A untold story of Milancovitch theory and Glaciers

Glacial

1. Glacier
Notes

2. Cryosphere
–sea ice
–ice shelves
–icebergs
–ice sheets
–glaciers
–lake ice
–river ice
–snow
–permafrost
All of the frozen areas on Earth's surface where
water exists in its solid form

3. Glacial Overview
•What are they?
•How do the form?
•How do they move?
•What kinds of features do they form?

4. Glaciers
Mass of ice formed by the recrystallization of snow under
its own weight
Compacted snow becomes “firn”
More snow has to be added
than melted in the previous
year's worth of snowfall so
that it can accumulate in layers

6. Types of Glaciers
1. Ice sheets (continental glaciers) --
cover large areas of land
2. Valley (alpine) glaciers --form at
mountain tops and flow down valleys

7. Glacier: a Flowing River of Ice
•Mountain (Alpine)
•Continental (Ice Sheets)

8. How Glaciers Move

9. Glacial Zones
Zone of Accumulation
•Snowfall exceeds ablation
–Ablation–reduction in glacial ice by
sublimation, melting, or calving
Zone of Melting (Ablation) (Wastage)
•Ablation exceeds snowfall

11. Anatomy of a Glacier

12. Calving the breaking off of chunks of ice at the
edge of a glacier
http://www.businessinsider.com/largest-ice-
glacier-calving-filmed-2015-1

13. ErosionalFeatures

14. U-Shaped Valley / Fjord / Trough

16. Hanging Glacier

17. Cirque
A semicircular or amphitheater-shaped feature
created as glaciers scour back into the mountain

18. Arete
Steep-sided, sharp-edged bedrock ridge formed by
2 glaciers eroding away on opposite sides of the
ridge

19. A pyramid-shaped mountain peak
created by several glaciers
eroding away at different sides
of the same mountain
Horn

20. Glacial Striations
Lines etched in bedrock under glaciers as
individual particles of rock embedded in the
glacier scratch the bedrock

21. Cirque
Arete
Horn

22. The Matterhorn
In the Swiss alps

23. ?
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24. Glacial Deposits
•Glacial deposit is called till.
–Glaciers pick up everything in their path, even
the largest boulders.
–Large amounts of sediment can be carried long
distances by glaciers.
–for unsortedsediment that is deposited directly
by a melting glacier

25. Depositional Features

26. Moraines
•A mound or ridge of till deposited by a
glacier
•The different places along a glacier’s
advance will result in the different types
of moraines
–Lateral (Sides)
–Medial (Middle)
–Terminal (End)

27. Lateral Moraine
Unconsolidated
material deposited
along the sidesof an
alpine glacier

28. Medial Moraine
When two alpine
glaciers flow together,
their lateral moraines
join, forming a medial
(middle) moraine

30. Terminal/End Moraine
End of glacier

31. •The terminus of a glacier may remain stationary for years.
•The sediment piles up in a ridge called an end moraine.
•If this marks the furthest extent of the glacier it is a terminal
moraine.
Formation of end moraine

32. Retreating Glacier
End moraine

34. lateral moraine
medial moraine

36. Esker
Long ridge formed by
sediment deposition in
sub-glacial streams

37. Kettle Lakes
Formed by melting
ice chunks in glacial
debris

38. Drumlin
A long, narrow, smooth hill of
unstratifitedglacial till. Points in the
direction of flow.

39. Erratics
Large boulders left
behind after glaciers
retreat

40. Continental Glaciation Landform Features
Southernmost
extent of
continental
glacier

43. Retreat of South Cascade Glacier,
Washington