2.1 Latitude and Longitude Mapping our world 2.1 Latitude and Longitude

Cartography- science of map making Uses imaginary gridlines to locate exact points on Earth The Equator separates the N and S hemispheres The Prime Meridian separates the W and E hemispheres

Latitude Run parallel to the Equator The Equator is 0o latitude The poles are located at 90o N and 90o S

Longitude Semicircles that extend pole to pole The Prime Meridian is 0o longitude Points west are numbered 0o-180o W Points east are numbered 0o-180o E

Time Zones There are 24 time zones on Earth Approx. 15o wide Some time zone boundaries may be shifted in order to make it more convenient locally

U.S Time Zones

Calendar Dates The International Date Line is located at the 180o meridian Traveling west across the International Date Line, you would move into tomorrow Traveling east across the International Date Line, you would move into yesterday

Mapping our world 2.2 Types of Maps

Maps- flat projections of a 3D Earth Mercator Projection Parallel lines of latitude and longitude Landmasses near poles are exaggerated

Conic Projection Projects points and lines from a globe onto a cone Distorts at top and bottom Very accurate for small maps Used for making road and weather maps

Gnomonic Projection Makes Great Circles Distort land and distance Shortest distance between two points Useful for plotting long distance air and sea travel

Topographic Maps Detailed maps showing hills and valleys Show changes in elevation Mountains Rivers Forests Etc…

Topographic Maps Contour Lines Contour Intervals Connect points of equal elevation Never cross Contour Intervals Steeper terrain will have closer lines or larger intervals See Index Contours

Depression Contour Lines Distinguish areas of lower elevation than the surrounding terrain Volcanic craters Mines Sinkholes

Map Legends and Scales Map Legends Map Scales Explanation of symbols found on a map Map Scales Ratio between the distances on a map and actual distances on the surface of the Earth May be graphic or verbal

Mapping our world 2.3 Remote Sensing

Remote Sensing The process of collecting data about Earth from far above Earth’s surface

Electromagnetic Spectrum Satellites detect different wavelengths of energy reflected or emitted from Earth’s surface Visible light, gamma rays, X rays, UV rays, infrared rays, radio waves, and microwaves

Landsat Satellites Use visible light and infrared radiation to map Earth’s surface This picture shows how the Texas coast was scarred by Hurricane Ike

Global Positioning System (GPS) Radio-navigation system of at least 24 satellites Allows users to determine exact position on Earth

Sea Beam Relies on sonar to map ocean floor Uses sound waves to detect and measure objects under water Sound waves are sent out and a receiving device picks up the echo and calculates the distance