Glacial processes and their landforms.

1. Glacial Processes and theirGlacial Processes and their
LandformsLandforms
A SeminarOn

2. CONTENTS:CONTENTS:
Glaciers
Glacial Processes
Glacial Landforms
Conclusion
References

3. Glaciers:Glaciers:
Glaciers are masses of ice and firn formed
by the recrystallization of snow and
meltwater which lies entirely or largely on
land and gives evidence of either present or
former movement.

4. Ahlmann’s Morphological Classification of GlaciersAhlmann’s Morphological Classification of Glaciers
Type A:
1. Continental Glaciers
2. Glacier Caps
3. Highland Glaciers
Type B:
4. Valley Glaciers
5. Transection Glaciers
6. Cirque Glaciers
7. Glacier Tongues
Type C:
8. Piedmont Glaciers
9. Foot Glaciers
10. Shelf Ice

5. Continental Glaciers
Type A:
Glacier
Caps

6. Highland Glaciers

7. Type B:Type B:
Valley
Glaciers
Transectional
Glaciers

8. Cirque
Glaciers
Glacier
Tongues

9. Type C:
Piedmont
Glaciers
Foot Glaciers

10. Shelf
Ice

11. Glacial Processes:Glacial Processes:
Glacial movement
occurs when the
growing ice mass
becomes too heavy
to maintain its rigid
shape and begins to
flow by plastic
deformation.
Flow of Glaciers:Flow of Glaciers:

12. Velocity of Glaciers:Velocity of Glaciers:
The velocity of flow of glacier ice is
influenced by a variety of factors such as
the gradient of the valley floor, the
temperature and thickness of the ice, and
the constriction caused by the valley walls.
The movement of ice over the ground in
most temperate glaciers is enhanced by a
process known as basal sliding ..

13. Glacial Erosion:Glacial Erosion:
 Abrasion
Scouring by rock fragments embedded in the
sliding ice. It produces rock flour, fine sediment
that becomes suspended in glacial lakes.
 Plucking (quarrying)
As the glacier flows over the bedrock's fractured
surface, it softens and lifts blocks of rock that
are brought into the ice.
Glacial erosion, transport and Deposition:Glacial erosion, transport and Deposition:

14. Glacial Transportation:Glacial Transportation:
Glaciers are capable of transporting very
large volumes of material over very large
distances..
The material carried by a glacier can be
classified as:
o Supraglacial- this is material carried on top of the
ice.
o Englacial - this is material carried within the
glacier itself
o Subglacial - this is material carried along in the
base of the glacier.

15. Glacial Deposition:Glacial Deposition:
Deposition of material carried by the glacier occurs
either as partial deposition as a result of a reduction
in the velocity of the glacier or complete deposition
as the glacier retreats and melts.
Glacial sediment is collectively known as drift.
Material that is deposited directly by ice is known as
till whereas material deposited by glacial meltwater,
are known as outwash deposits..

16. Glacial
Tills:
Lodgement till is where material beneath the
glacier has become lodged in the bed. When a
glacier is so overloaded with debris it smears
it onto the valley floor. An increase in ice
thickness can also increase friction beneath
the ice, causing lodgement.
Ablation till is where material is deposited as
the ice around it melts away. This may
because of solar radiation causing melting
along the margins of glaciers, or it may even
be due to the melting of basal ice due to
geothermal heating.

17. Glacial Landforms:Glacial Landforms:
Erosional Landforms:Erosional Landforms:
o Striations
o Cirques
o Glacial Horns
o Ar tesê
o Trim Lines
o U-shaped Valleys
o Roches Moutonn esé
o Overdeepenings
o Hanging Valleys.

18. o Moraines
o Eskers
o Kames
o Drumlins
o Erratics
Depositional Landforms:Depositional Landforms:

19. Lakes and ponds may also be caused by glacial
movement.
o Moraine-dammed lakes: Occurs when a stream (or snow
runoff) is dammed by glacial debris.
o Kettle lake: Depression, formed by a block of ice separated
from the main glacier, in which the lake forms.
o Glacial Lake: A lake that formed between the front of a
glacier and the last terminal moraine.
Glacial Lakes and Ponds:Glacial Lakes and Ponds:

20. Striations Cirques

21. Glacial Horns Ar tesê

22. Trim Lines U-shaped Valleys

23. Roches Moutonn esé Overdeepenings
FjordFjord
Fjord Lake
Fjord Lake

24. Hanging Valleys.

25. Moraines Eskers

26. Kames Drumlins

27. Erratics

28. Moraine-dammed lakes Kettle lakes

29. Glacial Lakes

30. Glaciers are rivers of ice in a continuous
movement.
Glacial motion occurs when the gradient
of the valley floor is sufficient for the
glacier to overcome friction.
Glacial erosion takes place by abrasion
and plucking
Glaciers can carry huge amount of
materials to vast distances.
Conclusion:Conclusion:

31. Glacial deposition can be in the form
of Lodgement Tills, Ablation Tills and
Outwash Deposits.
Glacial processes gives rise to erosional
landforms, depositional landforms and
lakes.

32. References:References:
Raina, V. K. (2006). Glaciers: The Rivers of Ice, Popular
Science Series No. 2, Geological Society of India, 6 pp.
Thornbury, W. D. (2004). Principles of Geomorphology, CBS
Publishers & Distributors Pvt. Ltd., pp. 346-382.
Websites:
http://cgz.e2bn.net/e2bn/leas/c99/schools/cgz/accounts/st
aff/rchambers/GeoBytes/AS
%20A2/A2/Glaciation.Web/glacial_deposition.htm
http://uregina.ca/~sauchyn/geog323/glacial2.html
http://en.wikipedia.org/wiki/Glacial_landform

33. Thank You!!!Thank You!!!