Peter Selkin: Teaching Living on the Edge in Physical Geology at University of Washington, Tacoma

Unit 1

• Although I attempted to use this unit as specified in the module—guiding students through the recurrence interval calculation—the students quickly overtook me and were able to do parts of the recurrence interval calculation themselves, using the handouts provided.
• The calculation catalyzed a whole-class discussion about what recurrence intervals meant and why the calculation was necessary in the first place. We have since modified the unit to emphasize the ideas of probability and extrapolation, to reduce the emphasis on calculation, and to allow more time for discussion.
• The prework for Unit 1 was combined with that of Unit 2 to make a single prework handout that was collected at the beginning of the class period.
• Post-work was done as a written assignment, handed in at the beginning of the following class.

• The prework handout for unit 2 refers to specific page numbers. Be careful to change these page numbers when combining the Unit 2 prework handout with that of Unit 1! I did not do this, and it confused the students.
• We used the non-Google-Earth (paper maps) version of this unit, since some students were having trouble accessing Google Earth in the classroom. I suggested that students bring their laptops to use Google Earth, but I think this suggestion needed to be made more clearly—some students had forgotten. Google Earth is very helpful for the school risk assessment activity, even if only some of the students have access to it. I highly encourage students to use it.
• Again, timing was tight in this unit. This was partially because we had gone over time doing the previous unit. It was a challenge to leave enough time for both the school risk analysis and the ensuing whole-class discussion. Both activities are necessary components of the unit.
• I presented the PowerPoint on seismic safety in construction to the class, but then had students discuss (in small groups) the reasons for the damage on the red background slides. It might have helped student groups to see the red background slides before the presentation, and then to analyze the images in greater depth afterward. Printing out the red background images would have been useful as well.

Unit 3

• Again, I combined the prework for Unit 3 with that of Unit 4. Because students will be bringing the prework with them to class and will be using it in class, it is important to give them the handout during the previous class, or to ask them to fill it out on their computer at home (since much of the work requires the use of a computer anyway) and print it out before they come to class. I specifically required students to fill out the prework in ink (or print it from their computers) before class, and to fill out the remainder in pencil in class so that I could see their changes. Nonetheless, it is useful to have some blank copies on hand for students who forgot or did not attend the previous class.
• Students were particularly engaged in the analysis of Nyiragongo and the effects of its eruption on the city of Goma. This is a classic example of risk depending on both natural and human factors. It prompted a good discussion on volcanic risk and predictability which, while not part of the day's agenda, contributed substantially to the students' responses on assessment questions on the midterm and final.

• Because timing was again tight, we focused mainly on analyzing GPS data from Eyjafjallajokull. Students responded well to the thought experiment on volcanic inflation, and were able to predict and analyze GPS time series later. I had introduced GPS previously (though not in as much depth) in a module on plate tectonics, so the students did have some prior background with vectors. Many had seen vectors already in a physics or math course.
• Gas emissions and seismic monitoring are introduced in Unit 3, so the fact that we largely skipped them in Unit 4 did not put the students at much of a disadvantage in Units 5-6, when the techniques of volcano monitoring come up again. However, some of the finer points of seismic monitoring (e.g. depth of earthquakes) are covered particularly well in the Unit 4 material, so I was disappointed to have skipped them.
• Using the gelatin volcano lab in conjunction with this activity gave students additional insights into the processes of volcanism and volcano monitoring. Our lab handout (Microsoft Word 2007 (.docx) 504kB Sep12 14) is here.

• Units 5 and 6 were combined into a single class period. These two are halves of the same simulation exercise, so it makes logistical sense to combine them. I used the prework for Unit 5 as prework for the combined unit.
• The main issue in combining these units is the prework for Unit 6 and the resulting changes in student groups in the jigsaw activity. In most of Unit 5, students are grouped by geological specialty (e.g. gas emissions, seismology, ground deformation), whereas in Unit 6, students from multiple geological specialty groups team up to focus on specific geographic locations. At the beginning of the day, I handed out data sheets for the geological specialty groups that were tagged with colored stickers. For example, one gas emission handout, one seismology handout, and one tilt data handout had green stickers. Unbeknownst to the students, the stickers corresponded to their geographic location groups. I announced which stickers corresponded to which geographic locations after the students had completed the the work on Unit 5, about 1 hour into class. Students then regrouped into geographic location teams, which worked fairly smoothly.
• Only 10 students attended class on the day of the simulation, and some were not there for the entire class period. To give students an idea of the possible range of hazards and risk during a volcanic eruption, each geographic location group had to assess the vulnerability of at least three sites.
• Due to time constraints, students only filled out characteristics of high vulnerability sites on the vulnerability characteristics table.
• Students had trouble interpreting tilt data, which were not presented in the previous units. We have since streamlined the tilt data section of the activity to use only radial tilt, which can conveniently described as a "measure of inflation." Still, we anticipate that students will have questions about the significance of positive and negative tilt. Ideally a video or lab exercise associated with tiltmeters would be useful.
• The students working on gas emissions had good questions about whether increases in gas emissions indicated an increase in volcanic activity, or a release of pressure (and so less of a hazard). These questions were an opportunity for students to learn why geoscientists use multiple data sets to assess volcanic alert level. I believe that students' struggle with this issue led to some thoughtful responses on the module summative assessment questions (see below).