Pedagogy in Action > Library > Teaching with SSAC > Examples > Bubbles in Magmas

Bubbles in Magmas

Module by Chuck Connor, University of South Florida, Tampa. This cover page by Ali Furmall, USF, now at U. Oregon.

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

Resources in this top level collection a) must have scored Exemplary or Very Good in all five review categories, and must also rate as “Exemplary” in at least three of the five categories. The five categories included in the peer review 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

For more information about the peer review process itself, please see http://serc.carleton.edu/NAGTWorkshops/review.html.



This page first made public: Oct 25, 2007

This material was originally developed by Spreadsheets Across the Curriculum as part of its collaboration with the SERC Pedagogic Service.

Summary

In this Spreadsheets Across the Curriculum activity, students are introduced to the process of bubble formation and rise within a magma. The ideal gas law is utilized to illustrate the change in volume of an individual bubble as it rises through the magma. Forces acting on the bubble (gravitational, viscous, and buoyant) determine the bubble's velocity. This is a self-paced activity in which students follow a PowerPoint presentation to create spreadsheets and graphs using Excel.


Learning Goals

Students will: In the process the students will:

Context for Use

Equipment: Each student or pair of students needs a computer with Excel and PowerPoint.

Classes: This module has been used in an Introductory Physical Volcanology course with upper level undergraduates.

In the class, the module was introduced during lab to be completed as homework due the following week. Students turned in hard-copies of the Excel spreadsheets and graphs, as well as their working Excel files. This worked well for junior and senior level students with excellent quantitative skills.

Description and Teaching Materials

Powerpoint SSAC-pv2007.QE522.CC2.1-student (PowerPoint 1.8MB Dec6 07) ]

If the embedded spreadsheets are not visible, save the PowerPoint file to disk and open it from there.

This PowerPoint file is the student version of the module. An instructor version is available by request. The instructor version includes the completed spreadsheet. Send your request to Len Vacher (vacher@usf.edu) by filling out and submitting the Instructor Module Request Form.

Teaching Notes and Tips

This module, like the others in this collection, works best if coordinated with lecture and lab material.

If students have difficulty in getting their equations to produce the correct numbers in the orange cells -- especially if their results are off by orders of magnitude -- tell them to check their unit conversions. You cannot ever emphasize unit conversions enough.

Some students jump ahead to the end-of-module assignments without working through the main part of the module carefully. Those students have trouble.

Assessment

The end-of-module questions can be used for assessment.

The instructor version contains a pre-test

References and Resources

Hurwitz, S., and O. Navon, 1994, Bubble nucleation in rhyolitic melts: experiments at high pressure, temperature, and water content. Earth and Planetary Science Letters 122: 267-280. [a very comprehensive introduction to essential research about bubbles in magmas].

Cashman, K.V. and Mangan, M.T., 1994, Physical aspects of magmatic degassing II. Constraints on vesiculation processes from textural studies of eruptive products. Reviews in Mineralogy, 30: 447-478. [a starting point for understanding bubbles in rocks]

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