Essay questions

Are you a Geography A-Level student, teacher or undergraduate looking for some practise essay questions as part of your exam revision? Try these questions out.

Periglaciation

What are the main landforms you might expect to form in a periglacial environment?

  • Rock glacier on James Ross Island

    Rock glacier on James Ross Island

    Key idea: difference between Paraglacial (recovering from glaciation; e.g. the mountains of Scotland), Periglacial (in the region around a glacier, typically in a cold environment; e.g. in Greenland or Iceland) and Permafrost (cold environment where the ground is frozen for more than 2 years in a row).

  • Periglacial landscapes are developed in a permafrost region.
  • Patterned ground, stone stripes, solifluction and gelifluction, ventifacts, rock glaciers, protalus ramparts, blockfields.
  • Frozen ground facilitates processes of slope movement (solifluction)
  • High snow fall results in landforms such as rock glaciers and protalus ramparts.
  • See Antarctic Periglacial Environments

Where are the modern permafrost environments found, and why do they form there?

What are the process-form relationships associated with periglacial environments?

Glaciers and glaciation

What are the main landforms associated with temperate depositional environments?

  • Supraglacial streams on San Jose Glacier with a small proglacial lake, James Ross Island.

    Supraglacial streams on San Jose Glacier with a small proglacial lake, James Ross Island.

    Key idea: temperate glaciers are capable of eroding, transporting and depositing large volumes of material

  • Key idea: difference between erosional and depositional landforms.
  • Depositional landforms: drumlins, moraines, sedimentary wedges
  • Key idea: ice-cored moraines are not normally associated with temperate environments
  • Ice stream depositional landforms: mega-scale glacial lineations
  • See Glacial Landforms

How do cirques form?

  • Cirques form in mountain environments
  • Snow accumulates on north-facing slopes (in the northern hemisphere) and south-facing slopes (in the southern hemisphere)
  • Snow builds up and transforms to ice under pressure
  • The glacier slips downslope under its own weight due to gravity.
  • The glacier abrades and plucks the ground underneath it, forming a bowl-shape on the side of the mountain.
  • See Types of Glacier, Glacier Flow and Glacier Processes.

Ice Streams

What is an ice stream, and what landforms are associated with ice streaming?

  • Velocity of the Antarctic Ice Sheet, using data from Rignot et al. 2011. Data set available from: Rignot, E., J. Mouginot, and B. Scheuchl. 2011. MEaSUREs InSAR-Based Antarctica Velocity Map, [list dates of data used]. Boulder, Colorado USA: NASA EOSDIS DAAC at NSIDC. http://nsidc.org/data/nsidc-0484.html

    Velocity of the Antarctic Ice Sheet, using data from Rignot et al. 2011. Data set available from: Rignot, E., J. Mouginot, and B. Scheuchl. 2011. MEaSUREs InSAR-Based Antarctica Velocity Map, [list dates of data used]. Boulder, Colorado USA: NASA EOSDIS DAAC at NSIDC. http://nsidc.org/data/nsidc-0484.html

    Key idea: ice sheets are not static, but dynamic features that are drained by fast-flowing ice streams.
  • Ice streams flow very rapidly and are responsible for most of the discharge from the Antarctic Ice Sheet.
  • See Ice Streams and Glacier Landforms.

How do glaciers flow and move? What causes different glaciers to move at different speeds?

  • Key idea: Glaciers flow under gravity
  • Key idea: difference between wet-based and cold-based glaciers
  • Key idea: Ice Streams
  • The thickness, geometry, ice temperature and valley shape combine to control the glacier’s thermal regime
  • The glacier’s velocity is controlled by steepness, accumulation rates, thermal regime, valley geometry.
  • Ice streams flow very rapidly and are fed by widespread tributaries.
  • See Glacier Flow, Glacier Processes and Ice Streams.
Ice streams in Antarctica. Courtesy of Neil Glasser.

Ice streams in Antarctica. Courtesy of Neil Glasser.

Glaciers and water

What landforms are associated with water in proglacial and subglacial environments?

  • Meltwater stream on Mendenhall Glacier, Alaska. From: Gillfoto, Wikimedia Commons

    Meltwater stream on Mendenhall Glacier, Alaska. From: Gillfoto, Wikimedia Commons

    Key idea: glaciers produce lots of meltwater, which results in key fluvioglacial landforms.

  • Proglacial landforms: sandur (braided channels), proglacial lakes, moraine-dammed lakes.
  • Subglacial landforms: Eskers, channels, Nye-Channels, subglacial canals, subglacial lakes.
  • See: Glacial Hydrology and Subglacial Lakes.

What causes glaciers to shrink?

  • Key idea: Glaciers receive snow (accumulation) and melt (ablate). If ablation exceeds acculation, the glacier will shrink.
  • Key idea: shrinking glaciers do not go backwards (see Common Misconceptions)
  • Mountain glaciers are shrinking worldwide and this results in sea level rise.

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