Earth s Layers Activity

Transcription

1 Earth s Layers Activity Purpose: To visualize the basic structure of the Earth and how we study it. Materials: Procedure: A piece of poster board shaped like a pizza slice with radius of about 16 cm Compass Colored pencils Calculators and rulers Computer and textbook for data collection 1. First, let s determine the Earth s real radius and the scale of our model. On your scale model, we ll give the Earth a radius of 13 cm and leave a couple of centimeters to show the thickness of the atmospheric layers as well. Earth s Radius Scale for Model 2. Now collect the data you will need to create your model of Earth s interior. Fill in the table below. The last two columns will require calculations. Inner Core Outer Core Mantle Crust Entire Atmosphere Troposphere Stratosphere Mesosphere Thermosphere Exosphere Actual Thickness of Layer (km) Percentage of Earth s Radius Thickness of Layer on Scale Model (cm) 3. Once you ve checked your calculations with your instructor, measure out the appropriate lengths for each layer on your pizza slice of poster board. Use a compass to draw circular arcs at each radius. Then use the colored pencils to give each layer its own color. Be sure to label each layer and include the actual radii you looked up somewhere on your model. 4. Look up the depth of the lithosphere and add this to your model. Use your model and the internet to answer the questions below. Be sure to use scientific sources. 1. What distinguishes each layer inside the Earth from the next layer?

2 2. What is the lithosphere, and why does it overlap with the mantle? 3. What distinguishes one layer of the atmosphere from the next? 4. Where does the atmosphere end? Can you find a simple answer to this question? Why or why not? 5. What is the greatest depth humans have ever drilled into the Earth? What layer does this put us in? 6. How do we know study the following layers of our planet: a. Inner core b. Outer core c. Mantle Summary: Briefly summarize what you ve learned from this activity. Were there any facts here that were surprising? Did your scale model come out the way you expected, or were some layers thicker or thinner than you anticipated? What methods did you learn about for studying our planet?

3 Greenhouse Gasses Activity Purpose: To better understand carbon dioxide s effect on the atmosphere. Introduction: A lot is being said in the news these days about the Greenhouse Effect and global warming. Much of the blame for the global warming issue is being placed on the burning of fossil fuels. But what isn t always clear is what fossil fuels really do add to the atmosphere, and how that added material causes the atmosphere to heat up. In this lab, we re going to look at the effect of carbon dioxide in the atmosphere. Carbon dioxide is a significant waste product produced by the burning of fossil fuels. It is also the gas that bubbles out of your Coke to make it fizzy. Carbon dioxide is an odorless, colorless gas which, at first glance, seems pretty harmless. It is non-flammable and occurs naturally in our atmosphere as a trace element. It is a necessary ingredient for photosynthesis, so without it, plant life could not survive. It is also necessary for human life on Earth because it helps keep our planet warm enough to support life. But what happens when we artificially increase the amount of carbon dioxide in our atmosphere? That s what we re going to look at more closely in this lab. Materials: 2 cans Coke at room temperature (brand name Coke works best) 2 identical, empty 2 liter bottles marked #1 and #2. 2 rubber stoppers 2 stirring rods 1 large beaker or jar 1 funnel 2 thermometers 1 timer or stopwatch Sunshine or heat lamp Graph paper Procedure: 1. Pour one can of Coke directly into Bottle #1. 2. Pour the second can of Coke into the beaker or jar. 3. Stir both drinks vigorously for at least 2 minutes to get them to release their carbon dioxide. One will be releasing the gas inside its bottle, the other into the room. 4. Pour the decarbonized soft drink from the jar into the Bottle #2. Use the funnel so none of the drink is lost. Both bottles should remain uncapped until the second drink is poured, so that the atmospheric pressure is the same in each. 5. Cap both bottles with the rubber stoppers and insert the thermometers. 6. Place the bottles under the heat lamp. The bottles should be the same distance from the lamp and sitting on identical surfaces. 7. Measure and record the temperature in the bottles every minute for the next 20 minutes. Use the timer to make sure you record the temperatures at equal time intervals and read the times in each bottle as close together as possible. Record the temperatures in the table below.

4 Time (minutes) Temperature of Bottle #1 ( C) Temperature of Bottle #2 ( C) Graph the data for each bottle. Make two lines, but put them on the same graph. Use a different symbol or color for each bottle. Then connect the points with lines. You should have time on the horizontal axis and temperature on the vertical axis. Be sure to label your axes, including units, and then turn in your graph with this lab. Questions: 1. Do you see a difference in the temperature graphs for the two bottles? How are they different?

5 2. What does this suggest about the effect of carbon dioxide on Earth s atmosphere? 3. Is this a good model of the Earth s atmosphere? Why or why not? If not, does the experiment offer some valid insights? 4. What are the important controls in this experiment? 5. What are the possible sources of error in this experiment? Conclusion: Write a short, well-structured paragraph describing what you have learned about carbon dioxide from this experiment and how this relates to the problem of global warming in the world today. Be sure to show how your calculations and graphs support your conclusions. Also, explain why your results make sense or don t make sense.

6 Impacts Activity Purpose: To determine the factors affecting the appearance and size of impact craters and ejecta. Materials 1 pan "lunar" surface material (flour works well) tempera paint, dry or some other material that will color your surface. Flour with a little food coloring shaken into it would work, as would thin dry sand. sieve or sifter 3 impactors (marbles or other spheres with different weights) meter stick ruler "Data Chart" for each impactor at the end of this lab Graph paper (If you don t have any, print it off the internet.) Solar System Cards, pages 9-16 of the second file in this lab. You can print these or just study them on your computer. Sample Classification System Third file in this lab. Hypothesis: Study some pictures of the moon, either from your text or online. Look for both wide field images and close up images. From what you can see in photographs of the Moon, how do you think the craters were formed? What do you think are factors that affect the appearance of craters and ejecta? Procedure: Surface Preparation 1. Fill a pan with surface material to a depth of about 6 cm. Smooth the surface, then tap the pan to make the materials settle evenly. 2. Sprinkle a fine layer of dry tempera paint evenly and completely over the surface. Use a sieve or sifter for more uniform layering. 3. What does this "lunar" surface look like before testing? Cratering Process

7 1. Measure the mass of each impactor. Record the mass on the "Data Chart" ( last 3 pages of this lab) for this impactor. 2. Drop impactor #1 from a height of 30 cm onto the prepared surface. 3. Measure and record the diameter and depth of the resulting crater. 4. Note the presence of ejecta (rays). Count the rays, measure, and determine the average length of all the rays. 5. Record measurements and any other observations you have about the appearance of the crater on the Data Chart. Make three trials and compute the average values. 6. Repeat steps 2 through 5 for impactor #1, increasing the drop heights to 60 cm, 90 cm, and 2 meters. Complete the Data Chart for this impactor. Note that the higher the drop height, the faster the impactor hits the surface. 7. Now repeat steps 1 through 6 for two more impactors. Use a separate Data Chart for each impactor. 8. Graph your results. Graph #1 is should be average crater diameter vs. impactor height. Graph #2 should be average ejecta (ray) length vs. impactor height. Note: On the graphs, use different symbols (e.g., dot, triangle, plus, etc.) for different impactors.

8 Questions 1. Is your hypothesis about what affects the appearance and size of craters supported by test data? Explain why or why not. 2. How does mass effect crater size? 3. What do the data reveal about the relationship between crater size and velocity of impactor. 4. What do the data reveal about the relationship between ejecta (ray) length and velocity of impactor. 5. If the impactor were dropped from 6 meters, would the crater be larger or smaller? How much larger or smaller? Explain your answer. (Note: the velocity of the impactor would be 1,084 centimeters per second.) 6. Based on the experimental data, describe the appearance of an impact crater.

9 7. The size of a crater made during an impact depends not only on the mass and velocity of the impactor, but also on the amount of kinetic energy possessed by the impacting object. Kinetic energy, energy in motion, is described as: KE = ½ mv 2 where m = mass and v = velocity. During impact, the kinetic energy of an asteroid is transferred to the target surface, breaking up rock and moving the particles around. Calculate the kinetic energy of each of your impactors and record this on your data sheet. To get kinetic energy from the height from which you drop the impactor, use the equation: Energy = mgh where m=mass, g=9.8 m/s 2 and h = height from which you dropped the object. Be sure your mass is in kg and your height is in meters. This will give you energy units of Joules. 8. Try plotting crater diameter vs. kinetic energy as Graph #3. How does the kinetic energy of an impacting object relate to crater diameter? Conclusion for Part I: Write a brief paragraph explaining how a crater s size, shape and overall appearance are related to the impactor s mass and velocity. Be sure you support your conclusion with your results and explain why your results seem reasonable. What are the implications of this data for Earth if we should determine that a major impact is imminent? How would we use the data?