Chapter 3 Test Review

A Mercator projection distorts the areas near the poles of the Earth. A polyconic projection is made as if a cone of paper had been wrapped around Earth. Mercator projection shows the whole world, except the extreme polar regions, on one map. Land masses are distorted away from the center point on a gnomonic projection. The Northern and Southern Hemispheres are divided by the equator.

The Eastern and Western Hemispheres are divided by the prime meridian and the 180º meridian. 180º of latitude separate the North and South Poles. The greatest number of degrees that a traveler can ever be from the prime meridian is 180º. A fractional map scale is indicated by a ratio. Ex. 1:1,000,000 or 1:24,000

The main method of mapping in the United States before the 1940s was plane-table surveying. Methods of remote sensing include: Landsat imaging, imaging radar, and Earth Observing System measurements. It can be hard to perceive different wavelengths of light on true-to-life color images so we use false-color images. A Global Positioning System (GPS) allows people to determine, their position, their speed, and the time, anywhere in the world.

Plane Table Survey

Remote Sensing

The following are elements involved with the Global Positioning System: satellites, master control station, and a GPS receiver. Contour intervals show differences between elevations at equal increments. Including sea level, how many contour lines would be on a map of an island 125ft tall? Contour Interval = 20 ft Depression contours are used to show craters of volcanoes.

A spot elevation of 1237 feet is shown on a topographic map A spot elevation of 1237 feet is shown on a topographic map. If the contour interval of the map is 20 feet, what is the value of the first contour line below the spot elevation? 1220 In addition to the distance between two points, what other fact must be known to determine the average slope between two points using a topographic map? Change in elevation

Which landform is shown by many contour lines that are very close together? Cliff When a contour line crosses a river, it bends to form a point in the direction of the river’s source.

Given a map of an island, be able to correctly shade in between isopluvials that connect equal average annual rainfall measurements. Identify two fundamental ways in which the meridian at 30º west is different from the parallel at 30º north. The meridian runs north/south whereas the parallel runs east/west. The meridian is a half-circle that runs from the North Pole to the South Pole whereas the parallel is a complete circle that runs around the world parallel to the equator.

How is the map scale on a topographic map of Chicago likely to be different from the map scale on an Apollo photograph of the entire moon? The moon photograph would probably be like a small-scale map, showing a very large area and thus having a scale with a very large ratio. The map of Chicago would probably be a large-scale map, showing a smaller area and thus having a scale with a smaller ratio.

Chicago, IL

The Moon