Topography Help

By — McGraw-Hill Professional
Updated on Sep 4, 2011


Unlike what early people believed, the Earth is far from flat. Even in plains or deserts where you can see for miles, there are slight changes in the elevation of the land. A mountain like Pike’s Peak in the Colorado Rocky Mountain Range rises 4301 m above sea level.

In geology, elevation is the height (altitude) of an area or landform above sea level.

In fact, spectacular changes in altitude, give the land masses their personality. They make Earth Science such a diverse field. One story tells of how the words of the song, “America the Beautiful” were written by Katharine Lee Bates, an English professor from Wellesley College, Massachusetts, in July of 1893. Professor Bates, who was teaching a summer class at Colorado College, took a carriage and wagon ride to the top of Pike’s Peak with a group of students and other faculty members. After seeing the magnificent summit view of other mountains and far away plains, Bates was inspired to write the words to the song upon returning to Colorado Springs that evening. “America the Beautiful” was first published in The Congregationalist , a weekly journal, on July 4, 1895. The poem was published with music (composed by Samuel A. Ward) in 1910.

Besides singing about the land, we also use maps to describe the landscape. Most maps give geological information as well as directions. If you study a road map that lists the highest elevations in Colorado, the elevation of Pike’s Peak would be listed as 4301 m. The map will also show the heights of many of the other 54 mountains in Colorado with heights over 4200 m. Mount Ebert, the highest mountain in the state, would be listed at an elevation of 4400 m.

Topography is the recording of the contours and physical features of an area, especially on the land.

The word topography comes from the Greek words topos meaning place and graphein meaning to write. Geologists use topographical maps to give better information about the contours or highs and lows and curves of a place. There are thousands, if not millions, of topographical maps that show the height and shape of different areas in the United States. Many more maps exist for land masses around the world.

Most people use maps to get directions or to just learn the “lay of the land.” Today, we have the Internet for maps and driving directions. Some vehicles have GPS (global positioning system) to direct them to their destinations.

Figure 15-8 shows a simple picture of an area and its topographical map. Topographical maps include the elevation in feet or meters of an entire area.

Weathering and Topography Rock Flow

Fig. 15-8. A mountain as it appears on a topographical map with elevations.

Two-dimensional maps, with only the length and width of an area shown, are called base maps . These are the standard road maps that get people from here to there. These maps are drawn in relation to the north and south poles, generally with north at the top.

Two-dimensional maps include longitude and latitude lines to increase the accuracy of pin-pointing a specific location. Longitude lines run north and south between the poles (||), while latitude lines run horizontally (=) around the globe. Site locations are often given by their nearness to a longitude and latitude intersection.

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