Coasts part 1- systems and processes Flashcards
closed system
Allows the input, transfer and output of energy but not matter.
open system
Allows the input and output of energy but not matter
example of closed system
domestic central heating
example of open
domestic water supply
inputs of a system
energy/ matter entering a system
outputs of a system
energy/ matter leaving a system
boundary of a system
edge of a particular system
store/ component
place where energy/ matter is stored/ held and matter can remain
flow/ transfer
movement of energy/ matter between systems
atmosphere
air that surrounds the earth made of gases and water vapour
lithosphere
the crust and uppermost mantle; constitutes the hard and rigid layers of the earth. This layer is split into tectonic plates
hydrosphere
discontinuous layer of water at or near the earth’s surface. It includes all liquid and frozen surface waters, groundwater held in soil and rock, and atmospheric water vapour.
biosphere
the total sum of living matter. The biological component of the earth’s systems.
negative feedback
system acts by lessening the effect of the original change and returning to equilibrium. (reversing effects)
positive feedback
change causes a further change and a snowball effect occurs. (effects are never undone)
tectonics influencing coastal landforms
movement of tectonic plates causes land to rise and fall; changing sea levels at coast and produce new coastal landforms. Sudden movements also cause tsunamis and flooding.
geology influencing coastal landforms
coastlines with harder rocks take longer to erode than coasts with harder rock; concordant and discordant coastlines create headlands and bays.
winds influencing coastal landforms
powerful winds in the direction of the coastline create constructive waves (leading to deposition) adn powerful winds away from coastline create destructive waves (leading to erosion).
vegetation influencing coastal landforms
coral reefs act as a buffer protecting coasts from erosion, preserving the coastline.
glaciation influencing coastal landforms
melting fresh waters from glaciers causes sea level rise as well as pushing heavier salt water downwards, changing ocean currents.
mass movement influencing coastal landforms
with rotational slumping, heavy rain is absorbed by unconsolidated material making up the cliff; the cliff becomes heavier and heavier eventually separating from the coastline and changing the coastline.
pollution influencing coastal landforms
an increased concentration of chemicals in the ocean by pollution, promotes the growth of algae which can damage the coastline and become fatal to wildlife.
temperatures influencing coastal landforms
frost erodes the coastline through freeze thaw weathering, creating landforms such as jagged edges and loose material falling from the coastline into the ocean.
UK prevailing winds
comes from the South West
wave formation
- water becomes shallower and circular orbit of water particles changes to an elliptical shape.
- wavelength and velocity both decrease, and the wave height increases
- this causes water to back up from behind and rise to a point where it starts to topple over and break.
fetch
distance of open water that the wind blows uninterrupted by land obstacles
wave refraction
depth of water increases rapidly off a headland; waves increase in height as their speed decreases. Erosion is then concentrated on the headland.
spring tide
The highest monthly tidal range, when the earth, sun and moon are in a straight line
neep tide
the lowest monthly tidal range, when the moon and sun are perpendicular to each other.
tidal range
vertical difference between high and low tides
surface ocean currents
typically wind driven
deep ocean currents
driven by wind, tides, coriolis force, the sun and water density differences