2. Geography & Hydrology
The Great Lakes - Superior,
Michigan, Huron, Erie and
Ontario - are a dominant part
of the physical and cultural
heritage of North America.
Shared with Canada and
spanning more than 750 miles
(1,200 kilometers) from west to
east, these vast inland
freshwater seas provide water
for consumption,
transportation, power,
recreation and a host of other
uses.
The Great Lakes are the
largest surface freshwater
system on the Earth. Only the
polar ice caps contain more
fresh water.
3. 84%
of North America's surface
fresh water
about 21% of the world's supply
of surface fresh water
5. Lake Erie
Lake
Erie is the fourth largest lake (by surface
area) of the five Great Lakes in North America,
and the tenth largest globally. It is the
southernmost, shallowest, and smallest
by volume of the Great Lakes and therefore also
has the shortest average water residence time. It
is bounded on the north by Ontario, on the south
by Ohio, Pennsylvania, and New York, and on the
west by Michigan. The lake is named after
the Erie tribe of Native Americanswho lived along
its southern shore. The outflow from the lake
provides hydroelectric power to Canada and
the U.S. as it spins huge turbines at Niagara Falls.
6. Lake Erie
the smallest by volume
the shallowest
warms rapidly in the spring and summer
frequently freezes over in winter
average depth is only about 62 ft. (19m)
The western basin (about 20% of the lake), is very
shallow with an average depth of 24 ft. (7.4m)
retention time = 2.6 years (a measure based on the
volume of water in the lake and the mean rate of
outflow)
Most of the area around the lake is urban or
agricultural.
17 metropolitan areas with populations over 50,000
within the Lake Erie basin
Significant effects from urban and agricultural runoff
9. Lake Huron
Lake
Huron is the third largest of the lakes by
volume with 3,540 km3 (850 cubic miles) of
water. Its average depth is 59 meters (195
feet) and its maximum depth is 229 meters
(750 feet). The Saginaw River basin is
intensively farmed and contains the Flint
and Saginaw-Bay City metropolitan areas.
Saginaw Bay, like Green Bay, contains a
very productive fishery.
10. Lake Huron
the
third largest by volume
vacation homes on the shallow, sandy
beaches of Huron and along the rocky
shores of Georgian Bay
Saginaw River basin is intensively farmed
Flint and Saginaw-Bay City metropolitan
areas.
Saginaw Bay contains a very productive
fishery
13. Lake Michigan
Lake Michigan is one of the five Great Lakes of North
America and the only one located entirely within
the United States. The other four Great Lakes are shared
by the US and Canada. It is the second largest of the
Great Lakes by volume and the third largest by surface
area, after Lake Superior and Lake Huron (and is slightly
smaller than the U.S. state of West Virginia). To the east, its
basin is conjoined with that of Lake Huron through the
wide Straits of Mackinac, giving it the same surface
elevation as its easterly counterpart. Lake Michigan is
bounded, from west to east, by the U.S.
states of Wisconsin, Illinois, Indiana, and Michigan. The
word "Michigan" originally referred to the lake itself, and is
believed to come from
the Ojibwa word mishigami meaning "great water".
14. Lake Michigan
the second largest
the only Great Lake entirely within the United States
variable climate, population density and
development
northern part: colder, less developed, sparsely
populated
southern basin: more temperate, among the most
urbanized areas in the Great Lakes system.
Milwaukee and Chicago metropolitan areas have
about 8 million people, 20% of the total population of
the Great Lakes basin
Green Bay has one of the most productive Great
Lakes fisheries but receives the wastes from the world's
largest concentration of pulp and paper mills
15.
16.
17. Lake Ontario
Lake Ontario is one of the five Great Lakes of North
America. It is bounded on the north and southwest
by the Canadian province of Ontario, and on the
south by the American state of New York. Ontario,
Canada's most populous province, was named for
the lake. In the Wyandot (Huron)
language, ontarío means “Lake of Shining Waters”. It
is the last in the Great Lakes chain and serves as the
outlet to the Atlantic Ocean via the St. Lawrence
River. Lake Ontario is also the only one of the five
Great Lakes not to share a coast with the state
of Michigan.
18. Lake Ontario
second
smallest by volume
average depth 283 ft. (86m)
retention time = 6 years (a measure based
on the volume of water in the lake and the
mean rate of outflow)
urban industrial centers (Hamilton and
Toronto) on the Canadian side
U.S. shore is less urbanized, not intensively
farmed
19.
20.
21. Lake Superior
Lake Superior is the largest of the five
traditionally demarcated Great Lakes of North
America. It is bounded to the north by
theCanadian province of Ontario and the U.S.
state of Minnesota, and to the south by the U.S.
states of Wisconsin and Michigan. It is generally
considered thelargest freshwater lake in the
world by surface area. It is the world's thirdlargest freshwater lake by volume.
22. Lake Superior
the
largest by volume
the deepest and coldest
retention time = 191 years (a measure based on
the volume of water in the lake and the mean
rate of outflow)
Most of the Superior basin is forested, with little
agriculture because of a cool climate and poor
soils.
Sparse population
Relatively few pollutants enter Lake Superior,
except through airborne transport
