The Earth on the Web

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ALTHOUGH I have always been fascinated with geography, I do not have fond memories of geography class. Most of my days in geography were spent labeling all kinds of black-andwhite outline maps of portions of the Earth. I even vaguely remember taking a test where I had to memorize and label 20 or so of the major rivers of Africa. Of all the curriculum areas that technology gives us the power to transform, geography may top the list. If I were building a high-tech middle school or high school, I would make a special computer lab for geography a high priority. I would also build a computer lab dedicated to the Earth sciences. Within the last five years or so, major websites such as Google, Microsoft, Yahoo, and various U.S. government sites have made it possible to conveniently view all kinds of high-resolution images and maps of the Earth's surface. Today, there is no longer a need for outline maps in geography classes. Students can simply fire up a browser and study an aerial photograph of the features of interest. Google Earth, released last June, has garnered a lot of attention, but Google is just one site offering Earth imaging. In this column I present an overview of several major Earth-imaging sites. Of course, to incorporate Web-based imaging productively into the classroom requires some planning, but it's fun planning. Microsoft's TerraServer website at http:// terraserver-usa.com was one of the first sites to offer high-resolution aerial photographic images of the U.S., mostly obtained from the U.S. Geological Survey (USGS). The TerraServer images are in black and white, but the resolution is incredible. You can zoom in close enough to pick out individual houses in towns across the country. The images on the TerraServer seem to be particularly detailed when they feature navigable rivers and waterways. I suppose the USGS likes to keep the Navy and the merchant marine industry well informed. Just last weekend I used TerraServer to study the Atlantic Intracoastal Waterway near my house to help find potentially good fishing sites. Waterway features such as sandbars and deep holes are relatively easy to pick out on TerraServer images. (Incidentally, did you know that Microsoft CEO Bill Gates owns the rights to more pictures and images than anyone else in the world?) Aside from NASA, the USGS probably has more maps and images than anyone else in the world. There is an excellent listing of Earth-imaging sites at http://education.usgs. gov/common/map_databases.htm. The USGS also has a site that graphically displays image databases by category at http://rockyweb. cr.usgs.gov/outreach/mapcatalog. Categories on this site include topography, geology, image, culture and history, international and world, and environmental. I visited the culture and history site and found an interesting historical map of the Lewis and Clark expedition. My Mac's Web browser, Safari, crashed while trying to download the map, which was a 16.8-MB file, so I switched to Internet Explorer, which successfully downloaded the map. While at the USGS site, I also downloaded a high-resolution orthographic image of my home state of Nebraska. This was a 98-MB image file that took about 12 minutes to download using Internet Explorer. Once downloaded, the only software I could get to open an image file this size--19,593 x 11,922 pixels--was PhotoShop 7. I mention these details to point out why schools will need a specialized geography lab with fast computers, a high-speed Internet connection, and network storage. To further illustrate the need for a specialized lab, consider the recommended requirements for Google Earth. Google recommends the following computer configuration: Windows XP; 2.4-GHz processor; 512-MB memory (I would insist on 1 GB); a 3-D graphics card, with 32-MB video memory; and a 1280 x 1024, 32-bit true color screen. That is not to say that you can't enjoy Earth-imaging sites without such a computer. …