It can be a challenge for students to visualize how seafloors spread without actually expanding in area. This Deep Earth Academy activity titled “Plate Tectonics and Contributions from Scientific Ocean Drilling” is a triple threat for grades 5 through 8 that can help. It provides an easy hands-on activity for students to create a model of spreading seafloor. It uses real data from ocean drilling expeditions to show how we know the seafloor spreads. And it includes a PowerPoint presentation that presents background info and activity instructions to students in a visually appealing way.
The hands-on model of this activity allows students to see how the seafloor can simultaneously gain and lose rock. Even better, every student can make their own models because the models are made out of fairly inexpensive materials (cardstock and paper). This is what a model would look like:
The strips of paper, representing seafloor plates, can be pulled through the slits so students can see how the seafloor simultaneously rises from and returns to the asthenosphere. They can also easily see why the further the rock is from the spreading center, the older it will be.
The activity also includes ages of sediment samples that were collected on previous ocean drilling expeditions. These data points can be plotted on a map that is included. (Another suggestion is to have students plot the ages where they think they would occur on one of the strips on their model that represents a seafloor plate). Plotting the data will help the students see how scientists have found evidence that the seafloor is spreading.
Finally there is a PowerPoint presentation that provides background information you can present to students about this activity with cool images like this one:
This is a great activity and everything you need for it can be found here.