The Dynamics of Plate Tectonics

When we look out on the terrain, everything seems very stable. The Earth’s crust, however, is quite dynamic. The crust itself is thin in comparison to the size of the globe. It is broken into pieces called plates, which rest on the molten rock of the mantle. The motion and interaction of the plates explain many natural phenomena, including earthquakes and volcanoes. 

To introduce plate tectonics, I begin by giving my students a puzzle. I have laminated a map of the Earth, labeled and divided into its respective plates, which I cut into pieces and give to the students to put back together. This helps students learn the shapes of the major plates and their names. You can also try this with a map of Pangaea. I also demonstrate the motion of the plates with a large dish of water on a hotplate with paper disks floating on top.  Students are able to see how convection currents cause the movement of the plates. There are also many wonderful animations of plate tectonics on the Internet.

From there, we discuss the three types of plate boundaries: divergent, transform, and convergent.  Students can visualize these by modeling them with their hands. In divergent boundaries, the plates separate, which causes sea floor spreading. Transform boundaries occur where plates slide past each other, the tension and release can cause earthquakes. Convergent plate boundaries in which plates collide are more complex, because the results depend on the type of crust. Oceanic crust is denser than continental crust, so it will sink below as the plates converge. This causes volcanoes, much like the ones created in the ring of fire around the Pacific Ocean. Oceanic convergence creates a similar subduction that causes volcanic island chains, such as the Hawaiian and Galapagos Islands, and creates deep ocean trenches. Where continental crust converges with more continental crust, the resulting uplifting of crust creates high mountains, like the Himalayas. In addition to using their hands, students can model what happens with each type of boundary with clay.

Once students can correctly model each type of boundary, I have them do research and present information about one of Earth’s landforms as it relates to plate tectonics. In addition to the landforms mentioned above, others to consider include the Pacific Northwest volcanoes, the Great Rift Valley in Africa, and the Mariana Trench. Applying the concepts of plate tectonics to actual features of the Earth will help students remember the importance and implications of this topic. An extension of this is to have students investigate the history of plate tectonic theory. This also emphasizes the nature of the scientific method, in which finding out new information is an important component. The lessons below will give you more inspiration for teaching tectonic theory.

Plate Tectonics Lesson Plans:

Real Evidence of a Subducting Plate  

Students examine data regarding subduction zone plate tectonics. They analyze data tables on plate boundaries on the west coast of South America, and construct a 3-D model of the events in that region.

Physical Characteristics of Places: The Fossil Record  

Students review the theory of plate tectonics. They discuss how plate movements affect climate in various land regions, research and record the ways that climate has changed in various world regions over the past one hundred million years and explain how animals in these regions might have been affected by climate changes.

What's the Difference?  

Students investigate volcanic processes at convergent and divergent tectonic plate boundaries. They read and analyze diagrams, complete a worksheet, and write an essay.

Cruising the Mantle  

Students explore the plate boundaries of the earth. Through the use of video, Internet and hands-on activities, students examine the types of plate boundaries. They create a model to illustrate the movement and interaction of the plates. Cross-curricular activities are available.

Heat and Density  

Students are introduced to the concepts of density and convection/conduction through demonstrations, notes and activities. They are exposed to real-world examples to model the processes that move and shape Earth's surface. Students research plate tectonics and the location of various plate boundaries, using science textbooks and the Internet.