# Guiding students through the Hypsometric Curve

*An instructor's guide to Reading the Hypsometric Curve*

^{by Dr. Eric M. Baer, Highline Community College Geology, and Dr. Jennifer M. Wenner, University of WI Oshkosh Geology.}

Jump to: Difficulties for students | What's left out | Resources

## What should the student get out of this module?

After completing this module, a student should be able to:- determine the percentage of the Earth's surface that is in any elevation range,
- read the hypsometric curve, and
- be better prepared to use other cumulative percent graphs.

## Why is it hard for students?

The hypsometric curve is generally unlike any graph ever seen by students. Often, the plots in textbooks also have significant amounts of extraneous data which can distract students. Finally, students often have never thought about distributions in any depth and so the graphical representation of a distribution is a novel concept that requires them to wrestle with numerous new ideas.

Finally, because reading the graph can sometimes be a challenge, students lose sight of the significance of the graph: that the Earth's surface is bimodally distributed, *prima facie* evidence that there are two types of crust on the Earth.

## What have we left out?

This page does not include a histogram of the distribution of topography of the Earth. In many textbooks the histogram is smoothed, which is an invalid way of graphically representing a distribution, even if it may be more intuitive.

This page does not explicitly teach the significance of slope on a cumulative percent graph, even though it is the slope that many geologists look at. This is because I have found that students eventually come to understand the importance of slope after they have interacted with cumulative percent graphs for a while, and that teaching the importance of slope on one of these graphs before they have mastered extracting data from a cumulative percent graph is overwhelming.

## Instructor resources

**The Cumulative percent graphs: Teaching the Hypsometric Curve/Graph and other similar plots page** in the Teaching Quantitative Literacy in the Geosciences website is a terrific place to look for ideas on teaching the hypsometric curve and other cumulative percent graphs.