1.2 Maps and globes are models of Earth.

Maps show natural and human-made features.

§  Any map you use is a flat model of Earth’s surface, showing features as seen from above.

§  A globe represents Earth as it is seen from outer space.  It shows relative sizes and shapes.

Land Features on Maps

§  A relief map shows how high or low each feature is on Earth.

§  Mountains- stand higher than the land around them.  A group of mountains is called a mountain range.  A group of mountain ranges is called a mountain belt. 

§  Plateaus- have fairly level surfaces but stand high above sea level.  Often found near mountain ranges. 

§  Plains- gently rolling or flat land features.  The U.S. has two types of plains: coastal and interior.

Scale and Symbols on Maps

§  The maps most often used are road and city maps.

§  A map scale relates distances on a map to actual distances on Earth’s surface.  A scale can be expressed as a ratio, a bar, or equivalent units of distance. 

§  A map legend, also called a key, is a chart that explains the meaning of each symbol used on a map. 

Latitude and Longitude show locations on the Earth

§  Latitude is based on an imaginary line that circles the Earth halfway between the north and south poles called the equator.

§  Latitude is a distance in degrees north or south of the equator, which is 0 degrees. 

§  Longitude is a distance in degrees east or west of the prime meridian, which is 0 degrees.  The prime meridian stretches from the north to the south pole through Greenwich, England.

Global Positioning System (GPS)

§  A network of 24 satellites that find the latitude, longitude, and elevation of any site. 

§  A computer inside a receiver uses the satellite signals to calculate the user’s exact location. 

§  Used by: pilots, drivers, sailors, hikers, and map makers.

Map Projections

§  Distort the view of Earth’s surface.

§  Projection- a way of representing Earth’s curved surface on a flat map.

§  Cylindrical projection (Mercator)

§    Problem:  They make areas farther away from the equator appear larger than they are.

§  Conic projections are based on the shape of a cone.

§    When the cone is flattened out, the latitude lines are curved slightly. 

§    Most useful for mapping large areas in the middle latitudes, such as the U.S. 

§    Problem:  Distortion of landmasses near the equator and the poles.

§  Planar projections- Developed to help people find the shortest distance between two points. 

§    Drawn as if a circle of paper were laid on a point on the Earth’s surface.

§    Sphere shape transferred to a flat map. 

§    Good for plotting ocean or air voyages. 

§    Problem: Landmasses farther away from the center point are greatly distorted.