Curriculum Filter Results
Dangerous Currents: Don’t Get Swept Away
It was the day after Christmas 2010. Dave Benjamin, a Great Lakes surfer, was winter surfing on Lake Michigan with some friends when he got into trouble. The leash to his surfboard failed, and he was out in the water, getting hit by wave after wave and was caught in a current. Water had breached his wetsuit. He was losing energy.
“I have been swimming in Lake Michigan all of my life,” said Benjamin. “All of that experience went out the window when panic set in. I came to a point where I was writing myself off. I came to the resolution that I’m not going home today.”
This lesson explores dangerous currents, including rip currents that commonly occur throughout the Great Lakes.
- Learn about the different types of dangerous currents and where they occur.
- Understand who is most at risk.
- Analyze data about rescues and deaths related to dangerous currents.
- Explain actions that will help prevent drowning.
External Curriculum Materials
Dangerous Currents 101
You may have heard about the rip tide or undertow before. These are terms that people commonly use to describe dangerous currents. However, since there are no tides in the Great Lakes (needed to form a rip tide) and currents don’t pull a person down under the water (undertow), they are a bit inaccurate. Instead, we call these dangerous currents. Also, most people know that ocean currents can be dangerous, but don’t suspect that there are such strong currents in the Great Lakes.
This lesson explores dangerous currents, including rip currents, that commonly occur throughout the Great Lakes.
- Learn what a dangerous current is and where they can be found.
- Understand the influences that contribute to dangerous current development in the Great Lakes.
- Explain several different types of dangerous currents found in the Great Lakes.
External Curriculum Materials
Out One Lake and In Another – How long does it take water to flow through the Great Lakes?
Water that is in a lake does not stay in that lake. Where does the water go? If you think about the water cycle, you will be able to figure out several places that it might go. The length of time that it takes for the amount of water in a lake to be completly replaced (enter the lake) is called retention time. Each of the Great Lakes has a different retention time. Lake Superior’s retention time is much longer than the others: 194 years compared to just 75 years for Lake Huron, for example. Since the water mixes as it pours in and out, over the course of 194 years only half of the water in Lake Superior actually leaves.
When you have completed this activity you will be able to:
- Construct an appropriate model of the water flow of the Great Lakes.
- Define the concepts of retention time and replacement time and, describe how they are different.
- Discuss how Lake Superior affects the dynamics of water flow, retention time and flushing rates for the Great Lakes system and why this is important