useless.
E.g. Wallasea Island, Essex, UK which converted 115 hectares of farmland into marshland in 2006 at a cost of 7.5 mil |
|
|
Term
|
Definition
SOFT
Managing where activity takes place and zoning off of certain locations to preserve the important parts of a coastline without damaging tourism.
+ Can help increase awareness
+ Less virtually intrusive
- Overmanagement can lead to disfunctioning
- Relies on visitor co-operation
- Not a standalone scheme |
|
|
Term
|
Definition
HARD
Vertical structures of concrete to withstand wave pounding and hydraulic action.
+ Appropriate for exposed frontages of high value
+ Takes up minimal space and allows development up to shoreline
+ Immediate Protection
- 200k+ per 100m
- Only lasts 30-50 years
- Can bounce back waves causing erosion elsewhere
E.g. Hornsea, Holderness, NE England |
|
|
Term
|
Definition
A sloping defence structure to absorb wave energy and strengthen the cliff base.
+ Allows longshore drift
+ Cheaper than other hard engineering
- Require maintenance + replacement
- Useless if sea level rises above revetment
- Does not provide a physical barrier
E.g. Easington Gas Terminal, Holderness |
|
|
Term
|
Definition
Collection of large rocks to absorb and dissipate wave energy.
+ Cheaper than concrete constructions
+ Longer lasting than sea walls
+ Can reduce mass land movement
- Can trap flotsam and jetsam (derelict ship wrecks and waste) leading to smell +infestation
- Rocks can be dragged into sea
- Provides safety hazard
E.g. Walton-on-the-Naze, Essex, SE Uk |
|
|
Term
|
Definition
Steel cages containing small boulders to absorb and dissipate wave energy.
+ Cheaper than rock armour
+ Cages can be refilled
+ Easy transport
- Only lasts 5-10 years
- Prone to cage weathering which could lead to subsequent breakage
- Can only be used at the back of a beach due to lack of resistance
E.g. Hengistbury Head, Bournemouth |
|
|
Term
|
Definition
Breakwaters perpendicular to coastlines to stop longshore drift and allow beach build-up.
+ Can create attraction
+ Low Maintenance
+ Relatively Cheap
- Leaves downcoast side of groyne with no supply of sediment
- Beach Replenishment required to manage sand distribution
E.g. Swanage Bay, Dorset, UK |
|
|
Term
|
Definition
Partly submerged wall to control water flow around estuaries whilst also improving navigation.
+ Can create HEP
+ Highly Reliable
+ Can hold back water
- Silt build up requiring dredging
- Sea level rise can make them pointless
- High start-up and maintenance costs
E.g. La Rance, St Malo,France |
|
|
