Exploring hypsometry in glacial and fluvial environments
Skills and concepts that students must have mastered
I expect students to be able to use Excel for simple calculations and plots.
How the activity is situated in the course
Content/concepts goals for this activity
Higher order thinking skills goals for this activity
Data manipulation in Excel
Comparison of different datasets over a range of parameters
Comparing published findings with exploration of new areas
Other skills goals for this activity
How to create cumulative distribution curves
Description and Teaching Materials
During the class session right before lab, we go over the mechanics of how to create a classic hypsometric curve (normalized, cumulative plot) as well as alternatives to this (non-cumulative, binned data). We brainstorm a series of mountain ranges around the world that fall under a range of climatic conditions (fluvial to glacial) and tectonic environments. Students each pick one mountain range to analyze in lab.
Prior to lab, I download 6 SRTM tiles in each mountain range and merge the DEMs into a single file. (Over time, I have built up datasets for most ranges students pick, so this is not onerous). You could have students do this themselves in lab, but then you risk problems like having the SRTM data servers down during lab.
In lab, each student extracts data from their DEMs and brings them into Excel. There, they create the different hypsometric curves. They are also responsible for estimating their local modern and LGM snowlines based on global curves. I collate all the data and post them for everyone to have access. Students are then asked to write up a report comparing 4-5 different locations.
Student handout (Microsoft Word 2007 (.docx) 21kB Jun11 14)
Teaching Notes and Tips
I have included dates in the handout attached here, so you can see the general timeline we use for data collection and analysis, posting to the class website, and for report writing.
This lab currently only covers elevation distributions, but I have also had students look at slope distributions and relief distributions, too. That is one potential extension of this. I have found it is a little harder for students to compare those datasets in a meaningful way.
References and Resources
Egholm, D.L., Nielson, S.B., Pedersen, V.K., and Lesemann, J.-E., 2009, Glacial effects limiting mountain height. Nature, v. 460, DOI:10.1038/nature08263.
Montgomery, D.R., Balco, G., and Willett, S.D., 2001, Climate, tectonics, and morphology of the Andes. Geology, v. 29, n. 7, pp. 579-582.