Investigate Tides | The Schools' Observatory

The sea level rises and falls every day. These changes are called tides. Tides happen because of the gravitational pull of the Moon and the Sun on Earth's oceans. The Moon has the strongest effect because it is much closer to Earth.

In this activity, you will use predicted tidal data to explore how tides change over time. You will plot real tide heights from Liverpool over 3 days, then analyze the graph to spot patterns and make predictions. It is recommended to do the Explore Tides activity first.

Earth-Moon-Sun system showing the effect of gravitational pull on Earth's tides

By the end of this resource you will:

Have plotted a graph using predicted tidal data
Have identified patterns in high and low tides
Understand how tides change over time
Be able to predict future tide times based on past data

To complete this resource you will need:

A copy of the worksheet
A pencil
A ruler
A coloured pencil (optional, to highlight trends)

Files or Documents

Investigate Tides - Worksheet

Investigate Tides - Additional notes Powerpoint slides

Investigate Tides - Answer Sheet

Approx Duration

30 - 60 mins

Have a go!

Your challenge is to explore how tides change over time by using real tidal data. You will plot data, analyse patterns, and make predictions to understand why tides happen at different times each day.

Step 1:

Download the worksheet linked on this page and gather all the materials you need before you begin.

Step 2:

Use the Predicted Tidal Data Sheet to plot each tide height on the Tide Graph Template at the correct time and connect the points with a smooth line.

Step 3:

Analyse your graph by identifying how many high and low tides occur each day, observing how their timing changes, and looking for patterns in tide heights over time.

Step 4:

Answer the worksheet questions by exploring why tides happen later each day, predicting the next high tide time, and comparing your findings to real-world tidal data.

Step 5:

Share your findings with your group or class. What did you learn about how tides change over time? How do these patterns help us predict future tides?

Step 6:

Read the additional notes slides to learn more about what tides are, how they happen, and different types of tides in the real world.

Well done – you have investigated tides just like a scientist!

If you liked this, why not try

Exploring tides

Finding out why the Earth has tides

Finding out why the Moon has phases