The Engine That Drives the Earth Children’s Ideas About Plate Tectonics

Below are common ideas children in grades K-6 have about this topic, compiled from research on children’s ideas about science (see the Session 1 Children’s Ideas Bibliography). Consider what evidence might refute this idea, and why a child would be likely to believe this?

1. Earth has a hot molten core that is the source of magma that flows out of volcanoes as lava.

Earth has a solid metallic inner core, and a liquid metallic outer core. Popular media often perpetuates the misconception that because the interior of the Earth is hot, it must also be molten. This can mislead students of all ages into believing that the magma seen coming out of volcanoes comes from the core. Current science knowledge informs us that the source of magma that erupts as lava out of a volcano is the solid mantle, which melts at low pressure near the surface to generate magma.

2. Many children in grades K-6 cannot readily explain why earthquakes occur, nor visualize what happens underground during an earthquake.

Earthquakes are usually caused by an abrupt shift and breaking of rock along fault lines. The cause of earthquakes can ultimately be traced back to plate tectonic processes. Children often struggle with visualizing a concept that cannot be directly observed.

3. Earthquakes and volcanoes only happen near one another, and earthquakes cause volcanic eruptions.

Most earthquakes occur along plate boundaries, because of abrupt shifts in the position of tectonic plates. Earthquakes are not thought to be a cause of volcanic eruptions. In fact, volcanoes often cause earthquakes instead. Volcanoes erupt when magma is less dense than the solid rock surrounding it in the mantle, and it begins to rise. Rising magma can sometimes cause earthquakes in the surrounding crust. As magma nears the surface, the gases in it expand, increasing the pressure and causing the volcano to erupt, much as the gases in soda ‘erupt’ when a can or bottle of soda is opened. Children do not necessarily associate earthquakes with the shifting and breaking of rock along fault lines, perhaps because this is often an unseen phenomenon. The connection between earthquakes and volcanoes may cause children to reason that they always co-occur.