1. Latitude to Climagraphs
Part 1
Latitude & Longitude
Basics
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2. Latitude & Longitude Readings: A video guide can be found at:
A transcript of the video can be found at:
Follow the links in the article above to various other articles with more specific information. See, in particular:
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3. Latitude and Longitude
Lat. and Long. are a series of imaginary lines that a) (Lat) ‘circle’ the globe parallel to the equator running E   W and b) (Long) a series of ‘semi-circles’ that run from pole to pole.
A primary function of these lines is to provide a means of locating a position on the earth’s surface.
The concept is ancient – the actual practical use of the system is relatively modern
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4. Some Assumptions
The main assumption that we will make is to consider the earth to be sphere
As a sphere it will have _________ degrees in its circumference
The earth is not, in fact, a perfect sphere. It is an oblate ellipsoid.
We will assume that ‘North’ is at the ‘top’ of our maps and of the globe
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5. Latitude Lines of Lat run horizontally on a map
They are parallel to each other (Parallels)
They are measured in degrees (o) as the primary unit of measurement
Because it is a unit of measurement, the lines measure distance
Each degree is approximately 111 km apart
Each degree is divided into 60 minutes (‘) and each minute into 60 seconds (“). Time ???
Decimal notation can also be used
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6. Longitude (Look for Similarities & Differences)
Lines of Long run from the North Pole   to the South Pole
They are not parallel. They meet at the poles.
They are called Meridians.
Degrees are the primary unit of measurement
The degrees measure distance
Each degree represents ~ 111 km at the E.
Degrees can be divided in minutes & seconds
Decimal notation can be used
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8. Latitude Lines of latitude begin at the equator
The equator is 0o of latitude
Lines of latitude increase to 90o of latitude at the North Pole (Geographic NP) and to 90o of latitude at the South Pole – 90o N and 90o S
Note that the last two references have a number, a unit, and a letter of direction whereas the Equator is simply 0o of latitude or just 0o if the context supports that description
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9. Longitude (Look for Similarities & Differences)
Lines of Long begin at the Prime Meridian
The PM runs through Greenwich, England (~ London); decided in 1884 (Why?); and is 0o of longitude
Values increase to 180o East and 180o West longitude
All descriptors of longitude have a Number, a Unit of Measurement and a Letter of Direction except for these three
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10. Latitude - Measurement
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11. Longitude - Measurement
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12. Latitude
The Equator divides the earth into the Northern Hemisphere and the Southern Hemisphere
There are five Special Lines of Latitude
From North to South they are:
Arctic Circle at _________
Tropic of Cancer at _________
Equator at _________
Tropic of Capricorn at _________
Antarctic Circle at _________
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14. Longitude (Look for Similarities & Differences)
The line on the opposite side of the earth that pairs with the PM is the International Date Line (180o East and 180o West)
These two lines divide the earth into the Eastern and Western Hemispheres
There are two Special Lines of Longitude:
The Prime Meridian at _______
The International Date Line at _______
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15. Additional Information
Any line that divides the earth into two equal halves is called a Great Circle
The E. would be a Great Circle
Are there any lines of Long that form a Great Circle?
Are there other lines that form Great Circles?
Where would Great Circles be useful?
What is the difference in distance between a line joining two points on a wall map and the same two points on a globe (same scale)?
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17. Additional Information
Why is the value for the Tropic of Cancer and Capricorn the value that it is?
What do you call the area between the Tropic of Cancer and Capricorn?
A “nautical mile” equals one minute of latitude. Therefore parallels of latitude are ~ 60 nautical miles apart
There are 3 zones of latitude – each 30o wide
Low latitude zone 0 – 30 degrees
Mid latitude xone 30 – 60 degrees
High latitude zone 60 – 90 degrees
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18. Co-ordinates Latitude and longitude represent a co-ordinate system.
A system where a group of numbers (in this case 2) identify a location on the earth’s surface. A 3rd could be elevation.
In referring to a position using co-ordinates for lat and long, lat is always given first
All lat and long co-ordinates must have a Number, Unit of Measurement and a Letter of Direction – except some (3) Special Lines
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