ocean motions wave action tides ocean water chemistry currents and climate table of contents
TRANSCRIPT
Ocean Motions
Wave Action
Tides
Ocean Water Chemistry
Currents and Climate
Table of Contents
Ocean Motions
What Is a Wave?
Most waves form when winds blowing across the water’s surface transmit their energy to the water.
- Wave Action
Ocean Motions
Water Motion Activity
Click the Active Art button to open a browser window and access Active Art about water motion.
- Wave Action
Ocean Motions
How Waves Change Near Shore
Near shore, wave height increases and wavelength decreases.
- Wave Action
Ocean Motions
How Waves Change Near Shore
A tsunami is usually caused by an earthquake beneath the ocean floor.
- Wave Action
Ocean Motions
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
Ocean Motions
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
Ocean Motions
Wave Characteristics
Click the Video button to watch a movie aboutwave characteristics.
- Wave Action
Ocean Motions
End of Section:Wave Action
Ocean Motions
What Causes Tides?
Tides are caused by the interaction of Earth, the moon, and the sun.
- Tides
Ocean Motions
What Causes Tides?
Spring tides and neap tides are caused by the positions of Earth, the sun, and the moon.
- Tides
Ocean Motions
Plotting Tides
This 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
Ocean Motions
Plotting Tides
Check students’ progress as they make their graphs. The number –1 should occur at the base of the y-axis.
Graphing:
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.)
- Tides
Ocean Motions
Plotting Tides
Make certain that students connect the correct points with lines.
Graphing:
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.
- Tides
Ocean Motions
Plotting Tides
During the first six days, the high-tide value increases steadily while the low-tide value decreases. On day 7, the trends reverse.
Interpreting Data:
How do the high and low tides change during the week?
- Tides
Ocean Motions
Plotting Tides
Spring tide might be occurring on day 6, when there is the greatest difference between high and low tides.
Inferring:
What type of tide might be occurring on day 6? Explain.
- Tides
Ocean Motions
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
Ocean Motions
More on Tides
Click the PHSchool.com button for an activity about tides.
- Tides
Ocean Motions
End of Section:Tides
Ocean Motions
The Salty Ocean
On average, one kilogram of ocean water contains about 25 grams of salts–that is, 35 parts per thousand.
- Ocean Water Chemistry
Ocean Motions
Calculating Density To calculate the density of a substance, divide the mass of the substance by its volume.
For example, 1 liter (L) of ocean water has a mass of 1.03 kilograms (kg).
Therefore,
Density = 1.03 kg/L
- Ocean Water Chemistry
Ocean Motions
Calculating Density
Practice Problem
A 5-liter sample of one type of crude oil has a mass of 4.10 kg. What is its density? If this oil spilled on the ocean’s surface, would it sink or float? Explain your answer in terms of density.
The density is 0.82 kg/L (4.10 kg ÷ 5.00 L). The oil would float on top of the ocean because it is less dense than ocean water.
- Ocean Water Chemistry
Ocean Motions
Changes With Depth
Conditions change as you descend to the ocean floor.
- Ocean Water Chemistry
Ocean Motions
Asking QuestionsBefore you read, preview the red headings. In a graphic organizer like the one below, ask a how or what question for each heading. As you read, write answers to your questions.
How salty is the ocean? Ocean water has an average salt concentration of 35 parts per thousand.
How does the ocean change with depth?
As you descend, the temperature decreases and the pressure increases.
Question AnswerOcean Water Chemistry
- Ocean Water Chemistry
Ocean Motions
Links on Ocean Water Chemistry
Click the SciLinks button for links on ocean water chemistry.
- Ocean Water Chemistry
Ocean Motions
End of Section:Ocean Water
Chemistry
Ocean Motions
Surface Currents
Surface currents, which affect water to a depth of several hundred meters, are driven mainly by winds.
- Currents and Climate
Ocean Motions
Deep Currents
Deep currents are caused by differences in the density of ocean water.
- Currents and Climate
Ocean Motions
Upwelling
Upwelling brings up tiny ocean organisms, minerals, and other nutrients from the deeper layers of the water. Without this motion, the surface waters of the open ocean would be very scarce in nutrients.
- Currents and Climate
Ocean Motions
Relating Cause and EffectAs you read, identify the main factors that cause surface and deep currents in the oceans. Write the information in a graphic organizer like the one below.
Surface currentsWinds
Differences in ocean-water density
Deep currents
- Currents and Climate
Cause Effect
Ocean Motions
Links on Ocean Currents
Click the SciLinks button for links on ocean currents.
- Currents and Climate
Ocean Motions
End of Section:Currents and
Climate
Ocean Motions
Graphic Organizer
Wave travels as a low swell.
How Waves Move
Wind creates a ripple on the ocean surface.
Wave touches the bottom in shallow water.
Wavelength decreases and wave height increases.
Wave breaks on shore.
Ocean Motions
End of Section:Graphic Organizer