Systems Flashcards
a system
a set of interrelated components that work together
3 types of system
closed, open, isolated
example of closed system
earth
example of open system
atmosphere, lithosphere, hydrosphere, biosphere which link together as a cascading system
zones of the coastline
backshore, foreshore, inshore, offshore, nearshore
backshore
area between HWM and landward limit of marine activity
foreshore
area lying between hwm and lwn- most important for marine processes
inshore
area between lwn and point where waves cease to have any influence on land beneath them
offshore
area beyond point where waves cease to impact upon seabed and which activity limited to deposition
nearshore
area extending seaward from hwm to area where waves begin
isolated system
no interactions with anything outside system boundary, no input/output of energy/matter
closed system
have transfers of energy both into and beyond the system boundary but not transfer of matter
open system
where matter & energy can be transferred from system across boundary into surrounding environment
dynamic equilibrium
when there is a balance between inputs and outputs so stores stay the same
feedback
if one of the elements of system changes, the stores change and equilibrium is upset
erosion
wearing away of earths surface by mechanical action of processes of glaciers, wind, rivers, marine waves, wind
fetch
the distance of open water over which a wind blows uninterrupted by major land obstacles
mass movement
movement of material downhill under the influence of gravity (also rainfall)
weathering
break down and/or decay of rock at/near earths surface creating regolith that remains in situ until it is moved by later erosional processes
backwash
action of water receding back down the beach towards the sea
constructive waves
waves with low wave height but with a long wavelength and low frequency of around 6-8/min, swash more powerful than backwash and beach material builds up
destructive waves
waves with a high wave height with a steep form and high frequency of 10-14/min, swash stronger than backwash so more sediment removed than added
swash
rush of water up the beach after a wave breaks
longshore/littoral drift
where waves approach the shore at an angle and swash and backwash then transport material along the coast in the direction of the prevailing wind and waves
wave refraction
when waves approach the coastline that is not a regular shape, they’re refracted and become increasingly parallel to the coastline
tides
the periodic rise and wall of the level of the sea in response to gravitational pull of the sun and moon
coastal sediment budget
balance between sediment being added to and removed from the coastal system, that system defined within each sediment cell
high energy coast
a coastline where strong, steady prevailing winds create high energy waves and the rate of erosion is greater than the rate of deposition
low energy coast
a coastline where wave energy is low and the rate of deposition often exceeds the rate of erosion of sediment
sediment cell
a distinct area of coastline separated from other areas by well-defined boundaries (headlands and stretches of deep water)
marine processes
operate upon a coastline and are connected with the sea such as waves, tides, lsd
sub-aerial processes
processes that slowly break down the coastline, weaken the underlying rocks and allow sudden movement/erosion to happen more easily
