APPENDIX 4 Using Google Earth

APPENDIX 4 Using Google Earth

Google Earth is a virtual, interactive globe that offers a unique spatial perspective on Earth’s surface. Google Earth uses geo-referenced satellite imagery, aerial photography, and GIS to portray Earth’s surface features in three dimensions.

Google Earth can be used with this book to enhance your understanding of key topics. Living Physical Geography offers a virtual tour and problem set with multiple-choice questions to strengthen your understanding of the text material. Digital “.kmz” files are provided at the LaunchPad website for this book: www.macmillanhighered.com/launchpad/gervais1e.

Getting Started

Google Earth is free to download on your personal electronic device and is often found installed on campus computers. It is not recommended that you use a smartphone to interface with Google Earth because the screen size is too small to discern many of the details that will be explored in this text and there is limited functionality. Once you have downloaded the program (at google.com/earth/download/ge/) or have accessed a device on which it is installed, find and double-click the program to get started.

Basic Functions and Practice Using Google Earth

PLACE SEARCHES: You can locate features by typing the location name, such as “Mount Everest,” in the upper left search sidebar (Figure A.6). The geographic coordinates of a feature, such as 27°59′8″ N, 86°55′24″ E, can also be entered. Doing either of these things allows you to “fly” to Mount Everest.

Figure A.6

A Google Earth view of Mount Everest. Tilting makes it possible to see the topographic profile of a feature such as Mount Everest. Each of the functions shown here with callout bubbles will be used in the Exploring with Google Earth feature at the end of each chapter.
(Source: © 2014 Google, Image Landsat, © 2014 Cnes/Astrium, © 2014 DigitalGlobe)

Practice: Type “Mount Everest” or “27°598N, 86°5524E” in the search sidebar.

TILTING: Notice in the Mount Everest view that it is initially very difficult to see the relief of the mountain. Tilting is an essential means of viewing and assessing vertical relief in a view. There are a number of ways to tilt your view:

Touch pad: Use the Tilt function in the upper right Navigation panel.

Keyboard: Hold the Shift key down and press the Up or Down arrow keys.

Computer mouse: Hold your mouse wheel down while moving the mouse toward or away from you.

Practice: Tilt your view so that you can see Mount Everest from the side (see Figure A.6).

ZOOMING IN AND OUT (CHANGING “EYE ALTITUDE”): Zooming in closer or out farther from the surface provides different scales of view. The “eye altitude” indicator is located in the lower right of the screen. There are several ways to zoom in or out:

Touch pad: Use the Zoom slider tool in the upper right Navigation panel.

Keyboard: Use the Page Up key to zoom in and the Page Down key to zoom out.

Computer mouse: Double-click the left mouse button to zoom in and the right button to zoom out, or use the mouse scroll wheel.

Practice: With Mount Everest in view, zoom to 350 km (200 mi) above Earth’s surface.

MOVING: Moving can be done either by sliding your finger across the touchscreen or by holding a mouse button and dragging the view. There is also a Move tool in the Navigation panel in the upper right of the screen.

SIDEBAR LAYERS: In the bottom left of the screen are the sidebar layers. Here you can activate different data layers, such as roads and borders, political labels, georeferenced photos, current weather, and many other useful data.

Practice: Activate the “Borders and Labels” layer. You should see yellow international borders appear with the names of political bodies such as countries, territories, and cities.

MEASURING DISTANCES: In the toolbar at the top of the screen there is a ruler icon that activates the measuring tool. Distance can be measured as a single line or as the cumulative distance along multiple points of a path. Different measurement units, such as kilometers or miles, are available in the pulldown menu.

Practice: Make sure that you are 350 km over Mount Everest with the “Borders and Labels” layer activated. Measure the distance between Mount Everest and the capital of Nepal, Kathmandu, in kilometers. (Your answer should be about 160 km.)

DETERMINING ELEVATION: You can quickly determine the elevation of any location by moving the cursor over that location and reading the elevation indicator at the bottom of the screen. Locations beneath the oceans are given in negative values to indicate their depth below sea level. In the Tools menu, then the Options menu, you can change the units of display from kilometers to miles or vice versa.

Practice: Enter 19°59N, 76°50W to fly to southern Cuba. What is the elevation at this location? Your answer should be about 1,300 m (4,300 ft). Now move your cursor south by about 30 km (20 mi). What is the greatest depth of water you can find? Your answer should be about –6,700 m (–22,000 ft).

ROTATING: North, by default, is at the top of the screen. Rotating provides different angles of view.

Touch pad: Touch and move the North arrow in the Navigation panel.

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Keyboard: Hold the Shift key down and press the Left or Right arrow keys.

Computer mouse: Hold your mouse wheel down while moving the mouse sideways.

Practice: Zoom in to an eye altitude of 20 km (12 mi) directly over Mount Everest. Rotate your view to examine all sides of the mountain.

THE GEOGRAPHIC GRID: You can turn the geographic grid on or off by pulling down the View menu and selecting or deselecting “Grid.”

Practice: Turn the geographic grid on and go to the origin by entering “0, 0.” Zoom out to an eye altitude of 4,000 km (2,400 mi). What country does the prime meridian first run through as it goes northward? Your answer should be Ghana. What country does the equator first run through as it goes eastward? Your answer should be Gabon.

Practice: Explore the geographic grid on your own by moving around the globe’s surface and viewing the grid system. Type in your home address to see the coordinates of where you live. Zoom in to see your house or apartment.

GEOGRAPHIC COORDINATES: Slowly roll your cursor across the screen and note the changing geographic coordinates in the lower right of the screen.

Practice: Type “Dead Sea” in the search sidebar. What are the geographic coordinates in degrees and minutes? Your answer should be near 31°20N, 35°30E.

HISTORICAL IMAGERY: You can assess changes in a given region by activating historical imagery.

Practice: Examine deforestation in the Amazon Basin by typing in the coordinates 10°7S, 63°32W and zooming out to 40 km (25 mi) eye altitude. Click the Historical Imagery button found in the toolbar. The Historical Imagery icon will appear in the upper right of your screen. Drag the slider tool to the far left, to June 1975, and note the state of the forest. Next drag the slider tool to the right in increments, noting how the forest changes. You should be able to see a progression of deforestation through time.

VIEWING CONTOUR LINES: You can view contour lines in Google Earth by switching to Google Maps mode. Do this by clicking the Google Maps icon in the toolbar.

Practice:Enter “Mayon Volcano” in the search sidebar. Click the Google Maps icon in the toolbar. In the pulldown menu in the upper left corner, select “Terrain.” You should be able to see the contour lines of the volcano. What is the interval between the index (dark) contours? Your answer should be 100 meters.

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