UNIT 1 LESSON MAPS & PROJECTIONS

THE STUDENT WILL BE ABLE TO…

Discuss the various functions of maps and understand what a projection is.

We’re only glancing at maps today b/c you did so much with them in “True Maps, False Impressions.”

MAPS

Maps are the basic tool that geographers use to describe where things are at.

A map is “a two-dimensional or flat-scale model of Earth’s surface” (Rubenstein, 2014, p. 5).

The science of mapmaking is called “cartography.” Present day geographers use computers and satellite imagery.

Maps can be used as either a reference tool or as a communication tool.

EARLY MAPS & REFERENCE

Earliest maps were reference tools. Used for navigation in getting from Point A to Point B

Eratosthenes (276-194 B.C.E): 1st person to use word Geography and made one of earliest maps.

Ptolemy (C.E. 100-170): Made maps that were not remade for about 1,000 years (No one improved on them)

Remake of Eratosthenes map in from the 1800’s

MAPS & COMMUNICATION

Maps are still used today for navigation, but we also use them a lot for communication.

The communication aspect really comes into play during a cholera outbreak (mentioned in your textbook). We’ll actually read a book 2nd semester on this.

See right how overlaying data communicates data differently.

MAP PROJECTIONS

The only way that a the Earth’s surface can be accurately represented is through a globe. (3 dimensional)

Otherwise; the Earth’s surface is represented on a projection.

When you draw the Earth (sphere) on a 2 dimensional piece of paper it creates distortion.

ALL maps have distortion! There are four types of a distortion, a map can only eliminate three at most.

4 TYPES OF DISTORTION

Shape: “appears more elongated or squat than in reality”

Distance: “between two points may become increased or decreased.”

Relative Size: “one area may appear larger than another on a map but is in reality smaller.”

Direction: “from one place to another can be distorted” (Rubeinstein, 2014, p. 9).

MAP TYPES/DISTORTION EXAMPLES

Mollweide ProjectionSizes are true, but distorts shapes.

AzimuthalDistorts directionDistances are correct only from the center.

Shape is distorted

MercatorOne of the most common maps

Direction is trueShape of landmass is trueSize is distorted (mostly along top, where less people live)

Used in navigation

Robinson Projection: What’s in your textbook.All four areas are distorted in an attempt to create balance.

SCALE

Scale answers the question of how much of the Earth’s surface to show on a map.

Map scale will influence the detail and amount of area covered.

Map scale is presented in three ways: Ratio or fraction: Shows numerical ratio between distances on the map and Earth’s surface 1/24,000 means one unit

Written scale: describes the relationship between map and earth distances in words; example 1 inch equals 1 mile on the map.

Graphic scale: Bar line marked to show the distance.

SCALE

USES OF MAPS: CARTOGRAM

These are sulpher emissions per country. Countries are displayed larger based on the amount that they represent.

MAPS LIE

Maps often reflect the bias of the mapmaker; it’s not always bad, they may eliminate things to emphasize other areas.

Sometimes, poor color choices, and how data is reported; it’s intentional to mislead the viewer or reader.

Sometimes map lie because they simply aren’t clear. Maps are often chosen based on the emotion that one is seeking to evoke with them; especially when used in political advertisements or in public speaking.

PRESIDENT RONALD REGAN ALWAYS USED MERCATOR PROJECTIONS WHEN TALKING ABOUT THE U.S.S.R. (RUSSIA)

PRESIDENT RONALD REGAN ALWAYS USED MERCATOR PROJECTIONS WHEN TALKING ABOUT THE U.S.S.R. (RUSSIA)