Term 1-Coastal systems and landscapes Flashcards
Define the term ‘Coast’
The coast is a dynamic zone where the land meets the sea. It is an area with distinctive landscapes formed by the interaction of a range of wind,marine and terrestrial processes.
What are the inputs of coastal systems?
Energy from:waves,wind,tides and sea currents.
sediment
geology of coastline
sea level change
What are the components of coastal systems?
Erosional landforms and landscapes
Depositional landforms and landscapes
What are the outputs of coastal systems?
Dissipation of wave energy
Accumulation of sediment above the tidal limit
Sediment removed beyond local sediment cells
Define dynamic equilibrium
The state of a reversible reaction in which the rate of the forwards reaction equals the rate of the backwards reaction.Concentrations of reactants and products are the same.
Define backshore
The part of the beach lying between the beach face(foreshore) and the coastline.
Define foreshore
Area above water level at low tide and underwater at high tide.
Define inshore
Area between low water mark and the point where the waves cease to have any influence on the land around them.
Define offshore
The area of deeper water beyond the point at which waves begin to break.
Define Nearshore
Where waves steepen and break and then re-form in their passage to the beach,where they break for the last time and surge up the foreshore.
Define swash zone
The area where a turbulent layer of water washes up the beach following a breaking wave.
Define Surf zone
The area between the point where a wave breaks,forming a foamy and bubbly surface and where the waves then move up the beach.
Define breaker zone
The area where waves approaching the coast begin to break usually in water with a depth of 5-10m.
What is an offshore bar?
Ridges of sand or shingle running parallel to the coast in an offshore zone.
What is a system?
A series of interacting components linked by flows or transfers of energy and materials.Made up of inputs,stores,processes and outputs.
What is an open system?
System which has external inputs and external outputs of energy and matter.
Example=Ocean
What is a closed system?
Have transfers of energy into and beyond the system but not the transfer of matter.
Example=Earth
What is a cascading system?
The transfer of mass and energy along a chain of component subsystems.The output from one subsystem becomes the input for the adjacent subsystem.
Define wave frequency
estimated by counting the number of waves breaking on the shore in 10 minutes
Define wave crest
Highest point of a wave
Define wave trough
Lowest point of a wave
Define wave steepness
Ratio of wave height to wave length
Define wave energy
Form of renewable energy that can be utilized from the motion of waves
What is a constructive wave?
A wave where the swash is stronger than the backwash.
What is a destructive wave?
A wave where the backwash is stronger than the swash.
Define swash
When a wave washes up onto the shoreline
Define backwash
When the water from a wave retreats back into the sea
What is the fetch?
Refers to the distance of the sea over which the wind has traveled.
Define wave refraction
The change in direction of waves as they move between materials with different properties.
What is a sediment cell?
Distinct areas of coastline which are separated from each other by distinct borders such as headlands or deep stretches of water.
Larger cells can be divided into into smaller sections,sub cells.This allows closer study and management.
There are 11 in the UK
What is the coriolis force?
Because the earth rotates on it’s axis,circulating air is deflected towards the right in the northern hemisphere and toward the left in the southern hemisphere.
Define wavelength
Distance between two crests
Define erosion
Wearing away of the Earth’s surface by the mechanical action of processes of glaciers,wind,rivers and marine waves.
What is upwelling?
Winds blow across ocean surface and push water away from an area.Water rises up from beneath the surface to replace the surface water.
Define longshore current
Waves approaching the coast at an angle create a current that runs parallel to the coast.
Define rip currents
strong currents moving away from shore,developed by water piling up on the coast where two breaking waves meet,this mass of water flows quickly back out to sea.
What is a thermohaline current?
driven by differences in the water’s density which is controlled by temp(thermo) and salinity(haline)
what is positive and negative feedback
a positive feedback loop increases effect of change and increases instability.
a negative feedback loop reduces effect of change and helps maintain balance.
what is coastal morphology
the shape and from of land features
define erosion
the wearing away of the earths surface by the mechanical action of processes of glaciers,wind,rivers,marine waves and wind.
what is mass movement
the movement of material downhill under influence of gravity but may be assisted by rainfall
define weathering
the breakdown and/or decay of rock at or near the earths surface
