1. Coastal Environments
Think of it as a battle ground, where individual battles are won but the war never will be….
The two sides…..
Allies……
Double Agents….
Munitions/weapons…
The war so far….
Future predictions

2. The Sea
The coastline is the narrow boundary between the sea and the land.
Waves, tides and currents interact with the rocks and sediments of the land. The nature of the land, the strength of the waves, the weather and the size of the tides all affect our coastline.
The changes can take place over hundreds of years but also on a daily basis. A storm can change the form of a beach within just one day.
The energy in waves is constantly affecting the shape of the coastline
We are also conscious that global warming could have a considerable effect on our coastline. One report, released in the spring of 2001, suggested that the sea level might rise by one metre in the next hundred years, an event that would have a dramatic effect on coastlines around the world.

3. Waves
The waves of the sea are generated by the energy of the wind. The friction of wind blowing across the surface of the sea causes the upper layer of the sea to be disturbed and dragged into waves. The stronger the wind, the bigger the waves.
The distance the wave travels also affects the size, strength or energy of the waves. Waves that travel across the thousands of kilometres of the Atlantic Ocean reach the shores of Cornwall to provide good waves for surfing and energy to do geomorphological work. Around other areas of Britain's coastline, the waves build up over a shorter distance and have less energy.
Because waves are built up by the wind, the most common direction of the wind, the prevailing wind, results in what are called dominant waves - the main waves affecting a particular section of coast. These waves are responsible for the processes of erosion, transportation and deposition.

4. CURRENTS
Currents are flows of seawater, generally following a regular pattern, caused by the rotation of the Earth, the tides and by the weather and climate.
For instance, the British Isles are kept relatively warm throughout the year by the North Atlantic Drift, a current which flows across the Atlantic Ocean from the warmer seas of the Caribbean. Because of this, temperatures in Britain do not fall in winter to the levels experienced by cities at the same latitude elsewhere in Europe.
On a smaller scale, local currents have an effect on the coastline, causing regular erosion, deposition and transportation of beach materials. Over the years the current has built up a spit such as that at Blakeney in north Norfolk, moved Spurn Head in Lincolnshire and removed the materials eroded from the cliffs at Covehithe in Suffolk.

5. Rip currents anre important for transporting sediment – caused by tidal motion or by waves breaking along a shore.
Once formed rip currents are formed, they modify the beach by creating cusps which perpetuate the current.

6. Tides
Tides are the daily process of the water level of the sea rising and falling. In most places around the world the tide goes "in" and "out" twice in each day. This is caused by the gravitational pull of the moon as it moves around the Earth. In many places the tide can rise and fall several metres every day whereas in other situations local conditions can cause greater or lesser tides, depending on how fast the water is able to move.

7. Tides continued Spring tides Neap tides Storm tides
Tides are greatest in bays and funnel shaped coastlines
Low pressure systems can raise the level by 10cm for every decrease of 10mb
Tidal range is the difference between high and low tide… which varies from an amphidromic point (place with no tidal range) and shape of the coast

8. Microtidal=low tidal range
Mesotidal =2-4m
Macrotidal = over 4m
These have importnant influences on coastal processes
=controlling vertical range of erosion
Weathering is affected by time between the tides
Velocity increases with the tidal range and has an important scouring effect.

9. TIDES
An example of local tidal effect is found at Korrieverechan, in the Western Isles of Scotland, where the narrow passage between islands causes the sea to flow rapidly as the tides rises and falls through a narrow gap. It can also meet a tidal flow in the opposite direction as the tide turns.

10. Intertidal Zone
On every beach there is an area called the intertidal zone. This is the area of rock pools and hard, flat sand which many like to explore when at the seaside. It is covered by the sea for part of the day, and uncovered at low tide. This area has its own features and is very changeable as the sea removes and deposits materials.
There is an extra effect known as Spring and Neap tides, caused by the moons distance from the Earth varying over a period of weeks. At Spring tides the moon is slightly nearer to the Earth, and it pulls the tide higher. At Neap tides, it is at its most distant, and the tidal range is less.
A combination of the extra height of a Spring tide and strong winds from a certain direction can cause severe action on the coastline, such as the great storm in the North Sea of These are known as storm surges.

11. Coriolis force
The effect of the earth’s rotation on moving air and water.
In northern hemisphere, this effect is deflection to the right
It can have a major effect on the tidal range … eg the rising tide from the SW (part will travel N. up the Irish sea where it will get deflected to the right – giving higher tides on the W. coast of Wales and England than Ireland.

12. Sea Bed/Coastline Morphology
Also affect the tidal range ..so as the tide enters the North sea .. It enters a sea which will get narrower and shallower , thus giving a funnelling effect, so resulting in increasingly high tides and tidal ranges (Dover several metres higher than Scotland)
Estuaries are also narrowing places forcing tides into the narrowing valley increasing the tidal range. River Severn = 13m Bay of Fundy 15m
Due to tidal ranges on the Rance it has the first tidal power station. The above tow have potential plans for this.
Bores are found on the Amazon and Severn due to extreme narrowing.
Mediterranean has the smallest tidal range (0.01m)

13. Storm Surges
Rapid rises in water level where water is piled up along the coastline far in excess of normal conditions.
Surges in populated areas form a natural hazard
Prone to this is North sea (associated with depressions) and Bay of Bengal (cyclones)

14. Other Factors influencing the battle for the Coast
Geology
Earthquakes
Global Warming
Cyclones
Coastal Flooding…SL change/atmospheric Change

15. Marine Geomorphology
There are a number of factors controlling coastal evolution.
The work of waves and currents, including LSD
The degree of exposure to wave action- ie trend of the coast
Variations in local geology such as rock type and structure
Long and short term changes in relative levels of land and sea
Special factors such as volcanic activity and glaciations
The effect of vegetation and animals
Human activities, particularly since the Coast Protection Act of 1949 and the use of improved marine engineering and land reclamation