Coasts and natural systems Flashcards
coastal environments are
open systems
coastal systems as open systems contain
inputs, components, transfers and outputs
when there is a balance between the inputs and outputs in a system it is said to be
in a state of dynamic equilibrium
if one of the elements in a system which is in dynamic equilibrium changes, but there is no corresponding change, then the equilibrium is upset in what is called
feedback
negative feedback is when a change in a system
counteracts the change which first disrupted equilibrium in the first place
coastal landscapes are an example of
geomorphological environments
geomorphological environments consist of a constantly changing array of
erosional and depositional landforms
erosional and depositional landforms are the result of
the continuous change in the elements of a coastal system as they push towards dynamic equilibrium
inputs of coastal landscapes include: (4 items)
- energy (from waves, wind, tides, and sea currents)
- sediment
- geology of coastline
- sea level change
erosional processes of the coastline include ( 4 items)
hydraulic action
abrasion
attrition
solution
erosional components of a coastline include ( 7 items)
cave, arch stack, stump
wave cut platform
headlands
blowholes
wind and water transfers include: (5 items)
traction saltation suspension solution long shore drift (LSD)
depositional components include: ( 7 items)
beach spit, bar or tombolo mud flat salt marsh sand dunes
outputs of a coastal system include: (3 items)
dissipation of wave energy
accumulation of sediment above the tidal limit
sediment removed beyond local sediment cells
a coast is
the part of the land near the sea; the edge of the land
a coastline is
regarded as an open system with inputs, processes and outputs’ interacts with surroundings
landforms are:
a feature of the Earth’s surface
landscapes are
all the visible features and landforms of an area of land, that are all interconnected in a system
the backshore is
the area between the high water mark (HWM) and the landward limit of marine activity. changes here normally takes place due to storm activity
the foreshore is
the area lying between the HWM and the low water mark (LWM). it is the most important zone for marine processes in times that are not influenced by storm activity
the inshore is
the area between the LWM and the point where waves cease to have any influence on the land beneath them
the offshore is
the area beyond the point where waves cease to impact upon the seabed in which activity is limited to deposition of sediments
the nearshore is
the area extending seaward from the HWM to the area where waves begin to break
the nearshore includes the three following zones:
swash zone, surf zone and breaker zone
the swash zone is
the area where a turbulent layer of water washes up the beach following the breaking of a wave
the surf zone is
the area between the point where waves break, forming a foamy, bubbly surface, and where the waves then move up the beach as swash in the swash zone
the breaker zone is
the area where waves approaching the coastline begin to break, usually where the water depth is 5-10 m
