Changing Landscapes uk

• Mechanical weathering: breakdown of rocks into smaller pieces by physical means without changin its chemical composition
• Chemical weathering: Breakdown of rock due to the action of water, air or other chemicals
• Salt weathering is the process by which salt crystals form on the surface of rocks and soil. In cracks and holes, the salt crystals can grow and eventually break down the rock.
• Biological weathering involves plants growing through cracks in rocks and breaking them apart as they expand with moisture.
• Freeze-thaw weathering occurs when water seeps into small gaps between grains of sandstone, freezes, expands and breaks up the rock.
• Carbonation weathering is weathering of limestone and chalk by acidic rainwater
• Mass movements are the movement of material downhill due to gravity causes coasts to retreat rapidly
• Slides are material shifts ina straight line
• Slumps are material shifts with a rotation
• Hydraulic action is the force of water pushing against the rock face and eroding it
• Abrasion: the process of scraping or wearing something away by friction
• Attrition: eroded particles smash into each other/ break into smaller fragments, edges round off
• Solution (erosion): acids contained in sea water dissolve rocks and minerals
• Destructive waves are waves that carry out erosional processes (high frequency, strong backwash)
• Longshore drift is the transport of sediment and water parallel to the beach in a zigzag movement along the shore.
• What do prevailing winds do?

  Determine direction longshore drift, coast vulnerable to erosion, coastal retreat
• prevailing winds


  winds that blow in the same direction over large areas of Earth
• Storms and coastal dynamics

  High energy destructive waves, costal retreat, intense rainfall
• Weather impact on coast

  can alter landscape, increase salt weathering
• Concordant coastline


  Have alternating layers of hard and soft rock that run parallel to the coast, eroded at same rate (fewer erosional landforms)
• Discordant coastline


  the layers of rock are perpendicular to the direction of the coastline.
• Discordant coast


  a coastline created when alternating hard and soft rocks occur at right angles to the coast, and are eroded at different rates (bays, headlands)
• Joints and faults


  weaknesses in rock
• Constructive waves


  waves that carry and deposit sand and other materials (strong swash weak backwash)
• Low energy waves/coasts


  Stretches of the coasts, waves are less powerful, Deposition, very little erosion (landforms like beaches, spits and coastal plains)
• When is the amount of deposited material increased?

  Lot's of erosion on the cost -> lot's of material available Lots of transportation into area
• When are beaches build up?

  Amount of deposition greater than amount of erosion
• Deposition


  the dropping or settling of eroded materials
• Solution (transportation)


  Soluble materials dissolve in the water and are carried along
• Suspension (transportation)


  Small particles like silt and clay are carried along by the water
• Saltation (transportation)


  Small pebbles and stones are bounced along the river bed
• Traction (transportation)


  Large boulders and rocks are rolled along the river bed
• longshore drift/transport

  water and sediment transport parallel to beach in zigzag movement
• transportation


  The movement of eroded material
• Swash


  The movement of water up the beach after a wave breaks.
• Backwash


  The backward movement of water down a beach when a wave has broken
• Destructive waves


  Waves that carry out erosional processes (high frequency, high/steep, strong backwash)
• Solution (erosion)

  Acids contained in sea water will dissolve some types of rock such as chalk or limestone.
• attrition


  Eroded particles smash into each other/break into smaller fragments, edges rounded off
• Abrasion


  a wearing away or rubbing away by friction; a scraped or worn area