Mapping the Earth’s Surface Created By: Mr. Kreeger

Homework and Page References  Page References- Page  HW- Explain the differences and similarities between the 3 map projections and explain the advantage and disadvantage of each.

Table of Contents 1. Definition of Maps a. Map Distortion images 2. Map Projection a.Mercator Projection b.Gnomonic (Polar) Projection c.Conic Projection

Introduction Video

1. Definition of Maps AAAA map is a flat representation of the earth’s curved surface WWWWhat occurs when you represent a curved surface on a flat area?? Distortion- A change in what the map represents. LLLLarge area-Increased Distortion SSSSmall Area-Decreased Distortion

1a. Map Distortion Images

Introduction Video to map Projection

2. Map Projection AAAA flat map that represents a 3D curved surface is called map projection. TTTThe way a paper is held against the globe determines the kind of projection made.

2a. Mercator Projection UUUUsed for navigation or maps of equatorial regions. DDDDistances are true only along Equator, but are reasonably correct within 15° of Equator. AAAAreas and shapes of large areas are distorted. Distortion increases away from Equator and is extreme in polar regions.

2b. Gnomonic (Polar) Projection  Used along with the Mercator by some navigators to find the shortest path between two points. (Great Circles)  Easy to draw a straight line between 2 points.  Little distortion at poles, increased distortion at equator.

2c. Conic Projection UUUUsed to show areas in mid latitudes. DDDDistances are only true along meridians and along 1 or 2 stranded parallels. DDDDirections shapes and sizes have little distortion but increases as you get further from stranded parallels- Best representation of a globe

Summary of Map Projections