3 differences between Constructive and destructive waves Destructive waves are created in storm conditions, Constructive waves are created in calm weather. Destructive waves erode the coast, Constructive waves deposit material Destructive waves have a weak swash and strong backwash whereas constructive waves are the opposite

Distinguish between a berm and a storm beach Berms are small ridges that develop at the position of the mean high tide mark resulting from deposition at the top of the swash. Berms are generally created by smaller waves which have less energy so the material is smaller. At the back of the beach, very strong swash during storm conditions may deposit larger material, forming a storm beach or ridge.

Name and explain the process that causes waves to appear to bend at a headland and become parallel to the coastline This is called wave refraction. As the waves approach the coast, they travel in a straight line, parallel to each other, as they travel in the same speed. However, as the front of the headland is shallower than the front of the bay, the waves encounter more friction and it slows down. This causes the waves to refract, where the waves bend towards the headlands and bends away at the bay. As the front of the bay is deeper than the front of the headland, the waves encounter less friction and its speed remains.

4 ways in which waves erode Hydraulic action. Air may become trapped in joints and cracks on a cliff face. When a wave breaks, the trapped air is compressed which weakens the cliff and causes erosion. Abrasion. Bits of rock and sand in waves grind down cliff surfaces like sandpaper. Attrition. Waves smash rocks and pebbles on the shore into each other, and they break and become smoother. Solution. Acids contained in sea water will dissolve some types of rock such as chalk or limestone.

Explain lithology of rock affects coastal erosion Lithology refers to the physical properties of a rock such as its resistance to erosion. The lithology of a coastline affects how quickly it’s eroded. Hard rocks (e.g., Gabbro) are resistant to weathering & erosion so a coastline made of granite (e.g., Land’s End) will change slowly. Soft rocks (e.g., Limestone) are more susceptible to weathering & erosion so a coastline made of chalk (e.g., Dorset) will change relatively quickly.

Explain how rock structure affects coastal erosion A discordant coastline, where rocks are at an angle to the edge of the coastline, will erode at different rates.

Briefly define the term ‘Sub aerial processes’ Weather. Weathering is the decay and disintegration of rock in situ. There are two main types of weathering that affect the coast. These are mechanical and biological weathering.

Briefly explain the process of ‘longshore drift’ The movement of material along a coast by waves which approach at an angle to the shore but recede directly away from it.

Explain how mass movement can affect the shape of cliffs There are four different types of mass movements: Rockfall, mudflow, landslip and soil creep. Rock fall is the rapid, free-fall of rock from a steep cliff face. Rock fragments fall from the face of the cliff because of the action of gravity. This is made worse by freezing-thaw action loosening the rock. Bare, well-jointed rock is very vulnerable to rock fall – water enters the joint, freezes and expands, cracking the rock. A scree slope of fallen rock is formed at the bottom of the cliff. Mudflow occurs on the steep slopes over 10®. It’s a rapid sudden movement which occurs after periods of heavy rain. When there is not enough vegetation to hold the soil in place, saturated soil flows over impermeable sub sol, causing great devastation and endangering lives. Landslips or land slumps are occasional, rapid movements of a mass of earth or rock sliding along the concave plane. They can occur after periods of heavy rain, when the water saturates overlying rock, making it heavy and liable to slide. Undercutting of a steep slope by river or sea erosion weakens the rock above, also making a slump likely.

Give 3 characteristics of a wave cut platform Formed by destructive waves hitting against the cliff face Causes undercutting between high and low marks, creating a wave-cut notch. Notch enlarges and becomes a cave Give the sequence of events leading to a formation of a named stump Caves occur when waves force their way into cracks in the cliff face. The water contains sand and other materials that grind away at the rock until the cracks become a cave. Hydraulic action is the predominant process. If the cave is formed in a headland, it may eventually break through to the other side forming an arch. The arch will gradually become bigger until it can no longer support the top of the arch. When the arch collapses, it leaves the headland on one side and a stack (a tall column of rock) on the other. The stack will be attacked at the base in the same way that a wave-cut notch is formed. This weakens the structure and it will eventually collapse to form a stump. The stack will be attacked at the base in the same way that a wave-cut notch is formed. This weakens the structure and it will eventually collapse to form a stump.

Name two areas of the UK famous for their cliff coastline Dover Norfolk

Distinguish between each of; ripples, ridges and runnels A ripple is a slight wave or undulation on the surface of water, a ridge is a long narrow raised land formation with sloping sidesesp one formed by the meeting of two faces of a mountain or of a mountain, buttress or spur and a runnel is a small stream or a small channel for water.

Describe the characteristics of a spit Spits are also created by deposition. A spit is an extended stretch of beach material that projects out to sea and is joined to the mainland at one end. Spits are formed where the prevailing wind blows at an angle to the coastline, resulting in longshore drift. An example of a spit is Spurn Head, found along the Holderness coast in Humberside. Development of a spurn head: Longshore drift moves material along the coastline. A spit forms when the material is deposited. Over time, the spit grows and develops a hook if wind direction changes further out. Waves cannot get past a spit, which creates a sheltered area where silt is deposited and mud flats or salt marshes form.

Outline the sequence of sand dune development The wind moves sand dried out at low tide inland by saltation; An obstacle (e.g. driftwood) will halt saltation and result in the accumulation of sand Pioneer plants (e.g. marram grass) can tolerate the harsh conditions and begin to colonise the area – this encourages further deposition and the growth of the dunes; another dune forms on the seaward side of the original dune (sheltering the original dune and resulting in changing environmental conditions) A sequence of dunes forms (oldest inland) and environmental conditions continue to change due to the presence of vegetation (e.g. simple soils form due to decaying vegetation). Number and diversity of plant species on the dunes increases – eventually the climax community is reached;