This lesson will help students understand how glacier movement is an example of water shaping Earth’s systems. Students will use radar glacial scans to practice analyzing data using tools and technologies in order to make valid and reliable scientific claims.
Two 45-minute class periods
- Students will be able to analyze radar data to determine glacier depth.
- Students will be able to communicate how water shapes Earth’s systems based on their analysis of data using tools and technologies.
Prep for Teachers
- If possible, arrange computer access for students to work individually or in small groups.
- Download and print the Glacier Analysis and Glacier Data Set handout. Alternatively, if individual computer access is available, upload the Glacier Analysis and Glacier Workbook to Google classroom or another document sharing platform.
- Begin the lesson by posing the question: How do glaciers move?
- What do you know about glaciers moving and shaping our current landscape?
- Are glaciers still moving today?
- Then, as a class, watch the video from the resource Fastest Glacier until minute 01:13, which features Jakobshavn Glacier, one of the fastest-flowing glaciers in the world. Ask students the following questions:
- How do scientists study glaciers?
- Do you think all glaciers move in similar patterns?
- How do glacier movements impact the rest of the planet?
- Then, as a class, watch the video from the resource Investigating Meerkat Group Behavior with Wave Based Technologies until minute 1:09 to introduce students to using radar to penetrate layers of natural material like the ground covering the meerkat den. Tell students that in this lesson, they will explore radar data in an effort to understand why two adjacent glaciers move at different rates.
- Inform students that they are going to study two glaciers, Bakaninbreen and Paulabreen. The glaciers flow together, and squeeze a band of rocks between them at their suture – the red line B <- A in the linked image. These glaciers are interesting because despite being in very close proximity to each other, they show very different flow behavior. Paulabreen flows faster than Bakaninbreen and there are other differences, but the students will focus on the speed. Dr. Booth from the Investigating Meerkat Group Behavior with Wave Based Technologies resource used similar radar technology to investigate why the glaciers display different flow behaviors. He scanned the suture with a similar radar to that used in the meerkat video and now students will analyze the scan provided in the Glacier Data Set.
- The radar records time (in nanoseconds), but in order to understand the glaciers’ flow the depth of the glaciers is more informative. The students must therefore convert time to depth, or distance. The equation to convert time to distance is:
distance = 0.5 x time x speed
Where distance is the depth of the glacier, time is how long it took the radar to travel through the glacier ice, and the speed of the radar in ice is 0.168 m/ns.
Work through the first example with the class. The bed of Paulabreen, in Figure 2 of the Glacier Data Set, at 0 m along the profile, appears at approximately 750 nanoseconds.
distance = 0.5 x 750 ns x 0.168 m/nsInstruct students to record this result in the table in Part I of their worksheet. Students should record the distance along the profile in the first column, the time in the second, and the calculated depth in the third. Students should select at least seven more points along the glacier bed line (light brown) and convert the radar travel time to distance. The points do not need to be evenly distributed, the time is fairly constant between 0 and 200 m along the profile. Students should select more points afterwards, between 200 and 350 m along the profile.
distance = 63 m
- Once students have calculated all the distances, they can plot the distance along the profile vs. the glacier depth. Students can use excel or other graphing software to create the graph, or they can draw the graph on graphing paper. The Glacier Workbook spreadsheet can be used to plot the distance along the profile vs. the glacier depth. Only eight rows, 2 – 9 are selected in the workbook, if students selected more than eight points they will need to adjust the chart. Here is an example of a finished graph.
- Instruct students to analyze their graphs and answer the questions in Part II of the worksheet. Guide students toward these answers:
- The moraine, or transition, between Paulabreen and Bakaninbreen is at 160 m.
- Paulabreen is much deeper than Bakaninbreen.
- Let the students’ creativity run free in the last question. They will explore it in more detail in the “Elaborate” section.
- Share with students that figuring out the bed profile, the technical term for their graphs, tells scientists where water would likely flow since water usually flows downhill. Changes in water at the glacier bed could influence the different flows of Paulabreen and Bakaninbreen. Next, Dr. Booth studied the reflection of the radar wave as well as the time traveled, to get a more accurate idea of how much water there is at the glacier bed.
- Wrap up the lesson by having students answer the following: What other scientific question could be addressed by radar exploration? They should write a one page paper describing what they are interested in and how radar could be used to explore this area.
Questions to consider:
- How is climate change impacting ice sheets in the Arctic?
- How does wreathing and erosion affect underwater formations, like coral reefs or bridge foundations?
- What type of structures do burrowing animals, like the meerkat, create?
The data for this activity was generously provided by Dr. Adam Booth. More information about Dr. Booth’s research can be found here.