Map projections and datums Maps are flat flat Earth is curved.
Scale and Projections Two confusing things about maps…
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Transcript of Scale and Projections Two confusing things about maps…
![Page 1: Scale and Projections Two confusing things about maps…](https://reader036.fdocuments.net/reader036/viewer/2022081514/5697bf7a1a28abf838c83139/html5/thumbnails/1.jpg)
Scale and Projections
Two confusing things about maps…
![Page 2: Scale and Projections Two confusing things about maps…](https://reader036.fdocuments.net/reader036/viewer/2022081514/5697bf7a1a28abf838c83139/html5/thumbnails/2.jpg)
Part 1: Scale
Sizing the Earth onto a Map
![Page 3: Scale and Projections Two confusing things about maps…](https://reader036.fdocuments.net/reader036/viewer/2022081514/5697bf7a1a28abf838c83139/html5/thumbnails/3.jpg)
A simple math problem…
Which number is larger?
½ or ¼
![Page 4: Scale and Projections Two confusing things about maps…](https://reader036.fdocuments.net/reader036/viewer/2022081514/5697bf7a1a28abf838c83139/html5/thumbnails/4.jpg)
A simple math problem…
Which number is larger?
½ or ¼
![Page 5: Scale and Projections Two confusing things about maps…](https://reader036.fdocuments.net/reader036/viewer/2022081514/5697bf7a1a28abf838c83139/html5/thumbnails/5.jpg)
A simple math problem…
Which number is larger?
½ or ¼
1/1,000 or 1/10,000
![Page 6: Scale and Projections Two confusing things about maps…](https://reader036.fdocuments.net/reader036/viewer/2022081514/5697bf7a1a28abf838c83139/html5/thumbnails/6.jpg)
A simple math problem…
Which number is larger?
½ or ¼
1/1,000 or 1/10,000
![Page 7: Scale and Projections Two confusing things about maps…](https://reader036.fdocuments.net/reader036/viewer/2022081514/5697bf7a1a28abf838c83139/html5/thumbnails/7.jpg)
What is the difference?
• 1:100 vs. 1/100
• What does this mean on a map? 1:10,000
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Two maps
• Scale of Map 1 - 1:10,000• Scale of Map 2 - 1:100
Which map has a bigger scale? Which map has a bigger view of the earth?
![Page 9: Scale and Projections Two confusing things about maps…](https://reader036.fdocuments.net/reader036/viewer/2022081514/5697bf7a1a28abf838c83139/html5/thumbnails/9.jpg)
Two maps…
• Which map has a smaller scale?
![Page 10: Scale and Projections Two confusing things about maps…](https://reader036.fdocuments.net/reader036/viewer/2022081514/5697bf7a1a28abf838c83139/html5/thumbnails/10.jpg)
The take-home message…
• Zoomed out maps (larger areas) have small scales.
• Zoomed in maps (smaller areas) have large scales.
• Advantages?• Disadvantages?
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Part 2: Projections
(what happens when something spherical is made flat)
![Page 12: Scale and Projections Two confusing things about maps…](https://reader036.fdocuments.net/reader036/viewer/2022081514/5697bf7a1a28abf838c83139/html5/thumbnails/12.jpg)
Watch closely as I magically convert this ball into a piece of paper…
What becomes distorted?
• Shape• Size• Distance• Direction
![Page 13: Scale and Projections Two confusing things about maps…](https://reader036.fdocuments.net/reader036/viewer/2022081514/5697bf7a1a28abf838c83139/html5/thumbnails/13.jpg)
Projection #1 – What’s Wrong?(Mercator Projection)
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Other attempts…(Mollweide Homolographic Projection)
![Page 15: Scale and Projections Two confusing things about maps…](https://reader036.fdocuments.net/reader036/viewer/2022081514/5697bf7a1a28abf838c83139/html5/thumbnails/15.jpg)
And still another attempt…
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