You may have noticed that the coastlines of South America and Africa look like puzzle pieces that fit together. They were once joined, and the Atlantic Ocean formed as they drifted apart.
You build a model of this process inside a shoebox. Paper strips slide through slits in the box to show new sea floor forming at mid-ocean ridges. The strips also slide into a trench to show subduction (one plate sinking under another).
As you pull the strips, magnetic stripe patterns appear on the new sea floor. The model shows where different types of earthquakes happen along plate boundaries.
Hypothesis
The hypothesis is that building a model of the Earth's outer 300 km will help to better understand the features of plate tectonics.
Earth's large surface pieces move apart at mid-ocean ridges, where new sea floor forms between them. You can model this process inside a shoebox with paper strips sliding through slits.
Hot rock rises through cracks in the ocean floor, pushing older rock outward and forming new sea floor at mid-ocean ridges. You model this inside a shoebox, where paper strips slide through slits to show new crust forming and moving apart. As you pull the strips, magnetic stripe patterns appear on the new sea floor — evidence of spreading that has played out over millions of years.
When one piece of ground slides under another, it sinks into a deep trench. In this shoebox model, paper strips slide into a trench to show subduction. You can watch one plate sinking under another, just like it happens deep underground.
Method & Materials
You will build a model of the Earth's outer 300 km using a cardboard shoebox, glue, scissors, a straight edge, and a safety razor blade.
You will need a cardboard shoebox, glue, scissors, a straight edge, and a safety razor blade.
Eureka Crate — engineering & invention kits for ages 12+ — monthly projects that build real-world skills. (Affiliate link)
After building the model, you can explore the features of plate tectonics, including sea-floor spreading, the pattern of magnetic stripes frozen into the sea floor, transform faulting, thrust faulting, subduction, and volcanism. The model also reveals that plates are moving at a rate of about 5 cm/y, which is about the rate that fingernails grow!
Why do this project?
This science project is interesting and unique because it allows students to explore the features of plate tectonics in a hands-on way.
Also Consider
Experiment variations to consider include adding color to the model to enhance it, or exploring different rates of plate movement.
Full project details
Additional information and source material for this project are available below.
