Seeing IS believing. Rocks are elastic!

Resource 4 Related Resources Lessons Videos Animations Seeing IS believing. Rocks are elastic! Novice Resource Files Instructor Guide—Student Worksheet Download All 1MB The notion of rocks as elastic solids underpins many seismological concepts including the earthquake cycle and seismic wave propogation. This demonstration physically illustrates this property as students explore several rock/mineral specimens. The demonstration is somewhat discrepant because students' prior experiences suggest that rocks are hard and inflexible. Using this as a starting point, the demonstration begins with attempts to bend a large hand sample of granite or marble. Next, a large mica sample is deformed elastically. Finally, the elastic deformation of a long thin marble slab allows students to see and feel, that solid rocks are indeed elastic. During the discussion students are introduced to the concepts of stress and strain.   Theory and research supporting the development and use of this activity can be found here: Hubenthal, M. (2018). Exploring undergraduates’ conceptions of elasticity, within a plate tectonics context, before and after experience with rock’s elastic behavior. Journal of Geoscience Education, 66(4), 261–277. http://doi.org/10.1080/10899995.2018.1493964 Objectives: Students will be able to Explain a method to demonstrate that solids, like rocks, can deform elastically Describe, in a short paragraph, how the elasticity of rocks is fundamental to the earthquake cycle Related Lessons Earthquake Machine 1—Defining an Earthquake Using a block-and-sandpaper model, students collaborate in small groups to investigate how energy is stored elastically in rocks and released suddenly as an earthquake (the earthquake cycle). This activity emphasizes the role of mechanical models in understanding and testing ideas in science. Lesson Novice Related Videos Elastic Rebound—Earthquake Machine & Rocks-can-bend Demo This demonstration shows that rocks are elastic by squeezing a slit core of rock. Video Novice Elastic Rebound Demonstration using a Yardstick Video lecture about elastic rebound and brittle material in the crust using a yardstick as a mechanical analog. This demonstrates elasticity, brittle fracture, and why it is difficult to predict earthquakes. Video Novice Related Animations Layers of the Earth The Earth has 3 main layers based on chemical composition: crust, mantle, and core. Other layers are defined by physical characteristics due to pressure and temperature changes. This animation tells how the layers were discovered, what the layers are, and a bit about how the crust differs from the tectonic (lithospheric) plates, a distinction confused by many. Animation Novice