Lesson 13:Louise Arner Boyd and Glaciers

Chapter 4
Glaciers
Newspaper reporters called Louise Boyd the “Ice Woman.”
One of Boyd’s greatest accomplishments was sharing her
knowledge of glaciers with the world. She helped others
understand how glaciers are formed and how they move.
Glaciers are very important to the planet. They cover about
10 percent of all the land on Earth. As much as 75 percent of all
fresh water on Earth is contained in glaciers. Glaciers are found
all over the world, although most glaciers exist in polar areas in
the Arctic and Antarctica.
How Glaciers Form
Glaciers require a certain climate to grow. They are found
in areas that receive lots of snow in the winter and remain cool
in summer. For a glacier to develop, it needs to be in a place
where the amount of snow received every winter is greater
than the amount of snow that melts in the summer. This type
of climate exists mostly in high mountain areas and near the
North and South poles.
Glaciers form when snow builds up over time. Snow that
lasts more than one year is called firn. Firn turns into ice when
new snow presses on top of it. This densely compressed ice
often takes on a bluish appearance.
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