1. Glaciers and Glaciation
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Glaciers and Glaciation

2. GLACIERS- Rivers of Ice A large mass of moving ice and snow
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GLACIERS- Rivers of Ice A large mass of moving ice and snow
Types of glaciers
a. ______________ glaciers form in mountain valleys at high elevations
Alpine or Valley
Continental
b. ___________ glaciers form over vast areas of land.
Show glacier video from my videos

3. Extent of the Northern Hemisphere Ice Sheets
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There is evidence of at least _____ major ice ages during the last 2 million years. 4
a. The time period between ice ages is called interglacial periods.
b. The most recent ice age ended only about 11,000 years ago

5. How do these large masses of ice move?
These large ice masses begin to move down hill by gravity
It can move several centimeters to several meters a year depending on its size
The steeper the slope or the warmer the temperatures the faster the rate.
Glaciers will settle into lower lying
areas as they move.

6. Because there is friction on the sides of the glacier, the middle is the fastest, just like a river.

7. Example of an Alpine Glacier

8. Example of an Alpine Glacier

9. Example of an Alpine Glacier

10. Example of an Alpine Glacier

11. Example of an Alpine Glacier

12. Example of an Alpine Glacier

13. What happens when glaciers meet water?

14. Icebergs are large pieces of glacier that break off into the water.

15. Icebergs
When a glaciers reaches the ocean, a large piece of it may break off and float away.
Iceberg: large piece of a glacier that enters the ocean
Large amounts of sediments may be frozen into an iceberg. As the iceberg melts, these sediments sink to the ocean bottom.

16. Most of the iceberg is below the surface of the water. Only a small
portion is visible above the
water’s surface.
Many ships have crashed. Navy keeps track of iceberg locations. They travel with the ocean currents and the path of wind.
Titanic: April 1912 it struck an iceberg and sank.
2,200 people were on board, only 705 were rescued.

17. Some glacial features to look for
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Some glacial features to look for
1) U-shaped valleys
2) Parallel grooves in bedrock
3) Scratched and polished rocks
4) Erratics
5) Long, deep, glacial lakes
6) Unsorted sediments
7) Drumlins
8) Kettle lakes
Learn these terms. Whenever you see one on a test or
on the regents the answer is always "GLACIERS".

18. This is a view of a
U-shaped glacial valley.
And another

19. Grand Teton National Park
A glacier valley
Grand Teton National Park
A hanging valley, Yosemite National Park
(Photo by C. C. Plummer)

20. The picture to the right shows bedrock exposed at the Bronx Zoo.
As glaciers flow, the rocks embedded in the bottom of the glacial ice cut deep PARALLEL GROOVES in the bedrock beneath
The picture to the right shows bedrock
exposed at the Bronx Zoo.
Above more parallel grooves and
scratches in exposed bedrock.

21. Kelley’s Grooves found on Kelley’s Island, Ohio (right)
Sometimes the grooves are
very deep and dramatic such as these from the Peruvian Andes Mtns(left)
Kelley’s Grooves found on
Kelley’s Island, Ohio (right)

22. SCRATCHED and POLISHED boulders are evidence of glacial erosion.
These rocks were embedded in the ice at the bottom of a glacier. As the glacier moved over bedrock it was rocks like these that cut the parallel grooves. In the process these rocks tumbled and rolled becoming SCRATCHED and
POLISHED.
SCRATCHED and POLISHED
boulders are evidence of glacial
erosion.

23. Why is this glacier dirty?
It picks up the dark sediment as it moves over the landscape.

24. Deposition and landscape features
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3. Erratic 2. 4. 1. 6.
5. Braided stream
7. terminal moraine is a pile of unsorted glacial till, dumped where the 8.
glacier stopped advancing. Long Island is a terminal moraine
9. Esker

26. Sierra Nevada, California
(Photo by C. C. Plummer)

27. Here’s a view of a glacier showing the Terminal Moraine
It forms at the point at which the rate of melting is equal to the flow of ice. You can also see a Medial Moraine in the middle of the glacier.

28. Drumlin in New York state

29. Sometimes glacial till is deposited in mounds or hills
These are called DRUMLINS
The drumlins below are found in Scotland but similar features are found all over the northern hemisphere
Often drumlins are so large that they cannot be appreciated for what they are except when photographed from high altitudes.

30. The material transported by a glacier is
called TILL. When the glacier melts the
till is deposited in a pile. There is no
sorting as occurs when a stream slows.
UNSORTED SEDIMENTS is good evidence
of glacial deposition.
Above and to the right are
pictures of unsorted glacial
till. Material from fine silt to
large boulders are mixed
together randomly.
You live on unsorted glacial
till since Long Island is composed completely of glacial material.

31. Esker in northeastern Washington

32. As glaciers retreat & melt huge blocks of ice may remain buried in the earth. As these blocks gradually melt they leave deep depressions which can fill in with water forming "KETTLE LAKES" such as those seen above. Kettle lakes represent more evidence that a region has undergone glaciation

33. This is a satellite view of the Finger Lakes region of New York State
The finger lakes are very deep, narrow parallel lakes scooped out during
the last ices age
The glaciers movement from north to south accounts for the N-S orientation of these bodies of water.
Lakes like these are found all over the world wherever the last continental icesheet scraped and scarred the land

34. Some erratics come
to rest in strange
places.
Some are deposited closer to home
like this boulder in Eastport.

36. How was Long Island formed?
Unsorted piles of sediment called moraines were deposited when the glaciers started to melt or retreat.

37. Long Island Glacial Erosional & Depositional Landscape Features
Erratics-
Random boulders that composition doesn’t match surrounding bedrock

38. Long Island Glacial Erosional & Depositional Landscape Features
Till- piles of Unsorted Sediments. Big & smalls, round with angular particles

39. Kettle Lake- Lake Ronkonkoma

40. Long Island Moraines

41. Long Island Moraines

42. Long Island Moraines
Moraines- direct glacial deposition of unsorted sediments

43. Outwash plain deposition of layered & sorted particles such as sand that flow out of the bottom of a glacier when it melts

44. Glaciers and New York’s Economy
Thick, fertile soils developed on till and outwash – foundation of agriculture in state
Microclimate associated with Lakes
Water moderates climate
Warmer in winter, cooler in summer
Ideal for growing grapes/producing wine
Aquifers – especially in outwash
Sand and gravel for construction

45. Lastly, a very quick review of essential terms
that are likely to appear on the next exam & the regents
What kind of sediments do glaciers produce?
UNSORTED
What kind of valleys are associated with glaciers?
U-SHAPED
What term applies to a boulder deposited by a glacier?
ERRATIC
What do glaciers do to the rocks they pass over?
They cut LONG,PARALLEL GROOVES
What evidence indicates that a rock was transported by
a glacier?
It may be SCRATCHED and POLISHED

46. He Scratches out mad grooves
DJ Glacier is Ice Kold, Yo!!!!
He Scratches out mad grooves

47. Glacier Exit Card Page 27 Glacial Erosion Features Shape of Valley
V or U shaped
Evidence Left on Bedrock
Evidence Left on Particles
Direct Deposition
Sorted or unsorted particle
Deposition from meltwater
List 3 other glacial Landscape features

48. Glaciers Lab Corrections:
Top of page 2 Question #5- What general direction did the last ice sheet…
Add to bottom of page 3 Question #9- What is the main difference between sediments deposited by water and sediments deposited by glaciers?
Top of page 4 Question #16- What evidence proves that Long Island formed from glacial deposition?

49. Answers to Questions on pp 28 & 29D B A A C