what is a wave? most waves form when winds blowing across the water’s surface transmit their...
TRANSCRIPT
What Is a Wave?Most waves form when winds blowing across
the water’s surface transmit their energy to the water.
- Wave Action
Water Motion Activity
Click the Active Art button to open a browser window and access Active Art
about water motion.
- Wave Action
How Waves Change Near ShoreNear shore, wave height increases and
wavelength decreases.
- Wave Action
How Waves Change Near ShoreA tsunami is usually caused by an earthquake
beneath the ocean floor.
- Wave Action
How Waves Affect the Shore As waves come into shore, water washes up the beach at an angle,
carrying sand grains. The water and sand then run straight back down the beach.
- Wave Action
What You Know
What You Learned
Using Prior KnowledgeBefore you read, look at the section headings
and visuals to see what this section is about. Then write what you know about waves in a graphic organizer like the one below. As you read, write what you learn.
1. There are waves in the ocean.2. Wind causes waves.
1. Waves move energy to the shore.2. Earthquakes cause tsunamis.
- Wave Action
Wave Characteristics
Click the Video button to watch a movie about
wave characteristics.
- Wave Action
End of Section:Wave Action
What Causes Tides?Tides are caused by the interaction of Earth,
the moon, and the sun.
- Tides
What Causes Tides?Spring tides and neap
tides are caused by the positions of Earth, the sun, and the moon.
- Tides
Plotting TidesThis table lists the
highest high tides and the lowest low tides for one week at the mouth of the Savannah River, where it meets the Atlantic Ocean in Georgia.
- Tides
Plotting TidesGraphing:
Use the data in the table to make a graph. On the horizontal axis, mark the days. On the vertical axis, mark tide heights ranging from 3.0 to –1.0 meters. (Hint: Mark the negative numbers below the horizontal axis.)
Check students’ progress as they make their graphs. The number –1 should occur at the base of the y-axis.
- Tides
Plotting TidesGraphing:
Plot the tide heights for each day on the graph. Connect the high-tide points with one line and the low-tide points with another line.
Make certain that students connect the correct points with lines.
- Tides
Plotting TidesInterpreting Data:
How do the high and low tides change during the week?
During the first six days, the high-tide value increases steadily while the low-tide value decreases. On day 7, the trends reverse.
- Tides
Plotting TidesInferring:
What type of tide might be occurring on day 6? Explain.
Spring tide might be occurring on day 6, when there is the greatest difference between high and low tides.
- Tides
Previewing VisualsBefore you read, preview Figure 11. Then
write two questions you have about the diagram in a graphic organizer like the one below. As you read, answer your questions.
Q. When do spring tides occur?
A. During the full and new moon phases
Q. What is a neap tide?
A. A smaller tide that happens at the first- and third-quarter moons
Spring and Neap Tides
- Tides
More on Tides
Click the PHSchool.com button for an activity about tides.
- Tides