coasts key idea 2a

processes, flows of energy, flows of material and formation of erosion all and depositions landforms

landforms of erosion: bays + headlands

• flows of energy- wave material

• flows of material- sediment transport

• formation- coastlines with alt layers of rock have differential erosion e.g Swanage Bay

landforms of erosion: cliffs

• processes: wave erosion, weathering, mass movement

• flows of energy- wave action

• flows of material- sediment supply

• formation- waves erode at base → undercut notch → weak cliff → collapse e.g White Cliffs of Dover

landforms of erosion: shore platforms

• processes- wave erosion, abrasion, chemical weathering

• flows of energy- wave energy

• flows of material- sediment transport

• formation- cliffs retreat bc of erosion → sloping platform is exposed at low tide → abrasion + chem weathering smooth it e.g Robin Hood’s Bay

landforms of erosion: geos

• processes- wave erosion, hydraulic action

• flows of energy- wave energy

• flows of material- rock removal (eroded rock carried away, deepens + widens geo)

• formation- waves exploit faults in headland → enlarged via hydraulic action → narrow steep inlets form e.g Hutton’s Unconformity

landforms of erosion: blowholes

• processes- hydraulic action, abrasion

• flows of energy- wave energy

• flows of material- erosion + transport

• formation- sea cave roof collapse/wave force air + water through vertical crack → eventually creates hole e.g Trevor’s Hole

landforms of erosion: caves, arches, stacks, stumps

• processes- wave erosion, hydraulic action, abrasion

• flows of energy- wave action

• flows of material- sediment removal (material erode, transported by wave action)

• formation- wave erode fault in headland + enlarges (caves) → erosion continue through headland (arch) → arch collapse due to gravity (stack) → erosion reduces stack (stump) e.g Old Harry Rocks

landforms of deposition: beaches

• processes- deposition, longshore drift, swash + backwash

• flows of energy- wave energy, tidal energy (redistribute sediment)

• flows of material- sediment supply (eroded cliffs, river input, etc.)

• formation- constructive waves deposit sand → sandy formed by finer sediment + gentle slope → shingle is steeper + coarser material e.g Bournemouth

landforms of deposition: spits

• processes- longshore drift, deposition

• flows of energy- wave energy, wind energy

• flows of material- sediment supply

• formation- change in direction of coastline → longshore drift continues to deposit material beyond land, forms narrow ridge of sand extending to sea → tip of spit curves landward due to wind direction change e.g Spurn Point

landforms of deposition: onshore bars

• processes- deposition, longshore drift

• flows of energy- wave + tidal energy

• flows of material- sediment transport

• formation- spit grows across bay/inlet → connects 2 headlands → enclose body of water behind, creating lagoon → deposition reduces depth + connects land on either side e.g Slapton Sands

landforms of deposition: tombolos

• processes- deposition, longshore drift, wave refraction

• flows of energy- wave energy

• flows of material- sediment transport

• formation- waves converge around island → reduce wave energy on leeward side → sediment deposited, builds natural causeway that connects island to mainland e.g Chesil Beach

landforms of deposition: salt marshes

• processes- deposition, sedimentation, biological processes

• flows of energy- tidal energy, wave energy

• flows of material- sediment deposition

• formation- sheltered, low energy environment where fine sediment deposits → deposits form mudflat → sediment accumulate + provide substrate for plants → trap more sediment → overtime accumulation raises level of marsh → allow more plant colonisation e.g Salt Marshes of the Wash