Download Map Projections notes from PPT

9/10/2015
Geographers Tools
• Geography “geo” Earth and “graphy” to write
– From the Greek ‘geographia’
• Maps – a 2-dimensional (flat) model of the 3dimensional Earth
– reference
– communication
• Cartography – the science of map making
• Spatial Organization – the location and patterns
of people, places, and events that connect us to
our landscapes (physical and human)
Ancient Guys to Know
Eratosthenes’ Map
• Eratosthenes (276? – 194?BCE)
– Calculated the circumference of the Earth within
15%
– Combination of geography and geometry!
• Ptolemy
– Calculated the circumference of the Earth as 9,000
miles smaller and regarded as truth
– Developed a grid system that became a
forerunner for latitude and longitude
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2-D Distorts
Mercator
• Globe is accurate, but limited
• Projections (Map) – the scientific method of
transferring locations on Earth’s surface to a
flat map
– Shape
– Distance
– Size
– Direction
Mercator
Mercator Projection
• Gerardus Mercator (1512 – 1594); Flemish
cartographer, philosopher, and mathematician
– Created the Mercator Projection in 1569
– 1569: Historical Context: Age of Exploration
– Fast Fact: first used the word atlas to describe a
collection of maps
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So What’s the Problem with
Mercator?
Loxodromes/Rhumb
Lines – straight lines of
constant compass
bearing; produced by
Mercator’s projection
- Meridians and parallels
cross at 90 degrees
- Excellent for navigation
- Beloved by explorers
Robinson Projection
• DIRECTION is true (thanks loxodromes!)
• SIZE is distorted (especially at the poles)
– Greenland and Antarctica
Robinson Projection
• Arthur H. Robinson (1915 – 2004); American
geographer and cartographer
– Created in 1961- 63 in response to Rand McNally
- Adopted by National Geographic in 1988, later
abandoned in favor of Van der Grinten
- Specifically intended to solve the problems of
other flat projections (neither equal area, or
preserving land mass, nor conformal, or
preserving angles)
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Peters Projection
So What’s the Problem with
Robinson?
• EVERYTHING is a little bit distorted
– Shape
– Size
– Distance
– Direction
• Helpful for general reference; often used in
classrooms
Peters Projection
• Dr. Arno Peters (1916 – 2002); German historian
and cartographer
– Introduced his version in Germany at a conference in
1974
- English version published in 1983
- Generated firestorm of debate immediately
- Eurocentric ideas vs. misleading maps for 500+ years
(interested in political propaganda)
- Based on Rev. James Gall’s projection, one of the first
equal area maps – now commonly the Gall-Peters
projection
So What’s the Problem with Peters?
• SIZE is true (land masses are equal and not
Eurocentric)
• SHAPE is distorted (looks unfamiliar!)
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Goode-Homolosine Projection
Goode-Homolosine Projection
• John Paul Goode (1862 – 1932) ; American
geographer and cartographer
– Introduced in 1923 as the “Evil Mercator”
- Attempt to offer an alternative to Mercator when
representing global relationships
- Equated map projections to an orange peel
- Interruptions and lobes
- In its most common form, the map interrupts the
North Atlantic, the South Atlantic, the South Pacific,
the Indian Ocean, and the entire east/west meridian
of the map.
So What’s the Problem with GoodeHomolosine?
• INTERRUPTED – points on the map are not continuous and
therefore distorts distance; however, continents and
regions are mostly intact rather than separated (sometimes
regions are repeated in order to avoid interruption)
• SIZE– preserved to insure accurate representation of the
continents
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Cartography is Concurrent
Waterman Butterfly (1996)
- Steve Waterman (d. 2015)
- Modeled after Bernard J.S. Cahill’s (1866 –
1944) rubber ball/butterfly map
- Life long pursuit to eliminate distortion in 2Dimensional maps
- All continents are uninterrupted
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