Sediment Input- where does coastal sediment come from

• How does coastal sediment come from LSD?


  Sediment is transported from one stretch of coastline (as an output) to another stretch of coastline (as an input)
• How does coastal sediment come from GLACIERS?


  In some parts of the world eg Alaska, ice shelves CALVE (chunks of ice breaking off a glacier or ice sheet) into the sea, depositing sediment trapped within the ice
• How does coastal sediment come from CLIFF EROSION?


  • Very important locally in areas of soft/unconsolidated rocks
  • eg Holderness coast has sand and clay cliffs and rates of erosion can be up to 10m a year
• How does coastal sediment come from OFFSHORE?


  • Sediment from offshore can be transported to the coastal (littoral) zone by waves, tides and currents
  • In UK, sea levels rose at the end of the last glacial period, resulting in a considerable amount of coarse sediment being bulldozed onto south coast of england to form landforms eg barrier beaches
  • Storm surges associated with tropical cyclones and tsunami waves also responsible for inputs of sediment into the coastal system
• How does coastal sediment come from WIND?


  • In glacial or hot arid environments, wind-blown sand deposited in coastal regions
  • Sand dunes are semi-dynamic features at the coast that represent both accumulations (sinks) of sand and potential sources.
• How does coastal sediment come from RIVERS?


  • Sediment that is transported in rivers often accounts for the vast majority of coastal sediment, especially in high-rainfall environments where active river erosion occurs
  • This sediment will be deposited in river mouths and estuaries where it will be reworked by waves, tides and currents