Chapter 2 Mapping

our World

Latitude and Longitude

• Imagine trying to explain to someone where this dot is located on this ping pong ball.

• It is equally difficult to describe specific locations on Earth. – To make it easier, we have a grid

system made up of lines that help locate specific points.

Latitude

• Latitude lines lie parallel with the earth’s equator.

• The equator’s latitude is 0 degrees.

• The north pole is 90 degrees NORTH.

• The south pole is 90 degrees SOUTH.

• Latitude is the angle a line draw to your location from the center of the earth would make with the equator.

• Latitude measurements are always followed with either an N for NORTH or an S for SOUTH

• What do you think the latitude of our school is?

• http://www.juggling.org/bin/un.cgi/map-find

Longitude• Longitude lines are long

and run up and down like telephone poles– The reference line for

Longitude is the PRIME MERIDIAN (0o longitude)

– Longitude lines are NOT parallel to the Prime Meridian or each other- they all touch at the poles!

• The longitude of the Prime Meridian is 0 degrees

• The International Date Line is 180 degrees and on the opposite side of the globe

• All other lines of Longitude are followed by either an E for East of the Prime Meridian or a W for West of the Prime Meridian– Where are we? – What is our LONGITUDE?– http://www.juggling.org/bin/un.cgi/map-find

PRACTICE

How are Latitude And Longitude Different?

Comparing Latitude and Longitude

• How are they different? Make a chart! (2-column)– Latitude lines run horizontally, Longitude run vertically– Latitude lines vary from 0-90, Longitude vary from 0-

180 degrees– Latitude lines are PARALLEL, Longitude lines all TOUCH

at the poles– Latitude measurements are followed by N or S,

Longitude by W or E– All Longitude lines lie along “GREAT CIRCLES” -

meaning they divide Earth into two perfect halves– Only one Latitude line is a Great Circle:

• THE EQUATOR!

– The size of one degree of Latitude is constant (111 kilometers) no matter where you are

– A degree of Longitude varies in size (longitude covers a bigger distance near the equator and a smaller distance near the poles!!)

MINUTES AND SECONDS

• Each degree of latitude and longitude is divided into 60 “minutes” (60 minutes = 1 degree). The symbol for a minute is: ‘– Remember: this type of minute measures DISTANCE,

not time!!

• Each minute is divided into 60 “seconds” (60 seconds = 1 minute). The symbol for a second is: “– An example of a position on Earth might be:– 43o 22’ 56” S, 28o 4’ 12” E– http://www.factmonster.com/ipka/A0001769.html

And FINALLY… TIME ZONES!

• Where have you been? What time was it?– How many different times are there on

planet Earth right now??

• The world is divided into 24 time zones• Your LONGITUDE determines your time

zone!

• How many degrees of longitude does each time zone cover?? – 360 degrees / 24 zones = 15 degrees

• Traveling WEST -- you wind the clock BACK as you cross time zone boundaries

• Traveling EAST -- you wind the clock FORWARD as you cross time zone boundaries

• This is because our globe is spinning towards the EAST– The sun seems to rise in the East as we spin towards it,

and the sun sets in the West as we spin away