Maps, Etc.

What are they, why do we use them, and how do we use them

Globes• 3 dimensional representation of the Earth

• Advantages – exactly as it is, just smaller

• Disadvantages – not easily portable, since it is a sphere, we can only see half at a time

Maps

• 2 Dimensional Representations of Earth, or just a portion

• Advantages: easily portable; can be drawn to any scale

• Disadvantages: DISTORTION – because you are trying to make a round thing flat

Map Projections

• Projections help us overcome/reduce distortion

• Planar (azimuthal) • Conical – shows pretty

accurate shapes and sizes of landmasses, but distorts the edges [good for showing just one big land mass

• Cylindrical – Shows the entire Earth, and there are 3 types

Types of Cylindrical Maps• Mercator – shapes of

continents are distorted at the poles (tops/bottoms), and compressed near equator

• Homolosine – accurate size and shape, but distances are wrong (interrupted)

• Robinson – entire earth, good shapes and sizes, but shape of land at the poles is flat (the one on the wall)

Uses/Types of Maps• General Reference – topographic

• Thematic – specific types of information shown, like climate or population

• Navigation – used by sailors and pilots

Surveying

• This is what you do to gather the info you need to make a map

• It all was manual in the past, now we use satellites and airplanes

Satellite Systems

• Landsat – series of satellites that update the entire Earth every 16 days

• GOES – Geostationary Operational Environment Satellite

More Satellite and Map Stuff

• GIS – Geographic Informational System – this layers information on to a map

• GPS – Global Positioning System – uses 24 Nav Stars to tell you exactly where you are [latitude, longitude, elevation, time]