January 10, 2016
Continental Drift, Sea-Floor Spreading, and Plate Tectonics
The year is truly flying by as we are nearing the end of Marking Period 2. We have concluded the Earth's Interior unit and have been examining the exterior of the Earth.
The first half of our unit covered the hypothesis of Continental Drift. Here, we explored the evidence that Alfred Wegener, a German meteorologist, collected to support his hypothesis. The hypothesis stated that at one time there was a supercontinent, Pangaea, that split apart over time to become our present-day continents. In order to think like Wegener did, we conducted a fossil safari where we looked at fossil correlations amongst the five southernmost continents. Next, we examined how this fossil evidence as well as glaciation, mountain ranges, and coal fields supported the hypothesis. We also used giant continents to re-enact the breakup of Pangaea. (See picture above!) We had a competition to see which group could create Pangaea, place the evidence, and then move the pieces to their current locations first. We had so much fun doing this! To end the first half of the unit we had a short quiz.
When we returned from break, we began the new year by discussing Sea-Floor Spreading and Plate Tectonics. First, we drew a diagram of sea-floor spreading. The following day we began to discuss the pieces of evidence that support sea-floor spreading and subduction. We loved getting the chance to be the oceanic crust while acting out the processes. After acting it all out, we developed a paper model showing how sea-floor spreading and subduction happens. Then, we watched a video about how Iceland was made, which covered how the landmass is continuing to grow due to sea-floor spreading. The final two lessons will have us exploring the mechanism that moves the continents (the theory of plate tectonics). Here, we will discover the three types of plate boundaries. To end the unit, we will do a project on the three types of plate boundaries.
Please let us know if you have any questions or concerns! We hope everyone had a very happy holiday season as well as a happy New Year.
Rachel Goldberg and Julianne Kovary