1. Glaciers

2. Glacial Ice
• A glacier begins when
snow doesn't
completely melt away
during the summer.
Each winter new snow
falls on top of the old
snow. Thick layers of
snow are gradually
compressed into glacial
ice.

3. Glacial Sediment
• Glaciers are made up of
more than just ice and
snow. They contain
water, rocks and
sediments. This can
make the ice look very
dirty.

4. Glacial Movement
• A glacier might look like a
solid block of ice, but it is
actually moving very slowly.
The glacier moves because
pressure from the weight of
the overlying ice causes it to
deform and flow.
Meltwater at the bottom of
the glacier helps it to glide
over the landscape.
Glaciers move very slowly. Most
of the time they only advance a
few centimetres to a few meters
each day. Occasionally a glacier
speeds up. This is called surging.
A surging glacier can advance
tens or even hundreds of meters
a day.

5. Glacial Meltwater
• Meltwater streams
begin in tunnels under
the ice. Meltwater
carries rock, gravel,
sand and mud away
from the glacier. The
debris is transported
and deposited by rivers
and in lakes.

6. Ice Shelves
• Ice shelves form when
glaciers reach the sea and
begin to float. The Ross
Ice Shelf in Antarctica is a
famous ice shelf.
• Chunks of ice can break
off an ice shelf or a
glacier that reaches the
sea. This is called calving.
The ice chunks form
icebergs up to 250 km
long and 100 km wide.

7. Moraines
• Piles and ridges of
sediment deposited at
the edges and front of
glaciers are called
moraines.
• Lateral moraines form
along the sides of alpine
glaciers.

8. • A medial
moraine forms
where two
glaciers join
together.

9. There are different types of glaciers:
• Alpine glaciers begin high
up in the mountains in
bowl-shaped hollows called
cirques. As the glacier
grows, the ice slowly flows
out of the cirque and into a
valley. Several cirque
glaciers can join together to
form a single valley glacier.
When valley glaciers flow
out of the mountains, they
spread out and join to form
a piedmont glacier.

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