MapsMaps

Chapter 6, Section 3Chapter 6, Section 3

Map ProjectionsMap Projections

►How is a How is a map map made?made?

► Points on a globe (3D) are Points on a globe (3D) are transferred to paper (2D).transferred to paper (2D). May distort shapes and sizes. May distort shapes and sizes.

► 3 types of map projections3 types of map projections MercatorMercator RobinsonRobinson ConicConic

Map ProjectionsMap Projections

►Mercator Mercator ProjectionProjection

► Lines of longitude are parallel.Lines of longitude are parallel.► Shapes are preserved but Shapes are preserved but

sizes are distorted.sizes are distorted. Areas near the poles appear Areas near the poles appear

largest.largest.

Map ProjectionsMap Projections

► Robinson Robinson ProjectionProjection

► Lines of latitude are parallel.Lines of latitude are parallel.► Lines of longitude are curved.Lines of longitude are curved.► Shapes are preserved but Shapes are preserved but

sizes are somewhat distorted.sizes are somewhat distorted.

Map ProjectionsMap Projections

► Conic Conic ProjectionProjection

►Made by projecting points Made by projecting points from a globe onto a cone.from a globe onto a cone.

► Useful for mapping small Useful for mapping small areas in the middle latitudes.areas in the middle latitudes.

Topographic MapsTopographic Maps

►What is a What is a topographitopographic map?c map?

► Shows changes in elevation.Shows changes in elevation. Includes both natural and Includes both natural and

cultural features.cultural features.

Topographic MapsTopographic Maps

► Reading Reading TopographiTopographic Mapsc Maps

► Contour LinesContour Lines Connect points of equal Connect points of equal

elevations.elevations.

► Contour IntervalContour Interval Change in elevation between Change in elevation between

two contour lines.two contour lines.

► Index ContoursIndex Contours Darker contour lines marked Darker contour lines marked

with an elevation.with an elevation.

Topographic MapsTopographic Maps

► Reading Reading TopographiTopographic Mapsc Maps

► Closed loops indicate hills or Closed loops indicate hills or depression.depression. Hachure marks indicate Hachure marks indicate

depressions.depressions.

► Contour lines will form V’s that Contour lines will form V’s that point upstream.point upstream.

► Closely spaced lines indicate Closely spaced lines indicate rapid change in elevation.rapid change in elevation.

Topographic MapsTopographic Maps

►Map ScaleMap Scale ► Ratio between distance on Ratio between distance on map and distance in real life.map and distance in real life. Given as a ratio (1:80,000) or as Given as a ratio (1:80,000) or as

a scaled bar.a scaled bar.

Topographic MapsTopographic Maps

►Map LegendMap Legend ► Explains symbols used on the Explains symbols used on the map.map.

Topographic MapsTopographic Maps

►Map SeriesMap Series ►Maps with the same Maps with the same dimension of latitude and dimension of latitude and longitude.longitude.

Geologic MapsGeologic Maps

►What are What are geologic geologic maps?maps?

► Show the arrangement and Show the arrangement and types of rock at the surface of types of rock at the surface of the Earth. the Earth.

► Cross-sections of the earth Cross-sections of the earth can be developed based on can be developed based on these maps.these maps.

Geologic MapsGeologic Maps

► 3-D Maps3-D Maps ► Can be made with computers Can be made with computers using digitizing.using digitizing. Digitizing is a process by which Digitizing is a process by which

points are plotted on a grid.points are plotted on a grid.

Remote SensingRemote Sensing

►What is What is remote remote sensing?sensing?

►Way of collecting info about Way of collecting info about Earth from a distance.Earth from a distance. Often uses satellites.Often uses satellites.

Remote Sensing Remote Sensing

► Types of Types of remote remote sensingsensing

► LandsatLandsat Uses pictures of the Earth taken Uses pictures of the Earth taken

with different wavelengths of with different wavelengths of light.light.

Remote SensingRemote Sensing

► Types of Types of remote remote sensingsensing

►Global Positioning SystemGlobal Positioning System Uses 24 satellites that transmit Uses 24 satellites that transmit

radio signals of position and radio signals of position and time.time.

Receivers use this info to Receivers use this info to calculate position.calculate position.