The Mystery of Ocean Tides

Introduction

Introduction

Have you ever wondered why the ocean seems to rise and fall regularly? Why is the shoreline sometimes covered with water and, hours later, exposed?

These regular changes in sea level are called ocean tides. Tides are influenced mainly by the gravitational pull of the Moon and, to a lesser extent, the Sun. The position of the Earth, Moon, and Sun also affects the strength of tides.

In this WebQuest, you will become a Junior Ocean Scientist. Your mission is to investigate the mystery behind ocean tides and explain how they affect people living near the sea.

Task

Your task is to investigate what causes ocean tides and why their heights change.

Working individually or in groups, you will create a “Tides Explained” infographic, poster, or digital presentation that includes:

What ocean tides are;
How the Moon's gravity affects Earth's oceans;
The role of the Sun in producing tides;
The difference between high tide and low tide;
The difference between spring tides and neap tides;
A labeled diagram showing the positions of the Sun, Earth, and Moon during spring and neap tides; and
One practical example of why understanding tides is important to people.

Process

Follow these steps to complete your WebQuest.

Step 1 – Activate Your Prior Knowledge

Before researching, answer these questions:

What do you think causes ocean tides?
Why does the ocean sometimes rise and sometimes fall?
What do you think is the role of the Moon?
Does the Sun affect tides?

Write your initial ideas in your notebook.

Step 2 – Investigate What Causes Tides

Read the NOAA resource about the causes of tides.

https://www.nesdis.noaa.gov/about/k-12-education/oceans-coasts/what-causes-tides?utm_source

Find evidence that explains:

The Moon's gravitational pull
Tidal bulges
High tides and low tides
Why there are generally two high tides and two low tides in many coastal areas

Step 3 – Investigate the Sun's Role

Read:

https://oceanservice.noaa.gov/education/tutorial_tides/tides06_variations.html?utm_source 

Determine:

  • When do spring tides occur?
  • When do neap tides occur?
  • How does the position of the Sun and Moon affect tidal height?

Step 4 – Explore NASA's Explanation

Explore:

https://science.nasa.gov/moon/tides/?utm_source 

Pay attention to the diagrams explaining the relationship among the Earth, Moon, Sun, and tidal bulges. NASA also explains that actual tides are affected by Earth's continents, shoreline shape, ocean depth, and other factors.

Step 5 – Compare Spring and Neap Tides

Complete this comparison:

Feature Spring Tide Neap Tide
Position of Sun, Earth and Moon    
Tidal range    
High tide    
Low tide    
Lunar phases associated    

Step 6 – Create Your Product

Using your research, create a Tides Explained infographic/poster/digital presentation.

Your output must contain:

Title: The Mystery of Ocean Tides

Part 1: What are tides?

Part 2: How does the Moon cause tides?

Part 3: How does the Sun affect tides?

Part 4: Spring Tide vs. Neap Tide

Part 5: Why are tides important?

Part 6: Answer the Challenge Question.

You may use Canva, PowerPoint, Google Slides, or another available tool.

Step 7 – Share and Reflect

Present your work to the class.

Evaluation

WebQuest Rubric – 100 Points

Criteria Excellent – 25 pts Good – 20 pts Developing – 15 pts Beginning – 10 pts
Scientific Accuracy Information is accurate and clearly explains tides Mostly accurate with minor errors Some inaccurate information Many inaccuracies
Use of Evidence Uses several reliable resources and evidence Uses adequate resources Limited evidence Little or no evidence
Content & Explanation Clearly explains Moon, Sun, spring and neap tides Explains most concepts Some concepts are unclear Concepts are poorly explained
Creativity & Presentation Very clear, creative, organized, and engaging Clear and organized Somewhat organized Difficult to understand
Reflection/Challenge Question Provides a clear answer supported by scientific reasoning Provides a reasonable answer Answer has limited explanation Answer is missing or unsupported

Total: 100 points

Grading Scale

  • 90–100 – Excellent
  • 80–89 – Very Good
  • 75–79 – Satisfactory
  • Below 75 – Needs Improvement

Conclusion

Congratulations, Junior Ocean Scientist!

Through this WebQuest, you investigated one of Earth's most predictable natural phenomena—ocean tides. You learned that tides are primarily caused by the gravitational effects of the Moon and Sun, while the positions of these bodies influence the strength of tides. When the Sun, Earth, and Moon are aligned, stronger spring tides occur; when the Sun and Moon are positioned at approximately right angles, weaker neap tides occur.

Tides are more than just the movement of ocean water. They are important to fishing, boating, navigation, coastal communities, and marine ecosystems.

Credits

WebQuest Title: The Mystery of Ocean Tides
Subject: Grade 8 Science
Topic: Ocean Tides
Learning Area: Earth and Space Science

Educational Resources:

National Oceanic and Atmospheric Administration (NOAA)
NOAA Tides & Currents
NOAA National Environmental Satellite, Data, and Information Service (NESDIS)
NASA Science

The scientific information in this WebQuest is based primarily on NOAA and NASA educational resources.

Teacher Page

Target Learners: Grade 8 students

Suggested Time: 2–3 class periods

Learning Objective: Students will be able to explain the causes of ocean tides and describe how the positions of the Earth, Moon, and Sun influence tidal patterns.

Materials: Internet-connected device, Student notebook, Computer/tablet or smartphone, Canva, PowerPoint, Google Slides, or similar presentation tool, Printed materials (if needed), Teaching Strategy

This WebQuest uses an inquiry-oriented learning approach. Students investigate online resources, gather evidence, compare information, construct an explanation, and create a product demonstrating their understanding.

Teacher's Role

The teacher acts as a facilitator by:

Introducing the inquiry question.
Guiding students toward reliable resources.
Monitoring student research.
Asking probing questions.
Checking the accuracy of student explanations.
Facilitating presentations and reflection.
Assessment

Assessment is based on the 100-point WebQuest rubric. Teachers may also assess:

Participation in research
Collaboration
Quality of evidence
Scientific reasoning
Presentation skills
Reflection