Lecture 10 Part 3

Periglacial Processes and Patterned Ground

Periglacial environments are characterized by the presence of permafrost and freeze-thaw cycles, leading to unique landforms.

Patterned Ground

Patterned ground is a result of the freeze-thaw process, creating polygons. These polygons can manifest in various shapes, from circles to octagons.

Examples:
  • Polygons: The freeze-thaw process creates these.
  • Circles/Octagons: Patterned ground formations due to freeze-thaw actions.
  • Patechins: exhibiting oleon shapes.
  • Pingos: Ice cored hills; their discovery involved digging through the scene to understand the processes.
  • Antarctic Patterned Grounds: These form over many freeze-thaw cycles despite being frozen solid with slight summer thaws.
  • Melt Channels: Indicate water flow and subsequent freezing.

Threats and Challenges to Alpine Environments

These environments face both natural and human-induced challenges.

Natural Processes:

  • Bushfires, which clear vegetation.
  • Significant seismic activity.
  • Extreme rainfall and snowfall events.

Human Impacts:

  • Resource Development: Removal of vegetation and hydro development.
  • Recreation: Seasonal population increase in mountainous regions.
  • Mineral Exploration. *Climate Change: A significant factor affecting alpine environments.
  • Urbanization: Encroachment into alpine areas, disrupting drainage, and building in unsafe zones.
    Example of a village relocation*:Due to mountain side collapse.
  • Wildfires: posing threat to the environment.

Climate Change Impact on Alpine Environments

Climate change, induced by human activities, poses substantial threats.

  • Glacier Valley: Classic glacial valley with recent stream incision.
  • Higher temperatures: Accelerating snow and ice melt, increasing stream and river discharges.
  • Reduction of Discharge: Occurs after initial increase due to snow and ice loss.
  • Himalayas and Andes: Concerns over glacial mass loss, affecting water supply for irrigation and potable use.
  • Seasonal Flooding: Earlier onset in mountain regions, such as the U.S.
  • Polar Ice Cover: Marked decrease in the Arctic, threatening indigenous ways of life.
  • Ecological Impact: In Europe, potential loss of 60% of mountain species by 2080 under high emission scenarios.
  • Species Extinction: In New Zealand, projections indicate up to 200-300 indigenous alpine species may face extinction by 2080.
  • Pygmy Possum: Susceptible to predation due to loss of snowpack cover in Australia.
  • winter recreational industries viability variability: threatened.

Economic Impacts

  • Winter Sports Industry: A rising snow line could severely impact or doom Australia's winter sports industry compared to New Zealand.

Geohazards

  • Glacier retreat destabilizes valley walls. This can trigger:
    • Increased catastrophic slope failures.
    • Rock avalanches and rockfalls.
    • Potential risks to inhabitants.

Summary of Mountain and Ice Cap Characteristics

Mountains and ice caps are areas of high relief, creating unique biophysical and geomorphic systems. They extend environmental attributes from polar regions to equatorial mountains. For example, you find alpine environments near the Equator in places like PNG or parts of Africa, and the Andes.

Weather Creation

Mountains create unique weather patterns, such as orographic rainfall and foehn winds. These can impact planetary-scale waves, influencing the track of depressions and cold fronts.

  • Katabatic Flows: Cold winds from ice sheets like those in Antarctica and Greenland.
  • Glacial Wind: Alpine glaciers generate their own katabatic wind.

Environmental Gradients

Mountain land systems feature steep topographic, meteorological, and edaphic (soil) gradients, stimulating steep ecological gradients. These are subject to change through:

  • Tectonic activity.
  • Climate variability.
  • Human influence.

Exam Information

The exam consists of 3 parts: A, B, and C.

  • Part A: Climate Geomorphology (Miguel's section).
  • Part B: Hydrology (Richard's section).
  • Part C: Coastal (Dan's Section).
    Each Part consist of three question options available from which the candidate must provide answers for only two.

Structure

Each part contains three questions, possibly with multiple sections (a, b, c).

  • Answer all subsections when answering a question.

Requirements

  • Answer two questions from each part (total of six questions).

  • Time allocation: ~20 minutes per question.

  • No word count.
    Support answers with diagrams; especially for Richard's hydrology section:

  • Diagrams should be large and clearly labeled.

Marking

  • All questions are of equal value.
  • No multiple-choice questions; the exam consists of short answer questions with supporting diagrams that will test one's comprehension of the lecture material.

Instructions

  • Answer each part in a separate answer booklet (A, B, C).

Exam Day

  • Exam papers and answer booklets will be provided.
  • Extra booklets are available upon request.
  • Clarification on questions can be requested during the exam.
  • Allowed items: University-approved calculator.
    Email during study period, if urgent, be aware that there may be delayed or limited responses from some staff as they are away from campus.
  • In the case you can't make the exam, notify the exam board.

How to Study

  • Review previous exams.
  • Study slides.
  • Identify recurring themes.
  • Focus on key topics for in-depth study.
  • Broad reading across all slides.
  • Utilize literature review and essay topics for potential questions.