Coastal Systems and Landscapes

• Abrasion : A form of erosion where loose material ‘sandpapers’ the walls and floors of the river, cliff or glacier. Also known as attrition.
• Backshore :The upper beach closest to the land, including any cliffs or sand dunes. Beach Morphology : The surface shape of the beach.
• Glacial Erosion : The removal of loose material by glacier ice, involving plucking, abrasion, crushing and basal meltwater. (necessary in the formation of Fjords).
• Coastal Recession : The retreat of a coastline due to erosion, sea-level rise or submergence.
• High-energy Environment : A coast where wave action is predominantly large destructive waves, causing much erosion.
• Hydraulic Action : The pressure of compressed air forced into cracks in a rock face will cause the rock to weaken and break apart.
• Corrosion : The acid in seawater and some types of seaweed attacks particular rock minerals, causing erosion and weakening.
• Corrasion : A form of erosion when breaking waves fling material (rocks, sediment, shells. etc) at a cliff face, physically knocking off material.
• Impermeable : A rock that does not allow rainwater to pass through.
• Isostatic : A change in local coastline or land height relative to sea level.
• Littoral Cell : A section of the coast, within which involves much sediment movement. A littoral cell is not a closed system.
• Discordant Coast : A coastline where bands of alternate geology run perpendicular to the shore.
• Dynamic Equilibrium : Where a natural system tries to achieve a balance by making constant changes in response to a constantly changing system.
• Fetch : The distance the wave travels before it reaches the coastline. Distance to the nearest land mass in the direction in which the wave travels.
• Mass Movement : The falling or movement of rock, often due to Gravity.
• Fjord : Long narrow inlet deeper in the middle section than at the mouth, created when sea levels rise relative to the land, flooding coastal glacial valleys.
• Freeze Thaw : A form of physical sub-aerial weathering where water freezes in the cracks of a rock, expands and enlarges the crack, therefore weakens the rock.
• Plant Succession : Change to a plant community due to growing conditions adapting (eg. sand dunes and salt marshes).
• Geology : The structure and arrangement of a rock.
• Sediment Cell : Sections of the coast bordered by prominent headlands. Within these sections, the movement of sediment is almost contained and the flows of sediment should act in dynamic equilibrium.
• Foreshore : The lower part of the beach covered twice a day at high tide (the part of the beach that receives the most regular wave action).
• Ria : Narrow winding inlet which is deepest at the mouth, formed when sea levels rise causing coastal valleys to flood.
• Saltation : Smaller sediment bounces along the sea bed, being pushed by currents.The sediment is too heavy to be picked up by the flow of the water.
• Sediment Budget : Use data of inputs, outputs, stores and transfers to assess the gains and losses of sediment within a sediment cell.
• SMP : Identifies all of the activities, both natural and human which occur within the coastline area of each sediment cell and then recommends a combination of four actions for each stretch of that coastline: Hold the Line, Advance the Line, Managed Realignment and No Active Intervention.
• Subaerial Processes : The combination of mass movement and weathering that affects the coastal land above sea.
• Till : Deposits of angular rock fragments in a finer medium.
• Wave Quarrying : When air is trapped and compressed against a cliff which causes rock fragments to break off the cliff over time.
• Eustatic : Global changes to sea levels.