Is the Earth’s Core Leaking? Guest Scientist: Dave Walker (Feb 2005)

Is the Earth’s Core Leaking?
Guest Scientist: Dave Walker

12 February 2005

Introduction to this Workshop

Here is the introductory slideshow presented by Dr. Passow.

Cutting-Edge Research

Is the Earth’s Core Leaking? One would have thought that the core would be a perfect waste repository. The gravitational and chemical stability of the system which put the core in place should be quite difficult to upset. The core formation process should not run backwards. And yet there is some evidence that the core is leaking a little bit. How this might happen is explored. One mechanism that reconciles some previously enigmatic observations involves the subduction of oxidized material from the Earth’s surface to the core-mantle boundary. A process like titration precipitates oxides from the core’s iron-rich substance as the result of the oxidizing subducted material reaching the liquid outer core. Oxides produced from the core are lighter than the core and join the mantle. It is interesting to speculate that there is a feedback between oxygen-generating biological processes and deep-earth core-mantle chemical interactions.

View Dr. Walker’s presentation about “The Leaking Core.”

Classroom Resources

Virtual Simulations of Microscopy and Optics – Make sure you check out the Polarized Light Microscopy to see how crystallized specimens appear when viewed through a polarized light microscope. Samples include a Moon rock, a dinosaur bone, spinach, amethyst and many others.
http://micro.magnet.fsu.edu/optics/tutorials/index.html

 

Other Resources Related to This Topic

IRIS Educational resources: http://www.iris.edu/hq/#

The Interior of the Earth (USGS) http://pubs.usgs.gov/gip/interior/index.html

What on Earth Is Plate Tectonics? (USGS) http://www2.nature.nps.gov/geology/usgsnps/pltec/pltec1.html

Virtual Journey to the Center of the Earth http://www.visionlearning.com/library/module_viewer.php?mid=69

3-D Earth Structure Model http://www.eas.purdue.edu/~braile/edumod/threedearth/threedearth.htm

 

Integrating Educational Technologies

Using Digital Cameras in the Classroom
By Cristiana Assumpção Ed. D.

The use of digital images can greatly enhance the learning of Earth Science in your classroom. These images can be obtained from the readily available resources offered to you on our website, or they can be made by your students, making the learning experience more personal, and encouraging student ownership of learning.

How can you use digital images? There are two selected sites below that start you off with some practical ideas and examples. But to be more specific, let’s think of some examples that could use the materials you are learning in the Earth 2 Class program.

 Some ideas to get you started…

1. Students take pictures of trees close to where they live, put them together to compare and guess which ones are the oldest and why.

2. Students could take pictures of cut trees and try to work with the rings, using software like Photoshop or other image editors to highlight certain areas and label them.

3. Students take pictures of a field trip they’ve been to (like the LDEO core lab) and prepare a presentation using the pictures to illustrate.

4. Students prepare a poster with only photos to illustrate their point of view about a topic they are studying (like the impact of mankind on climate change), and other students have to guess what they are trying to communicate through the photographs.

5. Students create a photographic manual on how to conduct a certain experiment (like building your own volcano) instead of only writing out the procedure.

6. Students create still animation by photographing clay models of the movement of the tectonic plates or of volcanic eruptions, or even the formation of a tsunami, and then make a short movie to show to the class.

As a classroom teacher, I’m sure you can come up with many more interesting examples yourself. To think about how to use a digital camera in your classroom, always think of how it can add value to the learning experience. Think about the following questions: (1) Does the camera allow me to do something that I already did, only better? (2) Does the camera allow me to do something that I could not do before (like illustrate a point that was very difficult for students to visualize)?

If the answer is yes to either question, then go ahead and use the camera. Technology is only truly beneficial when there is true added value to the learning experience. Cameras are great for illustrating procedures that are difficult to explain in writing, or creating simulations of phenomena students cannot normally observe, or even allowing students to share more about where they live, where they’ve visited or what they’ve presented as class work (look at digital portfolios for more details).

 So read and explore the two websites below, and share with us any ideas you may have for using digital cameras in your classroom! We’d love to see what you’re doing with your students.