in this presentation I will discus about the glacier, different type of glacier, formation of glacier and its movement from height toward lower area and supply water to our rivers

1. http://www.free-powerpoint-templates-design.
Glacier modification
Introduction of glacier, Formation and its
movements, differernt types and its effect on
landfrom.

2. Contents
Introduction of glaciers.
01
Structure of glaciers
02
Type of glaciers
03
Formation of glaciers
04
Movements of glaciers
05
Effect on landfrom.
06

3. Presentation of giaciers
PRESENTER NAMES
 USMAN
 UMAR FAROOQ
 HADI UL HASSAN
 SUFYAN IBRAHIM
 HUZAIFA BIN GHIAS
 GROUP :A
 PRESENTED TO: MZ UMAYYA ZAFAR

4. Glaciers are made up of fallen snow that
over many years compresses into large
thickened ice masses. Glaciers form
when snow remains in one location long
enough to transform into ice. What
makes glaciers unique is their ability to
flow. Due to sheer mass, glaciers flow
like very slow rivers. Some glaciers are
as small as football fields, while others
grow to be dozens or even hundreds of
kilometers long.
WHAT IS A GLACIER?

5. continu
Presently, glaciers occupy about 10 percent of the
world's total land area, with most located in polar
regions like Antarctica, Greenland, and the
Canadian Arctic. Glaciers can be thought of as
remnants from the last Ice Age, when ice covered
nearly 32 percent of the land, and 30 percent of the
oceans. Most glaciers lie within mountain ranges
that show evidence of a much greater extent during
the ice ages of the past two million years, and more
recent indications of retreat in the past few
centuries.

6. Continue…
 This photo was taken during a flight
over the Antarctic Ice Sheet. Bird
Glacier is visible in the background,
with Darwin Glacier in the foreground.
—Credit: Courtesy Ted Scambos and
Rob Bauer

7. Structure Of glaciers:

8. What types of glaciers are there?
There are two main type:
1 .Alpine glaciers
 Cirque glaciers
 Valley glaciers
 Piedmont glaciers
 Tidewater glaciers
2.Continental ice sheet glaciers

9. Alpine glaciers
A glacier that is confined by
surrounding mountain terrain; also
called a mountain glacier. Typical of
mountain glaciers, it is constrained
on all sides by mountainous terrain.
...
Example
Alpine glaciers are found in high
mountains of every continent except
Australia (although there are many
in New Zealand). The
Gorner Glacier in Switzerland and
the Furtwangler Glacier in Tanzania
are both typical alpine glaciers.

10.  cirque glaciers
 Glaciers confined by a valley ;forms in a
cirque(semicircular basin at head of valley
formed by plucking of bedrock by glaciers
moving down hill.
 Example
The Eel Glacier on Mt. Anderson (Olympic
National Park, Washington) is an
excellent example of a cirque glacier. ... They
are called "cirque glaciers" if they originate in
small bowls with steep headwalls (cirques).

11.  Valley glaciers
 a glacier usually originating in a cirque at
a valley head or in a plateau ice cap and
flowing downward between the walls of a
valley.
 Example
 Glaciers carve a set of distinctive, steep-
walled, flat-bottomed valleys. U-
shaped valleys, fjords, and
hanging valleys are examples of the
kinds of valleys glaciers can erode.

12.  Piedmont glaciers
 a glacier formed by convergence of
the ends of valley glaciers at the base
of mountains.
 example
Malaspina Glacier is one of the most
famous examples of this type
of glacier, and is the
largest piedmont glacier in the world..

13.  Tidewater glaciers
 Tidewater glaciers are
valley glaciers that flow all the way
down to the ocean. They often calve
numerous small icebergs, which can
sometimes pose problems for shipping
lanes.
 Example
 Current examples of this retreat are
Columbia Glacier and Guyot Glacier.
The most famous recent example of
this is the large retreat of Glacier Bay
and Icy Bay glaciers in Alaska that
occurred rapidly

14. 2.Continental or ice sheet glaciers
 an ice sheet, also known as
a continental glacier, is a mass
of glacial ice that covers
surrounding terrain and is greater
than 50,000 km2 (19,000 sq mi) Ice
sheets are bigger than ice
shelves or alpine glaciers. Masses
of ice covering less than
50,000 km2 are termed an ice cap.

15. Example of continental or ice sheet
 Continental glaciers are
continuous masses of ice that
are much larger than
alpine glaciers.
Small continental glaciers are
called ice fields. Greenland and
Antarctica are almost entirely
covered with ice sheets that are
up to 3500 m (11 500 ft) thick.

16. Formation of glaciers
 Glaciers begin to form when snow
remains in the same area year-round,
where enough snow accumulates to
transform into ice. Each year, new layers
of snow bury and compress the previous
layers. This compression forces the snow
to re-crystallize, forming grains similar in
size and shape to grains of sugar.

17. How are glaciers formed?
 Glaciers begin to form when snow remains in the same area year-round, where enough
snow accumulates to transform into ice. Each year, new layers of snow bury and
compress the previous layers. This compression forces the snow to re-crystallize,
forming grains similar in size and shape to grains of sugar. Gradually the grains grow
larger and the air pockets between the grains get smaller, causing the snow to slowly
compact and increase in density. After about a year, the snow turns into firn—an
intermediate state between snow and glacier ice. At this point, it is about two-thirds as
dense as water. Over time, larger ice crystals become so compressed that any air
pockets between them are very tiny. In very old glacier ice, crystals can reach several
inches in length. For most glaciers, this process takes more than a hundred years.

18. How does a glacier form?

21. Movement of glaciers
 Glacial motion is the motion of glaciers, which can be likened
to rivers of ice. It has played an important role in sculpting
many landscapes. Most lakes in the world occupy basins
scoured out by glaciers. Glacial motion can be fast (up to 30
meters per day (98 ft/d), ] or slow (0.5 meters per year
(20 in/year) on small glaciers or in the center of ice sheets),
but is typically around 25 centimeters per day (9.8 in/d).

22. Glacier movement
 Glacier move in two ways:
basal slip:
simple response due to the gravity whereby the ice
moves downhill over bedrock and slipping over a thin layer of water .
internal plastic flow:
if you stack a LOT of ice ,the pressure
increase and the ice behaves plastically ,meaning that the lower layer will
start to deform. flow in a glacier is smooth at depth ,but in the top ~50 m ice
is brittle and cracks .

23. Continue….
 Glaciers cover about 10 percent of the land surface near Earth’s poles
and they are also found in high mountains. During the Ice Ages, glaciers
covered as much as 30 percent of Earth. Around 600 to 800 million
years ago, geologists think that almost all of the Earth was covered in
snow and ice, called the Snowball Theory. Scientists use the evidence
of erosion and deposition left by glaciers to do a kind of detective work to
figure out where the ice once was and where it came from.

24. Do Glaciers move fast or slow?
 Most glaciers move very slowly—only a few centimeters a day. Some, though, can
move 50 meters (160 feet) a day. These fast-moving rivers of ice are called
galloping glaciers.
 What part of a glacier moves the slowest?
 A glacier is slowest moving where it comes in contact with the ground. This is actually
a pervasive physical phenomena that is also true about other flowing mediums like air
moving over an airplane wing or water flowing down a river.

25. Which are the fastest and slowest
moving glaciers on Earth?
 Jakobshavn Isbrae in Greenland is generally considered to be the fastest glacier in the
world, with speeds of up to 40 metres per day. Many glaciers in Greenland and in the
Antarctic Peninsula are accelerating, which is generally attributed to warmer conditions
and more meltwater lubricating the bed of the glacier. Jakobshavn Isbrae is an ice
stream, which means that it is very large, drains a large proportion of the ice sheet, and
flows very quickly.

26. Look at the table to see the velocities
measured for some of the fastest glaciers
in the world.
Glacier Glacier type Location Speed Date measured
Jakobshavn Isbrae Ice stream Greenland Ice Sheet 12600 m per year 2003
Pine Island Glacier Ice stream West Antarctica 2075 m per year 2007-2008
Fox Glacier (seracs in
upper ice fall)
Valley glacier New Zealand 182 m per year 1991

27. Causes of glaciers
What are causes of glaciers?
 Glaciers begin to form when snow remains in the same area year-round,
where enough snow accumulates to transform into ice. Each year, new
layers of snow bury and compress the previous layers. This compression
forces the snow to re-crystallize, forming grains similar in size and shape to
grains of sugar.

28. The causes of the global warming
 Certainly you have already heard about the global warming: an issue that is
permanently damaging our planet.
 The principal causes that are bringing to the global warming of the Earth’s surface are:
 the important production of CO2;
 the intensive combustion of fossil carbon;
 The extended process of deforestation.

29. Continue….
Air pollution – Picture
of Ishan via Unsplash
Deforestation – Picture
of Ales Krivec via
Unsplash
CO2 emissions –
Picture of Martin
Adams via Unsplash

30. Main effects of global warming
 All of these causes lead to serious consequences of the global warming that are
negatively affecting the planet Hearth and its inhabitants.
 Which are the effects of this phenomenon?
 The main consequences are:
 imbalance of the temperatures and rainfalls;
 risks for the life of the men and the animals;
 Melting of the polar and mountain glaciers.

31. What are the Effects of Melting
Glaciers?
Polar bears, the first victims of the melting glaciers

32. The main consequences of the melting
of the glaciers are:
 Increase of the level of the oceans. The level of the water is growing covering a big
part of the continental areas, that is some years could be completely submerged.
 Climate change . The equilibrium of the cyclonic and anticyclonic structures and the
weather conditions are getting worse.
 Imbalance of the food chain. The habitats of several marine and terrestrial species
are changing and they are preserving the natural cycle.