Chapter19 glacial systems

4,101 views

Published on

0 Comments
3 Likes
Statistics
Notes
  • Be the first to comment

No Downloads
Views
Total views
4,101
On SlideShare
0
From Embeds
0
Number of Embeds
7
Actions
Shares
0
Downloads
204
Comments
0
Likes
3
Embeds 0
No embeds

No notes for slide
  • Insert cover image for Chapter 19 (p. 522)
  • Insert Figure 19.1
  • Insert Figure 19.2
  • Insert Figure 19.3
  • Insert Figure 19.4
  • Insert Figure 19.5
  • Insert Figure 19.6
  • Insert Figure 19.7
  • Insert Figure 19.8 and 19.9
  • Insert Figure 19.10
  • Insert Figure 19.11
  • Insert Figure 19.12
  • Insert Figure 19.13
  • Insert Figure 19.11
  • Insert Figure 19.14
  • Insert Figure 19.15
  • Insert Figure 19.16
  • Insert Figure 19.17a and 19.17b
  • Insert Figure 19.17c and 19.17d
  • Insert Figure 19.18
  • Insert Figure 19.19 and 19.20
  • Insert Figure 19.22 and 19.23a
  • Insert Figure 19.23b and 19.23c
  • Insert Figure 19.25
  • Insert Figure 19.26
  • Insert Figure 19.27
  • Insert Figure 19.28
  • Insert Figure 19.30
  • Insert Figure 19.31
  • Insert Figure 19.32
  • Insert Figure 19.33 and 19.34
  • Insert Figure 19.35 and 19.36
  • Insert Figure 19.36b and 19.37
  • Insert Figure 19.38 and 19.39
  • Insert Figure 19.40
  • Insert Figure 19.41
  • Insert Figure 19.42
  • Insert Figure 19.43
  • Chapter19 glacial systems

    1. 1. Chapter 19: Glacial Systems and Landforms Physical Geography Ninth Edition Robert E. Gabler James. F. Petersen L. Michael Trapasso Dorothy Sack
    2. 2. Glacial Systems and Landforms
    3. 3. Glacial Systems and Landforms <ul><li>Glaciers </li></ul><ul><ul><li>Large masses of flowing ice </li></ul></ul><ul><ul><li>Glacier’s role </li></ul></ul><ul><ul><ul><li>Climate indicator’s </li></ul></ul></ul><ul><ul><ul><li>Long-term storage of fresh water as ice </li></ul></ul></ul><ul><ul><ul><li>Hydrologic cycle </li></ul></ul></ul><ul><ul><li>Process of erosion, transportation, and deposition by glaciers leaves a distinctive mark </li></ul></ul><ul><ul><li>Locations: </li></ul></ul><ul><ul><ul><li>Alps, Rocky Mountains, Himalayas, Andes </li></ul></ul></ul>
    4. 4. 19.1 Glacier Formation and the Hydrologic Cycle <ul><li>Glaciers </li></ul><ul><ul><li>Masses of flowing ice that have accumulated on land </li></ul></ul><ul><ul><li>Annual input of frozen precipitation exceeded yearly loss by melting and other processes </li></ul></ul><ul><ul><li>Snowflakes </li></ul></ul><ul><ul><ul><li>Compaction, melting and refreezing </li></ul></ul></ul><ul><ul><ul><li>Firn </li></ul></ul></ul>
    5. 5. 19.1 Glacier Formation and the Hydrologic Cycle <ul><li>Glaciers </li></ul><ul><ul><li>Open systems with: </li></ul></ul><ul><ul><ul><li>Input </li></ul></ul></ul><ul><ul><ul><li>Storage </li></ul></ul></ul><ul><ul><ul><li>Output </li></ul></ul></ul><ul><ul><li>Accumulation </li></ul></ul><ul><ul><li>Ablation </li></ul></ul><ul><ul><li>Sublimation </li></ul></ul><ul><ul><li>Calving </li></ul></ul><ul><ul><li>Icebergs </li></ul></ul>
    6. 6. 19.1 Glacier Formation and the Hydrologic Cycle <ul><li>Glaciers </li></ul><ul><ul><li>Controlled by 2 basic climatic conditions: </li></ul></ul><ul><ul><ul><li>Precipitation </li></ul></ul></ul><ul><ul><ul><li>Freezing temperatures </li></ul></ul></ul><ul><ul><li>2.25% of Earth’s total water </li></ul></ul><ul><ul><li>70% of Earth’s fresh water </li></ul></ul><ul><ul><li>Moves slowly with tremendous energy </li></ul></ul>
    7. 7. 19.2 Types of Glaciers <ul><li>Two Major categories </li></ul><ul><ul><li>Alpine </li></ul></ul><ul><ul><li>Continental </li></ul></ul><ul><li>Alpine (High elevation) </li></ul><ul><ul><li>Fed by ice and snow in mountain areas </li></ul></ul><ul><ul><li>Usually occupy preexisting valleys </li></ul></ul><ul><ul><li>Valley glaciers </li></ul></ul>
    8. 8. 19.2 Types of Glaciers <ul><li>Alpine (High elevation) </li></ul><ul><ul><li>Piedmont glaciers </li></ul></ul><ul><ul><ul><li>Ice flows beyond the valley, spreading out over flatter land </li></ul></ul></ul><ul><ul><li>Cirque glaciers </li></ul></ul><ul><ul><ul><li>Smallest type </li></ul></ul></ul><ul><ul><li>Locations: </li></ul></ul><ul><ul><ul><li>Rockies, Sierra Nevada, Cascades, Olympic, Coast Range </li></ul></ul></ul><ul><ul><ul><li>Andes, Himalaya, Mount Kenya and Kilimanjaro </li></ul></ul></ul>
    9. 9. 19.2 Types of Glaciers <ul><li>Continental glaciers </li></ul><ul><ul><li>Much larger and thicker </li></ul></ul><ul><ul><li>High latitude </li></ul></ul><ul><ul><li>2 polar ice sheets </li></ul></ul><ul><ul><ul><li>Greenland </li></ul></ul></ul><ul><ul><ul><li>Antarctica </li></ul></ul></ul><ul><ul><li>Ice caps </li></ul></ul><ul><ul><li>Q: How is radial ice flow both similar to and different from the radial drainage pattern observed for some stream systems? </li></ul></ul>
    10. 10. 19.3 How do Glaciers flow? <ul><li>Movement Processes </li></ul><ul><ul><li>Internal plastic deformation </li></ul></ul><ul><ul><ul><li>Weight of overlying ice, firn, and snow causes ice crystals at depth to arrange themselves in parallel layers that glide over each other </li></ul></ul></ul>
    11. 11. 19.3 How do Glaciers flow? <ul><li>Movement Processes </li></ul><ul><ul><li>Processes at base </li></ul></ul><ul><ul><ul><li>Basal sliding </li></ul></ul></ul><ul><ul><li>Processes at top </li></ul></ul><ul><ul><ul><li>Brittle ice </li></ul></ul></ul><ul><ul><ul><li>Fractures and cracks </li></ul></ul></ul><ul><ul><ul><li>Crevasses </li></ul></ul></ul><ul><ul><ul><li>Icefalls </li></ul></ul></ul>
    12. 12. 19.4 Glaciers as Geomorphic Agents <ul><li>Glaciers remove and entrain rock particles by 2 erosion processes </li></ul><ul><ul><li>Plucking </li></ul></ul><ul><ul><ul><li>Moving ice freezes onto loosened rocks, incorporating them into the flow </li></ul></ul></ul><ul><ul><li>Abrasion </li></ul></ul><ul><ul><li>Q: How does sediment load of a glacier differ from sediment load of a stream? </li></ul></ul>
    13. 13. 19.5 Alpine Glaciers <ul><li>Zone of accumulation (input) </li></ul><ul><li>Zone of ablation (ablation exceeds accumulation) </li></ul>
    14. 14. 19.5 Alpine Glaciers <ul><li>Equilibrium line (boundary) </li></ul><ul><li>Q: What additional information would be needed to assess if the boundary between the white and blue zones on this photo is the glacier’s annual equilibrium line? </li></ul>
    15. 15. 19.5 Alpine Glaciers <ul><li>Factors influencing Equilibrium line </li></ul><ul><ul><li>Latitude </li></ul></ul><ul><ul><li>Elevation </li></ul></ul><ul><ul><li>Temperature </li></ul></ul><ul><ul><li>Amount of insolation </li></ul></ul><ul><ul><li>Mountain slope </li></ul></ul><ul><ul><li>Wind </li></ul></ul><ul><li>Q: Do any slope characteristics vary by aspect in the region where you live? </li></ul>
    16. 16. 19.5 Alpine Glaciers <ul><li>Glacier’s head </li></ul><ul><ul><li>Cirque headwall </li></ul></ul><ul><ul><li>Bergschrund </li></ul></ul><ul><li>Terminus </li></ul>
    17. 17. 19.5 Alpine Glaciers <ul><li>Equilibrium and the Glacial Budget </li></ul><ul><ul><li>Changes throughout year </li></ul></ul><ul><ul><li>Growing or shrinking: </li></ul></ul><ul><ul><ul><li>Observe terminus </li></ul></ul></ul><ul><ul><ul><li>Advance (further down valley) </li></ul></ul></ul><ul><ul><ul><li>Retreat </li></ul></ul></ul><ul><ul><ul><li>Most receding since 1890 </li></ul></ul></ul>
    18. 18. 19.5 Alpine Glaciers <ul><li>Erosional Landforms of Alpine Glaciation </li></ul><ul><ul><li>Striations </li></ul></ul><ul><ul><ul><li>Linear scratches, grooves, and gouges </li></ul></ul></ul><ul><ul><ul><li>Direction of ice flow </li></ul></ul></ul><ul><ul><li>Q: Can the direction of ice flow be determined with certainty from the evidence in this photograph? </li></ul></ul>
    19. 19. 19.5 Alpine Glaciers <ul><li>Erosional Landforms of Alpine Glaciation </li></ul><ul><ul><li>Roches moutonnées </li></ul></ul><ul><ul><ul><li>Asymmetric bedrock hills or knobs </li></ul></ul></ul><ul><ul><ul><li>Smoothly rounded on the up-side by abrasion </li></ul></ul></ul><ul><ul><ul><li>Plucking on down-ice side </li></ul></ul></ul>
    20. 20. 19.5 Alpine Glaciers <ul><li>Erosional Landforms of Alpine Glaciation </li></ul><ul><ul><li>Cirque </li></ul></ul><ul><ul><ul><li>Bowls </li></ul></ul></ul><ul><ul><ul><li>Cirque lakes </li></ul></ul></ul><ul><ul><li>Arête </li></ul></ul><ul><ul><ul><li>Jagged sawtooth-shaped spine of rock </li></ul></ul></ul>
    21. 21. 19.5 Alpine Glaciers <ul><li>Erosional Landforms of Alpine Glaciation </li></ul><ul><ul><li>Horn </li></ul></ul><ul><ul><ul><li>3 or more cirques meet </li></ul></ul></ul><ul><ul><ul><li>Pyramid shape </li></ul></ul></ul><ul><ul><ul><li>Matterhorn </li></ul></ul></ul><ul><ul><li>Col </li></ul></ul><ul><ul><ul><li>Pass formed by headward erosion of 2 cirques </li></ul></ul></ul><ul><ul><li>Glacial trough </li></ul></ul>
    22. 22. 19.5 Alpine Glaciers <ul><li>Erosional Landforms of Alpine Glaciation </li></ul><ul><ul><li>Paternoster lakes </li></ul></ul><ul><ul><ul><li>Glacier creates rock steps and excavated basins </li></ul></ul></ul><ul><ul><ul><li>This forms Lake chains </li></ul></ul></ul><ul><ul><li>Fjord </li></ul></ul><ul><ul><ul><li>Abandoned glacial trough that use to extend down to ocean </li></ul></ul></ul>
    23. 23. 19.5 Alpine Glaciers <ul><li>Erosional Landforms of Alpine Glaciation </li></ul><ul><ul><li>Hanging Valleys </li></ul></ul><ul><ul><ul><li>Waterfall </li></ul></ul></ul><ul><ul><ul><li>Yosemite Valley, CA </li></ul></ul></ul>
    24. 24. 19.5 Alpine Glaciers <ul><li>Depositional Landforms of Alpine Glaciation </li></ul><ul><ul><li>Glaciofluvial </li></ul></ul><ul><ul><li>Drift </li></ul></ul><ul><ul><li>Moraines </li></ul></ul><ul><ul><li>Lateral moraines </li></ul></ul>
    25. 25. 19.5 Alpine Glaciers <ul><li>Depositional Landforms of Alpine Glaciation </li></ul><ul><ul><li>Medial moraine </li></ul></ul><ul><ul><li>End moraine </li></ul></ul><ul><ul><li>Terminal moraine </li></ul></ul><ul><ul><li>Recessional moraine </li></ul></ul><ul><ul><li>Ground moraine </li></ul></ul><ul><ul><li>Glacial outwash </li></ul></ul>
    26. 26. 19.6 Continental Glaciers <ul><li>Ice sheets & Ice caps </li></ul><ul><ul><li>Convex lens cross section </li></ul></ul><ul><ul><li>Thick in center and thinning toward edges </li></ul></ul><ul><ul><li>Q: How is this manner of ice flow difference from and similar to that of a valley glacier? </li></ul></ul>
    27. 27. 19.6 Continental Glaciers <ul><li>Existing Continental Glaciers </li></ul><ul><ul><li>Cover about 10% of Earth </li></ul></ul><ul><ul><li>Locations: Iceland, arctic islands, Greenland ice sheet, and Antarctic Ice Sheet </li></ul></ul><ul><ul><li>Outlet glaciers </li></ul></ul>
    28. 28. 19.6 Continental Glaciers <ul><li>Existing Continental Glaciers </li></ul><ul><ul><li>Antarctic Ice Sheet </li></ul></ul>
    29. 29. 19.6 Continental Glaciers <ul><li>Existing Continental Glaciers </li></ul><ul><ul><li>Antarctic Ice Sheet </li></ul></ul><ul><ul><li>Ice sheet </li></ul></ul>
    30. 30. 19.6 Continental Glaciers <ul><li>Pleistocene Glaciation </li></ul><ul><ul><li>Began 2.4 mya and ended 10,000 years ago </li></ul></ul><ul><ul><li>Maximum extent: ice covered 1/3 of Earth </li></ul></ul><ul><ul><li>Interglacial </li></ul></ul><ul><ul><li>Sea level changes </li></ul></ul>
    31. 31. 19.6 Continental Glaciers <ul><li>Continental Glaciers and Erosional Landforms </li></ul><ul><ul><li>Ice scoured plains </li></ul></ul>
    32. 32. 19.6 Continental Glaciers <ul><li>Continental Glaciers and Depositional Landforms </li></ul><ul><ul><li>End Moraines </li></ul></ul><ul><ul><li>Till Plains </li></ul></ul><ul><ul><li>Outwash Plains </li></ul></ul><ul><ul><li>Drumlins </li></ul></ul><ul><ul><li>Eskers </li></ul></ul><ul><ul><li>Kames </li></ul></ul><ul><ul><li>Erratics </li></ul></ul>
    33. 33. 19.6 Continental Glaciers <ul><li>End Moraines </li></ul>
    34. 34. 19.6 Continental Glaciers <ul><li>Till Plains </li></ul><ul><li>Outwash Plains </li></ul><ul><ul><li>Kettles </li></ul></ul><ul><ul><li>Kettle lakes </li></ul></ul><ul><li>Drumlin </li></ul>
    35. 35. 19.6 Continental Glaciers <ul><li>Esker </li></ul><ul><li>Kames </li></ul><ul><ul><li>Kame terraces </li></ul></ul><ul><li>Erratics </li></ul>
    36. 36. 19.7 Glacial Lakes <ul><li>Pleistocene ice sheets created numerous lake basins </li></ul><ul><ul><li>Finger Lakes, NY </li></ul></ul><ul><ul><li>Great lakes, US </li></ul></ul><ul><ul><li>Lake Chelan, WA </li></ul></ul><ul><ul><li>Ice-marginal lakes </li></ul></ul>
    37. 37. 19.7 Glacial Lakes <ul><li>Lake Missoula </li></ul><ul><ul><li>Scablands </li></ul></ul><ul><ul><li>Dry waterfalls </li></ul></ul>
    38. 38. 19.7 Glacial Lakes <ul><li>Great Lakes </li></ul><ul><ul><li>World’s largest lake system </li></ul></ul>
    39. 39. 19.8 Periglacial Landscapes <ul><li>Periglacial environments </li></ul><ul><ul><li>High latitudes of N. hemisphere </li></ul></ul><ul><ul><li>Lacking year round ice or snow undergoing intense frost action </li></ul></ul><ul><ul><li>Frost action </li></ul></ul><ul><ul><ul><li>Freezing/thawing of soil </li></ul></ul></ul><ul><ul><ul><li>Frost heave and thaw settlement </li></ul></ul></ul><ul><ul><li>Patterned ground </li></ul></ul>
    40. 40. 19.8 Periglacial Landscapes <ul><li>Permafrost </li></ul><ul><ul><li>Solifluction </li></ul></ul><ul><ul><li>Ice wedge polygons </li></ul></ul><ul><ul><li>Construction Techniques </li></ul></ul><ul><ul><ul><li>Build above ground </li></ul></ul></ul><ul><ul><li>Climate Change and permafrost </li></ul></ul><ul><ul><ul><li>Thermokarst development </li></ul></ul></ul><ul><ul><ul><li>Release of Carbon Dioxide and Methane </li></ul></ul></ul>
    41. 41. Physical Geography End of Chapter 19: Glacial Systems and Landforms

    ×