Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Large igneous province wikipedia , lookup
Global Energy and Water Cycle Experiment wikipedia , lookup
History of Earth wikipedia , lookup
Spherical Earth wikipedia , lookup
History of geomagnetism wikipedia , lookup
Future of Earth wikipedia , lookup
Age of the Earth wikipedia , lookup
History of geology wikipedia , lookup
Schiehallion experiment wikipedia , lookup
Amy Wagner Modeling Earth’s Inerior RL Moore Submission 2011 Lab Title: Modeling Earth’s Interior Purpose: To calculate density and relate it to Earth’s interior layers. To construct a model of Earth using an appropriate scale. To generate a graph that depicts Earth’s gradient and draw conclusions from the graph. Materials: Density cubes (Copper, Brass, Aluminum, and Steel), ruler, Play Doh (four different colors), plastic knife, string, triple beam balance, Microsoft Excel Background: Three centuries ago, the English scientist Isaac Newton calculated, from his studies of planets and the forces of gravity, that the average density of the Earth is twice that of surface rocks and therefore that the Earth's interior must be composed of much denser material. Our knowledge of what's inside the Earth has improved immensely since Newton's time, but his estimate of the density remains essentially unchanged. Our current information comes from studies of the paths and characteristics of earthquake waves traveling through the Earth, as well as from laboratory experiments on surface minerals and rocks at high pressure and temperature. Other important data on the Earth's interior comes from geological observation of surface rocks and studies of the Earth's motions in the Solar System, its gravity and magnetic fields, and the flow of heat from inside the Earth. The planet Earth is made up of three main shells: the very thin, brittle crust, the mantle, and the core; the mantle and core are each divided into two parts. Although the core and mantle are about equal in thickness, the core actually forms only 15 percent of the Earth's volume, whereas the mantle occupies 84 percent. The crust makes up the remaining 1 percent. Our knowledge of the layering and chemical composition of the Earth is steadily being improved by earth scientists doing laboratory experiments on rocks at high pressure and analyzing earthquake records on computers. Part I: Density of Earth’s Layers Procedure: 1. Draw the Density Data Table (on the back of this page) in your composition notebook with a ruler. Make sure that you include the title of the table. 2. The technician will obtain one of each of the four density cubes (Copper, Aluminum, Steel and Brass). Use the triple beam balance to measure the mass of the object. Record this information in your data table. 3. The maintenance director will use a ruler to determine the volume of the cube in cubic centimeters. Round numbers to the tenths place. Record this information in your data table. 4. Use the information collected to determine density and the layer of the earth represented. 5. Work with group members to answer the questions below the data table. Record your answer in your composition notebook using complete sentences. 1 Amy Wagner Modeling Earth’s Inerior RL Moore Submission 2011 Density Data Table Density Cube Mass (g) Volume (cm3) Density (g/cm3) Layer of Earth Represented Copper 1 Aluminum 2 Steel 3 Brass 4 *Use the internet to find the actual densities of Earth’s layers and determine which layer each cube represents.* Use complete sentences to answer the following question. 1. What trend do you notice in the density of Earth’s layers? ____________________________________________________________________________________ ____________________________________________________________________________________ 2. Why do Earth’s layers vary in density? How do you think they got this way? ____________________________________________________________________________________ ____________________________________________________________________________________ 3. How do you think scientists were able to determine what the composition of Earth’s layers? ____________________________________________________________________________________ ____________________________________________________________________________________ 2 Amy Wagner Modeling Earth’s Inerior RL Moore Submission 2011 Part II: Model of Earth’s Depth Background: The Earth's structure, scale and our place on it can be difficult to comprehend. Today we will use Play Doh to create a physical model. We will also scale the data to make an accurate model of Earth. At times it is difficult to visualize the relationships among numbers if they are in an inconvenient form or very big like Earth. The data table on the left contains a list of measurements. This raw data can be converted into a form that is easier to understand by dividing all the measurements by the value of the smallest (as shown in the table below). This process is called normalizing the data. Now it is easier to see the third measurement is 19 times larger than the first measurement. Raw Data (mm) Divided by = Normalized data 0.0625 0.0625 1 0.125 0.0625 2 1.1875 0.0625 19 0.875 0.0625 14 Procedure: 1. Draw the “Calculated Measurements” Data Table in your composition notebook with a ruler. Be sure to include the title of the data table. 2. Have the principle investigate obtain four different colors of Play Doh. The principle investigator should mass out the amount proper amount of Play Doh for each layer- consult the data table. The measurement (grams) must be exact. Return remaining clay. 3. Use the Play Doh you have massed to create a model of the earth and it’s layers. 4. Mass your model and measure the circumference of your model. Record this in your composition notebook. 5. Use plastic knife to cut Earth model in half. 6. Scale or normalize the data for the layer thickness of their model. Record in the “Calculated Measurements” data table that you create in your composition notebook with a ruler. Below is a data table that models how you normalize data. 3 Amy Wagner Modeling Earth’s Inerior RL Moore Submission 2011 Earth’s Layers Measurement Data Table Actual Depth Actual Volume (km) (x 109 km3) Inner core 1216 7.5 2 Outer core 2270 170 46 Mantle 2885 906 242 Crust 5 to 20 21 6 Layer Mass of clay in model (g) Calculated Measurements Layer Clay color used Actual layer Actual layer depth Layer in model Layer thickness of in your model depth (km) (normalized) depth in (mm) model (normalized) Inner core 1216 Outer core 2270 Mantle 2885 Crust 25 Analyzing Data String may be used to measure the circumference. a. Mass of Earth Model __________ g b. Circumference of Earth Model________ cm 1. How does the data you collected from your model compare to Earth’s actual mass and circumference? (You may refer to the figure on Page 2 of the lab to help you.) 2. Is the model you made an accurate representation of Earth’s internal layers, why or why not. Be sure to fully explain your answer. 4 Amy Wagner 3. Modeling Earth’s Inerior RL Moore Submission 2011 What is something you learned about Earth’s internal layers by creating this model that you did not know before? Part III: Modeling the Geothermal Gradient in Earth’s Crust Information: The geothermal gradient is the rate of increasing temperature with respect to increasing depth in the Earth's interior. Earth has different geothermal gradients based on the tectonic activity of aregion. In most areas of Earth the normal geothermal gradient is 25 °C/km. In different areas, where there are increased tectonic activities, such as a rift zone or divergent boundary, like the Mid Ocean Ridge, the gradient is 100 °C /km and a volcanic island arc such as Japan is 40 °C/km Geologic Setting Normal Mid Ocean Ridge (Iceland) Volcanic Island Arc (Japan) Geothermal Gradient (°C/km) 25 100 40 Directions: (Use the data table on the back of this page as you work through the steps below). 1. Working with a partner use Excel and create the data table of your geothermal gradient using a depth of 0 through value found in the data table (25 km). Plot the geothermal gradient of all three different geologic settings (normal gradient and rift zone or volcanic island arc). Use an interval of 1 km on the x – axis. 2. Create a Scatter Plot type graph of Geothermal Gradient. 3. Title of Graph = Geothermal Gradient of Earth’s Crust, X axis = Depth (km), Y axis = Temperature ( oC) 4. Email a copy of your graph to your instructor. Questions: 1. What is the relationship between temperature and depth? 2. Why is there so much heat beneath the surface of the Earth? (How was/is this heat created? Explain and give multiple examples.) 3. What are some ways in which the Earth releases its thermal energy? 4. What trend or trends have you noticed about the geothermal gradients you have graphed? 5 Amy Wagner Modeling Earth’s Inerior RL Moore Submission 2011 Depth Depth (km) Normal (25 C/km) 0 0 Rift Zone (80 C/km) Mid Ocean Ridge (100 C/km) 0 0 1 25 80 100 2 50 160 200 3 75 240 300 4 4 x 25 = 4 x 80 = 4 x 100 = 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 6 Amy Wagner Modeling Earth’s Inerior 7 RL Moore Submission 2011 Amy Wagner Modeling Earth’s Inerior RL Moore Submission 2011 Earth's Structure Misconceptions 1. Crust and Lithosphere (or plates) are synonymous terms 2. Asthenosphere is liquid (students are only familiar with liquid convection, not solid convection, many secondary education earth science films also specifically refer to a molten internal layer, and some fundamentalist religious groups specifically refer to the existence of a molten layer that is hell's physical location). 3. Lower Mantle is liquid (for reasons similar to above). 4. Earth's core is hollow, or that large hollow spaces occur deep within Earth (a relict of older cosmology and a mainstay of popular literature and Hollywood movies) The Core Summary: The Earth's outer core has stopped rotating. The result is disruptions in the planet's electromagnetic field, massive and dangerous electrical storms, and powerful solar generated microwaves that are capable of melting the Golden Gate Bridge and which eventually will "cook" planet Earth. In order to restart the liquid outer core's rotation a group of 'terranauts' must drill through the Earth's crust and mantle then set off nuclear bombs to initiate core movement. Dr. Brazzleton has developed a way to drill through rock using ultrasound waves. They make the journey to the inner core in a craft named Virgil, which is capable of drilling through the hard and dense mantle rocks. 8 Amy Wagner Modeling Earth’s Inerior Plate Boundaries 9 RL Moore Submission 2011