Coasts Flashcards
The littoral zone
The wider coastal zone
Includes adjacent land areas and shallow parts of the sea just offshore
Cliff, FS, BS, OS, NS
Cliff profile
The height and angle of a cliff face as well as its features such as wave-cut notches or changes in slope angle
Coastal accretion
The deposition of sediment at the coast and the seaward growth of the coastline, creating new land
Often involves sediment deposition being stabilised by vegetation
Dynamic equilibrium
The balanced state of a system when inputs and outputs balance over time
If one element in the system changes because of an outside influence, the internal equilibrium is upset and other components change
Through feedback, the system adapts to change and the equilibrium is regained
Faults
Major fractures in rock produced by tectonic forces and involving the displacement of rocks on either side of the fault line
Holocene
The geological epoch that began about 12,000 years ago at the end of the last Pleistocene ice age
Early stages were marked by sea level rises of about 35m and a warming interglacial climate
Unconsolidated sediment
Material such as sand, gravel and clay and silt that has not been compacted and cemented to become sedimentary rock (has not undergone lithification) so it is easily eroded as it is loose
Pore water pressure
The pressure water experiences at a particular point below the water table due to the weight of the water above it
Swash
The flow of water up a beach as a wave breaks
Backwash
When water runs back down the beach to meet the next incoming wave
Fetch
The uninterrupted distance across water over which a wind blows, and therefore the distance waves have to grow in size
Beach morphology
The shape of a beach, including its width and slope (the beach profile) and features such as berms, ridges and runnels
It also includes the type of sediment (shingle, sand and mud) found at different locations on the beach
Blow hole
Forms when a coastal cave turns upward and breaks through the flat cliff top
Usually because of erosion especially at weak strata or the presence of a fault line
Currents
Flows of seawater in a particular direction driven by winds or differences in water density, salinity or temperature
Some are almost continuous, the global thermohaline circulation
Others more sporadic e.g. longshore currents
Some for hours e.g. rip currents
Mass movement
The downslope movement of rock and soil; it is an umbrella term used for a wide range of specific movements including a landslide, rockfall and rotational slide