Shifting Sands: Quantifying Shoreline and Dune Migration at Indiana Dunes National Lakeshore
This Spreadsheets Across the Curriculum activity introduces Geology of National Parks students to the coastal zone of Indiana Dunes National Lakeshore at the southern end of Lake Michigan. The setting is one of beaches and dunes in a generally urban environment. The theme of the module is the interplay of engineering modifications and beach and dune dynamics. Students use data from air photos from 1939 and 2005, and three times in between, to study the retreat of the shoreline and the advance of the front of the dunes. The spreadsheet work involves calculating the average rate of change of the shoreline and dune front. The problem is solved using weighted averages, which are introduced with a problem involving the average driving speed in a car trip between Chicago and the park. The intent of the module is to have Geology of National Parks students make calculations that underscore the fact that the coastal zone is a dynamic environment in which engineering works have consequences.
This material is based upon work supported by the National Science Foundation under Grant Number NSF DUE-0836566. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.
- Read explanatory slides on the geologic setting of Indiana Dunes National Lakeshore, engineering modifications to the coastline, and basic background on beach erosion, beach nourishment, and dune growth and migration.
- View air photos of the shoreline and dune front from 1939, 1972, 1998, 2003, and 2005 and use them to calculate the rate that the shoreline has retreated and the rate that the dune front has advanced.
- Warm up for the calculation by working a weighted average problem to calculate the average speed traveled on a car trip from Chicago to the park given the speeds and travel times along the three legs of the trip (city traffic, interstate, country road). .
- Use a spreadsheet to determine the average movement of the shoreline and dune front (linear distance) from one date to the next from 14 distance measurements spaced equally along the length of the shoreline.
- Use the spreadsheet to calculate the rate (distance per time) of shoreline and dune-front migration for each time interval.
- Use the spreadsheet to calculate the average rate of shoreline and dune-front migration over the entire period from 1939 to 2005 (average of individual rates weighted by the length of time intervals).
In the process the students will:
- See effects of a longshore current and anthropogenic modifications to the shoreline.
- Learn about beach erosion and beach nourishment.
- Work with real data concerning the changing lakeshore.
- Get practice calculating averages from data with unequal weights.
- Be convinced that the coastal zone is a dynamic environment and that cause-and-effect relations must be considered carefully before making modifications to a stretch of shoreline.
Context for Use
Description and Teaching Materials
The module is a PowerPoint presentation with embedded spreadsheets. Click on the link below to download a copy of the module.
PowerPointSSACgnp.TC225.MHH1.1 (PowerPoint 6.6MB Jun1 13)
Optimal results are achieved with Microsoft Office 2007 or later; the module will function in earlier versions with slight cosmetic compromises. If the embedded spreadsheets are not visible, save the PowerPoint file to disk and open it from there.
The above PowerPoint presentation file is the student version of the module. It includes a template for students to use to complete the spreadsheet(s) and answer the end-of-module questions, and then turn in for grading.
An instructor version is available by request. The instructor version includes the completed spreadsheet. Send your request to Len Vacher (firstname.lastname@example.org) by filling out and submitting the Instructor Module Request Form.
Teaching Notes and Tips
The module is constructed to be a stand-alone resource. It can be used as a homework assignment, lab activity, or as the basis of an interactive classroom activity. It was used as an out-of-class activity in a senior-elective course, Environmental Geology of the National Parks (for geology majors and nonmajors), during development of the module in Spring 2010, and as an out-of-class activity in Computational Geology (a QL course for geology majors) in Fall 2010 and Fall 2011. In general, the students considered this module to be one of the more elementary modules in the collection. It is now one of the modules that is rotated into the online introductory-level Geology of National Parks course.
There is a slide at the end of the presentation that contains end-of-module questions. The end-of-module questions can be used to examine student understanding and learning gains from the module. Pre/post test, pre/post test answer key, and answer key for end-of-module questions are at the end of the instructor version of the module.
References and Resources
US National Park Service (NPS)
Indiana Dunes National Lakeshore
Michigan City Harbor, Indiana
Indiana Dunes National Lakeshore: Future