Glacio-fluvial landforms

• What are glacio-fluvial landforms?

  Landforms that are formed by meltwater
• When do glacial periods end?

  When global temperatures rise and fluctuate
• What are outwash materials?

  Materials deposited by meltwater
• What are the characteristics of outwash?

  Finer materials, smoother and rounder, sorted, and stratified
• When do meltwater streams have a higher discharge?

  In the summer months
• What is a jokulhlaup?


  Extreme glacial outbursts caused by geothermal/volcanic activities
• What is a Kame?

  Hills or hummocks composed of stratified sand/gravel laid down by meltwater
• What are the two types of Kames?

  Delta Kames and Kame Terraces
• Where are Delta Kames formed?

  East Lothian, Scotland
• What are Delta Kames?


  Icy land formed when meltwater streams flow through or around outwash
• How is a Delta Kame formed?


  Some are formed by englacial streams emerging at the snout of the glacier, losing energy and depositing their load
• Where are Kame Terraces found?

  Kingsdale valley of the Yorkshire Dale
• What is a Kame terrace?

  Ridges of material running along the edge of the valley floor
• How do Kame terraces form?

  Supraglacial streams on the edge of the glacier carry lateral moraine, which is deposited on the valley sides
• What is an Esker?

  A long sinuous ridge composed of stratified sand/gravel laid down by meltwater
• How is an Esker formed?

  Material is deposited in subglacial tunnels as the supply of meltwater decreases at the end of a glacial period
• What happens when deposition occurs in the formation of an Esker?

  Pressure is released and meltwater is released at the snout, moving the point of deposition backwards
• What is an outwash plain?

  A flat expanse of sediment in the pro-glacial area
• How is an outwash plain formed?

  Meltwater streams gradually lose energy as they enter lowland areas, depositing their load
• What are outwash plains drained by?

  Braided streams
• What are braided streams?

  River channels that are subdivided into more channels
• How do braided streams form?

  Braiding begins with a mid-channel bar that grows downstream, causing the channel to divide
• What causes the material deposited in braided streams to divide?

  The material deposited in the channel causes it to divide
• What happens to discharge after a flood or period of ablation in braided streams?

  Discharge decreases, causing coarser material to be dropped first
• How do temperatures affect glacio-fluvial landforms?

  As temperatures rise, more meltwater and vegetation are formed, leading to longer kames and bigger outwash plains and eskers
• What is post-glacial modification?

  Upland elevations and continued fluvial processes; isotonic readjustment due to no pressure
• What is a Kettle?

  A large depression in the ground formed by glacial deposition
• How are Kettles formed?

  When large blocks of ice become stranded and buried by deposited meltwater, leaving a depression when the ice evaporates