MAPPING OUR WORLD2.1 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 WORLD2.2 Types of Maps

Maps- flat projections of a 3D Earth

Mercator ProjectionParallel 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 elevationMountainsRiversForestsEtc…

Topographic Maps Contour Lines

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 terrainVolcanic cratersMinesSinkholes

Map Legends and Scales Map Legends

Explanation of symbols found on a map

Map ScalesRatio between the

distances on a map and actual distances on the surface of the Earth

May be graphic or verbal

MAPPING OUR WORLD2.3 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