Part I - Graphing the Earth's Magnetic Field Intensity Pre-lab prep The Research Question: How has Earth's magnetic field intensity changed during the last 800 thousand years? Your hypothesis: Test your hypothesis: Go to the following website to obtain the data to plot on a graph of Intensity vs. Age (Before Present Day). You will plot all of the data and yes there's a lot of it. Save your document often. You will need to add the following data point that is not included on the table: The age of the Earth is 0.0 representing today. The Earth's magnetic field strength intensity today is 11.5 units. This point has been entered on your spreadsheet for you. http://image.gsfc.nasa.gov/poetry/venus/Revstudent.html Scientists don't know for sure what the intensity level is that occurs when the Earth's magnetic poles reverse. but they are currently thinking it is around 2 intensity units or less. For the purpose of addressing the questions below we will assume that the field reverses when the intensity is around 1.9 units or less. Use your graph to answer the following questions. 1. Identify the dependent variable. Identify the independent variable. 3. Analyze the graph by answering the following questions. a. How many times has the field changed directions in the last 800 thousand years? b. How long ago was the magnetic field intensity least? What was the intensity ? c. How long ago was the magnetic field intensity greatest? What was the intensity ? 4. How do your results compare to your hypothesis? Explain 5. Use your graph to predict when the next reversal will occur. Explain your reasoning. Right click on the graph and select edit data. Overtype the numbers on the spreadsheet that opens. Enter the graph title, axes labels along with units