Modeling Plate Tectonics - A Reflection

As Kenyon, Schwarz, and Hug point out "a scientific model is a representation of a system that includes important parts of that system (along with rules and relationships of those parts) to help us think about and test ideas of the phenomenon (2008)." I stress this point to my students almost on a daily basis by helping them understand the fact that models help us understand things when size or time would be a problem for making observations. I frequently use models to provide concrete examples of abstract phenomena to difficult to replicate in true life scale.
In our earth science unit I use several methods to demonstrate the structure of the Earth and plate tectonics, from orange peels to lava lamps.

I implemented a lesson on plate tectonics during the unit on constructive and destructive forces of the Earth by using multiple models and media formats. I used an orange sliced in half as well as an orange with the peel cut into large sections to represent the tectonic plates. I also used a plate tectonics map for the students to cut and put together like a manipulative puzzle. To model the mechanism behind plate tectonics I used a lava lamp as well as a hot plate, aluminum pie pan, syrup, and graham crackers to demonstrate the convection of the mantle beneath the crust. The lesson was implemented over a two day period (total 90 minutes) in October to all three of my classes: on fifth grade level, above fifth grade level, and working toward fifth grade level.

Overall, all of the students were able to meet the goals of lesson in understanding the fact that Earth’s crust is divided into large sections called plates that move around and create landforms. This was ascertained through both formal and informal means. When students had opportunities to discuss in groups prior to sharing as a whole class, I walked around listening to insure they were on topic having meaningful conversations. Frequently I would ask “why?” or “how?” when I was with groups to further facilitate deeper explanation of the topic. This also allowed me opportunities to determine their level of understanding informally. Also, at the end of the lesson, students were required to make associations between the various models used and the parts of the Earth represented by each, as well as answer questions demonstrating their level of understanding of the plate tectonic process. This is more of a formal assessment and will be used to drive future lessons and groupings.

The most successful portion of the lesson was having the students use the plate tectonics map to make observations about the ways in which the plates move in relation to each other. This was certainly the case for my working toward level class as they are more kinesthetic learners, and really thrive on manipulating materials to enhance understanding. The students in all classes were able to visualize mountains being formed as two continents smashed into each other, or how the ocean floor could split apart as a result of a divergent boundary. All other media and modeling used in the lesson hinged on the plate tectonics map and the idea that the continents move across the surface of the planet. I use many forms of visual media in my lessons as many of my students are visual learners. Using models - whether student created, teacher demonstrated, or online interactive - readily lend themselves to this type of learning style.
In the future, I would like to use maps with fossil evidence spanning different continents as a transition lesson. Getting the students to make observations that fossils of the same species being found on different continents means that they had to be connected at one time in Earth’s history.

I would also like to add a model that demonstrates sea floor spreading and the ages of the rock surrounding the fissure by using butcher paper between two desks, and then having students slowly pull the paper from between desks making lines every inch. Students could stretch out the paper and label each layer with numbers from oldest to youngest. This type of model gives students the visual of how new rock is formed at the fissure then moves away from as the continents continue to separate.

I would also use a journal to transition from the movement of the plates to the mechanism behind plate movement. Perhaps a prompt such as “Looking at a map of the Earth, what evidence do you see that would lead you to believe the continents were once all connected together in a giant supercontinent?” This would hopefully get students to make observations about the shape of the continents, and make associations to interlocking puzzles. Whether I am teaching Earth Science, Physics, Life Science, or Environmental science, I try to make use of as many models as possible. Ideally, all models should be student created and student centered; however because of some safety concerns and equipment availability, this is not always possible. In order for students to do science, science teachers need to provide them the opportunity to manipulate objects making observations about interactions and relationships between phenomena. This is my goal on a daily basis.

References:

Kenyon, L., Schwarz, C., & Hug, B. (2008, October). The benefits of scientific modeling. Science & Children, 46(2), 40–44.