Glaciers

By Lauren Hendershot

Click to Begin

Table of Contents: What is a glacier? How are glaciers formed? How many glaciers are found in the world? Why are glaciers blue? How fast are the glaciers disappearing and wh

y? Photos of Glaciers… Quiz Answers to Quiz References

How many glaciers are found in the world? 10% of land area is covered with glaciers. Glaciers store about 75% of the land’s

freshwater. Most of the glaciers in the United States are

found in Alaska! Most of the world’s glaciers are located in

polar regions like Antarctica and Greenland.

Table of Contents

Why are glaciers blue?

Glacial ice often appears blue when it becomes very dense. Years of compression gradually make the ice denser over time, forcing out the tiny air pockets between crystals. When glacier ice becomes extremely dense, the ice absorbs all other colors in the spectrum and reflects primarily blue, which is what we can see. When glacier ice is white that usually means there are many tiny air bubbles still in the ice.

What is a glacier?

Table of contents

Glaciers form where more snow falls than melts over a period of years, compacts into ice, and becomes thick enough to begin to move. That is, a snow patch becomes a glacier when its deepest layers begin to deform due to the weight of the overlying snow and ice.

Alaskan Glacier

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 two winters, the snow turns into firn – an intermediate state between snow and glacier ice. At this point, it is about half as dense as water. Over time, large 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 over a hundred years.

Table of Contents

Aha I learned how to use hyperlinks on power point

Photos of Glaciers

Antarctica

Gorner Glacier, Zermatt, Switzerland

Next…

Climate change in the French Alps near Chamonix. 12 Mar 2007(left) and 12 Mar(2008) right

Glaciers are disappearing due to global warming and climate change. As you can see in these two photos below the melting of this glacier over the period of only a year. This glacier changed drastically in a year.

CLIMATE CHANGE

Table of Contents

Scientists believe that Greenland, with its melting icecaps and disappearing glaciers, is an accurate thermometer of global warming.

Photograph: Uriel Sinai/ Getty Images

Table of Contents

Quiz

1. What is a glacier made of?

2. Are all glaciers blue?

3. Where are most of the glaciers that are in the U.S. found?

4. What percent of the land is covered by glaciers?

5. Are glaciers disappearing?

To Answers

Answers

1. Compressed snow2. No, some are white. Aha not all glaciers are blue!3. Alaska4. 10%5. Yes, due to climate change, global warming.

How did you do?

The End

Photos from on-linewww.wikimedia.orgwww.guardian.co.uk

“We must do our part in reducing our carbon footprint if

we want our children’s children to have the opportunity

to see glaciers in nature!”

By Lauren HendershotAha there is

something we can do about the melting

of glaciers!

Research1. NSIDC

2. WWF Blog3.Encyclopedia

4. USGS

References Page: