Page 33 - (DK Eyewitness) Travel Guide 2017 - Alaska

A POR TR AIT OF ALASK A  31

Valley Glaciers are
created when the
weight of an icecap
is great enough to
make its edges flow
downhill, creat ing
rivers of ice that grind
away under lying rock
to form valleys. Valley
gla ciers are sub­
divided into outlet,
tidewater, and
piedmont glaciers.

Hanging glaciers in high Medial moraines are
mountain valleys may eventu­ wide, dark strips of debris and
ally become tributaries of a ground rock in the middle of
main valley glacier. valley or tide water glaciers.

Icefields, including the Juneau, Harding, and
Bagley Icefields, are formed between high
mountains when snow compresses into ice
under the weight of additional snowfall.
Liquid water beneath glaciers and shallow
portions of icefields is revealed in deep wells
called moulins, French for “mills.” Peaks rising
from icefields are called nunataks.

Growler ice is a small chunk of
floating ice that releases trapped air
as it melts, making a growling noise.

Hubbard Glacier
Located near the town of Yukutat,
Hubbard Glacier is North America’s
largest tidewater glacier, and one of
the only advancing glaciers in Alaska.
In 1986, it rammed across the mouth of
Russell Fjord in just a few days, turning
the fjord into a lake and trapping marine
life on the wrong side of the ice wall.
While the fjord has since reopened, the
Fjords, such as Prince William Sound’s College Fjord, are glacier still occasionally surges and may
narrow submarine valleys flanked by steep, glacier­carved eventually seal off the fjord.
walls that may erode into gentler slopes over time.

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