Introduction
Have you ever built a sandcastle at the beach, only to watch it slowly disappear under the waves a few hours later — even though it never rained? Or noticed that a pier that towered over the water in the morning seems half-submerged by afternoon?
You've witnessed one of the ocean's most powerful, predictable rhythms: the tides. Every single day, trillions of gallons of seawater rise and fall along coastlines around the world, pulled by forces you can't even see — the gravity of the Moon and the Sun, millions of kilometers away. Coastal communities plan their fishing trips, ferry schedules, and even emergency evacuations around this rhythm. Understanding tides isn't just a science fact to memorize — it's a real skill that fishers, sailors, surfers, and coastal engineers use every day.
In this WebQuest, you'll become a Junior Tide Scientist. Your mission: uncover what causes tides, learn to read real tide data, and create a tide forecast guide for a coastal town that's counting on you to get it right.
Task
Working individually or in pairs, you will research how and why ocean tides occur, then produce a Tide Forecast Guide (a one-page illustrated guide or short slide presentation) for a fictional coastal town council. Your guide must include:
- An explanation, in your own words, of why tides happen (the role of the Moon's and Sun's gravity).
- The difference between spring tides and neap tides, and when each occurs.
- A labeled diagram showing the Earth, the Moon, and the tidal bulge.
- Real tide data from a specific coastal location, used to predict the best and worst times for a boat launch that week.
- One real-world consequence of tides for the town (e.g., fishing schedules, flooding risk, ferry timing).
End product: A one-page illustrated guide OR a 5-slide presentation, submitted through the class LMS.
Process
Follow these steps to complete your Tide Forecast Guide:
Step 1 — Understand the Cause (individual research, ~20 minutes)
Read the NOAA Tides and Water Levels tutorial to answer: What causes tides? Why are there usually two high tides and two low tides each day? Take notes in your own words — do not copy sentences directly from the site.
Step 2 — Explore the Moon's Pull (simulation, ~20 minutes)
Open the PhET "Gravity and Orbits" simulation. Experiment with the Earth-Moon system. Observe how changing the distance between Earth and the Moon affects gravitational pull. Sketch what you notice — this will help you draw your diagram later.
Step 3 — Learn Spring vs. Neap Tides (reading + short video, ~15 minutes)
Using your tutorial notes and a short video (search "spring tide neap tide animation" and choose one from a science or education channel), identify when spring tides happen, when neap tides happen, and why they differ in strength.
Step 4 — Read Real Tide Data (data analysis, ~20 minutes)
Go to the NOAA Tides & Currents website. Choose a coastal station (your teacher may assign one, or pick a coastal city you're curious about). Identify the times of the highest and lowest tides for the current week.
Step 5 — Draw Your Diagram (~15 minutes)
Using what you learned in Steps 1–2, draw and label a diagram showing the Earth, the Moon, the direction of gravitational pull, and the tidal bulge on both the near and far sides of Earth.
Step 6 — Build Your Guide (~30 minutes)
Combine everything into your one-page guide or 5-slide presentation. Make sure all 5 required elements from the Task are included.
Step 7 — Submit and Reflect
Submit your guide through the class LMS, then complete the reflection question in the Conclusion section.
Evaluation
Your Tide Forecast Guide will be scored using the rubric below:
| Criteria | 4 – Excellent | 3 – Good | 2 – Developing | 1 – Beginning |
|---|---|---|---|---|
| Explanation of tide causes | Clear, accurate, in own words | Mostly accurate, minor gaps | Some inaccuracies or copied text | Missing or incorrect |
| Spring vs. neap tides | Clearly distinguished with correct timing | Mostly correct | Confused or incomplete | Missing |
| Diagram | Accurate, clearly labeled, shows understanding | Mostly accurate, minor labeling issues | Incomplete or unclear | Missing |
| Use of real tide data | Correctly reads and applies data to make a sound prediction | Mostly correct interpretation | Misreads data or unclear prediction | Missing or incorrect |
| Real-world connection | Thoughtful, specific, well-explained | Reasonable connection | Vague or generic | Missing |
Scoring scale: 18–20 = A · 14–17 = B · 10–13 = C · Below 10 = needs revision and resubmission
Conclusion
Congratulations — you've just done what real coastal scientists, fishers, and engineers do every day: used gravity, data, and observation to predict something invisible but powerful. Tides remind us that forces millions of kilometers away shape everyday life for people living along every coastline on Earth.
Reflection question (submit with your guide): What was the most surprising thing you learned about tides, and can you think of another everyday phenomenon that might be caused by a force you can't directly see?
Credits
This WebQuest was created as part of an educational technology course assignment. The WebQuest model itself was originally developed by Bernie Dodge and Tom March at San Diego State University.
Data and content sources referenced:
- National Oceanic and Atmospheric Administration (NOAA), Center for Operational Oceanographic Products and Services — Tides and Water Levels Tutorial and real-time tide data (tidesandcurrents.noaa.gov)
- University of Colorado Boulder, PhET Interactive Simulations — "Gravity and Orbits" simulation
Instructional design references:
- Spector, J. M. (2015). Foundations of Educational Technology: Integrative Approaches and Interdisciplinary Perspectives (2nd ed.). Routledge. — Used for grounding the learning objective and instructional strategy behind this WebQuest.
Teacher Page
Title: Riding the Rhythm: Investigating Ocean Tides
Author: [Your name]
Subject Area: Earth Science
Grade Level: Grade 8
Time Required: Approximately 2 class periods (one for research/simulation steps, one for building and submitting the guide)
Learning Objective:
Students will be able to explain how the gravitational pull of the Moon and Sun causes ocean tides, and predict the approximate timing of high and low tides using real tide data.
Standards Addressed:
- NGSS MS-ESS1-2 — Develop and use a model to describe the role of gravity in the motions within galaxies and the solar system (several state frameworks, including Massachusetts, explicitly extend this standard's scope to include the role of gravity in ocean tides).
- NGSS MS-PS2-4 — Construct and present arguments using evidence to support the claim that gravitational interactions are attractive and depend on the masses of interacting objects.
Curriculum Integration:
This activity fits within a unit on Earth's place in the solar system or Earth's systems, and can serve as either an introduction to gravity-driven phenomena or an application activity after gravity has already been taught.
Materials Needed:
- Computer or tablet with internet access per student or pair
- Access to the class LMS for submission
- Colored pencils or a simple drawing/diagramming app for the diagram step
- Optional: printed rubric copies for student self-assessment before submission
Instructional Notes:
- This WebQuest works well as a guided independent or paired activity; pairing is recommended for students who benefit from talking through the "why" of gravitational pull before writing it in their own words.
- Step 1 explicitly asks students to paraphrase rather than copy from the NOAA tutorial — consider briefly modeling what paraphrasing looks like before students begin, especially early in the school year.
- The PhET simulation (Step 2) has no download requirement and runs directly in a browser, making it accessible on shared or lower-spec school devices.
- If students struggle to find real tide data for Step 4, consider pre-selecting 3–4 coastal stations from the NOAA site as options, rather than leaving station choice fully open.
- The rubric is designed to be shared with students before they begin, so they understand exactly what "excellent" looks like for each criterion.
Assessment:
Formative: teacher circulates during Steps 1–5 to check notes and diagram sketches for accuracy before students move to building the final guide.
Summative: the completed Tide Forecast Guide, scored with the Evaluation rubric (out of 20 points).