Search

GEOGRAPHY EDUCATION

Supporting geography educators everywhere with current digital resources.

Tag

map projections

Map Projections: Sea Chase

SOURCE: XKCD

This is a fantastic comic strip that shows how map projections are perfect representation of planet Earth, but a 2D rendering of a 3D world. A map projection is like a personal perspective or worldview. There is no single perfect map projection (or perspective or worldview), but there are some strengths and limitations to organizing geographic and spatial information in any given system.

TAGS: map projections, XKCD, fun.

Mercator Puzzle Redux

“Play this interactive game–move the 15 red countries to their appropriate locations to turn the countries green.  If you give up, you can double click on a red country to locate it (but it will turn blue).” 

Source: bramus.github.io

The old link to this map quiz no longer works but here is a new version.  This online game where you return the “misplaced” country on the map is more than just and exercise in locating places (there are many online map quizzes for that sort of activity).  What makes this one unique is that as you move the country further north or south the country expands or contracts according to how that country would be projected if that were its actual location on a Mercator map.  This is a great way to introduce the importance of map projections.

 

Tags: map projections, mapping, cartography.

Boston schools ditch conventional world maps in favor of this one

Social studies classrooms throughout the Boston public school system are getting an upgrade some 448 years in the making.

Source: www.bostonglobe.com

Personally, I’m not a fan of this decision, but it’s as if they watched the classic West Wing clip and decided to roll with it. I think that the Peters projection map is better than the Mercator for most educational applications, but it isn’t the “right, best, or true” map projection.  Many viral videos comparing the two love to exaggerate and say things like “The maps you use are lying to you” or “the world is nothing like you’ve ever seen.”  Yes, Mercator maps distorts relative size, but it isn’t a “wrong” map anymore than the Peters projection.  All maps have distortion and map readers need to under that all maps are a mathematical representation of the Earth.  

 

Tags: mapping, visualization, map projections, cartography, perspectiveeducation, geography, geography educationBoston.

Interactive Gnomonic Map

Source: bl.ocks.org

As stated on USGS map projections page: “[Gnomonic maps are] used by some navigators to find the shortest path between two points.  Any straight line drawn on the map is on a great circle, but directions are true only from center point of projection.”  This interactive is a very fun way  to visualize this and to understand distortion.    

Why Mercator for the Web? Isn’t the Mercator bad?

“As you may know, Google Maps uses the Mercator projection. So do other Web mapping services, such as Bing Maps and MapQuest. Over the years I’ve encountered antipathy toward the use of the Web Mercator from map projection people. I know of two distinct schools of opposition. One school, consisting of cartographic folks and map aficionados, thinks the Mercator projection is ‘bad’: The projection misrepresents relative sizes across the globe and cannot even show the poles, they are so inflated. The other school, consisting of geodesy folks, thinks mapping services have corrupted the Mercator projection, whether by using the wrong formulæ for it or by using the wrong coordinate system for it.”

Source: www.mapthematics.com

In this article you will find a thoughtful discussion of the reasons why the Mercator projection is disliked by many, but still so prevalent.  For more resources on understanding map projections, click here


Tags: mapping, visualization, map projections, cartography, perspective, unit 1 Geoprinciples.

The true size of …

This site is used to highlight the distortion issues caused by the Mercator map projection. It can be used to show the true size of countries

How it Works

1. Enter a country or state name

2. Hover over selection for size information

3. Click on selection to drag

4. Right-click on selection to delete

Tags: mapping, visualization, map projections, cartography, perspective.

Source: thetruesize.com

Map Projection Transitions

“In some ways, all 2D maps of Earth are interrupted at some point, even if it’s just along the antimeridian at 180°. Interruptions are often in areas of less interest e.g. oceans for a land-focused map.”

Source: www.jasondavies.com

No screenshot could do justice to this animation.  It transforms a map of the world from one map projection to another, and in the 5 second interval it ‘spins the globe’ to give you a sense of the the spatial distortions inherent in all projections.  This is but one of the many visualizations from Jason Davies mapping project.   

Tags: mapping, visualization, map projections, cartography, perspective, unit 1 Geoprinciples.

Fruit and Map Projections

Source: jewelpie.com

Bare with me here; this culinary hack shows several images that are helpful for explaining how map projections represent parts of the Earth (or the orange in this example).  The Polar regions are often displayed in azimuthal projections which are most accurate near one specified point.  Slicing the orange at the top and bottom is akin to creating polar azimuthal projections.  Universal Transverse Mercator (UTM) is a system that divides Earth into 60 “slices” with each wedge representing 6 degrees of longitude.  Each wedge has a Meractor projection map with perfect representation along a central line of longitude.  If we imagine the peel adjacent to one wedge has been flattened out, that is good way to visualize UTM maps.  

Tagsmappingmap projections, cartography, perspective, map.

Map Projections

This video describes what map projections are, and how the Earth can be represented using map projections within a GIS.

Tags: Mapping, video, map projections, cartography.

Source: www.youtube.com

Blog at WordPress.com.

Up ↑