Waves Name:_________________________________
Reading Guide Page 236 – 237
1. What causes tsunamis?
2. According to this video clip, which ocean has the highest risk of tsunamis? Why? http://archives.cbc.ca/science_technology/natural_science/clips/10520/
3. What creates most waves on lakes and oceans?
4. Label the parts of the wave by writing each letter on the diagram:
A) Trough B) Wavelength C) Crest
5. Explain how you would move if you were floating in waves on the ocean.
6. Write the letter in the blank to match each description.
____ Winds push the top of the wave forward while water returning from the beach pushes at the bottom. The wave curls and breaks.
____ The circular motion of the water is smaller at greater depths.
____ As the waves move into shallow water, the bottom layers move more slowly and the wave begins to topple over.
7. List some benefits of waves.
8. List some problems due to waves.
Video “Waves, Beaches and Coasts”
1. What geologic processes cause change on the coast?
2. What percentage of the world’s population lives near the coast?
3. Longshore drift: Where does most sand come from?
4. How are dams useful?
5. What problems can occur as a result of damming a river?
6. Examine the photo below on page 237 in your textbook. How are the two structures different? How do they each affect the beach?
Try This: Making Waves
1. Using wet sand, build a sloping beach about 5 cm high along one edge of a plastic tray.
2. Pack the sand tightly.
3. Slowly and carefully add water to a depth of 2-3 cm.
4. Use a ruler to make waves by holding the length of the ruler in the water, and making small pushing motions every 2 seconds. Make waves that strike the beach “head – on”.
5. Make observations, and then repair your beach if needed.
6. Try waves that strike the beach at an angle.
Make notes of your observations (Describe what you see) below.