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Continental Glaciers
Alpine
glaciers make the landscape more
jagged through erosion, continental
glaciers make the landscape more gentle
through deposition.
Greenland and Antarctica are
the two remaining continental
glaciers (ice sheets) on Earth
today. About a million years
ago, North America had a
similar climate to Greenland.
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Within the last two million years
there was a continental glacier on
North America that advanced and
retreated at least four times. The
last glacial advance ended about
11,000 years ago
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Cape Cod
Continental Glaciers deposit
landforms
Moraines
Drumlins
Martha’s
Vineyard
Nantucket
Long Island
Eskers
Kames
Kettles
Moraines are ridges of
unsorted drift left by
glaciers.
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Drumlins are canoe-shaped
mounds of glacial till. They are
created as a continental glacier
overrides a previous moraine. They
often occur in swarms and can
show the direction of glacial
advance.
Eskers are formed from rivers
flowing within or under the glacier
which deposit material in the
tunnel. When the glacier melts a
long, narrow, sinuous mound of
material is left (like a huge mole
trail).
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Kames are cone-shaped hills
from river deposits at the
margin of a glacier.
Kettles are large depressions created
when a huge block of ice comes off
the end of a glacier and gets buried
in outwash. When the ice melts, a
kettle remains.
Nickname for Minnesota?
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Glacial Lakes
 Cirque
lakes (Tarns): a lake in a cirque (alpine
glaciers)!
 Kettle Lakes: when a kettle fills with water.
Minnesota has 10,000 of them (or so they say)!
 Moraine-dammed lake (finger lake): when an end
moraine dams a valley forming a long, thin lake.
North Star preserve used to be one.
Glacial and inter-glacial periods seem
to be cyclical. There are many
hypotheses as to why. Currently there
is much support for fluctuations in
Earth’s orbit causing periodic climatic
changes.
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