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.
§ 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.