Adopt a Blob

Catherine Cooper

Washington State University

This activity has been reviewed by 2 review processes (view details)

This activity was selected for the On the Cutting Edge Reviewed Teaching Collection

This activity has received positive reviews in a peer review process involving five review categories. The five categories included in the process are
- Scientific Accuracy
- Alignment of Learning Goals, Activities, and Assessments
- Pedagogic Effectiveness
- Robustness (usability and dependability of all components)
- Completeness of the ActivitySheet web page
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This activity has benefited from input from faculty educators beyond the author through a review and suggestion process. This review took place as a part of a faculty professional development workshop where groups of faculty reviewed each others' activities and offered feedback and ideas for improvements. To learn more about the process On the Cutting Edge uses for activity review, see http://serc.carleton.edu/NAGTWorkshops/review.html.

Initial Publication Date: February 23, 2010 | Reviewed: October 31, 2012 (see revision history: 2 events)

Summary

Blobs are everywhere in the deep Earth! Students will adopt a "blob" and develop the various associated observable anomalies for it (tomography, gravity, etc). There could also be a potential for students to adopt imaginary blobs that aren't physically real, but rather data artifacts. This assignment will help students in their own personal interpretation of deep Earth observables.

Geophysics | College Upper (15-16), Graduate/Professional

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Context

Audience

Introductory Geophysics Class or other upper level undergrad geology course or graduate student course

Skills and concepts that students must have mastered

Introductory Geology, Mineralogy, Calculus, Physics

How the activity is situated in the course

The activity could be used as an ongoing project in the course with the student building on observables & interpretations of their blob as new information is introduced.

Goals

Content/concepts goals for this activity

Developing a multi-disciplinary & potentially quantitative outlook on deep Earth structures.

Higher order thinking skills goals for this activity

Hopefully by creating their own anomalies, students can gain an intuitive critical sense of interpreting geophysical images.

Other skills goals for this activity

Description of the activity/assignment

At the beginning of the course, each student is assigned a unique blob - or a piece of material of a particular shape with specific material properties (density, bulk modulus, composition, viscosity, volatile content, etc) that is residing within the mantle at a specific environment (depth, pressure, temperature). Then as the semester continues as a topic is covered the student must assess (either quantitatively or qualitatively) what observable would be associated with their blob (for example, gravity anomalies, geoid anomalies, surface expressions, seismic tomography, phase transition topography). The student then develops a portfolio of their blob and its observables to then present at the end of the course with an explanation/interpretation for the source of the blob culiminating at building a geo-story around their anomaly.

Some blobs could be amorphous anomalies whereas other could have physical significance (though best not to tell the students ahead of time so they can make their own discovery as to what the blob is or isn't) such as subducted slabs at the CMB (or 660 km), plumes, lithospheric drip, lithospheric root, or a boring typical piece of the mantle.