How Did Rocks and Rivers Shape the Great Lakes?
The rocks in the Great Lakes Basin are of two main types: metamorphic/igneous and sedimentary. The metamorphic/igneous rocks formed long ago, when molten rock hardened and the heat changed other rocks nearby without melting them. This happened over one billion years ago. The sedimentary rocks in the Great Lakes Basin formed in an ocean that covered most of the basin beginning about 600 million years ago. Use maps skills to relate the hardness of rocks to topography and lake depth, describe the topography of the Great Lakes area, and relate the pre-glacial drainage system to the present size and position of the Great Lakes.
After completing this activity, each student will be able to:
- Relate the hardness of rocks to topography and lake depth.
- Describe the topography of the Great Lakes area.
- Relate the pre-glacial drainage system to the present size and position of the Great Lakes.
What causes the shoreline to erode?
Shorelines along the Great Lakes vary in the nature of their sediments and resistance to erosion. Natural causes of erosion include waves, currents, and effects of wind and storms on shoreline processes. Simulate the processes of shoreline erosion to investigate the ongoing changes in coastal areas.
Can You Say ‘Seiche?’
An Erie Times-News Newspapers in Education article on seiches in the Great Lakes
Lake Levels Fact Sheet
NOAA’s Great Lakes Environmental Research Laboratory discusses current and future water levels (February, 2017)
How Long Does it take Water to Flow Through the Great Lakes Basin?
Water that is in a lake does not stay in that lake. Where does the water go? The length of time that it takes for the amount of water in a lake to be completely replaced (enter the lake) is called retention time. Each of the Great Lakes has a different retention time. Construct an appropriate model of the water flow of the Great Lakes learn about retention time and replacement time, and how how Lake Superior affects the dynamics of water flow, retention time and flushing rates for the Great Lakes system.
How Does Water Move in the Great Lakes Basin?
You are familiar with the water cycle. The sun heats the surface of the earth, water evaporates, water vapor rises in the atmosphere cools and condenses, precipitation falls and then water flows in the streams, rivers, lakes and oceans. In this activity you will find out how water moves in the Great Lakes system.
When you complete this activity you will be able to:
- Locate and identify the Great Lakes on a map.
- Identify the connecting waters.
- Define water basin.
- Begin an analysis of the flow of water.
How Does Stratification Affect Water Quality?
Some lakes have water quality problems related to the layering of the lake’s waters, which occurs in the summer months. During the summer, the warm surface layer of water does not mix with the colder bottom layer of water. If a lot of algae has grown in the lake, decay of the dead algae on the lake bottom may use up all of the oxygen in the cold bottom water layer. In the fall, the surface water cools and mixes with the bottom water, resupplying the bottom water with oxygen needed for life. Learn how stratification of lake waters influences water quality and phosphorus affects oxygen levels in lakes.
When you complete the activity you will be able to:
- Describe how stratification of lake waters influences water quality.
- Explain how phosphorus affects oxygen levels in lakes.
How Well Do You Know the Great Lakes?
Many people, including a large portion of those who live close to the Great Lakes, do not a have a basic understanding of the individual characteristics of and the differences between the lakes. Since it is difficult to understand many of the Great Lakes issues, such as global climate change, pollution, and water use without a basic understanding of the lakes, this activity is designed to help visualize the differences in volume, shoreline length, human population distribution, and fish populations of the Great Lakes.
After completing this activity, students will be able to:
- Compare and contrast the differences between the Great Lakes in water volumes, length of shoreline, human population distribution, and the amount of fish harvested from each lake.
Students remove measured amounts of water from a five-gallon bucket, simulating the amount of fresh water available on earth.
Your Great Lake!
How much water does each Great Lake hold? Use this lesson as a demonstration or a classroom lesson to create visual representations of the Great Lakes, Lake Baikal, and the relationships between surface area, retention time and pollution effects.