Latitude to Climagraphs Part 1 Latitude & Longitude Basics 2/17/2019

Latitude & Longitude Readings: A video guide can be found at: http://bit.ly/LcNn0E A transcript of the video can be found at: http://bit.ly/Nb0mvI Follow the links in the article above to various other articles with more specific information. See, in particular: http://bit.ly/O7DD6y 2/17/2019

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 2/17/2019

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 2/17/2019

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 2/17/2019

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 2/17/2019

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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 2/17/2019

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 2/17/2019

Latitude - Measurement 2/17/2019

Longitude - Measurement 2/17/2019

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 _________ 2/17/2019

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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 _______ 2/17/2019

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)? 2/17/2019

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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 2/17/2019

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 2/17/2019