LANDSCAPES
PHYSICAL GEOGRAPHY
,3.1.3.1 Coasts as natural systems
NATURAL SYSTEMS
Open System- is a system that transfers both matter and energy can cross its boundary
to the surrounding environment
Closed System- is a system that transfers energy, but not matter, across its boundary to
the surrounding environment
Dynamic Equilibrium- a state of balance within a constantly changing system
Input- material or energy moving into the system from outside
Output- material or energy moving from the system to the outside
Stores- individual elements or parts of a system
Transfers- the links or relationships between the components
Positive Feedback- where a flow/transfer leads to increase or growth (can a positive of
negative thing; climate change)
Negative Feedback- where a flow/transfer leads to decrease or decline (can a positive of
negative thing; climate change)
, 3.1.3.2 Systems and processes SOURCES OF ENERGY AT THE COAST
Wind Waves
• Constructive
• Fetch is the length of water over which a given wind has blown - a long wavelength
- strong swash and a weak backwash
• The strength of the wind can affect the type of wave - This means they deposit more material on a beach tha
-build gentle beaches
• The duration of the wind affects the strength of the wind
• Destructive
• The Coriolis force is where the earth’s rotation affects the way that - short wavelength
winds travel over the earth - they tend to be steep and form during storm
- weak swash but powerful backwash
- remove material from a beach and produce a steep
breakpoint bars
Tides Low and High Energy Coastline
Spring Tides High Energy Environments
These tend to be
- A spring tide, produced when the Sun, Earth and Moon are aligned • Stretches of Atlantic-facing coast, where the waves a
- When this happens, the tidal forces of the Moon are reinforced by the much of the year
Sun’s producing higher than average high tides and lower than • Where the rate of erosion exceeds the rate of d
average low tides
Low Energy Environments
Neap Tides These tend to be
• Stretches of the coast where the waves are less pow
- When the Sun and the Moon are perpendicular to one another the coast is sheltered from large waves
- the height of the high tides is lowered and the tidal range is reduced • Where the rate of deposition exceeds the rate o