Becca Walker: Using Ice Mass and Sea Level Changes in Introduction to Oceanography at Mt. San Antonio College

Unit 1

• I needed approximately 45 minutes to implement Unit 1. Each student was given a hard copy of the Bangladesh text and figures to read (the photos were not provided in hard copy, but they were projected on PowerPoint slides), then they separated into groups of 3–4 and completed the (written) discussion questions together. My original intention was to have group report-outs for all of the discussion questions, but due to time constraints, we had a general whole-class discussion about the questions they had answered. Students seemed very interested in how the impact of sea level rise might be different in a developing country vs. an industrialized nation and the distribution of the impoverished population in Bangladesh. One of the students was from Bangladesh and shared her experiences there with the class. In the future, I plan to assign the reading as an online preparation exercise so students have more time to complete the reading, are familiar with the content before coming to class, and have the opportunity to see the images side-by-side with the text. This strategy will allow for more time to complete, reflect upon, and talk about the discussion questions. Some of the discussion questions may be appropriate as gallery walk questions.

Unit 2

• Students needed approximately 2 hours to complete Unit 2. We began with a group brainstorm about environmental factors that could lead to sea level changes, discussion about the concept of an anomaly, and orientation to reading a time series plot. Each student was given a hard copy of the in-class exercise and air temperature time series and sea level time series from 1992–present. They completed the exercise in their usual lab groups and submitted them for evaluation. The biggest struggles for students were making the initial rate of change calculations (they continued to improve on these calculations as they read subsequent time series in Units 3 and 4); understanding the concept of air temperature anomalies; and interpreting the temperature and sea level rise projections at the end of the exercise.

Unit 3

• Unit 3 was by far the most time- and labor-intensive unit for students to complete. It required approximately 4.5 hours of class time.
• 15 minutes: At the beginning of the class meeting, I posed a couple of questions to students about the GRACE video, and the lack of response indicated to me that they needed to watch the video again (or maybe for the first time).
• 10 minutes: Review of the work completed for Unit 2 linking sea level rise to rising air temperatures
• 10 minutes: Introduction to Greenland using selected PowerPoint slides. In introducing the study area, I paid particular attention to the four sites on which we would be concentrating (Helheim, Jakobshavn, Petermann, and NE Interior). Students recognized that Greenland and the Greenland Ice Sheet have topographic variation and indicated that they understood the concept of a marine terminating outlet glacier. I partially attribute this knowledge to the fact that we had looked at some Greenland marine terminating outlet glacier surface area time series a couple of weeks before.
• I divided students into three groups: two groups of 3 As (air temperature and snowmelt); one group of 3 and one group of 4 Bs (ice velocity); and two groups of 3 Cs (ice elevation). Each A and B group was provided with one color data set. All groups were provided with a reference map of Greenland illustrating the locations of Helheim, Jakobshavn, Petermann, and NE Interior study sites.
• 50 minutes: Students worked on the three data sets (snowmelt; ice elevation; and ice velocity). After 50 minutes, we took our usual 20-minute break. At this stage, the snowmelt and ice elevation groups had finished, but the ice velocity groups had not. During break, I looked at the prediction maps that the snowmelt and ice elevation groups had made.
• 20 minutes: The ice velocity group needed an additional 20 minutes to finish its work. During this time, I walked around the room and posed specific questions to the snowmelt and ice elevation groups about their prediction maps. In all cases, the groups decided to make some modifications to their prediction maps based on our discussion.
• 70 minutes: By the end of the class meeting, all groups had completed through Question 18. I let students know that they would have a chance to complete the activity during our next class meeting.
• During the next class meeting, we worked for roughly 1.5 hours to finish Unit 3. Students finished the in-class exercise (including the GRACE portion), and we talked as a group about how their predictions did (and did not) agree with the ice mass changes measured by GRACE. We finished Unit 3 with a discussion of some of the complexities (moulin formation, changes in ocean and atmospheric circulation, etc.) contributing to non-uniform ice mass loss across Greenland.
• What I would do differently the next time:
• I realized too late that there were not enough color data sets. When students worked in their first set of groups (A, B, C), I had a sufficient number of maps. However, it did not occur to me that when students got into their mixed groups (ABC, ABC, ABC), each of those groups would not have copies of all of the color data. This meant that students in their ABC groups spent quite a bit of time walking to other tables to look at the color data.
• I do not feel students were thinking robustly enough when making their prediction maps for ice mass change. As students were populating their maps with red and blue, I reminded them that they needed to provide written evidence/justification on their other map to support why they were coloring their maps the way that they were.
• To eliminate the time differential between the ice velocity, ice elevation, and snowmelt/air temperature groups, I would have restructured the ice velocity work so some students in that group would have worked on Petermann, others on Jakobshavn, and others on Helheim.

Unit 4

• Students needed approximately 1.5 hours to complete Unit 4, not including the time that it took them to watch the animation and answer the questions related to the animation.
• 1 hour: time required to complete the Unit 4 handout. As they had already dealt with time series plots in Units 2 and 3, they did not struggle significantly with the calculations.
• 30 minutes: whole-group wrap-up of what they learned about uplift vs. water input in the Helheim study area. My students were already familiar with the concepts of eustatic vs. local sea level change from previous class meetings, so this was a nice opportunity to review those concepts in the context of SE Greenland. Although they correctly characterized the sea level change as local and were able to articulate why sea level change was occurring, many of them struggled with the idea that sea level is decreasing in the study area. Several of them commented, "But I thought sea level was rising" (based on what they had considered in Units 1, 2, and 3). This confusion prompted them to consider what the impact on sea level would be in an area that is not glaciated.
• What I would do differently next time:
• Students had a tough time plotting their data on the diagram—oddly, they conceptually did not seem to understand which part of the diagram represented water and which part represented bedrock. The vertical scale with each tick mark corresponding to 10 mm of change seemed to be confusing as well. It would have helped to orient them to the diagram prior to beginning their plotting because some students miscalculated a sea level rise for the Helheim study area because they were marking the diagram incorrectly.
• I would probably play the animation at the beginning of class as I had the GRACE video in Unit 3.

Unit 5

• Unit 5 consumed approximately 1.75 hours of class time. At the beginning of the class meeting, we spent approximately 30 minutes reviewing Unit 4. The sea level gauge worksheet and discussion took approximately 20 minutes, and students spent roughly 60 minutes reading the New York City, Southern California, and adaptation strategy vignettes and responding (in writing in groups of 3–4) to the discussion questions. After they had completed the discussion questions, we spent approximately 30 minutes on the wall walk described on the Unit 5 page. I found the small group discussion on New York City, Southern California, and adaptation strategies to be relatively low energy, with relatively little product generated. In contrast, the wall walk was quite productive with respect to students offering justifications for their positions on the wall walk statements and students changing their opinions on some of the issues during the course of the wall walk.
• What I would do differently next time:
• Unit 5 was rushed. I wish that there had been more time for the wall walk and for students to study the map data in the New York City and Southern California case studies. In the future, I would definitely assign the New York City and Southern California readings as preparation work to allow more time for the group discussion and wall walk.