08 Mar CGEO110 The Physical Environment, Explore glacier features
CGEO 110 TMU The Physical Environment Questions
Answer the following questions and submit this document to the course website. Goals:
1. Explore glacier features, including thickness, velocity, distance from headwall, moraine deposition, accumulation and snow melt;
2. Understand the effects of temperature and precipitation on glacier balance (advance and recession);
3. Explain how glaciers can shape the Earth’s surface.
Glaciers and Glaciation
(This section is adopted from http://www.antarcticglaciers.org/students-3/geography-a-level-2/projects/) Navigate to the PHeT Glacier Simulation (http://phet.colorado.edu/en/simulation/glaciers), run it on your computer. The file will open up and you’ll see the two tabs, Introduction and Advanced. Move the Bear slider along to move up and down the valley. Activities (1 mark per question, a total of 14 marks) Introductory Questions
1. When you don’t change anything, what can you observe on the glacier? Is it advancing or retreating, or is it in steady state?
2. What happens to rocks beneath the glacier? What landforms are created as you watch the glacier?
3. What glacier structures can you see on the ice surface, and what happens to them? What does this tell you about the glacier’s flow? Equilibrium Line Altitude Using the radio buttons on the green left-hand box, select ‘Metric’ and ‘Equilibrium Line’. 1. What is the Equilibrium Line showing you?
2. Click on the Ice Drill and drill some holes in the glacier ice. What happens to your drill holes? Why does this happen?
3. Click on the Measuring tool and measure ice thickness. Where is the ice thickest? Why is this?
4. Click on the Thermometer Tool. How does the temperature change along the length of the glacier? What about at the tops and bottoms of the mountains? Why is this?
5. Use the GPS tool to measure the length of your glacier.
6. Place a Flag on your ice surface near the top of the glacier. What happens to it? What implications does this have for rocks that fall on the ice surface? Advance and Recession Now use the Sea-Level Temperature and Average Snowfall sliding bars to make the glacier grow and shrink. If your glacier disappears or runs away, you can reset it to the Glacier Steady State. Use the Bear Slider to move along your glacier.
1. What do you need to do to make the glacier shrink?
2. What does it tell you about the relationship between temperature, precipitation, and glacier length?
3. What happens to the Equilibrium Line as you make it colder or warmer? Why does it move? What does this mean for our understanding of Equilibrium Lines?
4. Use the Measure Tool to track changes in ice thickness through time as you grow and shrink your glacier. How does the ice thickness change? Why does the ice thickness change? Click on the Advanced Tab. Experiment with the options in the boxes.
1. Turn on Ice Flow Vectors. The length of the vector is proportional to glacier velocity. What do you notice about the length of the vectors along the length of the glacier, and from the ice surface to the bed?
