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Glaciers

Glaciers. Glaciers. A GLACIER is a large, slow-moving mass of ice , formed from compacted layers of snow, that slowly deforms and flows in response to gravity and high pressure. Glacial Features. Snowline Area of a glacier that snow/ice stays all year. Snowfield

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Glaciers

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  1. Glaciers

  2. Glaciers • A GLACIER is a large, slow-moving mass of ice, formed from compacted layers of snow, that slowly deforms and flows in response to gravity and high pressure.

  3. Glacial Features • Snowline • Area of a glacier that snow/ice stays all year. • Snowfield • Motionless mass of permanent snow and ice. • Firn • Grainy appearance of ice that melts and freezes (changes overtime).

  4. Explain what happens as snow accumulates: • Zone of Accumulation • Area of built up snow and ice on a glacier. • Zone of Wastage • Area on a glacier that melting is greater than accumulation.

  5. The growth of a glacier depends on : • The balance between snowfall received and ice lost by melting and evaporation.

  6. Glacial Features

  7. Types of Glaciers • Valley (Alpine) • form at high elevations where temperatures remain cold enough during the summer to keep the previous winter's snow from melting allowing snow and ice to accumulate.

  8. Types of Glaciers • Continental Glacier • form at high latitudes where temperatures remain cold enough during the summer to keep the previous winter's snow from melting allowing snow and ice to accumulate.

  9. Zone of Accumulation • Area of built up snow and ice on a glacier. • Zone of Wastage • Area on a glacier that melting is greater than accumulation. • Crevasses • Large cracks in a glacier (weak areas of ice).

  10. Describe the processes of glacial Advance and Retreat • Glacial Advance • occurs when the leading edge of a glacier is able to move ahead faster than it can melt. • Animation • Glacial Retreat • occurs when the melting of the front of the glacier happens faster than the forward motion of the glacier.

  11. Explain movement of Glaciers • Basal Slip • Movement of glaciers from the slipping of the bottom edge. • (ice skates) • Internal Plastic Flow • Movement in which the ice crystals flow over one another. • (melting plastic)

  12. Glacier Erosion • Plucking • It results when glacial ice freezes in the cracks and crevices of a bedrock projection and eventually pulls it loose.

  13. Glacier Erosion • Ice Wedging • A type of mechanical weathering in which rocks are broken by the expansion of water as it freezes in joints, pores, or bedding planes. Synonymous with frost wedging.

  14. Glacial Abrasion • Scratching of underlying rock.

  15. Glacial Features

  16. Glacial EROSION • Cirques • Bowl-shaped depression produced by a valley glacier.

  17. Cirques

  18. Glacial EROSION • Aretes • Sharp, jagged ridge formed between cirques.

  19. Glacial EROSION • Horns • Sharp, pyramid-like peak formed where several aretes join.

  20. Glacial EROSION • Hanging Valleys • Small abandoned glacial valley suspended on a mountain above the main glacial valley.

  21. Hanging Valley Formation

  22. Hanging Valleys

  23. Glacial EROSION • Striations • Markings on rock from glacial movement.

  24. Glacial EROSION • Kettle Lakes • Depression in a glacial outwash plain.

  25. Kettle Lakes Jackson, MI

  26. Glacial EROSION • ‘U’-Shaped Valleys • Glacial formed valley.

  27. U-Shaped Valley Formation

  28. Glacial DEPOSITION • Drumlins • Long, low tear shaped mound of till.

  29. Drumlin Formation

  30. Glacial DEPOSITION • Eskers • Long, winding ridge of gravel and coarse sand, deposited by a glacier.

  31. Esker Formation

  32. Glacial DEPOSITION • Kames • Irregular shaped hill or mound formed from glacial till.

  33. Kames

  34. MORAINES

  35. Glacial DEPOSITION • Moraines • Lateral • Deposited along side of glacier.

  36. Glacial DEPOSITION • Moraines • End/Recessional • Secondary terminal moraine formed during halt of melting glacier.

  37. Glacial DEPOSITION • Moraines • Medial • Two or more valley glaciers combine and form along center.

  38. Glacial DEPOSITION • Moraines • Terminal • Till at leading edge of melting glacier.

  39. Glacial DEPOSITION • Glacial Sediment • Erratics • Large boulder transported and deposited by a glacier.

  40. Glacial DEPOSITION • Glacial Sediment • Till • Unsorted Rock material deposited by a glacier.

  41. Till Formation

  42. Glacial DEPOSITION • Glacial Sediment • Outwash • deposit of sand and gravel carried by running water from the melting ice of a glacier and laid down in stratified deposits.

  43. Glacial Flow Lab

  44. Glacial Flow Lab

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