AQA Geography A-Level: Glacial Systems and Landscapes

Overview of Glacial Systems

• Accumulation: Addition of mass to glaciers, mainly snow at higher altitudes.
• Ablation: Loss of mass from glaciers, including meltwater, avalanches, sublimation, etc.
• Glacial Budget: Balance between accumulation and ablation determines if the glacier advances or retreats.

System Features of Glaciers

• Inputs: Precipitation such as snow, hail, and avalanches.
• Outputs: Meltwater and other ablation processes.
• Energy: Glaciers have kinetic energy that aids in erosion.
• Stores: Mass held within the glacier, such as ice or sediment.
• Flows: Transfer of mass or energy, e.g., compressional flow.
• Dynamic Equilibrium: Continuous balance of inputs and outputs.
• Feedback Loops:
  • Positive Feedback: Process that intensifies its own effects.
  • Negative Feedback: Process that counteracts changes.

Cold Environments

• Types:
  • Polar: High latitudes, consistently below freezing.
  • Alpine: High altitude with fluctuating temperatures.
  • Glacial: Areas facilitating glacial growth.
  • Periglacial: Edge environments with permafrost.
• Characteristics:
  • Cold climates with slow nutrient cycles.
  • Adapted vegetation like mosses and lichens.
  • Nutrient-poor, frozen soils.

Types of Glaciers

• Warm Based:
  • Environment: Alpine
  • Climate: Warmer temperatures, high erosion.
• Cold Based:
  • Environment: Polar
  • Climate: Consistently cold, little meltwater.

Development of Glaciated Landscapes

• Processes: Geomorphological, periglacial, and fluvioglacial.
• Erosion: Plucking, abrasion, frost action, and nivation.
• Ice Movement:
  • Internal deformation, basal sliding, compressional and extensional flow.
• Periglacial Processes:
  • Active layer, frost heave, solifluction.

Development of Landforms

• Geomorphological Landforms: Corries, arêtes, glacial troughs, etc.
• Fluvioglacial Landforms: Meltwater channels, eskers, outwash plains.
• Periglacial Landforms: Patterned ground, ice wedges, pingos.

Environmental Fragility and Human Impacts

• Cold environments are vulnerable due to slow nutrient cycles.
• Human impacts include climate change and pollution.

Management of Cold Environments

• Current strategies: Government agreements (e.g., Antarctic Treaty), sustainable tourism.
• Future strategies: Renewable energy, stricter policies, flood mitigation.