Using Maps and Mapping Technology

Map Projections Video Clip (approx 3 min) An attempt to portray the round - “spherical” Earth on a flat surface Creates large areas of distortions There are three common projections

Mercator Projection Features of Earth depicted in the form of a cylinder, stretched out on paper – usually a rectangular map Most accurate at point of contact – the equatorial areas Distortions away from point of contact - near the poles

Conic Projection A way of mapping the Earth in the shape of a cone ---point of cone situated directly over one of the poles A “birds-eye view” of the Earth Most accurate at point of contact - mid-latitudes Distortions away from point of contact - poles and equatorial areas

Polar Projection Portraying Earth or a portion of the Earth in a circular map Most accurate at point of contact – the poles Distortion further from the point of contact – mid-latitudes or equatorial area

Topographic Map Shows surface features or topography of the Earth natural and artificial features (fields, forests, rivers, lakes, glaciers, buildings, roads, power-lines, etc. elevation (with brown contour lines) Little to no distortion Much more later!

Satellite Imagery Photographs made by means of artificial satellites Most often used: To predict weather on Earth To help create maps of the seafloor, other planets, topography, etc. Military intelligence Typhoon near Japan

Satellite Image of Earth At Night

Satellite Image of Ocean Depth

Satellite Image – Gulf Oil Spill

GPS “Global Positioning System”

Problems with GPS Works poorly in the following areas: Dense forest Deep canyons Caves Underwater

Latitude & Longitude

Latitude Horizontal/parallel lines on a globe or map Measure north or south of the equator AKA – Parallels

On a map latitude looks like this… equator

Examples: What line of latitude runs through Canada? equator

Examples: What line of latitude runs through Florida? equator

Longitude Vertical lines on a globe or map Measures east or west of the prime meridian AKA - Meridians

On a map longitude looks like this… Prime meridian International Date Line

Examples What is the longitude for the middle of S. America? Prime meridian International Date Line

Examples What is the longitude for California? Prime meridian International Date Line

Putting it together… What are the coordinates for the following X Y Z IDL PM y x EQ z

Map Scales Verbal Scale Representative Fraction (R.F.) Graphic Scale Example 1 inch = 1 mile Representative Fraction (R.F.) Example 1:24,000 (1 map unit is equivalent to 24,000 land units.) Graphic Scale Example

Map Symbols