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.