1.3 Ways to Show Earth’s Surface

Daily Prompt: Page 21 SSIN What are different ways geographers show and view Earth’s surface? (Hint) Look around the classroom for clues

https://www.youtube.com/watch?v=fLdvInDrQ2c

Objectives: Student will be able to… identify ways that geographers show and view Earth’s surface. compare and contrast strengths and weaknesses of three different map projections.

Tools Geographers Use to Show Earth’s Surface? Globes Maps Atlas: Book of Maps GIS (geographic information systems) Photographs Aerial and Surface Would it be easy to find your way by just using a globe? No, instead we use maps which are flat representations of Earth’s surface. Globes are not to scale. Maps have a scale listed in order to figure out distance from one location to another.

Aerial and Satellite Photographs Aerial: Taken from sky to take measurements or make maps Satellite: Taken from space and can take large images or can zoom in up close. Yankee stadium and 1950’s drought on farms. Aerial photographs are taken from the sky from planes, balloons, and kites.

Geographic Information Systems Computer systems designed to help cartographers (people that make maps and chart the Earth) make changes to existing maps “A geographic information system (GIS) integrates hardware, software, and data for capturing, managing, analyzing, and displaying all forms of geographically referenced information.” – GIS.com Used for EVERYTHING

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Maps do have a challenge: Think-Pair-Share Look at the globe and then look at a map. Describe the challenge maps have? Cartographers (Map Makers) have had a really tough time developing the most accurate map

The challenge with maps showing Earth’s surface… Earth is round and maps are flat. 3D vs 2D If you flatten Earth it will not flatten perfectly. There will be distortions and a loss of accuracy. To make a two-dimensional map, cartographers have to project the spherical surface of the earth onto a two-dimensional piece of paper or computer screen.

What is a Map “Projection”? A way of making a 3 dimensional sphere of the Earth fit on a 2 dimensional surface. There are different map projections for different purposes depending on what you need the map for. Imagine the inflatable globes. They are 3-d versions and imagine making them flat on the desk.

The Mercator (mur KAYT ur)Projection Rectangular in shape Used primarily for marine navigation Pro: shows true directions from places Con: Does not show true sizes. Areas near the poles look bigger than they really are (distorted) In this map projection it shows greenland about the same size as south america when in fact greenland is about the size of Mexico. So we would not want to use this map projection to analyze size of land forms. Antartica also looks really large because it is distorted.

Gerardus Mercator Navigation map from 1569 When people first started drawing maps, they didn’t draw them with mathematical precision, because the necessary mathematics hadn’t been invented yet. The Greeks were the first to do rigorous geometry, and the Greek mathematician Ptolemy (90–168 CE) was the first to develop a map using lines of latitude and longitude and defining locations on a coordinate system. Islamic mapmakers in the Middle Ages built on his ideas, and the Chinese also drew coordinate-based maps to careful scale. In 1569, the Flemish geographer and cartographer Gerardus Mercator created a map using a mathematical formula to “project” points on the earth’s surface onto a map based on their latitude and longitude. His formula — called the Mercator projection — became the standard means of making maps for navigation, because the directions of the compass corresponded to directions on the map. North, east, south, and west were straight lines on paper, just as they are on the earth’s surface.

The Robinson Projection Rectangular in shape with ROUNDED edges. Most commonly used projection. Pro: Shows the correct size and shape of most land areas Con: North and South poles are flattened.

Winkel-Tripel (equal area)Projection Rounder in shape Minimal distortion in size of land, distance, and direction Cons: Latitude lines are curved and there are distortions on North and South poles. We’ve talked about lat. Lines being parallel but in this projection is showing they are not.

Don’t confuse these projections! Winkel Triple Closer to the shape of a globe Robinson Flat surface with rounded corners

Analyze the map projections Analyze the map projections. Pay attention to lines of longitude and distortions. Winkel Triple Robinson Mercator Mercator: lines are at right angles to one another Winkle triple: lines of latitude are straight but the lines of longitude are curved and meet at poles Robinson: prime meridian and all lines of latitude are straight but the other longitude lines are cureved.

How do geographers know which projection to use?

Exit Ticket Name three categories of map projections and list one characteristic of each. Don’t forget to put your name on the top and drop in the box on the way out of class.