Hands-on Ways to Visualize the Earth’s Layers
Even though we are drilling into rock above the ocean floor, our main objective is to understand better what is happening inside the earth’s mantle. Here are a couple activities that can help students visualize the Earth’s interior in a hands-on way.
One of these activities comes from a group that works with one of our co-chief scientists, Anthony Koppers. The website provides instructions on how to create a 3D model of the earth’s layers out of paper, cardboard, string and glue. The webpage then provides all the guidelines and resources necessary to lead students through a week of lessons using the 3D models, that, along with teaching about earth’s layers, can also be used to introduce students to plate tectonics. It can be found on the EarthRef.org website.
An important distinction to make when teaching the earth’s layer is that scientists actually have more than one way of dividing the earth into layers. The one that is probably most familiar to the average person is to layer the earth by crust, mantle and core. This is a system that breaks the earth into layers based on chemical composition. The layering system that needs to be taught along with a plate tectonics lesson is the one that breaks the earth up into lithosphere, asthenosphere and other -spheres. This system classifies layers of the earth based on their mechanical propreties: how solid they are versus how fluid, how rigid and brittle they are versus how flexible. The lithosphere refers to both the crust and the upper mantle, because this is the part of the earth that is rigid and brittle enough to break into tectonic plates.
An activity that allows students to feel the mechanical differences between the lithosphere and the asthenosphere can be found in Leslie Sautter’s plate tectonics activities website, from which I already shared an activity about seamounts. In the “Why is there Lithosphere?” activity, students use warm (but not melted) chocolate to represent the fluid, flexible asthenosphere and graham crackers to represent the hard, brittle lithosphere. Students use the chocolate and graham crackers to see how the lithosphere and asthenosphere interact with each other and also how the lithosphere can break into tectonic plates.