I finished up Plate Tectonics & Plumes, reviewing plate boundary characteristics in topography (using google Earth) and showing plate reconstructions for the globe and for North America. I then talked about plumes and hot spots, which is another mode of heat transport from the interior.
No in-class exercise today, but I distributed a homework assignment.
I finished up plate tectonics except for showing some historical plate configurations, which I will do next class. Students completed an in-class exercise related to sketching the main earthquake location patterns on global maps. A key pedagogical goal was to remind students of the importance of drafts in the development of anything, not just writing.
We finished our discussion of Earth’s interior and moved on to plate tectonics. Students completed an in-class exercise related to testing the idea of sea-floor spreading.
We discussed the nature of Earth’s interior: Crust, mantle, core. For the most part, gravity and early melting of planets enable them to for a spherically stratified structure with the most dense materials in the core. The process is not trivial, and since we have no samples of core material, we have to infer its composition from information on the materials available to “build” the planet, and the chemistry and physics that operate during the process.
Students completed an in-class activity related to the likely main component in Earth’s core.