Lake District: Valley Glacier

• Physical factors influencing landform formation: Climate

  P: Most significant factor at a regional and macro scale as it determines whether glaciers are present:

  E:

  • Present landscape of the Lake District is a result of Pleistocene glaciations as diagenesis occurred
  • Depositional landforms result from the most recent glaciation; the Loch Lamond Stadial 12,000 years ago.

  E: Diagenesis> ... > Glacial ice

  L: Global impact - changes in weather and climate patterns that can risk lives when extreme
• Physical factors influencing landform formation: Lithology

  P: Regional scale as it determines the type of landform: erosional or depositional

  1. Windermere Group - South Lake District:

  • Composed of weak sedimentary rock eg. mudstone and sandstone
  • Found in rounded hills and depositional landforms
  • Example: Kendal drumlin

  2. Borrowdale Volcanic Group (BVG) - Central Lake District:

  • Composed of igneous resistant rock eg. granite
  • Found in the highest mountains and jagged, angular erosional landforms
  • Example: Red Tarn Corrie

  L: Geology determines the type of landform, but requires a cold climate first
• Physical factors influencing landform formation: Aspect

  
  

  P: Local and micro scale as it determines where on the mountain the landform is created

  E: The majority of corries in the Lake District are North or North-East facing

  E:

  • Aspect away from sun (eg. North facing in the Northern hemisphere)> less solar radiation > decreased temperature> increased accumulation and decreased ablation > inputs exceed outputs> increased diagenesis> positive mass balance
  • Aspect faces sun > increased temperature and ablation > negative mass balance > fewer glaciers

  L: North facing aspect> increased erosion
• Physical factors influencing landform formation: Altitude

  P: Regional and micro scale as it determines the size of landforms through influencing the surrounding climate

  E: In the Lake District the temperature decreases by 1 degree/100 m

  E:

  • Increased altitude> decreased temperature> increased accumulation> valley glaciers
  • Increased latitude> increased curvature of the earth> increased dispersed radiation> decreased temperature> decreased ablation

  L: Regional scale> determines glacier types and therefore rate of erosion
• Erosional Landform examples in the Lake District:

  1. pyramidal Peak- Helvellyn 950 m
  2. Corries - Red Tarn Corrie
  3. Arete- Striding Edge
  4. Glacial Trough - Thirlmere
  5. Roche Moutonee -Norfolk Island
• Depositional Landform examples in the Lake District:

  1. Drumlins - A swarm of drumlins just south of Kendal
  2. Moraines - Blea Water Tarn (Recessional moraine)
• Changes over time to the landscape:

  1. glacial periods = landform creation
  2. inter-glacial periods = landform modification
• Glacial periods:

  Beginning:

  • Glaciers accumulate and corries start to form

  Middle:

  • Glaciers advance and reshape the previously deposited material
  • Glacial advance> increased plucking and abrasion> formation and enlargement of erosional landforms

  End/ beginning of interglacial:

  • Glaciers recede> increased deposition> formation of depositional landforms
  • Increased meltwater> formation of fluvio-glacial landforms
• Inter-glacial period:

  • Weathering breaks down material
  • Temperatures rise> increase of growing season for vegetation> depositional landforms and fluvio-glacial landforms become vegetated (eg. colonised by moss and grass)
  • Depositional landforms are further shaped by fluvial erosion and mass movement (eg. landslides/ rockfall)
• Physical factors influencing landform formation: Structure

  Cracks and weaknesses in rocks > more plucking and freee-thaw weathering occurs