2Map Projections How is a map made? Points on a globe (3D) are transferred to paper (2D).May distort shapes and sizes.3 types of map projectionsMercatorRobinsonConic
3Map Projections Mercator Projection Lines of longitude are parallel. Shapes are preserved but sizes are distorted.Areas near the poles appear largest.
4Map Projections Robinson Projection Lines of latitude are parallel. Lines of longitude are curved.Shapes are preserved but sizes are somewhat distorted.
5Map Projections Conic Projection Made by projecting points from a globe onto a cone.Useful for mapping small areas in the middle latitudes.
6Topographic Maps What is a topographic map? Shows changes in elevation.Includes both natural and cultural features.
7Topographic Maps Reading Topographic Maps Contour Lines Connect points of equal elevations.Contour IntervalChange in elevation between two contour lines.Index ContoursDarker contour lines marked with an elevation.
8Topographic Maps Reading Topographic Maps Closed loops indicate hills or depression.Hachure marks indicate depressions.Contour lines will form V’s that point upstream.Closely spaced lines indicate rapid change in elevation.
9Topographic Maps Map Scale Ratio between distance on map and distance in real life.Given as a ratio (1:80,000) or as a scaled bar.
10Topographic MapsMap LegendExplains symbols used on the map.
11Topographic Maps Map Series Maps with the same dimension of latitude and longitude.
12Geologic Maps What are geologic maps? Show the arrangement and types of rock at the surface of the Earth.Cross-sections of the earth can be developed based on these maps.
13Geologic Maps 3-D Maps Can be made with computers using digitizing. Digitizing is a process by which points are plotted on a grid.
14Remote Sensing What is remote sensing? Way of collecting info about Earth from a distance.Often uses satellites.
15Remote Sensing Types of remote sensing Landsat Uses pictures of the Earth taken with different wavelengths of light.
16Remote Sensing Types of remote sensing Global Positioning System Uses 24 satellites that transmit radio signals of position and time.Receivers use this info to calculate position.