Part 4—Use ANDRILL Animation to Simulate Climate Conditions
Step 1 Locate the ANDRILL drill site in on the map of AntarcticaExamine the map of research sites in Antarctica during the 2006-2007 season. Note the ANDRILL drill site in the lower portion of the map, near McMurdo Station.
Step 2 View the Climate Change AnimationIn this step, you will explore an animation of an ice shelf advancing and retreating. You will use the animation to create a model of a climate change cycle. Sediment layers are deposited over time. If a climate condition persists for a long period the sediment layer will be thick; if a climate condition lasts for only a short time the sediment layer will be thin. However, the rate of sedimentation (how fast the sediment layer is created) is not the same for each type of sediment. Refer to your sediment cards for a comparison.
- Click here to view the animation of ANDRILL drilling on the ice shelf.
- Click the start button below the animation. You will see the page pictured below. This image shows the current position of the Ross Ice Shelf and the location of the ANDRILL drill site. The column at the right shows sediment layers as they are being laid down at the drill site (they look like stripes of color). The thermometer shows the change in temperature of the Earth based on today's temperature. In other words, if you move the slider up 2 degrees C, Earth's temperature increases by 2 degrees C. The current average temperature of the Earth is about 15 degrees C.
Next, look at the two boxes in the lower left hand side, below the graphic. One box shows the time in years since the temperature changed. The other shows the distance of the ice shelf advancing (+ numbers), or retreating (- numbers), since the last change in temperature. At the start they both read "0" because the animation starts with today's conditions.
- Move the temperature slider up and down to increase, and then decrease, the temperature. Watch the animation and notice the change in the position of the ice shelf and the type of sediment layers being deposited. The higher the temperature, the faster Earth is warming, and the faster the ice shelf will retreat. The colder the temperature the faster Earth is cooling and the faster ice shelf will advance. Notice that even as the ice shelf advances and retreats, the location of the drill site does not change. The scale at the top of the page remains the same and shows the difference between where the ice shelf is today and its movement as you play the animation.
In the animation, the column at the right shows sediment deposits as they occur at the drill site. Note that the sediment types differ based on whether they were deposited under the ice or in open water. This is the information in the cores that researchers use to piece together Earth's climate history.
Step 3 Create a Climate Change Cycle
- Start the animation with a warm Earth, and then use the temperature slider to cool the Earth. When the glacier has grounded on the ocean floor, so the drill no longer goes through water, reverse the temperature slider and warm the Earth up again. As the animation runs, notice what kind of sediment is being deposited. Use the sediment cards from Part 1 as reference.
- Determine the different kinds of sediment that would occur during each part of the climate cycle you created above, as the ice shelf is advancing and retreating.
- Make a chart in your journal, or on a piece of paper, showing the sequence of these sediment types throughout the climate cycle you created. Keep track of the time interval for each sediment type deposited. Recall that the longer the time interval, the thicker the sediment layer that is deposited; the shorter the time interval the thinner the layer.
How does the amount of change in temperature effect the sediment layer thickness?
The greater the number of degrees of change in temperatureeither increase or decreasein a given time period, the faster the rate of change in climate. A fast change produces a thinner sediment layer representing that change. A slower the climate change event produces a thicker layer. Think of it like a slow moving snow storm: a slow storm has time to leave a larger deposit of snow before moving out.
Step 4 Create a Core Diagram in PSICAT
- Launch PSICAT program and create a sediment core that would be recovered at the drill site portrayed in the animation that you created in the previous step. Use the notes from the previous step to help you recall the thicknesses and time intervals. In your core diagram you will:
- Use all four of the types of sediment graphics to represent a full climate cycle.
- Pay attention to the thickness of the sediment layers as represented by the time length of each interval.
Step 5 Examine and Explain your Core Diagram
- Export your core diagram as a .jpeg or .png file. Insert it into a word processing document. In the document, explain where in the sediment core you see change events in the climate.
- Consider the following question. Even when scientists observe the same data, the conclusions that are drawn can vary. How might your core differ from core created by others who complete this activity?