Glacier Group Purpose Lesson Overview Materials Fig 1

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1 Glacier Group Name Purpose To determine which of the following parameters slope, ice temperature, or basal conditions affects the glacier speed the most. Lesson Overview This lesson is intended to teach students about variables that affect glacier flow: ice (flubber) temperature, slope, and basal conditions. Students will conduct an experiment to examine which of these factor influences glacier speed. Materials Rulers Flubber (optional 3 different colors, blue (cold), white (normal), and red (warm) see recipe in appendix PVC pipe cut in half (61 cm (24 ) long 10 cm (4.0 ) inner diameter) 150 grit Sandpaper (rough base) Tinfoil and cooking spray (wet base) Stopwatches Protractor Tape Toothpicks Graph paper Fig 1 Satellite image of three glaciers converging in one valley, Alaska. Mars Landforms Glacier Lab Student s version 1

2 Why studying glaciers is important? Scientific data, whether taken in the field or relayed from satellites orbiting Earth or Mars, form the foundation for the scientific research that informs the world about our planet and our climate systems. Because they are so sensitive to temperature fluctuations, glaciers provide clues about the effects of climate and global warming. Knowing which factors control glacier mobility allows scientists better model and more accurately predict what will happen to glaciers in response to Earth s changing climate. Procedure First mark the half-pipe with a start, middle and finish lines along the length of pipe. Be sure to leave 13 cm (5 inches) at the top of the half-pipe to give you an area to place the flubber at the start. The single recipe of flubber makes an appropriate amount to use for the experiments, with the exception of experiment 4, which uses half the amount of flubber. Before placing the flubber in the half-pipe to start the trial, ball it up place it in the halfpipe but don t handle it too much so as not to warm the flubber and hold it in place for a few seconds at the top of the so that it grips the sides of the half-pipe. NOTE: Don t get the flubber on carpets, upholstery, wood furniture, paper, or pets. Enough water will dissolve the mixture - sometimes. Try to keep clean dirt will allow mold to grow on the mixture. When not in use keep in container. Before the students begin the glacier experiment, have them hypothesize what will happen and write down their predictions. Which factor will cause the flubber to flow more quickly: temperature, slope, or basal condition? How would environmental conditions produce these factors in a glacier? EXPERIMENT 1: Slope Effects First experiment will test how changes in slope affect glacier flow. Students will test whether ice flows at the same velocity at slopes of 30, 40, and 50. Use the same temperature flubber in all trials. 1. Incline half-pipe at 30. Check degree of inclination with protractor. 2. Place flubber at top of pipe, behind start line. Fig. 2 A three-dimensional image of Mars South Pole glacier. Mars Landforms Glacier Lab Student s version 2

3 4. Record the time when flubber reaches the halfway point 5. Stop timing when the flubber crosses the finish line 6. Record time and distance results in lab sheet 7. Repeat steps 2 through 6 but this time incline the half-pipe to Repeat steps 2 through 6 but this time incline the half-pipe to 50. EXPERIMENT 2: Basal Roughness The next experiment will test how changes in basal condition affect glacier flow. Students will test whether ice flows at the same velocity with varying basal condition from rough, to smooth, to lubricated. Use the same temperature flubber in all trials. Part 1: If you did experiment 1 then you can skip to part 2 of experiment 2 and write your results from experiment 1 in the data sheet for this part. 2. Place flubber at top of pipe, behind start line. 5. Record time and distance results in lab sheet Part 2: 1. Line the inside of the half pipe with 150 grit sand paper between the start and finish lines. Cut sheet of sand paper in half and tape down the two halves at the ends. Double sided tape may be used to help conform the sandpaper to the half-pipe. 2. Incline half-pipe at 40. Check degree of inclination with protractor. 3. Place flubber at top of pipe, behind start line. 4. Start timing the flubber when it crosses the start line 5. Stop timing when the flubber crosses the finish line 6. Record time and distance results in lab sheet Mars Landforms Glacier Lab Student s version 3

4 Part 3: 1. Line the inside of the half pipe with aluminum foil between the start and finish lines, place tape at both ends. 2. Incline half-pipe at 40. Check degree of inclination with protractor. 3. Lubricate foil lined half-pipe with 2 Tbls. of cooking oil. 4. Place flubber at top of pipe, behind start line. 5. Start timing the flubber when it crosses the start line 6. Stop timing when the flubber crosses the finish line 7. Record time and distance results in lab sheet EXPERIMENT 3: Temperature Dependence The next experiment will test how variations in ice temperature affect glacier flow. Flubber will be heated (either microwaved until warm to the touch, about 1 minute, or left in the Sun), kept a room temperature, and cooled (either chill briefly in the freezer or kept in a cooler on ice). Part 1: If you did experiment 1 then you can skip to part 2 of experiment 3 and write your results from experiment 1 in the data sheet for this part. 2. Place room temperature flubber at top of pipe, behind start line. 5. Record time and distance results in lab sheet Part 2: 2. Place warmed flubber at top of pipe, behind start line. Mars Landforms Glacier Lab Student s version 4

5 5. Record time and distance results in lab sheet Part 3: 2. Place chilled temperature flubber at top of pipe, behind start line. 5. Record time and distance results in lab sheet EXPERIMENT 4: Mass Dependence This next experiment will test whether the mass has any bearing on flow velocity of the glacier. 2. Place half the amount of flubber used in experiment 1 at top of pipe, behind start line. 4. Record the time when flubber reaches the halfway point 5. Stop timing when the flubber crosses the finish line 6. Record time and distance results in lab sheet Experiment 5 (Optional): Multi-component analysis This optional experiment will test the response of varying two factors: temperature and basalt condition. Experiments two and three tested these variables independently, but here students are going to measure these factors simultaneously. Students will test whether varying flubber temperature (e.g., heated, kept a room temperature, and cooled) and basal condition (rough, to smooth, to lubricated) simultaneously will return different results than predicted from experiments two and three. On the basis of experiments two and three, have students hypothesize the velocity for each experiment (there are nine experiments in this section, 3 different temperatures and 3 different basal conditions) and place them in order of slowest to fastest, and briefly describe why/how they came up with that list. Mars Landforms Glacier Lab Student s version 5

6 Conduct experiments A, B, and C with the same temperature flubber, and then repeat the experiments with flubber of a different temperature. Part A: 2. Place flubber at top of pipe, behind start line. 5. Record time and distance results in lab sheet Part B: 1. Line the inside of the half pipe with 150 grit sand paper between the start and finish lines. Cut sheet of sand paper in half and tape down the two halves at the ends. Double sided tape may be used to help conform the sandpaper to the half-pipe. 2. Incline half-pipe at 40. Check degree of inclination with protractor. 3. Place flubber at top of pipe, behind start line. 4. Start timing the flubber when it crosses the start line 5. Stop timing when the flubber crosses the finish line 6. Record time and distance results in lab sheet Part C: 1. Line the inside of the half pipe with aluminum foil between the start and finish lines, place tape at both ends. 2. Incline half-pipe at 40. Check degree of inclination with protractor. 3. Lubricate foil lined half-pipe with cooking spray. 4. Place flubber at top of pipe, behind start line. 5. Start timing the flubber when it crosses the start line 6. Stop timing when the flubber crosses the finish line 7. Record time and distance results in lab sheet Mars Landforms Glacier Lab Student s version 6

7 Experiment 6 (optional): Glacier Deformation For this experiment, push toothpicks (vertically) into the surface of the flubber. Draw how they move/change direction during the experiment. What do you think this means about how the flubber is flowing? 2. Place flubber at top of pipe, behind start line. 3. Push toothpicks (vertically) into the surface of the flubber so they make a 4 by 4 array of toothpicks. Draw picture here Mars Landforms Glacier Lab Student s version 7

8 Glacier Experiment Lab Sheet: Remember velocity = distance divided by time. Experiment Condition Distance Time Velocity 1 Slope Effects Half-distance 30 Incline Full-distance 30 Incline Half-distance 40 Incline Full-distance 40 Incline Half-distance 50 Incline Full-distance 50 Incline 2 Basal Roughness Normal PVC Sandpaper Al-foil & oil 3 Temperature Dependence Room Temp. Warmed Chilled 4 Mass Dependence Half-distance 40 Incline Full-distance 40 Incline 5 Multi component Flubber Temp. Basal Condition Room Temp. Normal PVC Sandpaper Al-foil & oil Warmed Normal PVC Sandpaper Al-foil & oil Chilled Normal PVC Sandpaper Al-foil & oil Questions (You will need read the background reading in order to answer some of these questions) 1. Plot the velocity of all experiments conducted so that they all fit on the same graph. 2. Compare your hypotheses with the data. Consider experiments 1, 2, 3, and 4 which experiment produced ice flows of the greatest velocity and which experiment produce flows with the slowest velocity. How do these results compare with your original hypotheses? Mars Landforms Glacier Lab Student s version 8

9 3. Eliminating the exterior variables that cause glaciers to flow (e.g., ice temperature, basalt condition and incline), what causes glaciers to move at all? Hint: combine the data from experiment 1, half and full distance time on the 40 incline, and experiment 4 to construct your hypothesis. 4. Compare and contrast the properties (e.g., temperature, rheology or ability to flow) of flubber and ice. 5. What properties of a glacier did flubber simulate well and which did it no simulate well. On this basis determine whether flubber is a good analog to ice? 6. Can the advance or retreat of glaciers serve as evidence for changes in climate or season? Cite your experiments as evidence where appropriate. Expected Results Result #1: Flubber flowed faster over steep slopes flubber was not as sensitive to changes in slope as was expected. This experiment works best within a fairly narrow range of slopes (slopes that are too small prevent flow and slopes that are too high cause the flubber to roll instead of flow down the PVC pipe!) Result #2: Flubber consistently flowed faster over the wet bed than the rough one. Result #3: Warm flubber flowed the fastest, and cold flubber flowed the slowest (regardless of the basal conditions Experiment #4). Result #4 (High level observation, not expectant to recognize): While results are not entirely realistic (the temperature range of flubber greatly exaggerates the natural range of ice temperatures), the activity illustrates that ice velocity is sensitive to a number of different variables. Mars Landforms Glacier Lab Student s version 9