EarthLabs for Educators > Climate and the Cryosphere > Lab 5: Evidence of Recent Change

Lab 5: Evidence of Recent Change

The lab activity described here was developed by Erin Bardar and Candace Dunlap of TERC for the EarthLabs project.

Open the Student Activity in a New Window Use the button at the right to navigate to the student activity pages for this lab. To open the student pages in a new tab or window, right-click (control-click on a Mac) the "Open the Student Activity" button and choose "Open Link in New Window" or "Open Link in New Tab."


Investigation Summary and Learning Objectives

In this lab, students will explore evidence of recent change in the cryosphere. In Part A, they will use an online interactive to visually explore how six Alaskan glaciers have changed over the last hundred years. They will also use image processing software to measure how much area a glacier in the Himalayas has lost over time due to rising temperatures. In Part B, students will study recent trends in Arctic sea ice extent. In Part C, they will explore the ice-albedo feedback effect and think about causal connections between climate and the cryosphere.

After completing this investigation, students will be able to:

For more information about the topic, read the section titled Background Information under Additional Resources below.

Activity Overview and Teaching Materials

In Part A: Students first visually examine photograph pairs to see how glaciers and the surrounding landscape change over time. They then use ImageJ to measure the area lost by the Gangotri Glacier in India since 1780. NOTE: All student computers will need to have ImageJ installed before beginning Part A of this lab.


About ImageJ:

ImageJ is free public domain image processing software developed at the National Institutes of Health. Its power and flexibility allow it to be used as a research tool by scientists in many disciplines, from medicine to astronomy. Installers are available for Windows, MacOS and OSX, and Linux.

You can use ImageJ to display, annotate, edit, calibrate, measure, analyze, process, print, and save raster (row and column) image data. It reads most common raster image formats as well as raw data files in text format, such as from spreadsheets. ImageJ also supports stacks - multiple images in a single window - for animation and analysis.


To Download and Install ImageJ:

Go to the ImageJ Download page, and download and install the application for your operating system.

    Click the ImageJ Download page and it will open in a new window. Click the link that appears directly below the name of your computer's operating system (e.g. Mac, Linux, Windows). This action will transfer a compressed file of the software to your computer. Your browser should automatically expand the file, creating an ImageJ folder on your computer's hard drive.

    ImageJ Download page

For more details, or if you have problems running the application, access ImageJ's Installation Instructions then select your operating system.


Updating ImageJ Software

ImageJ Updater Window

Double-click the ImageJ icon to launch the application and choose Help > Update ImageJ.... A window will appear, telling you the version you are currently running and a list of upgrade versions. Choose the version you want to upgrade to (usually the most recent, or default version) and click OK. After the update downloads, re-launch ImageJ to run the new version. NOTE: Some users have reported problems updating ImageJ in certain versions of Windows. To fix this problem, you will need to manually update ImageJ.

  1. Right-click the link at right to download the ij.jar file. Be sure to save it as simply ij.jar. ij.jar (Jar Archive 1.4MB Feb8 10)
  2. When prompted where to save the file, navigate to the ImageJ folder and save the file there. Replace the existing ij.jar file.
  3. For most installations, the ImageJ folder will be in the Program Files directory on your hard drive. The path to the ImageJ folder is c:\Program Files\ImageJ.

The ImageJ Toolbar

The ImageJ toolbar contains both built-in and customized tools for manipulating images. Most of the tools are similar to those used in other graphics programs.

ImageJ Tool Bar

Time estimate: 50-75 minutes

In Part B: Students study recent trends in Arctic sea ice extent and revisit the topic of albedo.
Time estimate: 25-50 minutes

In Part C: Students Students learn about the concept of albedo and the ice-albedo feedback effect using the online interactive Earth's Albedo and Global Warming. They will also do a "Connection Circles" activity to explore the concept of feedback loops.
Time estimate: 50 minutes


Printable Materials


Teaching Notes and Tips

In Part A: Make sure ImageJ is installed on all student computers before beginning the lab. Practice the exercise yourself before teaching so that you are prepared to answer student questions during the lab.

In Part C: Practice the Connection Circle before doing the activity with students.

Purpose of the discussion: This discussion will help students better understand positive and negative feedback loops.

Facilitation Tips: Hang each group's Connection Circle in the classroom and do a "gallery walk" before beginning the discussion, so that students can see what others have come up with for their Connection Circles.

Primary discussion questions:

  • Are the Connection Circles in the classroom all the same? Identify some similarities and some differences.
  • Compare the feedback loops you found in the Ice-Albedo Feedback Connection Circle. Does the feedback loop amplify the initial change or dampen it? What makes you think so?

Wrap Up: Although their will likely be similarities among all the groups' Connection Circles, there are also likely to be differences depending on students' understanding/interpretation of the "story elements" and the depth to which they thought about connections. Encourage students to talk about these differences and to think about additional connections they may not have made during the original activity. Before moving on, be sure that your students have a good understanding of the difference between positive and negative feedback loops. Also, make sure students think about the balances between positive and negative feedbacks and how equilibrium is typically maintained, with significant changes to climate occurring only when the normal balance is tipped in one direction or another.


Student Notebooks

Suggestions for how to use Student Notebooks for Lab 5:


Assessment

There are several options for assessment of student understanding of material introduced in this lab. Teachers can choose from the following list, or create their own assessments.

Assessment Options:
  1. Assess student understanding of topics addressed in this investigation by grading their responses to the Stop and Think questions.
  2. Teachers may want to collect and grade the graphing activities or weather observation forms.
  3. Written Test for Lab 5 (Microsoft Word 2007 (.docx) 102kB May21 13) (Test key (Microsoft Word 2007 (.docx) 213kB May21 13))


State and National Science Teaching Standards

Cryosphere TEKS Alignment (Microsoft Word 127kB Nov15 11)

Cryosphere lab activities are aligned to standards in this document:

Texas Essential Knowledge and Skills (TEKS)

Lab 5 addresses the following Next Generation Science Standards (NGSS) Disciplinary Core Ideas:

HS-ESS2: Earth's Systems

ESS2.A: Earth's Materials and Systems

1. Earth's systems, being dynamic and interacting, cause feedback effects that can increase or decrease the original changes. (HS-ESS2-1) (HS-ESS2-2)

3. The geological record shows that changes to global and regional climate can be caused by interactions among changes in the sun's energy output or Earth's orbit, tectonic events, ocean circulation, volcanic activity, glaciers, vegetation, and human activities. These changes can occur on a variety of time scales from sudden (e.g., volcanic ash clouds) to intermediate (ice ages) to very long-term tectonic cycles (HS-ESS2-4)



Additional Resources

Background Information


Content Extension


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