Maps…When GPS just wont do. Teacher’s Edition

Today’s Main Idea: People have long used maps to find their way around and to explain the physical layout of the world around them. As time has progressed maps have changed and so has how they depict the world, but their purpose has remained the same. The purpose has always been to help depict (show) the world, area, or region a person lives in.

Map Versus Globe: A globe is a round projection of a round surface, but a map is a flat projection of a round surface. A globe is an exact representation of the earth because it is the same basic shape. No distortions. However a map is laid flat and it will cause distortions: areas that are larger or smaller than they actually are. Map Projection – a way of showing the curved earth on a flat surface

Map Projection Types There are a number of map types that have been created to try show the earth. Some were created specifically to try and reduce the distortions.

Mercator Projection: It was created for sailors to use in the 1400’s It allowed them to accurately view which direction was North, South, East and West Lands near the Equator are accurately portrayed Areas near the edge are distorted For example Greenland appears bigger then South America, when South America is really 8x bigger!

Mercator Projection

Interrupted Projection: Shows land masses correct sizes by slicing up the oceans You cannot measure distance accurately because areas are divided Especially the Ocean

Interrupted Projection

Peter’s Projection: Shows the correct sizes of oceans and land masses Distorts the appearance of South America and South Africa – they appear longer and thinner then they really are

Peter’s Projection

Robinson Projection: Correct sizes of lands and oceans Distorts the images on the edges

Maps are also used for… Maps are used to show topography and vegetation Topography – physical features of a place or region Vegetation – plant life of place or region Different types of landforms/topography a map might show: Mountains Elevation Hills Plains Plateaus

Maps can also show… Climate!! Climate – average, overall weather of a place over a period of 20 to 30 years Climate depends on numerous factors related to location: Proximity (nearness) to the equator Why is always hotter in the south? In the tropics? Elevation – distance above sea level Relative location to the sea or ocean