Edexcel A-level Geography – Coasts Questions With 100% Correct Answer

Littoral Zone - ANSWER Area of shoreline where land is subject to wave action Littoral Zone Subdivisions - ANSWER - Offshore - Nearshore - Foreshore - Backshore - Beach Offshore - ANSWER Where waves begin to break in the deeper water. Friction between the waves and the sea bed may cause some distortion of the wave shape. Nearshore - ANSWER Friction between the seabed and waves distorts the wave sufficiently to cause it to break. Possible breakpoint bar formation. Foreshore - ANSWER The area between the high tide and the low tide mark. Backshore - ANSWER The area above the high tide mark, affected by wave action only during major storm events. Why are Littoral zones dynamic zones of rapid change? - ANSWER Short term - Changing inputs, through flows and outputs of energy and material. High and low tide variation, wave energy due to weather. Long term - Sea level variation due to climate change Classifying Coasts - Long Term Criteria (2) - ANSWER - Geology - Sea Level Change Classifying Coasts - Geology - ANSWER - Characteristics of land, including lithology (rock type) and structure (arrangement of rock units). - Used to classify coasts as cliffed, sandy, estuarine, concordant and discordant Cliffed Coastline (4) - ANSWER - High energy environment - Rate of Erosion exceeds Deposition. - High relief varying from a few meters to hundreds of meters - Resistant Geology Sandy Coastline (5) - ANSWER - Low Relief with Sand Dunes and Beaches - Less Resistant Geology - Low energy environment - Rate of Deposition exceeds Erosion - Constructive waves Estuarine Coastline (5) - ANSWER - Low Relief with Salt Marshes and Mudflats - Form in River Mouths - Low energy environment - Rate of Deposition exceeds Erosion - Less Resistant Geology Classifying Coasts - Sea Level Change - ANSWER - Used to Classify Coasts as Emergent or Submergent - Caused by eustatic/isostatic changes - Caused by climate change Climate Change caused by Cycles - ANSWER - Sea Levels rise and fall in 100,000 year cycles - Due to Earths Orbit - Falls for 90,000 years as ice sheets expand - Rises for 10,000 years during interglacial periods - Rises when all surface ice melts Emergent Coastline - ANSWER As Sea Levels fall, coastline land is exposed which was previously covered by the sea Submergent Coastline - ANSWER As Sea Levels rise, the land is covered Concordant Coastline - ANSWER - Alternating bands of rock that run parallel to the coastline - Also called Dalmatian Coasts Discordant Coastline - ANSWER - Alternating bands of rock that run at 90 degrees to the coastline - Also called Atlantic Coasts Classifying Coasts - Short Term Criteria (3) - ANSWER - Energy Inputs - Sediment Inputs - Advancing/Retreating Classifying Coasts - Energy Inputs (5) - ANSWER - Used to classify High/Low Energy Coastlines - Waves (Main Input) - Tides (Moon's Gravitational Pull) - Currents - Rivers Classifying Coasts - Sediment Inputs - ANSWER - Sediment is added through deposition and removed through erosion - Sediment Inputs received by waves and wind, tides, currents, mass movement and tectonic processes Classifying Coasts - Advancing/Retreating - ANSWER - Classified as Advancing/Retreating due to processes - Long Term Processes = Emergent/Submergent Coastline - Short Term Processes = Eroding/Outbuilding Coastline Outbuilding Coastline - ANSWER - Erosion < Deposition - Net gain of sediment - Coastline advances Eroding Coastline - ANSWER - Erosion > Deposition - Net loss of sediment - Coastline retreats Cliffed Coasts - UK - ANSWER - Occupy 1,000km of UK coastline - Mainly located in North and West - High relief = 427m (Conachair Cliff, Isle of Hirtha) - Low Relief = 3m (Chappel Porth, Cornwall) Weathering - ANSWER Breakdown of rock in situ, and may be a mechanical, biological or chemical process. Erosion - ANSWER Wearing away of land due to wave action Mass movement - ANSWER Downslope movement of material due to the force of gravity. Formation of Coastal Plains - ANSWER - Formed by Coastal Accretion (Continuous net deposition causes coastline to extend seawards) - Can extend biologically if plants colonise shallow water, trapping sediment Where does Coastal Accretion come from? (2) - ANSWER - Offshore sources (transported by waves, currents and tides) - Terrestrial sources (transported by rivers, glaciers, wind or mass movement) Dynamic Equalibrium - ANSWER - When Erosion = Deposition - Continuous flows of energy and material through the coast but size of stores remains unchanged Concordant coastline - Lulworth Cove - ANSWER - Resistant Portland Limestone forms a protective stratum layer parallel to sea. - Less Resistant Purbeck Limestone and Wealden Clay lie behind the Portland Limestone. - Portland limestone erodes very slowly, retreating landwards by marine undercutting. - At points where Portland Limestone is weaker, erosion managed to break through leading to the erosion of the less resistant Purback Limestone and Wealden Clay. This is done by lateral erosion. - Destructive waves have a stronger backwash so material is dragged out the cove. This can cause small beaches. - Waves continue to erode Portland Limestone. Attrition and abrasion are responsible for the erosion and the cove is widened more and more. Concordant Coastline - Croatia - ANSWER - Dalmatian coastline on the Adriatic Sea (Croatia in particular) - Formed where the geological structure consists of folds parallel to the coastline - Folded Ridges (Anticlines) and Down Folded Valleys (Synclines) are aligned parallel to the coast - Sea Level rise at the end of the Devensian glacial period caused flooding of Synclines - This produced narrow islands parallel to the coast that are seperated by narrow sea channels