Glacial Landscapes Notes

Glacial Landscapes

Glacial Processes

Glacial landscapes are formed by glacial erosion and accumulation during ice ages.

  • Glacier: A large mass of ice formed by the accumulation and settling of snow.

Ice Age Conditions

  • Last Ice Age: 2 million - 12,000 years ago.
  • Average air temperature was 5-6°C lower than today.
  • Sea level was 125 m lower.
  • 30% of the Earth's surface was covered by ice.

Types of Glaciation

  1. Mountain Glaciation:
    • Occurs in mountain ranges above the snow line.
    • Examples: Alps, Himalayas, Andes; Triglav Glacier and Glacier under Skuta in Slovenia.
  2. Continental Glaciation:
    • Occurs in polar regions.
    • Large areas covered with thick ice sheets.
    • Examples: Antarctica, Greenland; during the ice age, it covered Northern, Western, and parts of Eastern and Central Europe.

Glacial Erosion

  • The immense mass exerts pressure and slides across the surface.
  • It tears off pieces of rock and carries them.
  • The detached pieces further grind the surface.

Glacial Landforms

  • U-shaped Valley: Formed when a glacier erodes and deepens a river valley.
  • Sharpened Peaks: Highest parts not covered by ice, but smoothed by glaciers.
  • Cirque (Krnica): Semicircular basin shaped beneath steep walls.
  • Fjords: Glacial valleys flooded by the sea, extending far inland.
  • Hanging Valleys

Glacial Accumulation

  • Melting glaciers cause accumulation of material.
  • Material is deposited in the form of moraines.
  • Glacial Lakes: Formed in basins behind deposited glacial material (moraines) and in basins carved out by glaciers.
    • Examples: Lake Bled, Lake Garda.
  • Moraine: Embankment of debris, sand, and mud deposited by a glacier.
  • Erratic (Balvan): Large rocks carried and deposited by a glacier.

Significance of Glacial Regions for Humans

  • Sparse population in (sub)polar regions.
  • Animal husbandry and forestry at the bottom of U-shaped valleys.
  • Transportation, agriculture, settlements, hydroelectric power plants, and tourism.

Sustainable Development

  • Tourism, transportation, economic activities.
  • Noise, built-up areas, pollution, endangering animal and plant species.

Interesting Facts

  • Glaciers hold 75% of the Earth's freshwater.
  • Important source of data for research (trapped air, gases contain data on climate change).