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Published byGeraldine Phillips Modified over 8 years ago
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Cartography – science of mapmaking
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Equator circles Earth halfway between the north and south poles ◦ Separates Earth into 2 equal halves (hemispheres)
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Latitude – distance North or South of equator ◦ Parallel ◦ Measured from 0 ° at equator and 90 ° at poles
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Each degree of latitude is 111km on Earth Can be broken into 60 smaller units called minutes (‘) Minutes can be broken into seconds (“)
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Longitude - distance in degrees east or west of the prime meridian. ◦ Prime meridian (Greenwich meridian) – 0 ° longitude ◦ Large semi-circles that extend vertically from poles ◦ Not parallel
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West of the prime meridian are numbered from 0° to 180° W East of the prime meridian are numbered from 0° to 180° E
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Both latitude and longitude are needed to locate a coordinate LATITUDE ALWAYS COMES FIRST!!!!
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Locating coordinates on a map.
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Earth is divided into 24 times zones Each time zone is approx. 15 ° Why are some of the time zone boundaries irregularly shaped?
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There are 6 time zones in the US
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International Date Line – 180 meridian ◦ West across IDL – you advance 1 calendar day (lose a day) ◦ East – move back 1 day (gain a day)
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Calculating time in other time zones
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Maps are flat models of the 3D Earth Projection – transferring points and lines on a globe’s surface to sheet of paper
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Mercator projection ◦ Parallel lines of latitude and longitude Conic projection ◦ Projecting points from a globe onto a cone Gnomonic projection ◦ Projecting points from a globe onto a piece of paper that touch the globe at a single point
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Topographic maps show elevations of hills and valleys of an area. use lines, symbols, and colors to represent changes in elevation
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3 Dimensional Maps ◦ Used to visualize earth 3 dimensionally to show rivers, mountains, valleys, and hills
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Contour Lines –Contour line connects points of equal elevation. –Elevation - distance of a location above or below sea level. Contour lines that are closer together indicate a steep slope
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–Contour interval - difference in elevation between two side-by-side contour lines –Depends on the terrain –Index Contours – contour lines labeled with a number What is the contour interval on this map? Contour Interval = 20, which means each line represents a change of 20 units Index Contour
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What is the contour interval? Contour Interval = 20
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–Depression contour lines - represent features that are lower than the surrounding area –Have hachures –short angled lines that point toward lower elevation
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Map legend explains what the symbols represent. Maps include both human- made and natural features that are located on Earth’s surface
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Map scale - ratio between distances on a map and actual distances on the surface of Earth Graphic Verbal Representative fraction
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Topographic Mapping
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