GeoMapApp
This program allows the user to graph data geographically. The range of available databases is impressive, including climate, plate tectonics, seismic and many other datasets.
The National Science Foundation’s MARGINS program (http://serc.carleton.edu/margins/) includes a number of educational outreach projects, including a set of “Mini-Lessons” using GeoMapApp developed by various educators. The lessons are mostly aimed at college level students taking introductory geology courses, but these mini-lessons can also be adapted for middle and high school. The MARGINS program is currently being replaced by the GeoPRISMS (http://www.geoprisms.org/), which will also engage in educational outreach.
The following exercises are designed to highlight some of the more interesting data applications. As you go through the exercises, please think about how you could use this application in your classroom. Once everyone is done with the exercises, we will discuss our ideas as a group.
Open the “GeoMapApp 3.0.1” application (click on “agree” on the agreement screen). The default base map is a Mercator projection, and the initial colors indicate elevation and bathymetry. On the tool bar (below the menu bar), choose the “grid” option. This panel contains a number of useful options for manipulating the map. I like to turn the “Sun Illumination” off.
Click the “Set Contour Interval and Range” button and hit “Okay”. This makes contour intervals visible on the map. Back on the tool bar above the map, click on the zoom icon. Zoom in on South Carolina and observe the contour lines.
Question One: Why are there so few contour lines in this area, but so many in other areas?
Turn off the contour intervals in the Global Grids box by clicking the “Set Contour Interval and Range” button. Now choose the “Distance/Profile” button beside the contour interval button. We will use this tool to create a profile of South Carolina. Click and hold on a spot in the mountains, and drag the line offshore. A new window will pop open showing the profile of the topography along that line. Move your cursor to the profile’s line. A red bulls eye will appear on the white line on the map corresponding to the geographic position of that elevation.
Question Two: Which is greater, the height of the mountains or the depths of the ocean?
Use the un-zoom button on the tool bar to zoom out until you can see all of North America. Under the “Basemaps” menu, choose “Select from searchable tear-off menus”, which will open a new window. Open “Global Maps” then “NASA Visible Earth (Blue Marble Imagery” and “Blue Marble Next Generation (January)”. Now click on “Blue Marble Next Generation (July)”. These two maps show how the Earth looks from space (on average) in those two months. Notice that you can only see the last baseman chosen. To switch which baseman is visible, go to the “Layer Manager” window and use the up and down buttons to switch the layers around.
Question Three: Other than the snow cover, how does the view of North America change from winter to summer?
Get rid of the Blue Marble base maps by clicking on the big “x” in each layer’s information in the Layer Manager window. Feel free to explore the other base maps before moving on to the next section. When you are done, close the base maps window.
Tear off the “Portals” menu next and double click “Earthquake locations, epicenter depths and magnitudes (ISC). The program will retrieve data from the International Seismologic Station website and plot the positions of all recorded earthquakes with magnitudes between 5.0-9.0 from 1964-1995 (you can sample subsets of this range on the submenu to the right of the map). Zoom out to the global scale.
Question Four: Are the earthquakes randomly distributed?
Zoom in on South America and choose the “Distance / profile” tool from the toolbar. Draw a profile from the Pacific Ocean to the Atlantic Ocean just below the widest part of South America. There is an obvious trench just off the coast of South America, with earthquakes becoming deeper toward the east (a Benioff Zone) where the Nazca plate is subducting beneath the South American plate.
Question Five: Where else on the world map do you see similar Benioff zones bordered by trenches?
Tear off the “Datasets menu” and choose “Earthquakes and Plate Boundaries -> Earthquake Locations – USGS-NEIC -> M1 and Greater Earthquakes, last 7 days (USGS).” Note that a data table appears below the map with information about each of the data points on the map. Choose the arrow tool from the toolbar and click on any of the gray dots. The information about that particular point will be highlighted on the data table. Some data sets have links to more information online (e.g., pictures and explanations), but this one does not.
Examine the toolbox to the right of the map. Click on the “Color” button and then select column “magnitude” from the pull-down menu. A graphic showing the scale will appear in a separate window. Change the color scheme by clicking on “Palettes” and choosing “rainbow”. You can similarly differentiate the data by using the “scale” button.
The “Graph” button allows you to do a simple bivariate scatter plot of any two columns of data. Click “Graph” and make sure that “Magnitude” and “Depth” are chosen and hit “okay”. The plotted data will pop up in a new window. Clicking on a data point in the graph will highlight the corresponding data point on the map and data table.
Question Six: Does there appear to be a correlation between the earthquake’s depth and magnitude?
Please use the remaining time to continue exploring GeoMapApp and thinking about exercises you could use in your classroom. Our classroom discussion start when everyone has had a chance to finish the exercises, but feel free to brainstorm with your fellow classmates before we begin our whole-class discussion.