The Flat Green pastures of the Severn Estuary do not inspire the awe of the rocky Cornish coast or the majestic Scottish Islands orindeed the feelings of Englishness at seeing the White Cliffs of Dover but has much beauty nevertheless. The British coastline offerssome of the best places in the country to visit - care must be taken on cliffs and on the shoreline - rocks and rock pools are often very slippy and in places it's very easy to get cut off by fast approaching tides. The Royal National Lifeboat Institution and the Coastguard patrol the coast butcommon sense should always be used.The classic atlas ‘picture’ of the British Isles is etched upon the mind from early schooldays but is not as it would haveappeared a few million years ago. Much erosion has taken place, indeed the British Isles were once connected to the European mainland.The erosion of the land by the constant battering of the sea's waves, primarily by the processes of hydraulic action, corrasion, attrition and corrosion. Hydraulic action, occurs when the force of the waves compresses air pockets in coastal rocks and cliffs. The air expands explosively, breaking the rocks apart.Rocks and pebbles flung by waves against the cliff face wear it away by the process of corrasion. Chalk and limestone coasts are often broken down by solution (also called corrosion). Attrition is the process by which the eroded rock particles themselves are worn down, becoming smaller and more rounded.Frost shattering (or freeze-thaw), caused by the expansion of frozen sea water in cavities, and biological weathering, caused by the burrowing of rock-boring molluscs, also result in the breakdown of the coastal rock.Where resistant rocks form headlands, the sea erodes the coast in successive stages. First it exploits weaknesses, such as faults and cracks, in cave openings and then gradually wears away the interior of the caves until their roofs are pierced through to form blowholes. In time, caves at either side of a headland may unite to form a natural arch. When the roof of the arch collapses, a stack is formed. This may be worn down further to produce a stump and a wave-cut platform.With larger areas of land such as that around the Isle of Wight, the course of the old Solent River ran through what is now Poole Harbour and entered the English Channel to the East of what is now the Island. Constant battering of the waves between the Isle of Purbeck and the Isle of Wight has eroded the coastline where the rock is younger and softer. A band of white chalk running between younger and older rock formations can clearly be seen showing where Old Harry Rocks on the mainland were joined to the Needles on the Isle of Wight.Beach erosion occurs when more sand is eroded and carried away from the beach than is deposited by longshore drift. Beach erosion can occur due to the construction of artificial barriers, such as groynes, or due to the natural periodicity of the beach cycle, whereby high tides and the high waves of winter storms tend to carry sand away from the beach and deposit it offshore in the form of bars. During the calmer summer season some of this sand is redeposited on the beach.In Britain, the southern half of the coastline is slowly sinking (on the east coast, at the rate of half a centimetre a year) whilst the northern half is rising, as a result of rebounding of the land mass (responding to the removal of ice from the last Ice Age). Some areas may be eroding at a rate of 6 m / 20 ft per year. Current opinion is to surrender the land to the sea, rather than build costly sea defences in rural areas. In 1996, it was reported that 29 villages had disappeared from the Yorkshire coast since 1926 as a result of tidal battering.Many stretches of coastline are so severely affected by erosion that beaches are swept away, threatening the livelihood of seaside resorts, and buildings become unsafe.To reduce erosion, several different forms of coastal protection may be employed. Structures such as sea walls attempt to prevent waves reaching the cliffs by deflecting them back to sea. Such structures are expensive and of limited success. Adding sediment (beach nourishment) to make a beach wider causes waves to break early so that they have less power when they reach the cliffs. Wooden or concrete barriers called groynes may also be constructed at right angles to the beach in order to block the movement of sand along the beach (longshore drift).Longshore Drift is the movement of material along a beach. When a wave breaks obliquely, pebbles are carried up the beach in the direction of the wave (swash). The wave draws back at right angles to the beach (backwash), carrying some pebbles with it.In this way, material moves in a zigzag fashion along a beach.Longshore drift is responsible for the erosion of beaches and the formation of spits (ridges of sand or shingle projecting into the water). Attempts are often made to halt longshore drift by erecting barriers, or groynes, at right angles to the shore.
The Coastline around the UK stretches for some 6,000 miles - a coast of contrasts as the scenery changes from Estuaries, Shingle beaches, Salt Marshes, Sand Dunes, Rugged Cliffs, Sandy Beaches and Rocky Shores to Industrial Harbours and Oil Refineries.