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Weekly Online LessonOnline Lesson ArchiveGrade Level: 5-9
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Disappearing Sand
After
weeks of wind and pounding surf, Florida's famous sand beaches are disappearing.
Erosion is causing the sand to drift out to sea, leaving very little sand
on the beaches for people seeking a day of fun in the sun.
Experts say the sand will gradually return in the spring and summer, as it usually does. But winter is when many tourists head to Florida to escape the cold. Without sandy beaches, fewer tourists will come, and that will hurt Florida's economy.
To make tourists happy, some communities may end up dredging offshore to replenish the eroded beaches. It costs about $2 million to replace 75,000 cubic yards of sand along a five-mile stretch of beach.
Get ready for some fun in the sun. This week's online lesson is about sand, beaches, and ocean ecology.
Sand Grains
You
know grains of sand are tiny particles, but what exactly is sand made
of? That depends on where you are; sand can be a lot of different things.
To see and read about grains of sand, go to Sand
Grains at the Wayne's Word site. As you read you will learn what
sand looks like, how sand dunes are formed, and why sand can be white,
black, red, or other colors. Pictures on this page show you what sand
looks like when magnified. What kinds of minerals make sand? What kinds
of plant and animal life can make sand? What do the grains look like to
you?
How many grains of sand are there in the world? How would you even begin to guess? Some mathematicians at the University of Hawaii tried once. Go to the Miami Museum of Science Tripod to learn how they came up with their estimate. What was their answer?
Beach Erosion
Beach
erosion is a serious, ongoing problem for many coastal communities. For
an in-depth look at beach erosion, visit the WhyFiles site and read the
Beach
Erosion article. First you will read why the Cape Hatteras Lighthouse
was moved back a quarter of a mile to protect it from the encroaching
sea. Beaches are constantly on the move, so permanent structures like
lighthouses need to move too or be swallowed up. After reading the first
page, click More at the bottom to move on to the next page.
How bad is the problem of erosion? Why don't sea walls work? What is a breakwater and how successful is it?
Dr. Beach
Which
is the best beach in the United States? Who decides? How do officials
know if a beach is healthy or sick? And if a beach is sick, who do they
call? The answer is Dr. Beach, also known as Stephen P. Leatherman. Dr.
Leatherman is a professor at Florida International University in Miami,
but he studies beaches around the world for a living. What a great job!
To learn more about beaches, visit his web site at DrBeach.org. First click America's Best Beaches 2001 to read Leatherman's picks for the best beaches. Which beach tops the list this year?
To learn more about beach erosion, which is a problem for Florida right now, click Physical Therapy and read this page. Why is sand important to coastal communities? What causes beach erosion? What are the three major approaches to dealing with beach erosion? What is beach nourishment and how expensive is it?
Before leaving, click Prevention. This section talks about ocean hazards and staying safe when visiting a beach. What tops the list of beach perils? What are rip currents and how do you avoid them? Are sharks a big problem?
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