Part 1—Download GeoMapApp and Explore a Visualization of the Seafloor
Step 1 – Download and Open GeoMapApp
- Open the GeoMapApp homepage in a new window.
- From the Download Links panel on the left, click the link for your computer's operating system.
- On the web page that comes up for your computer, scroll to the bottom of the page, read the terms of distribution, and click AGREE to download the software.
- Click Agree to select the default Mercator Base Map.
- You may be prompted to create a directory or folder to store preferences for the program. If so, you can click Cancel to skip this step for your initial exploration.
Step 2 – Examine a Visualization of the Seafloor
When we look at world maps, we usually focus on the continents. Try to reverse your thinking and look at the ocean floor as the main feature of this map. As you visually explore the map below, you may notice some interesting features:
- What do you think the different colors represent on this map?
- Do you have any ideas for how the map might have been made?
- Why do you think some continents appear twice?
Step 3 – Explore Some Features of GeoMapApp
Zoom in and out
To zoom in on the map, click the magnifying glass with a plus sign in the toolbar then click on the location you want to enlarge. Use the magnifying glass with the minus sign to zoom out.
Read the cursor location
Click the arrow pointer on the left of the toolbar and move your cursor across the map image and notice the changing values at the top of the map. These values show your cursor's location as a set of latitude and longitude coordinates. The longitude value (E or W) tells how far east or west of the prime meridian the location is. The latitude value (N or S) tells how far north or south of the equator the location is.
Display a distance scale
To enable the distance scale, select Overlays > Distance Scale from the drop-down menu. The Scale will display on the left of the map.
A NOTE ABOUT SCALES: On rectangular maps of our round planet, distance scales change with latitude. Scales in GeoMapApp only apply to the latitude where they are displayed. To see a distance scale for other latitudes, click the arrows at the side or bottom of the window to scroll the map: the map image will "slide" beneath the stationary scale and the scale will adjust to show accurate distances at whatever latitude it is displayed. This is particularly apparent if you have zoomed in to a location.