Introducing the Great Lakes

• The Great Lakes and their connecting channels form

the largest fresh surface water system on Earth.

– Visible from the moon

• One of the youngest natural features on the North American continent.

• Cover more than 94,000 square miles and drain more than twice as much land.

• Hold an estimated 6 quadrillion gallons of water, about one-fifth of the world's fresh surface water supply and nine-tenths of the U.S. supply.

• Spread evenly across the contiguous 48

states, the lakes' water would be about 9.5 feet deep.

• All five of the Great Lakes are among the world's 18 largest lakes by area and volume.

• The Great Lakes and islands within them have more than 10,000 miles of coastline.

• The Great Lakes watershed includes part

or all of eight U.S. states (Minnesota, Wisconsin, Illinois, Indiana, Michigan, Ohio, Pennsylvania and New York) and the Canadian province of Ontario.

• Today, more than 33 million people inhabit this drainage basin: more than one-tenth of the population of the United States and one-quarter of the population of Canada.

The Great Lakes Watershed

• Lake Superior is the largest of the Great Lakes in surface area and volume.

• L. Superior has the largest surface area of any freshwater lake in the world.– The lake stretches 350 miles

from west to east and 160 miles north to south.

– Its shoreline is nearly 2,800 miles long.

L. Superior is also the coldest and deepest of the five Great Lakes.

Average depths are close to 500 feet; the deepest point in the lake reaches 1,332 feet.

• Lake Michigan is the second largest of the Great Lakes by volume

• The only Great Lake entirely within the United States.

• Averages 279 feet deep– Reaches 925 feet at its deepest point

• L. Michigan is approximately 118 miles wide and 307 miles long and boasts more than 1,600 miles of shoreline, including many sandy beaches. – The world's largest freshwater sand dunes

line the shores of Lake Michigan.

• Lake Huron is the third largest of the Great Lakes by volume

• The shores of Huron extend more than 3,800 miles

– the longest shoreline of the Great Lakes, counting the shorelines of its 30,000 islands.

– Manitoulin Island in Lake Huron is the largest freshwater island in the world.

– characterized by shallow, sandy beaches and the rocky coasts of Georgian Bay.

• L. Huron is 206 miles wide and approximately 183 miles from north to south.

• Lake Huron averages a depth of 195 feet and is home to many ship wrecks,.

• Hydrologically speaking, Lakes Michigan and Huron are actually "one" Great Lake, separated by the Straits of Mackinaw.

– The Mackinac Bridge spans the straits, connecting Michigan's upper and lower peninsulas.

• Lake Erie is the shallowest of the Great

Lakes (averaging only 62 feet) and overall the smallest by volume.

• L. Erie is also exposed to the greatest effects from urbanization and agriculture.

• L. Erie measures 241 miles wide and 57 miles from north to south, and has 871 miles of shoreline.

• Because it's not as deep as the other lakes, Erie warms rapidly in the spring and summer, and is frequently the only Great Lake to freeze over in winter.

• Lake Erie is the warmest and most

biologically productive of the Great Lakes.

• The Lake Erie walleye fishery is widely considered the best in the world.

• Lake Ontario is similar to

Lake Erie in surface area and physical dimensions, but is a much deeper lake, averaging 283 feet.

• Lake Ontario holds almost four times more water than Lake Erie.

• L. Ontario ranks fourth among the Great Lakes in maximum depth, but its average depth is second only to Lake Superior.

• Lake Ontario lies 325 ft (99 m) below Lake Erie, at the base of Niagara Falls.

• Niagara Falls were always an obstacle to navigation into the upper lakes until the Trent-Severn Waterway, along with the Welland and Erie canals were built to allow ships to pass around this bottleneck.

• Assignment for Wednesday – Look up the history of the

Great Lakes or the United States

– Find out the name of the explorer or missionary to first see each of the Great Lakes.

– Name the person’s country of origin.

– Indicate the year of the discovery.